exports.ts

Build a predicate deciding whether an export specifier is blocked, per Node's resolution semantics: an exact (starless) key wins outright, else the best-matching wildcard key (comparePatternKeys) decides — and when that winner's target is null, the subpath is not exported.

Blocking is only observable when blocked keys exist, so this returns null for the common no-blocked-keys case and callers skip specifier computation entirely.

Exported for consumers reading ParsedExports.blocked directly — this is the one implementation of the interpretation rule.

Discover source files using package.json exports field.

Reads package.json, parses exports, maps dist paths to source paths, expands wildcard patterns, and loads file content.

Returns {files: null} when no package.json or no exports field exists, signaling the caller to fall back to glob discovery. Returns {files: []} when exports exist but resolve no source files (likely misconfigured mapping).

For concrete exports, maps directly to source paths and verifies existence. For wildcard exports, globs the source directory for matching files.

Null-target keys are honored with Node's resolution semantics: a subpath whose most-specific matching key is null is not exported, so its file is not discovered — "./internal/*": null beside the usual "./*.js" wildcards keeps src/lib/internal/ out of discovery exactly as it keeps the subpaths unresolvable for consumers (the src/lib/internal/ convention's exports half).

A parsed entry from package.json exports field.

Options for discoverFromExports.

Result of discovering source files from package.json exports.

Self-contained: includes both the discovered files and any error diagnostics (e.g., files that exist but could not be read).

Map a dist file path to its source file path.

Replaces the dist directory prefix with the source directory and maps file extensions based on the export condition.

Result of reading and parsing package.json exports.

Read and parse the exports field from package.json.

Handles all Node.js export formats: strings, objects with conditions, nested conditions, fallback arrays (first usable element), null exclusions (surfaced on blocked for best-match blocking during discovery), and wildcard patterns.