css_cache.ts

Cached extraction result for a single file. Uses null instead of empty arrays to avoid allocation overhead.

Creates the cache-path lookup the generators share: a file's cache path under cache_dir in project_root, or null on CI, where nothing is cached.

CSS cache version. Bump when any of these change:

• CachedExtraction schema
• extract_css_classes_with_locations() logic or output
• ExtractionDiagnostic or SourceLocation structure

v1: Initial version with classes and diagnostics v2: Use null instead of empty arrays, add explicit_classes, elements, css_variables. v3: Add explicit_elements, explicit_variables for @fuz-elements/@fuz-variables comments. v4: Filter incomplete CSS variables in dynamic templates (e.g., var(--prefix_{expr})). v5: Remove css_variables and explicit_variables (now detected via simple regex scan). v6: Re-add explicit_variables for @fuz-variables comments (regex scan misses dynamic templates). v7: Add extraction_key, so a change to acorn_plugins or cache_salt misses.

Default cache directory relative to project root.

Deletes a cached extraction file. Best-effort: every unlink error is swallowed, not just not_found - the cache is disposable and callers delete fire-and-forget.

Converts a cached extraction back to the runtime format. Preserves null semantics (null = empty).

Computes the cache file path for a source file. Cache structure mirrors source tree: src/lib/Foo.svelte → .fuz/cache/css/src/lib/Foo.svelte.json

Computes cache path for a file, handling both internal and external paths. Internal files use relative paths mirroring source tree. External files (outside project root) use hashed absolute paths in _external/.

Whether this is a CI run (CI=1, CI=true, or another truthy value): there's no point writing a cache the next run won't reuse.

Loads a cached extraction result from disk. Returns null if the cache is missing, corrupted, or has a version mismatch. This makes the cache self-healing: any error triggers re-extraction.

Saves an extraction result to the cache. Uses atomic write (temp file + rename) for crash safety. Normalizes empty collections to null to avoid allocation overhead on load.

Computes the part of the cache key that comes from configuration rather than file content: a fingerprint of the configured acorn plugins (their source text) and the consumer's cache_salt, or null when neither is set. A plugin's options live in its closure, where the source text can't see them, so a consumer who changes only a plugin's options bumps cache_salt.