Phase 4: Normalize codebase for shared package extraction

[edvilme]

Overview

Phase 4 normalization for mypy as part of the shared package extraction effort.

Tracking issue: microsoft/vscode-python-tools-extension-template#290

What is normalization?

All 5 Python tool extensions (black-formatter, flake8, isort, mypy, pylint) were originally scaffolded from the same template and share ~70% of their code. Over time, each repo diverged: functions were renamed, parameters changed, utilities landed in different files, and features were added to some repos but not others.

Normalization is the process of re-aligning these codebases so that:

1. Equivalent functions have identical signatures — e.g., normalize_path() should accept the same parameters everywhere
2. Equivalent functionality lives in the same file — e.g., if _get_settings_by_path() exists in 4 repos' lsp_server.py, the 5th repo should have it too
3. Missing shared features are backported — e.g., localization files that exist in 3 repos should be added to the other 2

Why is this needed?

The end goal (template#290) is to extract the shared code into a reusable package (vscode-python-tool-lsp). For this to work, we need a clean 1:1 mapping between repo code and package code. If function signatures differ or utilities live in different files, extraction becomes a messy per-repo special case instead of a clean "delete shared file, import from package" operation.

All changes are backwards-compatible — adding optional parameters with defaults, aligning function signatures, and moving code to the correct files. No behavioral changes.

Tasks

Structural Alignment (methods in the right files)

• 4.S5 Rename _get_env_vars() to _get_updated_env() in lsp_server.py (align with other repos)

Python Normalizations (bundled/tool/)

• 4.2a Align _debug_server.py to USE_DEBUGPY gate pattern (currently checks DEBUGPY_PATH directly)
• 4.2d Add resolve_symlinks=True parameter to normalize_path() in lsp_utils.py
• 4.2e Align is_match() — make workspace_root parameter optional with None default

Note: mypy does not use lsp_jsonrpc.py or lsp_runner.py (uses dmypy daemon directly). These files are not applicable.

TypeScript Normalizations (src/common/)

• 4.0f Remove duplicate expandTilde() from settings.ts (already in envFile.ts)
• 4.1d Upgrade configWatcher.ts to robust disposal pattern (error handling + disposed flag)
• 4.1e Align settings.ts to base ISettings interface with shared fields
• 4.1f Parameterize server.ts via ToolConfig.hooks interface
• 4.1g Converge extension.ts to thin wrapper (depends on 4.1e + 4.1f)

Feature Parity

• 4.0b Add package.nls.*.json for all 14 locales (currently missing localization)

PR Strategy

Each task gets its own branch and PR for focused review:

• Branch naming: phase4/<task-slug>
• All changes are backwards-compatible
• Tests must pass before merge