v5.26.0

Minor Changes

• Add experimental support for Node.js package maps through a new packageMap option, which takes the path of the configuration file (or a file: URL) or an already-parsed packages object. When it is set, a bare specifier is resolved through the importing package's dependencies table and the target package's location is handed to the regular pipeline, instead of walking node_modules; relative and absolute requests and node: builtins are unaffected. Because several package entries may share one url, the package a request resolved into is exposed as packageId on the result and can be passed back in as context.packageId to resolve from that package unambiguously. Package maps are stability 1 (experimental) in Node.js, and this option tracks that specification and may change with it. (by @alexander-akait in #667)

• Explain an exports/imports field whose conditions wrap subpaths, instead of failing with a message that points at the request. A field shaped like { "import": { ".": "./esm/index.js", "./*": "./esm/*.js" }, "require": "./build/bundle.js" } is not supported by Node.js: the subpaths inside a condition are read as condition names, so they match nothing, and every request into the package failed as "./foo" is not exported under the conditions [...] — which reads as though the package forgot to export ./foo. Such a failure now names the offending keys and shows the arrangement that works, with the subpaths at the top level and the conditions nested inside them. Resolution itself is unchanged: the diagnosis runs only on a request that has already failed, so nothing that resolves today starts failing, and a successful resolve does no extra work. Errors raised while processing either field also name the package.json they came from, which previously only appeared in the resolver log. (by @alexander-akait in #676)

• Generate the published type declarations with TypeScript instead of webpack/tooling, which is no longer a dependency. Every name the package exported before is still exported, and types.d.ts is still the entry point, but the declarations themselves now live in types/ and are emitted by tsc from the JSDoc in lib/. Two shapes follow the sources more closely than the previous generator did: the object form of Plugin no longer declares this: Resolver on apply (it is called as plugin.apply(resolver), so this is the plugin), and the entries of ResolveContext.stack declare name: string | undefined rather than an optional name. Class fields that the old generator dropped, such as the cache backends on CachedInputFileSystem, are now part of the declarations. (by @alexander-akait in #675)

Patch Changes

• Size the ancestor path and segment arrays that getPathsCached keeps to what they actually hold: a push-built store keeps room for 17 entries while a path has a handful, and the cache holds these for the filesystem's lifetime. (by @alexander-akait in #681)