From 70ca4bf5f8924a3c8af9ffcd7dace4e6b3ed8f99 Mon Sep 17 00:00:00 2001
From: Olaf Tomalka <olaf@tomalka.me>
Date: Mon, 14 Nov 2022 19:31:29 +0100
Subject: [PATCH 01/13] [TMP] Added SemVer opaque types

---
 .../snaps-cli/src/cmds/init/initHandler.ts    |   6 +-
 .../src/snaps/SnapController.ts               |  17 +--
 .../snaps-controllers/src/snaps/utils/npm.ts  |  21 ++-
 .../snaps-utils/src/manifest/validation.ts    |   3 +-
 packages/snaps-utils/src/snaps.ts             |   3 +-
 packages/snaps-utils/src/types.ts             |  10 +-
 packages/snaps-utils/src/versions.test.ts     | 118 +++++++++-------
 packages/snaps-utils/src/versions.ts          | 131 ++++++++++++++----
 8 files changed, 208 insertions(+), 101 deletions(-)

diff --git a/packages/snaps-cli/src/cmds/init/initHandler.ts b/packages/snaps-cli/src/cmds/init/initHandler.ts
index 8a8a06c0f5..51a4b7bb65 100644
--- a/packages/snaps-cli/src/cmds/init/initHandler.ts
+++ b/packages/snaps-cli/src/cmds/init/initHandler.ts
@@ -4,6 +4,8 @@ import {
   readJsonFile,
   satisfiesVersionRange,
   NpmSnapPackageJson,
+  SemVerVersion,
+  SemVerRange,
 } from '@metamask/snaps-utils';
 import { promises as fs } from 'fs';
 import pathUtils from 'path';
@@ -19,7 +21,7 @@ import {
   yarnInstall,
 } from './initUtils';
 
-const SATISFIED_VERSION = '>=16';
+const SATISFIED_VERSION = '>=16' as SemVerRange;
 
 /**
  * Creates a new snap package, based on one of the provided templates. This
@@ -35,7 +37,7 @@ export async function initHandler(argv: YargsArgs) {
   const { directory } = argv;
 
   const isVersionSupported = satisfiesVersionRange(
-    process.version,
+    process.version as SemVerVersion,
     SATISFIED_VERSION,
   );
 
diff --git a/packages/snaps-controllers/src/snaps/SnapController.ts b/packages/snaps-controllers/src/snaps/SnapController.ts
index 79587bb621..89b338c7dc 100644
--- a/packages/snaps-controllers/src/snaps/SnapController.ts
+++ b/packages/snaps-controllers/src/snaps/SnapController.ts
@@ -28,14 +28,15 @@ import {
   getSnapPrefix,
   gtVersion,
   InstallSnapsResult,
-  isValidSnapVersionRange,
+  isValidSemVerRange,
   LOCALHOST_HOSTNAMES,
   NpmSnapFileNames,
   PersistedSnap,
   ProcessSnapResult,
   RequestedSnapPermissions,
-  resolveVersion,
+  resolveVersionRange,
   satisfiesVersionRange,
+  SemVerRange,
   Snap,
   SnapId,
   SnapIdPrefixes,
@@ -536,7 +537,7 @@ type SnapControllerArgs = {
 type AddSnapArgsBase = {
   id: SnapId;
   origin: string;
-  versionRange?: string;
+  versionRange?: SemVerRange;
 };
 
 // A snap can either be added directly, with manifest and source code, or it
@@ -1535,10 +1536,10 @@ export class SnapController extends BaseController<
     await Promise.all(
       Object.entries(requestedSnaps).map(
         async ([snapId, { version: rawVersion }]) => {
-          const version = resolveVersion(rawVersion);
+          const version = resolveVersionRange(rawVersion);
           const permissionName = getSnapPermissionName(snapId);
 
-          if (!isValidSnapVersionRange(version)) {
+          if (!isValidSemVerRange(version)) {
             result[snapId] = {
               error: ethErrors.rpc.invalidParams(
                 `The "version" field must be a valid SemVer version range if specified. Received: "${version}".`,
@@ -1585,7 +1586,7 @@ export class SnapController extends BaseController<
   private async processRequestedSnap(
     origin: string,
     snapId: SnapId,
-    versionRange: string,
+    versionRange: SemVerRange,
   ): Promise<ProcessSnapResult> {
     try {
       validateSnapId(snapId);
@@ -1688,7 +1689,7 @@ export class SnapController extends BaseController<
   ): Promise<TruncatedSnap | null> {
     const snap = this.getExpect(snapId);
 
-    if (!isValidSnapVersionRange(newVersionRange)) {
+    if (!isValidSemVerRange(newVersionRange)) {
       throw new Error(
         `Received invalid snap version range: "${newVersionRange}".`,
       );
@@ -2052,7 +2053,7 @@ export class SnapController extends BaseController<
     packageName: string,
     versionRange: string,
   ): Promise<FetchSnapResult> {
-    if (!isValidSnapVersionRange(versionRange)) {
+    if (!isValidSemVerRange(versionRange)) {
       throw new Error(
         `Received invalid Snap version range: "${versionRange}".`,
       );
diff --git a/packages/snaps-controllers/src/snaps/utils/npm.ts b/packages/snaps-controllers/src/snaps/utils/npm.ts
index 2d3efee1fb..ac2433ec1a 100644
--- a/packages/snaps-controllers/src/snaps/utils/npm.ts
+++ b/packages/snaps-controllers/src/snaps/utils/npm.ts
@@ -4,6 +4,9 @@ import {
   isValidUrl,
   getTargetVersion,
   validateNpmSnap,
+  assertIsSemVerVersion,
+  SemVerRange,
+  SemVerVersion,
 } from '@metamask/snaps-utils';
 import { isObject } from '@metamask/utils';
 import createGunzipStream from 'gunzip-maybe';
@@ -26,7 +29,7 @@ export const DEFAULT_NPM_REGISTRY = 'https://registry.npmjs.org';
  */
 export async function fetchNpmSnap(
   packageName: string,
-  versionRange: string,
+  versionRange: SemVerRange,
   registryUrl = DEFAULT_NPM_REGISTRY,
   fetchFunction = fetch,
 ): Promise<SnapFiles> {
@@ -56,7 +59,7 @@ export async function fetchNpmSnap(
   // object if they exist.
   return validateNpmSnap(
     snapFiles,
-    `npm Snap "${packageName}@${actualVersion}" validation error: `,
+    `npm Snap "${packageName}@${actualVersion}" validation error: ` as `${string}: `,
   );
 }
 
@@ -75,10 +78,10 @@ export async function fetchNpmSnap(
  */
 async function fetchNpmTarball(
   packageName: string,
-  versionRange: string,
+  versionRange: SemVerRange,
   registryUrl = DEFAULT_NPM_REGISTRY,
   fetchFunction = fetch,
-): Promise<[ReadableStream, string]> {
+): Promise<[ReadableStream, SemVerVersion]> {
   const packageMetadata = await (
     await fetchFunction(new URL(packageName, registryUrl).toString())
   ).json();
@@ -89,11 +92,15 @@ async function fetchNpmTarball(
     );
   }
 
-  const targetVersion = getTargetVersion(
-    Object.keys((packageMetadata as any)?.versions ?? {}),
-    versionRange,
+  const versions = Object.keys((packageMetadata as any)?.versions ?? {}).map(
+    (v) => {
+      assertIsSemVerVersion(v);
+      return v;
+    },
   );
 
+  const targetVersion = getTargetVersion(versions, versionRange);
+
   if (targetVersion === null) {
     throw new Error(
       `Failed to find a matching version in npm metadata for package "${packageName}" and requested semver range "${versionRange}"`,
diff --git a/packages/snaps-utils/src/manifest/validation.ts b/packages/snaps-utils/src/manifest/validation.ts
index 09d423c7da..4c67ee91f9 100644
--- a/packages/snaps-utils/src/manifest/validation.ts
+++ b/packages/snaps-utils/src/manifest/validation.ts
@@ -20,7 +20,8 @@ import {
 
 import { CronjobSpecificationArrayStruct } from '../cronjob';
 import { NamespacesStruct } from '../namespace';
-import { NameStruct, NpmSnapFileNames, VersionStruct } from '../types';
+import { VersionStruct } from '../versions';
+import { NameStruct, NpmSnapFileNames } from '../types';
 
 // 0xd36e6170 - 0x80000000
 export const SIP_6_MAGIC_VALUE = `1399742832'` as `${number}'`;
diff --git a/packages/snaps-utils/src/snaps.ts b/packages/snaps-utils/src/snaps.ts
index 3f0b021ee3..4e925c7bf7 100644
--- a/packages/snaps-utils/src/snaps.ts
+++ b/packages/snaps-utils/src/snaps.ts
@@ -5,6 +5,7 @@ import { SerializedEthereumRpcError } from 'eth-rpc-errors/dist/classes';
 
 import { SnapManifest, SnapPermissions } from './manifest/validation';
 import { SnapId, SnapIdPrefixes, SnapValidationFailureReason } from './types';
+import { SemVerVersion } from './versions';
 
 export const LOCALHOST_HOSTNAMES = new Set(['localhost', '127.0.0.1', '::1']);
 export const SNAP_PREFIX = 'wallet_snap_';
@@ -119,7 +120,7 @@ export type Snap = {
   /**
    * The version of the Snap.
    */
-  version: string;
+  version: SemVerVersion;
 
   /**
    * The version history of the Snap.
diff --git a/packages/snaps-utils/src/types.ts b/packages/snaps-utils/src/types.ts
index b3aae7ff6f..04ce7203a4 100644
--- a/packages/snaps-utils/src/types.ts
+++ b/packages/snaps-utils/src/types.ts
@@ -3,33 +3,25 @@ import {
   SnapKeyring as Keyring,
 } from '@metamask/snaps-types';
 import { assertStruct, Json } from '@metamask/utils';
-import { valid as validSemver } from 'semver';
 import {
   Infer,
   is,
   object,
   optional,
   pattern,
-  refine,
   size,
   string,
   type,
 } from 'superstruct';
 
 import { SnapManifest } from './manifest/validation';
+import { VersionStruct } from './versions';
 
 export enum NpmSnapFileNames {
   PackageJson = 'package.json',
   Manifest = 'snap.manifest.json',
 }
 
-/**
- * A struct for validating a version string.
- */
-export const VersionStruct = refine(string(), 'Version', (value) => {
-  return validSemver(value) !== null;
-});
-
 export const NameStruct = size(
   pattern(
     string(),
diff --git a/packages/snaps-utils/src/versions.test.ts b/packages/snaps-utils/src/versions.test.ts
index 87b28c14c4..b97446f9cc 100644
--- a/packages/snaps-utils/src/versions.test.ts
+++ b/packages/snaps-utils/src/versions.test.ts
@@ -4,22 +4,38 @@ import {
   DEFAULT_REQUESTED_SNAP_VERSION,
   getTargetVersion,
   gtVersion,
-  isValidSnapVersionRange,
-  resolveVersion,
+  isValidSemVerRange,
+  resolveVersionRange,
   satisfiesVersionRange,
+  SemVerRange,
+  SemVerVersion,
 } from './versions';
 
+function v(value: string[]): SemVerVersion[];
+function v(value: string): SemVerVersion;
+function v(value: string | string[]): SemVerVersion | SemVerVersion[] {
+  return value as any;
+}
+
+function r(value: string): SemVerRange {
+  return value as SemVerRange;
+}
+
 describe('resolveVersion', () => {
   it('defaults "latest" to DEFAULT_REQUESTED_SNAP_VERSION', () => {
-    expect(resolveVersion('latest')).toBe(DEFAULT_REQUESTED_SNAP_VERSION);
+    expect(resolveVersionRange('latest')).toBe(DEFAULT_REQUESTED_SNAP_VERSION);
   });
 
   it('defaults an undefined version to DEFAULT_REQUESTED_SNAP_VERSION', () => {
-    expect(resolveVersion(undefined)).toBe(DEFAULT_REQUESTED_SNAP_VERSION);
+    expect(resolveVersionRange(undefined)).toBe(DEFAULT_REQUESTED_SNAP_VERSION);
   });
 
   it('returns the requested version for everything else', () => {
-    expect(resolveVersion('1.2.3')).toBe('1.2.3');
+    expect(resolveVersionRange('1.2.3')).toBe('1.2.3');
+  });
+
+  it.each([null, 1, {}, Error])('throws on invalid input', (value) => {
+    expect(() => resolveVersionRange(value)).toThrow('asd');
   });
 });
 
@@ -39,99 +55,105 @@ describe('getSnapPrefix', () => {
   });
 });
 
-describe('isValidSnapVersionRange', () => {
+describe('isValidSemVerRange', () => {
   it('supports *', () => {
-    expect(isValidSnapVersionRange('*')).toBe(true);
+    expect(isValidSemVerRange('*')).toBe(true);
   });
 
   it('supports normal version ranges', () => {
-    expect(isValidSnapVersionRange('^1.2.3')).toBe(true);
-    expect(isValidSnapVersionRange('1.5.0')).toBe(true);
+    expect(isValidSemVerRange('^1.2.3')).toBe(true);
+    expect(isValidSemVerRange('1.5.0')).toBe(true);
   });
 
   it('supports pre-release versions', () => {
-    expect(isValidSnapVersionRange('1.0.0-beta.1')).toBe(true);
-    expect(isValidSnapVersionRange('^1.0.0-beta.1')).toBe(true);
+    expect(isValidSemVerRange('1.0.0-beta.1')).toBe(true);
+    expect(isValidSemVerRange('^1.0.0-beta.1')).toBe(true);
   });
 
   it('rejects non strings', () => {
-    expect(isValidSnapVersionRange(null)).toBe(false);
-    expect(isValidSnapVersionRange(undefined)).toBe(false);
-    expect(isValidSnapVersionRange(2)).toBe(false);
-    expect(isValidSnapVersionRange(true)).toBe(false);
-    expect(isValidSnapVersionRange({})).toBe(false);
+    expect(isValidSemVerRange(null)).toBe(false);
+    expect(isValidSemVerRange(undefined)).toBe(false);
+    expect(isValidSemVerRange(2)).toBe(false);
+    expect(isValidSemVerRange(true)).toBe(false);
+    expect(isValidSemVerRange({})).toBe(false);
   });
 });
 
 describe('gtVersion', () => {
   it('supports regular versions', () => {
-    expect(gtVersion('1.2.3', '1.0.0')).toBe(true);
-    expect(gtVersion('2.0.0', '1.0.0')).toBe(true);
-    expect(gtVersion('1.0.0', '1.2.3')).toBe(false);
-    expect(gtVersion('1.0.0', '2.0.0')).toBe(false);
+    expect(gtVersion(v('1.2.3'), v('1.0.0'))).toBe(true);
+    expect(gtVersion(v('2.0.0'), v('1.0.0'))).toBe(true);
+    expect(gtVersion(v('1.0.0'), v('1.2.3'))).toBe(false);
+    expect(gtVersion(v('1.0.0'), v('2.0.0'))).toBe(false);
   });
 
   it('supports pre-release versions', () => {
-    expect(gtVersion('1.0.0-beta.2', '1.0.0-beta.1')).toBe(true);
-    expect(gtVersion('1.0.0-beta.2', '1.2.3')).toBe(false);
-    expect(gtVersion('1.0.0', '1.0.0-beta.2')).toBe(true);
-    expect(gtVersion('1.2.3-beta.1', '1.0.0')).toBe(true);
-    expect(gtVersion('1.2.3-beta.1', '1.2.3-alpha.2')).toBe(true);
+    expect(gtVersion(v('1.0.0-beta.2'), v('1.0.0-beta.1'))).toBe(true);
+    expect(gtVersion(v('1.0.0-beta.2'), v('1.2.3'))).toBe(false);
+    expect(gtVersion(v('1.0.0'), v('1.0.0-beta.2'))).toBe(true);
+    expect(gtVersion(v('1.2.3-beta.1'), v('1.0.0'))).toBe(true);
+    expect(gtVersion(v('1.2.3-beta.1'), v('1.2.3-alpha.2'))).toBe(true);
   });
 });
 
 describe('getTargetVersion', () => {
   it('supports *', () => {
-    expect(getTargetVersion(['1.2.3', '3.0.0'], '*')).toBe('3.0.0');
+    expect(getTargetVersion(v(['1.2.3', '3.0.0']), r('*'))).toBe('3.0.0');
   });
 
   it('supports pre-release versions', () => {
-    expect(getTargetVersion(['1.0.0-beta.1'], '*')).toBe('1.0.0-beta.1');
-    expect(getTargetVersion(['1.0.0-beta.1', '1.0.0-beta.2'], '*')).toBe(
+    expect(getTargetVersion(v(['1.0.0-beta.1']), r('*'))).toBe('1.0.0-beta.1');
+    expect(getTargetVersion(v(['1.0.0-beta.1', '1.0.0-beta.2']), r('*'))).toBe(
       '1.0.0-beta.2',
     );
 
     expect(
-      getTargetVersion(['1.0.0-beta.1', '1.0.0-beta.2'], '^1.0.0-beta.1'),
+      getTargetVersion(v(['1.0.0-beta.1', '1.0.0-beta.2']), r('^1.0.0-beta.1')),
     ).toBe('1.0.0-beta.2');
 
-    expect(getTargetVersion(['1.0.0-alpha.2', '1.0.0-beta.1'], '*')).toBe(
+    expect(getTargetVersion(v(['1.0.0-alpha.2', '1.0.0-beta.1']), r('*'))).toBe(
       '1.0.0-beta.1',
     );
 
-    expect(getTargetVersion(['0.9.0', '1.0.0-alpha.0'], '*')).toBe('0.9.0');
+    expect(getTargetVersion(v(['0.9.0', '1.0.0-alpha.0']), r('*'))).toBe(
+      '0.9.0',
+    );
   });
 
-  it('doesnt return pre-release versions by default', () => {
-    expect(getTargetVersion(['1.0.0-beta.1', '1.0.0', '1.2.3'], '*')).toBe(
-      '1.2.3',
-    );
+  it("doesn't return pre-release versions by default", () => {
+    expect(
+      getTargetVersion(v(['1.0.0-beta.1', '1.0.0', '1.2.3']), r('*')),
+    ).toBe('1.2.3');
 
-    expect(getTargetVersion(['1.0.0-beta.1', '1.0.0', '1.2.3'], '^1.0.0')).toBe(
-      '1.2.3',
+    expect(
+      getTargetVersion(v(['1.0.0-beta.1', '1.0.0', '1.2.3']), r('^1.0.0')),
+    ).toBe('1.2.3');
+    expect(getTargetVersion(v(['1.0.0-beta.1', '1.0.0']), r('*'))).toBe(
+      '1.0.0',
     );
-    expect(getTargetVersion(['1.0.0-beta.1', '1.0.0'], '*')).toBe('1.0.0');
   });
 });
 
-describe('satifiesVersionRange', () => {
+describe('satisfiesVersionRange', () => {
   it('supports *', () => {
-    expect(satisfiesVersionRange('3.0.0', '*')).toBe(true);
+    expect(satisfiesVersionRange(v('3.0.0'), r('*'))).toBe(true);
   });
 
   it('supports exact versions', () => {
-    expect(satisfiesVersionRange('1.0.0-beta.1', '1.0.0-beta.1')).toBe(true);
-    expect(satisfiesVersionRange('1.0.0', '1.0.0')).toBe(true);
-    expect(satisfiesVersionRange('1.2.3', '1.0.0')).toBe(false);
+    expect(satisfiesVersionRange(v('1.0.0-beta.1'), r('1.0.0-beta.1'))).toBe(
+      true,
+    );
+    expect(satisfiesVersionRange(v('1.0.0'), r('1.0.0'))).toBe(true);
+    expect(satisfiesVersionRange(v('1.2.3'), r('1.0.0'))).toBe(false);
   });
 
   it('supports non-exact version ranges', () => {
-    expect(satisfiesVersionRange('1.2.3', '^1.0.0')).toBe(true);
-    expect(satisfiesVersionRange('2.0.0', '^1.0.0')).toBe(false);
+    expect(satisfiesVersionRange(v('1.2.3'), r('^1.0.0'))).toBe(true);
+    expect(satisfiesVersionRange(v('2.0.0'), r('^1.0.0'))).toBe(false);
   });
 
-  it('prereleases can satisfy version range', () => {
-    expect(satisfiesVersionRange('1.0.0-beta.1', '*')).toBe(true);
-    expect(satisfiesVersionRange('1.0.0-beta.1', '^1.0.0')).toBe(false);
+  it('pre-releases can satisfy version range', () => {
+    expect(satisfiesVersionRange(v('1.0.0-beta.1'), r('*'))).toBe(true);
+    expect(satisfiesVersionRange(v('1.0.0-beta.1'), r('^1.0.0'))).toBe(false);
   });
 });
diff --git a/packages/snaps-utils/src/versions.ts b/packages/snaps-utils/src/versions.ts
index 574e1650f8..8f559dadd3 100644
--- a/packages/snaps-utils/src/versions.ts
+++ b/packages/snaps-utils/src/versions.ts
@@ -1,12 +1,104 @@
-import { Json } from '@metamask/utils';
+import { assertStruct, Json } from '@metamask/utils';
 import {
   gt as gtSemver,
   maxSatisfying as maxSatisfyingSemver,
   satisfies as satisfiesSemver,
-  validRange as validRangeSemver,
+  valid as validSemVerVersion,
+  validRange as validSemVerRange,
 } from 'semver';
+import { is, refine, string, Struct } from 'superstruct';
 
-export const DEFAULT_REQUESTED_SNAP_VERSION = '*';
+export const DEFAULT_REQUESTED_SNAP_VERSION = '*' as SemVerRange;
+
+/**
+ * {@link https://codemix.com/opaque-types-in-javascript/ Opaque} type for SemVer ranges.
+ * Castable from string.
+ */
+declare type SemVerRange = {
+  __TYPE: 'semver_range';
+} & string;
+/**
+ * {@link https://codemix.com/opaque-types-in-javascript/ Opaque} type for singular SemVer version.
+ * Castable from string.
+ */
+declare type SemVerVersion = {
+  __TYPE: 'semver_version';
+} & string;
+export { SemVerRange, SemVerVersion };
+
+/**
+ * A struct for validating a version string.
+ */
+export const VersionStruct = refine<SemVerVersion, null>(
+  string() as unknown as Struct<SemVerVersion, null>,
+  'Version',
+  (value) => {
+    if (validSemVerVersion(value) === null) {
+      return `Expected SemVer version, got "${value}"`;
+    }
+    return true;
+  },
+);
+
+export const VersionRangeStruct = refine<SemVerRange, null>(
+  string() as unknown as Struct<SemVerRange, null>,
+  'Version range',
+  (value) => {
+    if (validSemVerRange(value) === null) {
+      return `Expected SemVer range, got "${value}"`;
+    }
+    return true;
+  },
+);
+
+/**
+ * Checks whether a SemVer version is valid.
+ *
+ * @param version - A potential version.
+ * @returns `true` if the version is valid, and `false` otherwise.
+ */
+export function isValidSemVerVersion(
+  version: unknown,
+): version is SemVerVersion {
+  return Boolean(
+    typeof version === 'string' &&
+      validSemVerVersion(version, { includePrerelease: true }) !== null,
+  );
+}
+
+/**
+ * Checks whether a SemVer version range is valid.
+ *
+ * @param versionRange - A potential version range.
+ * @returns `true` if the version range is valid, and `false` otherwise.
+ */
+export function isValidSemVerRange(
+  versionRange: unknown,
+): versionRange is SemVerRange {
+  return is(versionRange, VersionStruct);
+}
+
+/**
+ * Asserts that a value is a valid concrete SemVer version.
+ *
+ * @param version - A potential SemVer concrete version.
+ */
+export function assertIsSemVerVersion(
+  version: unknown,
+): asserts version is SemVerVersion {
+  assertStruct(version, VersionStruct);
+}
+
+/**
+ * Asserts that a value is a valid SemVer range.
+ *
+ * @param range - A potential SemVer range.
+ */
+export function assertIsSemVerRange(
+  range: unknown,
+): asserts range is SemVerRange {
+  assertStruct(range, VersionRangeStruct);
+}
 
 /**
  * Checks whether a SemVer version is greater than another.
@@ -15,7 +107,10 @@ export const DEFAULT_REQUESTED_SNAP_VERSION = '*';
  * @param version2 - The right-hand version.
  * @returns `version1 > version2`.
  */
-export function gtVersion(version1: string, version2: string): boolean {
+export function gtVersion(
+  version1: SemVerVersion,
+  version2: SemVerVersion,
+): boolean {
   return gtSemver(version1, version2);
 }
 
@@ -27,8 +122,8 @@ export function gtVersion(version1: string, version2: string): boolean {
  * @returns Whether the version satisfied the version range.
  */
 export function satisfiesVersionRange(
-  version: string,
-  versionRange: string,
+  version: SemVerVersion,
+  versionRange: SemVerRange,
 ): boolean {
   return satisfiesSemver(version, versionRange, {
     includePrerelease: true,
@@ -46,9 +141,9 @@ export function satisfiesVersionRange(
  * or `null` if none of them do.
  */
 export function getTargetVersion(
-  versions: string[],
-  versionRange: string,
-): string | null {
+  versions: SemVerVersion[],
+  versionRange: SemVerRange,
+): SemVerVersion | null {
   const maxSatisfyingNonPreRelease = maxSatisfyingSemver(
     versions,
     versionRange,
@@ -72,24 +167,10 @@ export function getTargetVersion(
  * @returns `*` if the version is `undefined` or `latest", otherwise returns
  * the specified version.
  */
-export function resolveVersion(version?: Json): Json {
+export function resolveVersionRange(version?: Json): SemVerRange {
   if (version === undefined || version === 'latest') {
     return DEFAULT_REQUESTED_SNAP_VERSION;
   }
+  assertIsSemVerRange(version);
   return version;
 }
-
-/**
- * Checks whether a SemVer version range is valid.
- *
- * @param versionRange - A potential version range.
- * @returns `true` if the version range is valid, and `false` otherwise.
- */
-export function isValidSnapVersionRange(
-  versionRange: unknown,
-): versionRange is string {
-  return Boolean(
-    typeof versionRange === 'string' &&
-      validRangeSemver(versionRange, { includePrerelease: true }) !== null,
-  );
-}

From 1bf305bd476b4b878600227af256231fd73b90cc Mon Sep 17 00:00:00 2001
From: Olaf Tomalka <olaf@tomalka.me>
Date: Mon, 14 Nov 2022 20:39:43 +0100
Subject: [PATCH 02/13] Added opaque types for SemVers

---
 .../src/cronjob/CronjobController.test.ts     |  7 +-
 .../src/snaps/SnapController.test.ts          | 28 +++++--
 .../src/snaps/SnapController.ts               |  7 +-
 packages/snaps-utils/jest.config.js           |  2 +-
 .../snaps-utils/src/test-utils/manifest.ts    | 20 +++--
 packages/snaps-utils/src/test-utils/snap.ts   | 23 +++--
 packages/snaps-utils/src/versions.test.ts     | 83 +++++++++++++++++--
 packages/snaps-utils/src/versions.ts          | 26 +++---
 8 files changed, 152 insertions(+), 44 deletions(-)

diff --git a/packages/snaps-controllers/src/cronjob/CronjobController.test.ts b/packages/snaps-controllers/src/cronjob/CronjobController.test.ts
index 875aafec1b..8b50c9ffb5 100644
--- a/packages/snaps-controllers/src/cronjob/CronjobController.test.ts
+++ b/packages/snaps-controllers/src/cronjob/CronjobController.test.ts
@@ -3,6 +3,7 @@ import {
   HandlerType,
   deepClone,
   TruncatedSnap,
+  SemVerVersion,
 } from '@metamask/snaps-utils';
 import {
   MOCK_ORIGIN,
@@ -315,7 +316,7 @@ describe('CronjobController', () => {
       id: MOCK_SNAP_ID,
       initialPermissions: {},
       permissionName: '',
-      version: '',
+      version: '1.0' as SemVerVersion,
     };
     // @ts-expect-error Accessing private property
     cronjobController._handleEventSnapInstalled(snapInfo);
@@ -367,7 +368,7 @@ describe('CronjobController', () => {
       id: MOCK_SNAP_ID,
       initialPermissions: {},
       permissionName: '',
-      version: '',
+      version: '1.0' as SemVerVersion,
     };
 
     // @ts-expect-error Accessing private property
@@ -432,7 +433,7 @@ describe('CronjobController', () => {
       id: MOCK_SNAP_ID,
       initialPermissions: {},
       permissionName: '',
-      version: '',
+      version: '1.0' as SemVerVersion,
     };
 
     // @ts-expect-error Accessing private property
diff --git a/packages/snaps-controllers/src/snaps/SnapController.test.ts b/packages/snaps-controllers/src/snaps/SnapController.test.ts
index 0b5c6e2a9c..2ca937df96 100644
--- a/packages/snaps-controllers/src/snaps/SnapController.test.ts
+++ b/packages/snaps-controllers/src/snaps/SnapController.test.ts
@@ -9,6 +9,7 @@ import {
   DEFAULT_ENDOWMENTS,
   getSnapSourceShasum,
   HandlerType,
+  SemVerVersion,
   SnapCaveatType,
   SnapManifest,
   SnapStatus,
@@ -30,8 +31,7 @@ import fetchMock from 'jest-fetch-mock';
 import { createAsyncMiddleware, JsonRpcEngine } from 'json-rpc-engine';
 import { createEngineStream } from 'json-rpc-middleware-stream';
 import pump from 'pump';
-import { Duplex } from 'stream';
-
+import { Duplex } from 'stream';;
 import { NodeThreadExecutionService, setupMultiplex } from '../services';
 import {
   ExecutionEnvironmentStub,
@@ -2545,7 +2545,7 @@ describe('SnapController', () => {
       fetchSnapSpy.mockImplementationOnce(async () => {
         const manifest: SnapManifest = {
           ...getSnapManifest(),
-          version: '1.1.0',
+          version: '1.1.0' as SemVerVersion,
         };
 
         return Promise.resolve({
@@ -2580,7 +2580,7 @@ describe('SnapController', () => {
       fetchSnapSpy.mockImplementationOnce(async () => {
         const manifest: SnapManifest = {
           ...getSnapManifest(),
-          version: '0.9.0',
+          version: '0.9.0' as SemVerVersion,
         };
 
         return Promise.resolve({
@@ -2625,7 +2625,7 @@ describe('SnapController', () => {
         .mockImplementationOnce(async () => {
           const manifest: SnapManifest = {
             ...getSnapManifest(),
-            version: '1.1.0',
+            version: '1.1.0' as SemVerVersion,
           };
 
           return Promise.resolve({
@@ -2757,7 +2757,7 @@ describe('SnapController', () => {
       fetchSnapSpy.mockImplementationOnce(async () => {
         const manifest: SnapManifest = {
           ...getSnapManifest(),
-          version: '1.1.0',
+          version: '1.1.0' as SemVerVersion,
         };
 
         return Promise.resolve({
@@ -2864,7 +2864,7 @@ describe('SnapController', () => {
       fetchSnapSpy.mockImplementationOnce(async () => {
         const manifest: SnapManifest = {
           ...getSnapManifest(),
-          version: '1.1.0',
+          version: '1.1.0' as SemVerVersion,
         };
 
         return Promise.resolve({
@@ -3143,7 +3143,13 @@ describe('SnapController', () => {
         });
       /* eslint-enable @typescript-eslint/naming-convention */
 
+<<<<<<< HEAD
       callActionSpy.mockImplementation((method, ...args: unknown[]): any => {
+=======
+      callActionSpy.mockImplementation((method, ...params) => {
+        assert(params.length > 0);
+        const request: any = params[0];
+>>>>>>> c8c60447 (Added opaque types for SemVers)
         if (method === 'PermissionController:hasPermission') {
           return true;
         } else if (method === 'ApprovalController:addRequest') {
@@ -3949,6 +3955,10 @@ describe('SnapController', () => {
           ) {
             return true;
           }
+<<<<<<< HEAD
+=======
+
+>>>>>>> c8c60447 (Added opaque types for SemVers)
           return (originalCall as any)(method, ...args);
         });
 
@@ -3979,6 +3989,10 @@ describe('SnapController', () => {
               },
             };
           }
+<<<<<<< HEAD
+=======
+
+>>>>>>> c8c60447 (Added opaque types for SemVers)
           return (originalCall as any)(method, ...args);
         });
 
diff --git a/packages/snaps-controllers/src/snaps/SnapController.ts b/packages/snaps-controllers/src/snaps/SnapController.ts
index 89b338c7dc..c7fce0de55 100644
--- a/packages/snaps-controllers/src/snaps/SnapController.ts
+++ b/packages/snaps-controllers/src/snaps/SnapController.ts
@@ -1536,10 +1536,8 @@ export class SnapController extends BaseController<
     await Promise.all(
       Object.entries(requestedSnaps).map(
         async ([snapId, { version: rawVersion }]) => {
-          const version = resolveVersionRange(rawVersion);
-          const permissionName = getSnapPermissionName(snapId);
-
-          if (!isValidSemVerRange(version)) {
+          const [err, version] = resolveVersionRange(rawVersion);
+          if (err) {
             result[snapId] = {
               error: ethErrors.rpc.invalidParams(
                 `The "version" field must be a valid SemVer version range if specified. Received: "${version}".`,
@@ -1547,6 +1545,7 @@ export class SnapController extends BaseController<
             };
             return;
           }
+          const permissionName = getSnapPermissionName(snapId);
 
           if (
             this.messagingSystem.call(
diff --git a/packages/snaps-utils/jest.config.js b/packages/snaps-utils/jest.config.js
index 03abb3f1aa..1b4f207447 100644
--- a/packages/snaps-utils/jest.config.js
+++ b/packages/snaps-utils/jest.config.js
@@ -14,7 +14,7 @@ module.exports = deepmerge(baseConfig, {
   ],
   coverageThreshold: {
     global: {
-      branches: 93.15,
+      branches: 93.45,
       functions: 95.18,
       lines: 98.07,
       statements: 98.07,
diff --git a/packages/snaps-utils/src/test-utils/manifest.ts b/packages/snaps-utils/src/test-utils/manifest.ts
index 68f3192130..5ccce7ff76 100644
--- a/packages/snaps-utils/src/test-utils/manifest.ts
+++ b/packages/snaps-utils/src/test-utils/manifest.ts
@@ -1,3 +1,4 @@
+import { SemVerVersion } from '../versions';
 import { SnapManifest } from '../manifest/validation';
 import {
   Chain,
@@ -8,7 +9,10 @@ import {
 import { NpmSnapPackageJson } from '../types';
 import { DEFAULT_SNAP_SHASUM } from './snap';
 
-type GetSnapManifestOptions = Partial<Omit<SnapManifest, 'source'>> & {
+type GetSnapManifestOptions = Partial<
+  Omit<SnapManifest, 'source' | 'version'>
+> & {
+  version?: SemVerVersion | string;
   shasum?: string;
   filePath?: string;
   packageName?: string;
@@ -16,6 +20,10 @@ type GetSnapManifestOptions = Partial<Omit<SnapManifest, 'source'>> & {
   iconPath?: string;
 };
 
+type GetPackageJsonOptions = Partial<Omit<NpmSnapPackageJson, 'version'>> & {
+  version?: SemVerVersion | string;
+};
+
 /**
  * Get the default package repository, in a format compatible with
  * `package.json`.
@@ -47,7 +55,7 @@ export const getDefaultRepository = () => {
  * @returns The snap manifest.
  */
 export const getSnapManifest = ({
-  version = '1.0.0',
+  version = '1.0.0' as SemVerVersion,
   description = 'The test example snap!',
   proposedName = '@metamask/example-snap',
   // eslint-disable-next-line @typescript-eslint/naming-convention
@@ -59,7 +67,7 @@ export const getSnapManifest = ({
   iconPath = 'images/icon.svg',
 }: GetSnapManifestOptions = {}): SnapManifest => {
   return {
-    version,
+    version: version as SemVerVersion,
     description,
     proposedName,
     repository,
@@ -94,14 +102,14 @@ export const getSnapManifest = ({
  */
 export const getPackageJson = ({
   name = '@metamask/example-snap',
-  version = '1.0.0',
+  version = '1.0.0' as SemVerVersion,
   description = 'The test example snap!',
   main = 'src/index.js',
   repository = getDefaultRepository(),
-}: Partial<NpmSnapPackageJson> = {}): NpmSnapPackageJson => {
+}: GetPackageJsonOptions = {}): NpmSnapPackageJson => {
   return {
     name,
-    version,
+    version: version as SemVerVersion,
     description,
     main,
     repository,
diff --git a/packages/snaps-utils/src/test-utils/snap.ts b/packages/snaps-utils/src/test-utils/snap.ts
index 603efc078a..7b1cf00858 100644
--- a/packages/snaps-utils/src/test-utils/snap.ts
+++ b/packages/snaps-utils/src/test-utils/snap.ts
@@ -1,3 +1,4 @@
+import { SemVerVersion } from '../versions';
 import {
   getSnapSourceShasum,
   PersistedSnap,
@@ -27,6 +28,16 @@ export const MOCK_SNAP_ID = 'npm:@metamask/example-snap';
 export const MOCK_LOCAL_SNAP_ID = 'local:@metamask/example-snap';
 export const MOCK_ORIGIN = 'example.com';
 
+type GetPersistedSnapObjectOptions = Partial<Omit<PersistedSnap, 'version'>> & {
+  version?: string | SemVerVersion;
+};
+type GetSnapObjectOptions = Partial<Omit<Snap, 'version'>> & {
+  version?: string | SemVerVersion;
+};
+type GetTruncatedSnapOptions = Partial<Omit<TruncatedSnap, 'version'>> & {
+  version?: string | SemVerVersion;
+};
+
 export const getPersistedSnapObject = ({
   blocked = false,
   enabled = true,
@@ -40,13 +51,13 @@ export const getPersistedSnapObject = ({
   versionHistory = [
     { origin: MOCK_ORIGIN, version: '1.0.0', date: expect.any(Number) },
   ],
-}: Partial<PersistedSnap> = {}): PersistedSnap => {
+}: GetPersistedSnapObjectOptions = {}): PersistedSnap => {
   return {
     blocked,
     initialPermissions,
     id,
     permissionName,
-    version,
+    version: version as SemVerVersion,
     manifest,
     status,
     enabled,
@@ -67,13 +78,13 @@ export const getSnapObject = ({
   versionHistory = [
     { origin: MOCK_ORIGIN, version: '1.0.0', date: expect.any(Number) },
   ],
-}: Partial<Snap> = {}): Snap => {
+}: GetSnapObjectOptions = {}): Snap => {
   return {
     blocked,
     initialPermissions,
     id,
     permissionName,
-    version,
+    version: version as SemVerVersion,
     manifest,
     status,
     enabled,
@@ -88,12 +99,12 @@ export const getTruncatedSnap = ({
   version = getSnapManifest().version,
   enabled = true,
   blocked = false,
-}: Partial<TruncatedSnap> = {}): TruncatedSnap => {
+}: GetTruncatedSnapOptions = {}): TruncatedSnap => {
   return {
     initialPermissions,
     id,
     permissionName,
-    version,
+    version: version as SemVerVersion,
     enabled,
     blocked,
   } as const;
diff --git a/packages/snaps-utils/src/versions.test.ts b/packages/snaps-utils/src/versions.test.ts
index b97446f9cc..2fa7837804 100644
--- a/packages/snaps-utils/src/versions.test.ts
+++ b/packages/snaps-utils/src/versions.test.ts
@@ -1,10 +1,14 @@
+import { assert } from '@metamask/utils';
 import { getSnapPrefix } from './snaps';
 import { SnapIdPrefixes } from './types';
 import {
+  assertIsSemVerRange,
+  assertIsSemVerVersion,
   DEFAULT_REQUESTED_SNAP_VERSION,
   getTargetVersion,
   gtVersion,
   isValidSemVerRange,
+  isValidSemVerVersion,
   resolveVersionRange,
   satisfiesVersionRange,
   SemVerRange,
@@ -13,29 +17,48 @@ import {
 
 function v(value: string[]): SemVerVersion[];
 function v(value: string): SemVerVersion;
+/**
+ * Utility to cast string to version.
+ *
+ * @param value - String to cast.
+ * @returns The same string with different type.
+ */
 function v(value: string | string[]): SemVerVersion | SemVerVersion[] {
   return value as any;
 }
 
+/**
+ * Utility to cast string to range.
+ *
+ * @param value - String to cast.
+ * @returns The same string with different type.
+ */
 function r(value: string): SemVerRange {
   return value as SemVerRange;
 }
 
 describe('resolveVersion', () => {
   it('defaults "latest" to DEFAULT_REQUESTED_SNAP_VERSION', () => {
-    expect(resolveVersionRange('latest')).toBe(DEFAULT_REQUESTED_SNAP_VERSION);
+    expect(resolveVersionRange('latest')[1]).toBe(
+      DEFAULT_REQUESTED_SNAP_VERSION,
+    );
   });
 
   it('defaults an undefined version to DEFAULT_REQUESTED_SNAP_VERSION', () => {
-    expect(resolveVersionRange(undefined)).toBe(DEFAULT_REQUESTED_SNAP_VERSION);
+    expect(resolveVersionRange(undefined)[1]).toBe(
+      DEFAULT_REQUESTED_SNAP_VERSION,
+    );
   });
 
   it('returns the requested version for everything else', () => {
-    expect(resolveVersionRange('1.2.3')).toBe('1.2.3');
+    expect(resolveVersionRange('1.2.3')[1]).toBe('1.2.3');
   });
 
-  it.each([null, 1, {}, Error])('throws on invalid input', (value) => {
-    expect(() => resolveVersionRange(value)).toThrow('asd');
+  it.each([null, 1, {}, Error])('returns error on invalid input', (value) => {
+    const [err, result] = resolveVersionRange(value);
+    assert(err !== undefined);
+    expect(err.message).toMatch('Expected a string, but received: ');
+    expect(result).toBeUndefined();
   });
 });
 
@@ -55,6 +78,48 @@ describe('getSnapPrefix', () => {
   });
 });
 
+describe('assertIsSemVerVersion', () => {
+  it('shows descriptive errors', () => {
+    expect(() => assertIsSemVerVersion('>1.2')).toThrow(
+      'Expected SemVer version, got',
+    );
+  });
+});
+
+describe('assertIsSemVerRange', () => {
+  it('shows descriptive errors', () => {
+    expect(() => assertIsSemVerRange('.')).toThrow(
+      'Expected SemVer range, got',
+    );
+  });
+});
+
+describe('isValidSemVerVersion', () => {
+  it.each([
+    'asd',
+    '()()',
+    '..',
+    '.',
+    '.1',
+    null,
+    undefined,
+    2,
+    true,
+    {},
+    Error,
+  ])('rejects invalid version', (version) => {
+    expect(isValidSemVerVersion(version)).toBe(false);
+  });
+
+  it('supports normal version ranges', () => {
+    expect(isValidSemVerVersion('1.5.0')).toBe(true);
+  });
+
+  it('supports pre-release versions', () => {
+    expect(isValidSemVerVersion('1.0.0-beta.1')).toBe(true);
+  });
+});
+
 describe('isValidSemVerRange', () => {
   it('supports *', () => {
     expect(isValidSemVerRange('*')).toBe(true);
@@ -77,6 +142,13 @@ describe('isValidSemVerRange', () => {
     expect(isValidSemVerRange(true)).toBe(false);
     expect(isValidSemVerRange({})).toBe(false);
   });
+
+  it.each(['asd', '()()(', '..', '.', '1.'])(
+    'rejects invalid ranges',
+    (range) => {
+      expect(isValidSemVerRange(range)).toBe(false);
+    },
+  );
 });
 
 describe('gtVersion', () => {
@@ -128,6 +200,7 @@ describe('getTargetVersion', () => {
     expect(
       getTargetVersion(v(['1.0.0-beta.1', '1.0.0', '1.2.3']), r('^1.0.0')),
     ).toBe('1.2.3');
+
     expect(getTargetVersion(v(['1.0.0-beta.1', '1.0.0']), r('*'))).toBe(
       '1.0.0',
     );
diff --git a/packages/snaps-utils/src/versions.ts b/packages/snaps-utils/src/versions.ts
index 8f559dadd3..ce1a19cb4a 100644
--- a/packages/snaps-utils/src/versions.ts
+++ b/packages/snaps-utils/src/versions.ts
@@ -6,20 +6,24 @@ import {
   valid as validSemVerVersion,
   validRange as validSemVerRange,
 } from 'semver';
-import { is, refine, string, Struct } from 'superstruct';
+import { is, refine, string, Struct, validate } from 'superstruct';
 
 export const DEFAULT_REQUESTED_SNAP_VERSION = '*' as SemVerRange;
 
 /**
  * {@link https://codemix.com/opaque-types-in-javascript/ Opaque} type for SemVer ranges.
- * Castable from string.
+ *
+ * Use {@link assertIsSemVerRange} and {@link isValidSemVerRange} to cast to proper type.
+ * If you know what you're doing and want to side-step type safety, casting from a string works correctly.
  */
 declare type SemVerRange = {
   __TYPE: 'semver_range';
 } & string;
 /**
  * {@link https://codemix.com/opaque-types-in-javascript/ Opaque} type for singular SemVer version.
- * Castable from string.
+ *
+ * Use {@link assertIsSemVerVersion} and {@link isValidSemVerVersion} to cast to proper type.
+ * If you know what you're doing and want to side-step type safety, casting from a string works correctly.
  */
 declare type SemVerVersion = {
   __TYPE: 'semver_version';
@@ -60,10 +64,7 @@ export const VersionRangeStruct = refine<SemVerRange, null>(
 export function isValidSemVerVersion(
   version: unknown,
 ): version is SemVerVersion {
-  return Boolean(
-    typeof version === 'string' &&
-      validSemVerVersion(version, { includePrerelease: true }) !== null,
-  );
+  return is(version, VersionStruct);
 }
 
 /**
@@ -75,7 +76,7 @@ export function isValidSemVerVersion(
 export function isValidSemVerRange(
   versionRange: unknown,
 ): versionRange is SemVerRange {
-  return is(versionRange, VersionStruct);
+  return is(versionRange, VersionRangeStruct);
 }
 
 /**
@@ -167,10 +168,11 @@ export function getTargetVersion(
  * @returns `*` if the version is `undefined` or `latest", otherwise returns
  * the specified version.
  */
-export function resolveVersionRange(version?: Json): SemVerRange {
+export function resolveVersionRange(
+  version?: Json,
+): [undefined, SemVerRange] | [Error, undefined] {
   if (version === undefined || version === 'latest') {
-    return DEFAULT_REQUESTED_SNAP_VERSION;
+    return [undefined, DEFAULT_REQUESTED_SNAP_VERSION];
   }
-  assertIsSemVerRange(version);
-  return version;
+  return validate(version, VersionRangeStruct);
 }

From c97d2a049fffa3ff4c1dbd428a517306a13f0882 Mon Sep 17 00:00:00 2001
From: Olaf Tomalka <olaf@tomalka.me>
Date: Mon, 14 Nov 2022 20:57:45 +0100
Subject: [PATCH 03/13] Better documentation

---
 packages/snaps-utils/src/versions.ts | 35 ++++++++++++++++++++++++----
 1 file changed, 31 insertions(+), 4 deletions(-)

diff --git a/packages/snaps-utils/src/versions.ts b/packages/snaps-utils/src/versions.ts
index ce1a19cb4a..488c4e5420 100644
--- a/packages/snaps-utils/src/versions.ts
+++ b/packages/snaps-utils/src/versions.ts
@@ -13,17 +13,44 @@ export const DEFAULT_REQUESTED_SNAP_VERSION = '*' as SemVerRange;
 /**
  * {@link https://codemix.com/opaque-types-in-javascript/ Opaque} type for SemVer ranges.
  *
- * Use {@link assertIsSemVerRange} and {@link isValidSemVerRange} to cast to proper type.
- * If you know what you're doing and want to side-step type safety, casting from a string works correctly.
+ * @example Use {@link assertIsSemVerRange} and {@link isValidSemVerRange} to cast to proper type.
+ * ```typescript
+ * const unsafeRange: string = dataFromUser();
+ * assertIsSemVerRange(unsafeRange);
+ * unsafeRange
+ * // ^? SemVerRange
+ * ```
+ * @example If you know what you're doing and want to side-step type safety, casting from a string works correctly.
+ * ```typescript
+ * const unsafeRange: string = dataFromUser();
+ * unsafeRange as SemVerRange;
+ * // ^? SemVerRange
+ * ```
+ * @see {@link assertIsSemVerRange}
+ * @see {@link isValidSemVerRange}
  */
 declare type SemVerRange = {
   __TYPE: 'semver_range';
 } & string;
+
 /**
  * {@link https://codemix.com/opaque-types-in-javascript/ Opaque} type for singular SemVer version.
  *
- * Use {@link assertIsSemVerVersion} and {@link isValidSemVerVersion} to cast to proper type.
- * If you know what you're doing and want to side-step type safety, casting from a string works correctly.
+ * @example Use {@link assertIsSemVerVersion} and {@link isValidSemVerVersion} to cast to proper type.
+ * ```typescript
+ * const unsafeVersion: string = dataFromUser();
+ * assertIsSemVerVersion(unsafeRange);
+ * unsafeVersion
+ * // ^? SemVerVersion
+ * ```
+ * @example If you know what you're doing and want to side-step type safety, casting from a string works correctly.
+ * ```typescript
+ * const unsafeVersion: string = dataFromUser();
+ * unsafeRange as SemVerVersion;
+ * // ^? SemVerVersion
+ * ```
+ * @see {@link assertIsSemVerVersion}
+ * @see {@link isValidSemVerVersion}
  */
 declare type SemVerVersion = {
   __TYPE: 'semver_version';

From a7a11f0592c5d596e7bb335b8f36e0d5227b06de Mon Sep 17 00:00:00 2001
From: Olaf Tomalka <olaf@tomalka.me>
Date: Mon, 14 Nov 2022 21:19:35 +0100
Subject: [PATCH 04/13] Removed versions.test.ts utillity functions

---
 packages/snaps-utils/src/versions.test.ts | 181 +++++++++++++++-------
 1 file changed, 123 insertions(+), 58 deletions(-)

diff --git a/packages/snaps-utils/src/versions.test.ts b/packages/snaps-utils/src/versions.test.ts
index 2fa7837804..71554b38e5 100644
--- a/packages/snaps-utils/src/versions.test.ts
+++ b/packages/snaps-utils/src/versions.test.ts
@@ -15,28 +15,6 @@ import {
   SemVerVersion,
 } from './versions';
 
-function v(value: string[]): SemVerVersion[];
-function v(value: string): SemVerVersion;
-/**
- * Utility to cast string to version.
- *
- * @param value - String to cast.
- * @returns The same string with different type.
- */
-function v(value: string | string[]): SemVerVersion | SemVerVersion[] {
-  return value as any;
-}
-
-/**
- * Utility to cast string to range.
- *
- * @param value - String to cast.
- * @returns The same string with different type.
- */
-function r(value: string): SemVerRange {
-  return value as SemVerRange;
-}
-
 describe('resolveVersion', () => {
   it('defaults "latest" to DEFAULT_REQUESTED_SNAP_VERSION', () => {
     expect(resolveVersionRange('latest')[1]).toBe(
@@ -153,80 +131,167 @@ describe('isValidSemVerRange', () => {
 
 describe('gtVersion', () => {
   it('supports regular versions', () => {
-    expect(gtVersion(v('1.2.3'), v('1.0.0'))).toBe(true);
-    expect(gtVersion(v('2.0.0'), v('1.0.0'))).toBe(true);
-    expect(gtVersion(v('1.0.0'), v('1.2.3'))).toBe(false);
-    expect(gtVersion(v('1.0.0'), v('2.0.0'))).toBe(false);
+    expect(gtVersion('1.2.3' as SemVerVersion, '1.0.0' as SemVerVersion)).toBe(
+      true,
+    );
+
+    expect(gtVersion('2.0.0' as SemVerVersion, '1.0.0' as SemVerVersion)).toBe(
+      true,
+    );
+
+    expect(gtVersion('1.0.0' as SemVerVersion, '1.2.3' as SemVerVersion)).toBe(
+      false,
+    );
+
+    expect(gtVersion('1.0.0' as SemVerVersion, '2.0.0' as SemVerVersion)).toBe(
+      false,
+    );
   });
 
   it('supports pre-release versions', () => {
-    expect(gtVersion(v('1.0.0-beta.2'), v('1.0.0-beta.1'))).toBe(true);
-    expect(gtVersion(v('1.0.0-beta.2'), v('1.2.3'))).toBe(false);
-    expect(gtVersion(v('1.0.0'), v('1.0.0-beta.2'))).toBe(true);
-    expect(gtVersion(v('1.2.3-beta.1'), v('1.0.0'))).toBe(true);
-    expect(gtVersion(v('1.2.3-beta.1'), v('1.2.3-alpha.2'))).toBe(true);
+    expect(
+      gtVersion(
+        '1.0.0-beta.2' as SemVerVersion,
+        '1.0.0-beta.1' as SemVerVersion,
+      ),
+    ).toBe(true);
+
+    expect(
+      gtVersion('1.0.0-beta.2' as SemVerVersion, '1.2.3' as SemVerVersion),
+    ).toBe(false);
+
+    expect(
+      gtVersion('1.0.0' as SemVerVersion, '1.0.0-beta.2' as SemVerVersion),
+    ).toBe(true);
+
+    expect(
+      gtVersion('1.2.3-beta.1' as SemVerVersion, '1.0.0' as SemVerVersion),
+    ).toBe(true);
+
+    expect(
+      gtVersion(
+        '1.2.3-beta.1' as SemVerVersion,
+        '1.2.3-alpha.2' as SemVerVersion,
+      ),
+    ).toBe(true);
   });
 });
 
 describe('getTargetVersion', () => {
   it('supports *', () => {
-    expect(getTargetVersion(v(['1.2.3', '3.0.0']), r('*'))).toBe('3.0.0');
+    expect(
+      getTargetVersion(
+        ['1.2.3', '3.0.0'] as SemVerVersion[],
+        '*' as SemVerRange,
+      ),
+    ).toBe('3.0.0');
   });
 
   it('supports pre-release versions', () => {
-    expect(getTargetVersion(v(['1.0.0-beta.1']), r('*'))).toBe('1.0.0-beta.1');
-    expect(getTargetVersion(v(['1.0.0-beta.1', '1.0.0-beta.2']), r('*'))).toBe(
-      '1.0.0-beta.2',
-    );
+    expect(
+      getTargetVersion(['1.0.0-beta.1'] as SemVerVersion[], '*' as SemVerRange),
+    ).toBe('1.0.0-beta.1');
 
     expect(
-      getTargetVersion(v(['1.0.0-beta.1', '1.0.0-beta.2']), r('^1.0.0-beta.1')),
+      getTargetVersion(
+        ['1.0.0-beta.1', '1.0.0-beta.2'] as SemVerVersion[],
+        '*' as SemVerRange,
+      ),
     ).toBe('1.0.0-beta.2');
 
-    expect(getTargetVersion(v(['1.0.0-alpha.2', '1.0.0-beta.1']), r('*'))).toBe(
-      '1.0.0-beta.1',
-    );
+    expect(
+      getTargetVersion(
+        ['1.0.0-beta.1', '1.0.0-beta.2'] as SemVerVersion[],
+        '^1.0.0-beta.1' as SemVerRange,
+      ),
+    ).toBe('1.0.0-beta.2');
 
-    expect(getTargetVersion(v(['0.9.0', '1.0.0-alpha.0']), r('*'))).toBe(
-      '0.9.0',
-    );
+    expect(
+      getTargetVersion(
+        ['1.0.0-alpha.2', '1.0.0-beta.1'] as SemVerVersion[],
+        '*' as SemVerRange,
+      ),
+    ).toBe('1.0.0-beta.1');
+
+    expect(
+      getTargetVersion(
+        ['0.9.0', '1.0.0-alpha.0'] as SemVerVersion[],
+        '*' as SemVerRange,
+      ),
+    ).toBe('0.9.0');
   });
 
   it("doesn't return pre-release versions by default", () => {
     expect(
-      getTargetVersion(v(['1.0.0-beta.1', '1.0.0', '1.2.3']), r('*')),
+      getTargetVersion(
+        ['1.0.0-beta.1', '1.0.0', '1.2.3'] as SemVerVersion[],
+        '*' as SemVerRange,
+      ),
     ).toBe('1.2.3');
 
     expect(
-      getTargetVersion(v(['1.0.0-beta.1', '1.0.0', '1.2.3']), r('^1.0.0')),
+      getTargetVersion(
+        ['1.0.0-beta.1', '1.0.0', '1.2.3'] as SemVerVersion[],
+        '^1.0.0' as SemVerRange,
+      ),
     ).toBe('1.2.3');
 
-    expect(getTargetVersion(v(['1.0.0-beta.1', '1.0.0']), r('*'))).toBe(
-      '1.0.0',
-    );
+    expect(
+      getTargetVersion(
+        ['1.0.0-beta.1', '1.0.0'] as SemVerVersion[],
+        '*' as SemVerRange,
+      ),
+    ).toBe('1.0.0');
   });
 });
 
 describe('satisfiesVersionRange', () => {
   it('supports *', () => {
-    expect(satisfiesVersionRange(v('3.0.0'), r('*'))).toBe(true);
+    expect(
+      satisfiesVersionRange('3.0.0' as SemVerVersion, '*' as SemVerRange),
+    ).toBe(true);
   });
 
   it('supports exact versions', () => {
-    expect(satisfiesVersionRange(v('1.0.0-beta.1'), r('1.0.0-beta.1'))).toBe(
-      true,
-    );
-    expect(satisfiesVersionRange(v('1.0.0'), r('1.0.0'))).toBe(true);
-    expect(satisfiesVersionRange(v('1.2.3'), r('1.0.0'))).toBe(false);
+    expect(
+      satisfiesVersionRange(
+        '1.0.0-beta.1' as SemVerVersion,
+        '1.0.0-beta.1' as SemVerRange,
+      ),
+    ).toBe(true);
+
+    expect(
+      satisfiesVersionRange('1.0.0' as SemVerVersion, '1.0.0' as SemVerRange),
+    ).toBe(true);
+
+    expect(
+      satisfiesVersionRange('1.2.3' as SemVerVersion, '1.0.0' as SemVerRange),
+    ).toBe(false);
   });
 
   it('supports non-exact version ranges', () => {
-    expect(satisfiesVersionRange(v('1.2.3'), r('^1.0.0'))).toBe(true);
-    expect(satisfiesVersionRange(v('2.0.0'), r('^1.0.0'))).toBe(false);
+    expect(
+      satisfiesVersionRange('1.2.3' as SemVerVersion, '^1.0.0' as SemVerRange),
+    ).toBe(true);
+
+    expect(
+      satisfiesVersionRange('2.0.0' as SemVerVersion, '^1.0.0' as SemVerRange),
+    ).toBe(false);
   });
 
   it('pre-releases can satisfy version range', () => {
-    expect(satisfiesVersionRange(v('1.0.0-beta.1'), r('*'))).toBe(true);
-    expect(satisfiesVersionRange(v('1.0.0-beta.1'), r('^1.0.0'))).toBe(false);
+    expect(
+      satisfiesVersionRange(
+        '1.0.0-beta.1' as SemVerVersion,
+        '*' as SemVerRange,
+      ),
+    ).toBe(true);
+
+    expect(
+      satisfiesVersionRange(
+        '1.0.0-beta.1' as SemVerVersion,
+        '^1.0.0' as SemVerRange,
+      ),
+    ).toBe(false);
   });
 });

From f969ada6394461971c0035d8376c01be27e4a159 Mon Sep 17 00:00:00 2001
From: Olaf Tomalka <olaf@tomalka.me>
Date: Tue, 15 Nov 2022 17:17:39 +0100
Subject: [PATCH 05/13] Used ts-opaque

---
 packages/snaps-utils/package.json    |  3 ++-
 packages/snaps-utils/src/versions.ts | 12 +++++++++---
 yarn.lock                            |  8 ++++++++
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/packages/snaps-utils/package.json b/packages/snaps-utils/package.json
index fefe857cf7..22f92bf0d6 100644
--- a/packages/snaps-utils/package.json
+++ b/packages/snaps-utils/package.json
@@ -62,7 +62,8 @@
     "rfdc": "^1.3.0",
     "semver": "^7.3.7",
     "ses": "^0.17.0",
-    "superstruct": "^0.16.7"
+    "superstruct": "^0.16.7",
+    "ts-opaque": "^3.0.1"
   },
   "devDependencies": {
     "@lavamoat/allow-scripts": "^2.0.3",
diff --git a/packages/snaps-utils/src/versions.ts b/packages/snaps-utils/src/versions.ts
index 488c4e5420..5ba122fcf3 100644
--- a/packages/snaps-utils/src/versions.ts
+++ b/packages/snaps-utils/src/versions.ts
@@ -7,6 +7,7 @@ import {
   validRange as validSemVerRange,
 } from 'semver';
 import { is, refine, string, Struct, validate } from 'superstruct';
+import Opaque from 'ts-opaque';
 
 export const DEFAULT_REQUESTED_SNAP_VERSION = '*' as SemVerRange;
 
@@ -29,9 +30,12 @@ export const DEFAULT_REQUESTED_SNAP_VERSION = '*' as SemVerRange;
  * @see {@link assertIsSemVerRange}
  * @see {@link isValidSemVerRange}
  */
+/*
 declare type SemVerRange = {
   __TYPE: 'semver_range';
-} & string;
+} & string;*/
+export type SemVerRange = Opaque<string, typeof semVerRange>;
+const semVerRange = Symbol('Opaque branding for SemVerRange type');
 
 /**
  * {@link https://codemix.com/opaque-types-in-javascript/ Opaque} type for singular SemVer version.
@@ -52,10 +56,12 @@ declare type SemVerRange = {
  * @see {@link assertIsSemVerVersion}
  * @see {@link isValidSemVerVersion}
  */
+/*
 declare type SemVerVersion = {
   __TYPE: 'semver_version';
-} & string;
-export { SemVerRange, SemVerVersion };
+} & string;*/
+export type SemVerVersion = Opaque<string, typeof semVerVersion>;
+const semVerVersion = Symbol('Opaque branding for SemVerVersion type');
 
 /**
  * A struct for validating a version string.
diff --git a/yarn.lock b/yarn.lock
index cf2aa0857e..a74494a5f5 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3281,6 +3281,7 @@ __metadata:
     ses: ^0.17.0
     superstruct: ^0.16.7
     ts-jest: ^29.0.0
+    ts-opaque: ^3.0.1
     typescript: ~4.8.4
   languageName: unknown
   linkType: soft
@@ -16256,6 +16257,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"ts-opaque@npm:^3.0.1":
+  version: 3.0.1
+  resolution: "ts-opaque@npm:3.0.1"
+  checksum: 146f71d08d5915ead4551dce310719c53ead762a3ca6219373beacf273c84a7988b7716e5f8b9d0e9013d87ed84bc9f1e794ecdc4ff14083723ceacd9899040c
+  languageName: node
+  linkType: hard
+
 "tsc-watch@npm:^4.5.0":
   version: 4.5.0
   resolution: "tsc-watch@npm:4.5.0"

From 1207f4d0fda6ffe7acba4d79f5609bfd860381f2 Mon Sep 17 00:00:00 2001
From: Olaf Tomalka <olaf@tomalka.me>
Date: Tue, 15 Nov 2022 17:30:16 +0100
Subject: [PATCH 06/13] Removed debug comments

---
 packages/snaps-utils/src/versions.ts | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/packages/snaps-utils/src/versions.ts b/packages/snaps-utils/src/versions.ts
index 5ba122fcf3..1de68d72c9 100644
--- a/packages/snaps-utils/src/versions.ts
+++ b/packages/snaps-utils/src/versions.ts
@@ -30,10 +30,6 @@ export const DEFAULT_REQUESTED_SNAP_VERSION = '*' as SemVerRange;
  * @see {@link assertIsSemVerRange}
  * @see {@link isValidSemVerRange}
  */
-/*
-declare type SemVerRange = {
-  __TYPE: 'semver_range';
-} & string;*/
 export type SemVerRange = Opaque<string, typeof semVerRange>;
 const semVerRange = Symbol('Opaque branding for SemVerRange type');
 
@@ -56,10 +52,6 @@ const semVerRange = Symbol('Opaque branding for SemVerRange type');
  * @see {@link assertIsSemVerVersion}
  * @see {@link isValidSemVerVersion}
  */
-/*
-declare type SemVerVersion = {
-  __TYPE: 'semver_version';
-} & string;*/
 export type SemVerVersion = Opaque<string, typeof semVerVersion>;
 const semVerVersion = Symbol('Opaque branding for SemVerVersion type');
 

From b8d3f94873716700b26600de507ad829995c320c Mon Sep 17 00:00:00 2001
From: Olaf Tomalka <olaf@tomalka.me>
Date: Tue, 15 Nov 2022 18:35:11 +0100
Subject: [PATCH 07/13] Coverage

---
 packages/snaps-utils/jest.config.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/snaps-utils/jest.config.js b/packages/snaps-utils/jest.config.js
index 1b4f207447..3e571aa81e 100644
--- a/packages/snaps-utils/jest.config.js
+++ b/packages/snaps-utils/jest.config.js
@@ -15,7 +15,7 @@ module.exports = deepmerge(baseConfig, {
   coverageThreshold: {
     global: {
       branches: 93.45,
-      functions: 95.18,
+      functions: 95.45,
       lines: 98.07,
       statements: 98.07,
     },

From 08b53e567bf02b00bc1b383c5e5a7d512c0f9a76 Mon Sep 17 00:00:00 2001
From: Olaf Tomalka <olaf@tomalka.me>
Date: Wed, 16 Nov 2022 17:17:32 +0100
Subject: [PATCH 08/13] PR review

---
 .../src/cronjob/CronjobController.test.ts     |  8 +++++---
 .../src/snaps/SnapController.test.ts          | 19 ++++---------------
 packages/snaps-utils/src/test-utils/common.ts | 12 ++++++++++++
 .../snaps-utils/src/test-utils/manifest.ts    | 10 +++-------
 packages/snaps-utils/src/test-utils/snap.ts   | 13 ++++---------
 5 files changed, 28 insertions(+), 34 deletions(-)
 create mode 100644 packages/snaps-utils/src/test-utils/common.ts

diff --git a/packages/snaps-controllers/src/cronjob/CronjobController.test.ts b/packages/snaps-controllers/src/cronjob/CronjobController.test.ts
index 8b50c9ffb5..40410254df 100644
--- a/packages/snaps-controllers/src/cronjob/CronjobController.test.ts
+++ b/packages/snaps-controllers/src/cronjob/CronjobController.test.ts
@@ -78,6 +78,8 @@ const MOCK_CRONJOB_SINGLE_JOB_PERMISSION = {
   parentCapability: SnapEndowments.Cronjob,
 };
 
+const MOCK_VERSION = '1.0' as SemVerVersion;
+
 describe('CronjobController', () => {
   beforeEach(() => {
     jest.useFakeTimers().setSystemTime(new Date('2022-01-01'));
@@ -316,7 +318,7 @@ describe('CronjobController', () => {
       id: MOCK_SNAP_ID,
       initialPermissions: {},
       permissionName: '',
-      version: '1.0' as SemVerVersion,
+      version: MOCK_VERSION,
     };
     // @ts-expect-error Accessing private property
     cronjobController._handleEventSnapInstalled(snapInfo);
@@ -368,7 +370,7 @@ describe('CronjobController', () => {
       id: MOCK_SNAP_ID,
       initialPermissions: {},
       permissionName: '',
-      version: '1.0' as SemVerVersion,
+      version: MOCK_VERSION,
     };
 
     // @ts-expect-error Accessing private property
@@ -433,7 +435,7 @@ describe('CronjobController', () => {
       id: MOCK_SNAP_ID,
       initialPermissions: {},
       permissionName: '',
-      version: '1.0' as SemVerVersion,
+      version: MOCK_VERSION,
     };
 
     // @ts-expect-error Accessing private property
diff --git a/packages/snaps-controllers/src/snaps/SnapController.test.ts b/packages/snaps-controllers/src/snaps/SnapController.test.ts
index 2ca937df96..6cdfc9f4b7 100644
--- a/packages/snaps-controllers/src/snaps/SnapController.test.ts
+++ b/packages/snaps-controllers/src/snaps/SnapController.test.ts
@@ -31,7 +31,7 @@ import fetchMock from 'jest-fetch-mock';
 import { createAsyncMiddleware, JsonRpcEngine } from 'json-rpc-engine';
 import { createEngineStream } from 'json-rpc-middleware-stream';
 import pump from 'pump';
-import { Duplex } from 'stream';;
+import { Duplex } from 'stream';
 import { NodeThreadExecutionService, setupMultiplex } from '../services';
 import {
   ExecutionEnvironmentStub,
@@ -3143,13 +3143,7 @@ describe('SnapController', () => {
         });
       /* eslint-enable @typescript-eslint/naming-convention */
 
-<<<<<<< HEAD
       callActionSpy.mockImplementation((method, ...args: unknown[]): any => {
-=======
-      callActionSpy.mockImplementation((method, ...params) => {
-        assert(params.length > 0);
-        const request: any = params[0];
->>>>>>> c8c60447 (Added opaque types for SemVers)
         if (method === 'PermissionController:hasPermission') {
           return true;
         } else if (method === 'ApprovalController:addRequest') {
@@ -3955,10 +3949,9 @@ describe('SnapController', () => {
           ) {
             return true;
           }
-<<<<<<< HEAD
-=======
-
->>>>>>> c8c60447 (Added opaque types for SemVers)
+          // TypeScript doesn't allow variadic list of arguments into non-variadic functions.
+          // messenger.call is a union of functions that take a constant amount of arguments, and
+          // so, TypeScript errors.
           return (originalCall as any)(method, ...args);
         });
 
@@ -3989,10 +3982,6 @@ describe('SnapController', () => {
               },
             };
           }
-<<<<<<< HEAD
-=======
-
->>>>>>> c8c60447 (Added opaque types for SemVers)
           return (originalCall as any)(method, ...args);
         });
 
diff --git a/packages/snaps-utils/src/test-utils/common.ts b/packages/snaps-utils/src/test-utils/common.ts
new file mode 100644
index 0000000000..a15d6c88f5
--- /dev/null
+++ b/packages/snaps-utils/src/test-utils/common.ts
@@ -0,0 +1,12 @@
+import { SemVerVersion } from '../versions';
+
+/**
+ * Tens/hundreds legacy tests use creation utils.
+ *
+ * Updating them to use proper type casting is unfeasible at this time.
+ * We use this function to make creation utils backwards compatible,
+ * until we're ready to update tests.
+ */
+export type MakeSemVer<T> = {
+  [K in keyof T]: K extends 'version' ? SemVerVersion | string : T[K];
+};
diff --git a/packages/snaps-utils/src/test-utils/manifest.ts b/packages/snaps-utils/src/test-utils/manifest.ts
index 5ccce7ff76..02f50a05e2 100644
--- a/packages/snaps-utils/src/test-utils/manifest.ts
+++ b/packages/snaps-utils/src/test-utils/manifest.ts
@@ -8,11 +8,9 @@ import {
 } from '../namespace';
 import { NpmSnapPackageJson } from '../types';
 import { DEFAULT_SNAP_SHASUM } from './snap';
+import { MakeSemVer } from './common';
 
-type GetSnapManifestOptions = Partial<
-  Omit<SnapManifest, 'source' | 'version'>
-> & {
-  version?: SemVerVersion | string;
+type GetSnapManifestOptions = Partial<MakeSemVer<SnapManifest>> & {
   shasum?: string;
   filePath?: string;
   packageName?: string;
@@ -20,9 +18,7 @@ type GetSnapManifestOptions = Partial<
   iconPath?: string;
 };
 
-type GetPackageJsonOptions = Partial<Omit<NpmSnapPackageJson, 'version'>> & {
-  version?: SemVerVersion | string;
-};
+type GetPackageJsonOptions = Partial<MakeSemVer<NpmSnapPackageJson>>;
 
 /**
  * Get the default package repository, in a format compatible with
diff --git a/packages/snaps-utils/src/test-utils/snap.ts b/packages/snaps-utils/src/test-utils/snap.ts
index 7b1cf00858..57e36081da 100644
--- a/packages/snaps-utils/src/test-utils/snap.ts
+++ b/packages/snaps-utils/src/test-utils/snap.ts
@@ -7,6 +7,7 @@ import {
   TruncatedSnap,
 } from '../snaps';
 import { getSnapManifest } from './manifest';
+import { MakeSemVer } from './common';
 
 /**
  * A mock snap source and its shasum.
@@ -28,15 +29,9 @@ export const MOCK_SNAP_ID = 'npm:@metamask/example-snap';
 export const MOCK_LOCAL_SNAP_ID = 'local:@metamask/example-snap';
 export const MOCK_ORIGIN = 'example.com';
 
-type GetPersistedSnapObjectOptions = Partial<Omit<PersistedSnap, 'version'>> & {
-  version?: string | SemVerVersion;
-};
-type GetSnapObjectOptions = Partial<Omit<Snap, 'version'>> & {
-  version?: string | SemVerVersion;
-};
-type GetTruncatedSnapOptions = Partial<Omit<TruncatedSnap, 'version'>> & {
-  version?: string | SemVerVersion;
-};
+type GetPersistedSnapObjectOptions = Partial<MakeSemVer<PersistedSnap>>;
+type GetSnapObjectOptions = Partial<MakeSemVer<Snap>>;
+type GetTruncatedSnapOptions = Partial<MakeSemVer<TruncatedSnap>>;
 
 export const getPersistedSnapObject = ({
   blocked = false,

From 1ab518a2daec22656488486d37288a51955e8636 Mon Sep 17 00:00:00 2001
From: Olaf Tomalka <olaf@tomalka.me>
Date: Fri, 18 Nov 2022 14:33:30 +0100
Subject: [PATCH 09/13] Coverage

---
 packages/snaps-utils/jest.config.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/snaps-utils/jest.config.js b/packages/snaps-utils/jest.config.js
index 3e571aa81e..a84cb899d8 100644
--- a/packages/snaps-utils/jest.config.js
+++ b/packages/snaps-utils/jest.config.js
@@ -16,8 +16,8 @@ module.exports = deepmerge(baseConfig, {
     global: {
       branches: 93.45,
       functions: 95.45,
-      lines: 98.07,
-      statements: 98.07,
+      lines: 98.34,
+      statements: 98.34,
     },
   },
   testTimeout: 2500,

From eb04a9b0a7a176ba69be3b0017d670299d420dc5 Mon Sep 17 00:00:00 2001
From: Olaf Tomalka <olaf@tomalka.me>
Date: Fri, 18 Nov 2022 14:40:01 +0100
Subject: [PATCH 10/13] Lint

---
 .../snaps-controllers/src/snaps/SnapController.test.ts     | 1 +
 packages/snaps-controllers/src/snaps/SnapController.ts     | 4 ++--
 packages/snaps-controllers/src/snaps/utils/npm.ts          | 6 +++---
 packages/snaps-utils/src/manifest/validation.ts            | 2 +-
 packages/snaps-utils/src/test-utils/manifest.ts            | 4 ++--
 packages/snaps-utils/src/test-utils/snap.ts                | 4 ++--
 packages/snaps-utils/src/versions.test.ts                  | 7 ++++---
 7 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/packages/snaps-controllers/src/snaps/SnapController.test.ts b/packages/snaps-controllers/src/snaps/SnapController.test.ts
index 6cdfc9f4b7..e9f872a490 100644
--- a/packages/snaps-controllers/src/snaps/SnapController.test.ts
+++ b/packages/snaps-controllers/src/snaps/SnapController.test.ts
@@ -32,6 +32,7 @@ import { createAsyncMiddleware, JsonRpcEngine } from 'json-rpc-engine';
 import { createEngineStream } from 'json-rpc-middleware-stream';
 import pump from 'pump';
 import { Duplex } from 'stream';
+
 import { NodeThreadExecutionService, setupMultiplex } from '../services';
 import {
   ExecutionEnvironmentStub,
diff --git a/packages/snaps-controllers/src/snaps/SnapController.ts b/packages/snaps-controllers/src/snaps/SnapController.ts
index c7fce0de55..b259c91440 100644
--- a/packages/snaps-controllers/src/snaps/SnapController.ts
+++ b/packages/snaps-controllers/src/snaps/SnapController.ts
@@ -1536,8 +1536,8 @@ export class SnapController extends BaseController<
     await Promise.all(
       Object.entries(requestedSnaps).map(
         async ([snapId, { version: rawVersion }]) => {
-          const [err, version] = resolveVersionRange(rawVersion);
-          if (err) {
+          const [error, version] = resolveVersionRange(rawVersion);
+          if (error) {
             result[snapId] = {
               error: ethErrors.rpc.invalidParams(
                 `The "version" field must be a valid SemVer version range if specified. Received: "${version}".`,
diff --git a/packages/snaps-controllers/src/snaps/utils/npm.ts b/packages/snaps-controllers/src/snaps/utils/npm.ts
index ac2433ec1a..510e14a959 100644
--- a/packages/snaps-controllers/src/snaps/utils/npm.ts
+++ b/packages/snaps-controllers/src/snaps/utils/npm.ts
@@ -93,9 +93,9 @@ async function fetchNpmTarball(
   }
 
   const versions = Object.keys((packageMetadata as any)?.versions ?? {}).map(
-    (v) => {
-      assertIsSemVerVersion(v);
-      return v;
+    (version) => {
+      assertIsSemVerVersion(version);
+      return version;
     },
   );
 
diff --git a/packages/snaps-utils/src/manifest/validation.ts b/packages/snaps-utils/src/manifest/validation.ts
index 4c67ee91f9..ebfe4e8c92 100644
--- a/packages/snaps-utils/src/manifest/validation.ts
+++ b/packages/snaps-utils/src/manifest/validation.ts
@@ -20,8 +20,8 @@ import {
 
 import { CronjobSpecificationArrayStruct } from '../cronjob';
 import { NamespacesStruct } from '../namespace';
-import { VersionStruct } from '../versions';
 import { NameStruct, NpmSnapFileNames } from '../types';
+import { VersionStruct } from '../versions';
 
 // 0xd36e6170 - 0x80000000
 export const SIP_6_MAGIC_VALUE = `1399742832'` as `${number}'`;
diff --git a/packages/snaps-utils/src/test-utils/manifest.ts b/packages/snaps-utils/src/test-utils/manifest.ts
index 02f50a05e2..d045780d47 100644
--- a/packages/snaps-utils/src/test-utils/manifest.ts
+++ b/packages/snaps-utils/src/test-utils/manifest.ts
@@ -1,4 +1,3 @@
-import { SemVerVersion } from '../versions';
 import { SnapManifest } from '../manifest/validation';
 import {
   Chain,
@@ -7,8 +6,9 @@ import {
   SessionNamespace,
 } from '../namespace';
 import { NpmSnapPackageJson } from '../types';
-import { DEFAULT_SNAP_SHASUM } from './snap';
+import { SemVerVersion } from '../versions';
 import { MakeSemVer } from './common';
+import { DEFAULT_SNAP_SHASUM } from './snap';
 
 type GetSnapManifestOptions = Partial<MakeSemVer<SnapManifest>> & {
   shasum?: string;
diff --git a/packages/snaps-utils/src/test-utils/snap.ts b/packages/snaps-utils/src/test-utils/snap.ts
index 57e36081da..dcae80cca0 100644
--- a/packages/snaps-utils/src/test-utils/snap.ts
+++ b/packages/snaps-utils/src/test-utils/snap.ts
@@ -1,4 +1,3 @@
-import { SemVerVersion } from '../versions';
 import {
   getSnapSourceShasum,
   PersistedSnap,
@@ -6,8 +5,9 @@ import {
   SnapStatus,
   TruncatedSnap,
 } from '../snaps';
-import { getSnapManifest } from './manifest';
+import { SemVerVersion } from '../versions';
 import { MakeSemVer } from './common';
+import { getSnapManifest } from './manifest';
 
 /**
  * A mock snap source and its shasum.
diff --git a/packages/snaps-utils/src/versions.test.ts b/packages/snaps-utils/src/versions.test.ts
index 71554b38e5..7874a0e46b 100644
--- a/packages/snaps-utils/src/versions.test.ts
+++ b/packages/snaps-utils/src/versions.test.ts
@@ -1,4 +1,5 @@
 import { assert } from '@metamask/utils';
+
 import { getSnapPrefix } from './snaps';
 import { SnapIdPrefixes } from './types';
 import {
@@ -33,9 +34,9 @@ describe('resolveVersion', () => {
   });
 
   it.each([null, 1, {}, Error])('returns error on invalid input', (value) => {
-    const [err, result] = resolveVersionRange(value);
-    assert(err !== undefined);
-    expect(err.message).toMatch('Expected a string, but received: ');
+    const [error, result] = resolveVersionRange(value);
+    assert(error !== undefined);
+    expect(error.message).toMatch('Expected a string, but received: ');
     expect(result).toBeUndefined();
   });
 });

From 338856d56f02fe389b24fc80f6ea99f71a3a848e Mon Sep 17 00:00:00 2001
From: Olaf Tomalka <olaf@tomalka.me>
Date: Fri, 18 Nov 2022 14:55:58 +0100
Subject: [PATCH 11/13] Removed ts-opaque dependency

---
 packages/snaps-utils/src/types.ts    | 5 +++++
 packages/snaps-utils/src/versions.ts | 7 ++++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/packages/snaps-utils/src/types.ts b/packages/snaps-utils/src/types.ts
index 04ce7203a4..29020359b7 100644
--- a/packages/snaps-utils/src/types.ts
+++ b/packages/snaps-utils/src/types.ts
@@ -158,3 +158,8 @@ type KeyringParameters = KeyringParameter<Keyring[keyof Keyring]>;
 export type SnapExportsParameters =
   | ObjectParameters<SnapFunctionExports>
   | KeyringParameters;
+
+// We use a symbol property name instead of { _type: Brand }, because that would show up in IDE suggestions,
+// while internal symbols do not.
+declare const brand: unique symbol;
+export type Opaque<Base, Brand extends symbol> = Base & { [brand]: Brand };
diff --git a/packages/snaps-utils/src/versions.ts b/packages/snaps-utils/src/versions.ts
index 1de68d72c9..c34bf64dc5 100644
--- a/packages/snaps-utils/src/versions.ts
+++ b/packages/snaps-utils/src/versions.ts
@@ -7,7 +7,8 @@ import {
   validRange as validSemVerRange,
 } from 'semver';
 import { is, refine, string, Struct, validate } from 'superstruct';
-import Opaque from 'ts-opaque';
+
+import { Opaque } from './types';
 
 export const DEFAULT_REQUESTED_SNAP_VERSION = '*' as SemVerRange;
 
@@ -31,7 +32,7 @@ export const DEFAULT_REQUESTED_SNAP_VERSION = '*' as SemVerRange;
  * @see {@link isValidSemVerRange}
  */
 export type SemVerRange = Opaque<string, typeof semVerRange>;
-const semVerRange = Symbol('Opaque branding for SemVerRange type');
+declare const semVerRange: unique symbol;
 
 /**
  * {@link https://codemix.com/opaque-types-in-javascript/ Opaque} type for singular SemVer version.
@@ -53,7 +54,7 @@ const semVerRange = Symbol('Opaque branding for SemVerRange type');
  * @see {@link isValidSemVerVersion}
  */
 export type SemVerVersion = Opaque<string, typeof semVerVersion>;
-const semVerVersion = Symbol('Opaque branding for SemVerVersion type');
+declare const semVerVersion: unique symbol;
 
 /**
  * A struct for validating a version string.

From b0c909bec87e4e9f4625478f2ec2d6e59f1716ad Mon Sep 17 00:00:00 2001
From: Olaf Tomalka <olaf@tomalka.me>
Date: Fri, 18 Nov 2022 15:08:36 +0100
Subject: [PATCH 12/13] PR review

---
 packages/snaps-utils/package.json    | 3 +--
 packages/snaps-utils/src/versions.ts | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/packages/snaps-utils/package.json b/packages/snaps-utils/package.json
index 22f92bf0d6..fefe857cf7 100644
--- a/packages/snaps-utils/package.json
+++ b/packages/snaps-utils/package.json
@@ -62,8 +62,7 @@
     "rfdc": "^1.3.0",
     "semver": "^7.3.7",
     "ses": "^0.17.0",
-    "superstruct": "^0.16.7",
-    "ts-opaque": "^3.0.1"
+    "superstruct": "^0.16.7"
   },
   "devDependencies": {
     "@lavamoat/allow-scripts": "^2.0.3",
diff --git a/packages/snaps-utils/src/versions.ts b/packages/snaps-utils/src/versions.ts
index c34bf64dc5..8fcd36553a 100644
--- a/packages/snaps-utils/src/versions.ts
+++ b/packages/snaps-utils/src/versions.ts
@@ -196,7 +196,7 @@ export function getTargetVersion(
  */
 export function resolveVersionRange(
   version?: Json,
-): [undefined, SemVerRange] | [Error, undefined] {
+): [error: undefined, range: SemVerRange] | [error: Error, range: undefined] {
   if (version === undefined || version === 'latest') {
     return [undefined, DEFAULT_REQUESTED_SNAP_VERSION];
   }

From 07d06501367593dbaac0157733dd79c523d3498c Mon Sep 17 00:00:00 2001
From: Olaf Tomalka <olaf@tomalka.me>
Date: Fri, 18 Nov 2022 15:12:03 +0100
Subject: [PATCH 13/13] Yarn.lock

---
 yarn.lock | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/yarn.lock b/yarn.lock
index a74494a5f5..cf2aa0857e 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3281,7 +3281,6 @@ __metadata:
     ses: ^0.17.0
     superstruct: ^0.16.7
     ts-jest: ^29.0.0
-    ts-opaque: ^3.0.1
     typescript: ~4.8.4
   languageName: unknown
   linkType: soft
@@ -16257,13 +16256,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"ts-opaque@npm:^3.0.1":
-  version: 3.0.1
-  resolution: "ts-opaque@npm:3.0.1"
-  checksum: 146f71d08d5915ead4551dce310719c53ead762a3ca6219373beacf273c84a7988b7716e5f8b9d0e9013d87ed84bc9f1e794ecdc4ff14083723ceacd9899040c
-  languageName: node
-  linkType: hard
-
 "tsc-watch@npm:^4.5.0":
   version: 4.5.0
   resolution: "tsc-watch@npm:4.5.0"