[Dmitriy Antipov (THEb0nny)]

Improvement #10042

Summary

This PR implements block disabling/enabling in MakeCode with seamless roundtrip preservation across Blocks, TypeScript, and Python:

1. Context Menu & Workspace Support:

   • Enables Blockly's disable: true workspace option.
   • Registers the blockDisable context menu entry ("Disable Block" / "Enable Block") with telemetry.
   • Patches legacy blocks so that only explicitly user-disabled blocks (MANUALLY_DISABLED) remain disabled.

2. Code Generation (Blocks -> TS / Python):

   • Disabled statement blocks emit clean natural comments: // ... in TypeScript and # ... in Python without custom symbols or prefixes.
   • Multi-line statements (like if, while, loops) and top-level event blocks properly comment out their entire subtrees.
   • Prevents duplicate comment prefixes when a block already has an attached block comment (avoiding // // in TS and # // in Python).

3. Decompilation (TS / Python -> Blocks):

   • Distinguishes commented-out code from human notes: parses comments using isBlockCode and converts valid MakeCode statement code to disabled blocks (disabled="true" disabled-reasons="MANUALLY_DISABLED").
   • Human text notes (e.g. // TODO: ..., // Note: ..., sentences) remain preserved as comment notes / sticky notes.
   • Trailing comments at the end of Python files are now preserved when converting to TypeScript (py2ts) instead of being dropped.

4. Variable Handling:

   • Fixes variable hoisting and duplication: leftoverVars only emits declarations for variables actively referenced in enabled blocks (v.firstReference && v.firstReference.isEnabled()).
   • Disabled variable setters (e.g. // let y = 0) stay in their original position without duplicating or swapping order with other variables.

5. Upstream Bug Fix:

   • Fixed TypeError: Cannot read properties of undefined (reading 'splice') in pxtcompiler/emitter/decompiler.ts when ownerStatement.comment is undefined.

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Verification & Testing

• All 166 decompiler tests pass (npm run test:decompiler / gulp testdecompiler).
• All 26 Python decompiler tests pass (gulp testpydecomp).
• Verified roundtrips in pxt-microbit editor:
  • Disabling action blocks (led.plot, basic.showNumber).
  • Switching Blocks ⇄ TypeScript ⇄ Python.
  • Adding/editing comments on disabled blocks.
  • Disabling variables without reordering or duplication.

[Dmitriy Antipov (THEb0nny)]

Microsoft.MakeCode.for.micro_bit.-.Google.Chrome.2026-10-28.03-11-33-compressed.mp4

[Dmitriy Antipov (THEb0nny)]

Update: Bidirectional translation for commented-out code statements between TypeScript and Python

When disabling blocks or commenting out code in the text editor, switching between TypeScript and Python previously retained the commented text verbatim (e.g. // motors.largeB.run(50) remained # motors.largeB.run(50) instead of adapting to Python's naming conventions and syntax).

This commit adds bidirectional statement transpilation for commented-out code:

1. TypeScript → Python (pydecompiler.ts, service.ts):

   • service.ts runs preprocessDisabledBlocks during pydecompile, parsing commented-out code statements as AST nodes with a leading /*__disabled__*/ marker.
   • pydecompiler.ts transpiles the statement with standard Python naming and casing (e.g., motors.largeB.run(50) $\to$ motors.large_b.run(50)), strips the internal marker, and prefixes the emitted Python code with # .
   • Regular human notes/comments remain untouched.

2. Python → TypeScript (converter.ts, parser.ts, ast.ts):

   • During Python AST parsing, single-line comments representing executable statements (method/function calls, assignments) are identified and converted into AST statement nodes tagged with _disabled = true.
   • In toTS(), these statements are transpiled to TypeScript syntax (e.g., # motors.large_b.run(50) $\to$ motors.largeB.run(50)).
   • converter.ts:stmt() emits _disabled statements wrapped with // .
   • Diagnostic errors for _disabled statements are suppressed so disabled or deprecated code does not block project conversion.
   • Non-code human notes (# TODO, explanations) remain regular comments without changes.

3. Roundtrip with Blocks:

   • Commented statements seamlessly roundtrip across Blocks $\leftrightarrow$ TypeScript $\leftrightarrow$ Python without losing block disable state or breaking when uncommented in either language.

[Dmitriy Antipov (THEb0nny)]

BrickCode.for.EV3.-.Google.Chrome.2026-10-28.22-16-38-compressed.mp4