Add platform-specific default paths for Poetry cache and virtualenvs

[karthiknadig]

Fixes #1182
Fixes #1184

[Copilot]

Pull request overview

This PR updates Poetry environment discovery to use platform-correct default cache/virtualenvs locations and adds logic to resolve Poetry’s {cache-dir} placeholder (addressing issues #1182 and #1184).

Changes:

• Add getDefaultPoetryCacheDir() / getDefaultPoetryVirtualenvsPath() and use them as fallbacks for Poetry virtualenv discovery.
• Add {cache-dir} placeholder resolution via poetry config cache-dir.
• Add isMac() helper and unit tests for the new default-path helpers.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/managers/poetry/poetryUtils.ts	Implements platform-specific defaults and {cache-dir} resolution for Poetry virtualenv paths.
src/common/utils/platformUtils.ts	Adds isMac() platform helper.
src/test/managers/poetry/poetryUtils.unit.test.ts	Adds unit tests for the new default Poetry cache/virtualenv path helpers.

Comments suppressed due to low confidence (2)

src/managers/poetry/poetryUtils.ts:210

• resolveVirtualenvsPath() can return the original string containing {cache-dir} when it can’t resolve the placeholder. getPoetryVirtualenvsPath() then persists that unresolved value to workspace state, which can permanently break discovery until the state is cleared. Consider returning undefined (or falling back to getDefaultPoetryVirtualenvsPath()) when the placeholder can’t be resolved, and only caching paths that are resolved (no {…}) and absolute.

This issue also appears on line 303 of the same file.

                // Poetry might return the path with placeholders like {cache-dir}
                // Resolve the placeholder if present
                if (venvPath.includes('{cache-dir}')) {
                    poetryVirtualenvsPath = await resolveVirtualenvsPath(poetry, venvPath);
                } else if (path.isAbsolute(venvPath)) {
                    poetryVirtualenvsPath = venvPath;
                } else {
                    // Not an absolute path and no placeholder, use platform-specific default
                    poetryVirtualenvsPath = getDefaultPoetryVirtualenvsPath();
                }

                if (poetryVirtualenvsPath) {
                    await state.set(POETRY_VIRTUALENVS_PATH_KEY, poetryVirtualenvsPath);
                    return poetryVirtualenvsPath;
                }

src/managers/poetry/poetryUtils.ts:311

• The “last resort” branch returns virtualenvsPath unchanged even though it still contains {cache-dir} and is likely unusable. Since callers treat a non-empty string as valid and may cache it, it would be safer to return undefined/throw, or to fall back to getDefaultPoetryVirtualenvsPath() so the rest of the code doesn’t propagate an invalid path.

    // Fall back to platform-specific default cache dir
    const defaultCacheDir = getDefaultPoetryCacheDir();
    if (defaultCacheDir) {
        return virtualenvsPath.replace('{cache-dir}', defaultCacheDir);
    }

    // Last resort: return the original path (will likely not be valid)
    return virtualenvsPath;
}

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Comments suppressed due to low confidence (1)

src/test/features/projectManager.initialize.unit.test.ts:352

• Same formatting issue here: add spaces inside the braces for readability (or revert to brace-less one-liners if preferred).

                if (key === 'pythonProjects') {return [] as unknown as T;}
                if (key === 'defaultEnvManager') {return 'ms-python.python:venv' as T;}
                return defaultValue;