Add logical assignment operator by Kingwl · Pull Request #37727 · microsoft/TypeScript

Wenlu Wang (Kingwl) · 2020-04-01T03:09:33Z

Daniel Rosenwasser (DanielRosenwasser) · 2020-04-01T09:13:10Z

~~The GitHub app is terrible so I can't review properly, but test 5 uses a function type returning void | undefined. That's probably a mistake.~~

Resolved

Daniel Rosenwasser (DanielRosenwasser) · 2020-04-01T19:36:52Z

+    }
+
+    function foo2 (f?: (a: number) => void) {
+        f ||= (a => a)


Great test!

Daniel Rosenwasser (DanielRosenwasser) · 2020-04-01T19:39:42Z

+        if (thing &&= thing.original) {
+            console.log(thing.name);
+                        ~~~~~
+!!! error TS2532: Object is possibly 'undefined'.


Glad the test caught this - that was part of my intent when I wrote it. As you probably know, this needs to be fixed because thing.original should be defined. Let Anders Hejlsberg (@ahejlsberg) or Ron Buckton (@rbuckton) know if you need help with that.

I spent all afternoon And evening in this one😂

Yeah, the code can be hard to get through, and I've honestly never wired up the CFG. Also, binary expressions recently changed to use a "trampolining" approach to avoid stack overflows on deep traversals. You can ask Wesley Wigham (@weswigham) about that.

If you want to play around to see if you can get it working, I'll provide a few tips and Wesley Wigham (@weswigham) and Anders Hejlsberg (@ahejlsberg) can weigh in case I'm totally off.

First take a look at some of the logic at

TypeScript/src/compiler/binder.ts

Line 1418 in b58a29b

const preRightLabel = createBranchLabel();

and

TypeScript/src/compiler/binder.ts

Line 1513 in b58a29b

if (operator === SyntaxKind.AmpersandAmpersandToken || operator === SyntaxKind.BarBarToken || operator === SyntaxKind.QuestionQuestionToken) {

The binder needs to create branch labels for these new compound assignment operators (similar to in bindLogicalExpression) while creating at least one flow node that's considered an assignment after the expression (as in bindAssignmentTargetFlow). At a glance, I think that a lot of the logic can be reused and the changes can be added around here

Eventually in getTypeAtFlowNode in the type-checker, you need to try to find a way to combine the logic when flags & FlowFlags.Assignment and flags & FlowFlags.Label both apply. To start, I'd just get something working, then worry about how to share the code.

Feel free to ask some questions if you need help. If you'd prefer, I'm also sure we could send a PR if you'd like, but it's up to you.

Daniel Rosenwasser (DanielRosenwasser) · 2020-04-01T19:43:29Z

            || token === SyntaxKind.ExclamationToken;
    }

+    export function isLogicalAssignmentOperator(token: SyntaxKind): boolean {


Consider isShortCircuitingAssignmentOperator or isLogicalOrCoalescingAssignmentOperator

Daniel Rosenwasser (DanielRosenwasser) · 2020-04-01T19:47:37Z

                return 14;
            case SyntaxKind.AsteriskAsteriskToken:
                return 15;
+            case SyntaxKind.BarBarEqualsToken:


This section doesn't seem to cover any of the assignment or compound assignment operators. I'd get clarity from whoever originally wrote this function whether this should be here, because I think these 3 cases don't belong here.

Yeah, it seems to be caught by getOperatorPrecedence above.

Wenlu Wang (Kingwl) · 2020-04-02T08:05:12Z

It seems works, but i don't know why.🤷🏻‍♂️

Daniel Rosenwasser (DanielRosenwasser) · 2020-04-02T08:06:42Z

TypeScript Bot (@typescript-bot) pack this

TypeScript Bot (typescript-bot) · 2020-04-02T08:06:47Z

Heya Daniel Rosenwasser (@DanielRosenwasser), I've started to run the tarball bundle task on this PR at 1c92781. You can monitor the build here.

Wenlu Wang (Kingwl) · 2020-04-02T08:23:15Z

Current CFG is

"
Call (results.push(100)) ─ ArrayMutation (results.push(100)) ─ Branch ┬ True (results) ─────────────────────────────────────────────────┬ Start  
                                                                      ├ True (results ||= []) ─┬ Assignment (results) ─ False (results) ╯   
                                                                      ╰ False (results ||= []) ╯                                            
"

the same as downlevel result

"
Call (results.push(100)) ─ ArrayMutation (results.push(100)) ─ Branch ┬ True (results) ─────────────────────────────────────────────────┬ Start  
                                                                      ├ True ((results = [])) ─┬ Assignment (results) ─ False (results) ╯   
                                                                      ╰ False ((results = [])) ╯                                            
"

Wenlu Wang (Kingwl) · 2020-04-02T08:54:58Z

TypeScript Bot (@typescript-bot) pack this.

TypeScript Bot (typescript-bot) · 2020-04-02T08:55:04Z

Heya Wenlu Wang (@Kingwl), I've started to run the tarball bundle task on this PR at a6e0086. You can monitor the build here.

TypeScript Bot (typescript-bot) · 2020-04-02T09:10:52Z

Hey Wenlu Wang (@Kingwl), I've packed this into an installable tgz. You can install it for testing by referencing it in your package.json like so:

{
    "devDependencies": {
        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/70160/artifacts?artifactName=tgz&fileId=686926927B2177B6DF8E5E65AF663CA3F21F8E4A6BB13BA2F0D55123942814F102&fileName=/typescript-3.9.0-insiders.20200402.tgz"
    }
}

and then running npm install.

Wenlu Wang (Kingwl) · 2020-04-04T15:00:39Z

TypeScript Bot (@typescript-bot) pack this.

TypeScript Bot (typescript-bot) · 2020-04-04T15:01:16Z

Heya Wenlu Wang (@Kingwl), I've started to run the tarball bundle task on this PR at 8a9e234. You can monitor the build here.

TypeScript Bot (typescript-bot) · 2020-04-04T15:15:34Z

Hey Wenlu Wang (@Kingwl), I've packed this into an installable tgz. You can install it for testing by referencing it in your package.json like so:

{
    "devDependencies": {
        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/70428/artifacts?artifactName=tgz&fileId=0F5F796F0B11C552E9CE937F66A4E8AFB940559C729165A9D4B3FAFEB190B56302&fileName=/typescript-3.9.0-insiders.20200404.tgz"
    }
}

and then running npm install.

Wenlu Wang (Kingwl) · 2020-04-07T02:09:45Z

Does the playground not supported pull request build now?🤷🏻‍♂️

Daniel Rosenwasser (DanielRosenwasser) · 2020-04-07T18:31:10Z

Does the playground not supported pull request build now?

Wesley Wigham (@weswigham) or Orta Therox (@orta) might know

Orta Therox (orta) · 2020-04-07T21:49:40Z

Thanks for the ping, looks like I need to dig into the playground builder - been red for a week
https://github.com/orta/make-monaco-builds/actions - looks like a master build of TS gives a new error in the monaco-typescript codebase

Orta Therox (orta) · 2020-04-07T22:03:55Z

Made a PR: microsoft/monaco-typescript#59

Orta Therox (orta) · 2020-04-07T22:10:53Z

and with orta/make-monaco-builds@f17ca4a in

I can request a playground again - TypeScript Bot (@typescript-bot) pack this.

TypeScript Bot (typescript-bot) · 2020-04-07T22:10:57Z

Heya Orta Therox (@orta), I've started to run the tarball bundle task on this PR at 8a9e234. You can monitor the build here.

TypeScript Bot (typescript-bot) · 2020-04-07T22:24:56Z

Hey Orta Therox (@orta), I've packed this into an installable tgz. You can install it for testing by referencing it in your package.json like so:

{
    "devDependencies": {
        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/70644/artifacts?artifactName=tgz&fileId=C1043CC14B2BF52EEC192CF7805DCDB9972F4A315657B65C7F9096429256B57A02&fileName=/typescript-3.9.0-insiders.20200407.tgz"
    }
}

and then running npm install.

There is also a playground for this build.

Wenlu Wang (Kingwl) · 2020-05-16T00:57:55Z

Only one pipeline failed with ECONNRESET.

Daniel Rosenwasser (DanielRosenwasser) · 2020-05-20T00:14:12Z

Looks like this needs to be rebased onto the latest master.

Daniel Rosenwasser (DanielRosenwasser) · 2020-05-20T21:23:09Z

One more review?

Daniel Rosenwasser (DanielRosenwasser) · 2020-05-27T23:03:23Z

One more peek Ron Buckton (@rbuckton)?

Wenlu Wang (Kingwl) · 2020-06-03T13:54:04Z

up👆

Amin Pakseresht (aminpaks) · 2020-06-16T03:03:40Z

Wenlu Wang (@Kingwl) I mentioned a case in here. Would you confirm that this is not a bug?

Flavien Volken (Xample) · 2020-07-24T10:40:36Z

Glad to see things moved since #20378 😀

Gaurang Patel (g-patel) · 2020-09-03T20:21:48Z

What version of typescript will this be available in?

ExE Boss (ExE-Boss) · 2020-09-03T20:44:35Z

Gaurang Patel (@g-patel) This shipped in TypeScript 4.0.

Daniel Rosenwasser (DanielRosenwasser) reviewed Apr 1, 2020

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Comment thread src/compiler/transformers/utilities.ts Outdated

Daniel Rosenwasser (DanielRosenwasser) requested changes Apr 1, 2020

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Wenlu Wang (Kingwl) force-pushed the logical_assignment branch from 2f6dfd7 to 1c92781 Compare April 2, 2020 08:04

Daniel Rosenwasser (DanielRosenwasser) reviewed Apr 2, 2020

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Comment thread src/compiler/binder.ts Outdated

Daniel Rosenwasser (DanielRosenwasser) reviewed Apr 2, 2020

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Daniel Rosenwasser (DanielRosenwasser) reviewed Apr 2, 2020

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Wenlu Wang (Kingwl) force-pushed the logical_assignment branch from 17b858c to 1ed6a3e Compare April 4, 2020 14:11

Wenlu Wang (Kingwl) marked this pull request as ready for review April 4, 2020 14:32

add missing semi

39ae072

Wenlu Wang (Kingwl) force-pushed the logical_assignment branch from f17eb88 to 39ae072 Compare May 16, 2020 00:11

Wenlu Wang (Kingwl) added 2 commits May 16, 2020 08:13

fix rebase conflict

acc167d

accept new baseline

6f393e9

Daniel Rosenwasser (DanielRosenwasser) requested changes May 20, 2020

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Comment thread src/compiler/parser.ts Outdated

Merge branch 'master' into logical_assignment

b59e4c5

Wenlu Wang (Kingwl) force-pushed the logical_assignment branch from ad70d78 to b59e4c5 Compare May 20, 2020 02:18

Ron Buckton (rbuckton) suggested changes May 20, 2020

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Wenlu Wang (Kingwl) added 3 commits May 21, 2020 10:19

Fix type and simplify code

b73411c

fix names

2997860

Accept baseline

fed922a

Daniel Rosenwasser (DanielRosenwasser) approved these changes May 27, 2020

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Ron Buckton (rbuckton) approved these changes Jun 9, 2020

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Daniel Rosenwasser (DanielRosenwasser) merged commit e832e04 into microsoft:master Jun 9, 2020

Wenlu Wang (Kingwl) deleted the logical_assignment branch June 10, 2020 00:35

Evan Wallace (evanw) mentioned this pull request Jun 20, 2020

Side effect bugs with logical assignment #39172

Closed

Joe Calzaretta (jcalz) mentioned this pull request Aug 7, 2020

Logical Unary Assignment Operators &&= and ||= #31011

Closed

Johannes Schickling (schickling) mentioned this pull request Jan 27, 2021

Support logical assignment operator evanw/esbuild#715

Closed

Jon Culver (jonculver) mentioned this pull request Jul 13, 2021

Extension fails to load on remotes microsoft/vscode-test-adapter-converter#5

Closed

github-actions Bot mentioned this pull request Oct 4, 2022

[Korean] Fix weird expressions like '_제네릭_' microsoft/TypeScript-Website-Localizations#171

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