VS Code Extension Anatomy

Purpose

This skill captures the core extension structure needed in this repo: activation events, command contributions, and command handlers. It helps keep extension changes aligned with how VS Code loads and exposes functionality.

When to Use

• •When adding or updating command registration.
• •When modifying extension activation behavior.
• •When checking that manifest contributions match runtime code.

Inputs

• •extension/package.json.
• •extension/extension.js.
• •Command IDs and titles used by the extension.

Outputs

• •Consistent activation events and command contributions.
• •Matching runtime command registrations.
• •Reduced extension-load/config mismatch risk.

Procedure

1. •Read extension/package.json for activationEvents and contributes.commands.
2. •Confirm matching registrations in extension/extension.js.
3. •Verify each command has a stable ID/title pair and callable handler.
4. •Confirm activation assumptions still match current behavior.

Constraints

• •Must:
  • •Keep activation events and command contributions consistent with runtime handlers.
  • •Keep command IDs stable unless there is an explicit migration plan.
• •Must Not:
  • •Assume activation behavior without checking extension/package.json.
  • •Leave commands contributed but unregistered in runtime code.
• •Avoid:
  • •Broad refactors when only manifest/runtime alignment is needed.

Examples

• •Example 1:
  • •Context: A new command is added for terminal-title diagnostics.
  • •Steps:
    • •Add the command to contributes.commands.
    • •Add onCommand:<id> activation.
    • •Register the command in extension/extension.js.
  • •Expected result:
    • •Command appears in Command Palette and executes.

Verification

• •Check command is present in extension/package.json and registered in extension/extension.js.
• •Launch Extension Development Host and run the command from the Command Palette.