#989: allow expressions in template variable definitions

[Paras14]

This PR fixes #989

Implements #989 and supersedes the $[ask:...] / $[secret:...] syntax of #2179.

Closes #2165.

Implemented changes

• Added new package com.devonfw.tools.ide.expression with the expression syntax @«function-name»([«arg»[,«arg»]*]) resolved during variable resolution.
• ExpressionFunction - interface implemented by every function.
• ExpressionFunctionManager - registry to look up functions by name so further functions can be registered with new IDEasy releases.
• ExpressionParser - locates function calls and parses their arguments. A RegEx is only used to locate the start of a call, the argument list is scanned manually since a RegEx cannot express a balanced list of arguments containing quoted commas, quoted parenthesis or nested calls.
• ExpressionContext - gives a function access to the IdeContext, variable lookup and persistence.
• Added function @path(«path»[, unix|native]) that normalises a path, by default replacing backslashes with slashes.
• Added functions @ask-variable(«name»[, «question»[, «default»]]) and @ask-secret(...) with masked input. An already defined variable is returned without asking, an empty 1st argument always asks, and an empty string as 3rd argument permits empty input.
• Added functions @if-windows, @if-mac, @if-linux and @if-unix that insert their argument if the OS matches.
• Added IdeContext.askForSecret(String, String) analogous to askForInput. AbstractIdeContext implements the prompt loop and the batch mode contract and delegates reading to the new protected readSecretLine(), which IdeContextConsole overrides with Console.readPassword().
• Values entered for a workspace template are persisted to conf/ide.properties so the question is only asked the first time. A value that could not be asked for in batch mode is not persisted.
• Arguments are resolved through the regular variable resolution, so a String argument may itself contain variables (e.g. @path('$[IDE_HOME]/software/node')).
• Text that does not call a registered function is left untouched.

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Testing instructions

Masked input needs a real console, so run this from a normal terminal and not from the IDE.

1. Build the branch and dump the classpath, from the repository root:

mvn -pl cli -am install -DskipTests
mvn -pl cli dependency:build-classpath "-Dmdep.outputFile=cp.txt"
$CP = (Get-Content cli\cp.txt -Raw).Trim()
$CLASSES = "C:\projects\IDEasy\workspaces\main\IDEasy\cli\target\classes"

(make sure you add your path correctly for the cli target classes: "\cli\target\classes")

2. In a test project create IDEasy\settings\workspace\update\ai-test.properties:

ai.backend.url=@ask-variable('MY_URL')
ai.api.key=@ask-secret('MY_TOKEN', 'Enter your API key (from the portal):')
ai.node.path=@path('$[IDE_HOME]/software/node/node', native)
ai.other=@ask-secret('MY_OPTIONAL', 'Password (may be empty):', '')

Make sure MY_URL, MY_TOKEN and MY_OPTIONAL are not yet defined in IDEasy\conf\ide.properties.

3. From the project directory, run the local build:

java -cp "$CLASSES;$CP" com.devonfw.tools.ide.cli.Ideasy update

4. You are asked three times. MY_URL is echoed while typing, MY_TOKEN and MY_OPTIONAL are not. The question for MY_TOKEN is shown as given, including the parenthesis. Press enter without typing anything for MY_OPTIONAL.

5. IDEasy\workspaces\main\ai-test.properties contains the three entered values and ai.node.path with backslashes. IDEasy\conf\ide.properties contains MY_URL, MY_TOKEN and MY_OPTIONAL.

6. Run again. There is no prompt and the file keeps the same values.

7. Remove MY_URL, MY_TOKEN and MY_OPTIONAL from IDEasy\conf\ide.properties and run again with --batch. There is no prompt, the workspace merge fails with CliAbortException: Aborted by end-user. and nothing is added to IDEasy\conf\ide.properties, as an undefined variable cannot be asked for in batch mode.

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Checklist for this PR

Make sure everything is checked before merging this PR. For further info please also see
our DoD.

• When running mvn clean test locally all tests pass and build is successful
• PR title is of the form #«issue-id»: «brief summary» (e.g. #921: fixed setup.bat). If no issue ID exists, title only.
• PR top-level comment summarizes what has been done and contains link to addressed issue(s)
• PR and issue(s) have suitable labels
• Issue is set to In Progress and assigned to you or there is no issue (might happen for very small PRs)
• You followed all coding conventions
• You have added the issue implemented by your PR in CHANGELOG.adoc unless issue is labeled
  with internal
• You have formulated clear instructions on how to test your contribution under "Testing instructions"

[coveralls]

Coverage Report for CI Build 31163534185

Coverage increased (+0.2%) to 73.032%

Details

• Coverage increased (+0.2%) from the base build.
• Patch coverage: No coverable lines changed in this PR.
• 148 coverage regressions across 4 files.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

148 previously-covered lines in 4 files lost coverage.

File	Lines Losing Coverage	Coverage
com/devonfw/tools/ide/context/AbstractIdeContext.java	104	71.46%
com/devonfw/tools/ide/context/IdeContext.java	20	76.92%
com/devonfw/tools/ide/environment/AbstractEnvironmentVariables.java	17	82.73%
com/devonfw/tools/ide/context/IdeContextConsole.java	7	0.0%

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Coverage Stats

Relevant Lines:	17691
Covered Lines:	13477
Line Coverage:	76.18%
Relevant Branches:	7847
Covered Branches:	5174
Branch Coverage:	65.94%
Branches in Coverage %:	Yes
Coverage Strength:	3.24 hits per line

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💛 - Coveralls