fix: correctly resolve remapped directories

CHANGELOG.md

@@ -12,7 +12,7 @@
 - `[jest-environment-node]` [**BREAKING**] Add default `node` and `node-addon` conditions to `exportConditions` for `node` environment ([#11924](https://github.com/facebook/jest/pull/11924))
 - `[@jest/expect]` New module which extends `expect` with `jest-snapshot` matchers ([#12404](https://github.com/facebook/jest/pull/12404), [#12410](https://github.com/facebook/jest/pull/12410), [#12418](https://github.com/facebook/jest/pull/12418))
 - `[@jest/expect-utils]` New module exporting utils for `expect` ([#12323](https://github.com/facebook/jest/pull/12323))
-- `[jest-resolver]` [**BREAKING**] Add support for `package.json` `exports` ([11961](https://github.com/facebook/jest/pull/11961))
+- `[jest-resolve]` [**BREAKING**] Add support for `package.json` `exports` ([#11961](https://github.com/facebook/jest/pull/11961), [#12373](https://github.com/facebook/jest/pull/12373))
 - `[jest-resolve, jest-runtime]` Add support for `data:` URI import and mock ([#12392](https://github.com/facebook/jest/pull/12392))
 - `[@jest/schemas]` New module for JSON schemas for Jest's config ([#12384](https://github.com/facebook/jest/pull/12384))
 - `[jest-worker]` [**BREAKING**] Allow only absolute `workerPath` ([#12343](https://github.com/facebook/jest/pull/12343))

e2e/runtime-internal-module-registry/__tests__/runtimeInternalModuleRegistry.test.js

@@ -13,10 +13,10 @@ describe('Runtime internal module registry', () => {
   it('behaves correctly when requiring a module that is used by jest internals', () => {
     const fs = require('fs');
 
-    // We require from this crazy path so that we can mimick Jest (and it's
-    // transitive deps) being installed along side a projects deps (e.g. with an
+    // We require from this crazy path so that we can mimick Jest (and its
+    // transitive deps) being installed alongside a projects deps (e.g. with an
     // NPM3 flat dep tree)
-    const jestUtil = require('../../../packages/jest-util');
+    const jestUtil = require('jest-util');
 
     // If FS is mocked correctly, this folder won't actually be created on the
     // filesystem

packages/jest-resolve/src/__tests__/resolve.test.ts

@@ -234,6 +234,20 @@ describe('findNodeModule', () => {
         path.resolve(conditionsRoot, './node_modules/exports/nestedDefault.js'),
       );
     });
+
+    test('supports separate directory path', () => {
+      const result = Resolver.findNodeModule('exports/directory/file.js', {
+        basedir: conditionsRoot,
+        conditions: [],
+      });
+
+      expect(result).toEqual(
+        path.resolve(
+          conditionsRoot,
+          './node_modules/exports/some-other-directory/file.js',
+        ),
+      );
+    });
   });
 });
 

packages/jest-resolve/src/defaultResolver.ts

@@ -5,14 +5,13 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {isAbsolute} from 'path';
+import {dirname, isAbsolute, resolve as pathResolve} from 'path';
 import pnpResolver from 'jest-pnp-resolver';
-import {sync as resolveSync} from 'resolve';
+import {SyncOpts as UpstreamResolveOptions, sync as resolveSync} from 'resolve';
 import {
   Options as ResolveExportsOptions,
   resolve as resolveExports,
 } from 'resolve.exports';
-import slash = require('slash');
 import {
   PkgJson,
   isDirectory,
@@ -36,6 +35,9 @@ interface ResolverOptions {
   pathFilter?: (pkg: PkgJson, path: string, relativePath: string) => string;
 }
 
+type UpstreamResolveOptionsWithConditions = UpstreamResolveOptions &
+  Pick<ResolverOptions, 'conditions'>;
+
 // https://github.com/facebook/jest/pull/10617
 declare global {
   namespace NodeJS {
@@ -45,6 +47,58 @@ declare global {
   }
 }
 
+function getPathInModule(
+  path: string,
+  options: UpstreamResolveOptionsWithConditions,
+): string {
+  if (isAbsolute(path) || path.startsWith('.')) {
+    return path;
+  }
+
+  const segments = path.split('/');
+
+  let moduleName = segments.shift();
+
+  if (moduleName) {
+    // TODO: handle `#` here: https://github.com/facebook/jest/issues/12270
+    if (moduleName.startsWith('@')) {
+      moduleName = `${moduleName}/${segments.shift()}`;
+    }
+
+    let packageJsonPath = '';
+
+    try {
+      packageJsonPath = resolveSync(`${moduleName}/package.json`, options);
+    } catch {
+      // ignore if package.json cannot be found
+    }
+
+    if (packageJsonPath && isFile(packageJsonPath)) {
+      const pkg = readPackageCached(packageJsonPath);
+
+      if (pkg.exports) {
+        // we need to make sure resolve ignores `main`
+        delete pkg.main;
+
+        const subpath = segments.join('/') || '.';
+
+        const resolved = resolveExports(
+          pkg,
+          subpath,
+          createResolveOptions(options.conditions),
+        );
+
+        // TODO: should we throw if not?
+        if (resolved) {
+          return pathResolve(dirname(packageJsonPath), resolved);
+        }
+      }
+    }
+  }
+
+  return path;
+}
+
 export default function defaultResolver(
   path: string,
   options: ResolverOptions,
@@ -55,16 +109,23 @@ export default function defaultResolver(
     return pnpResolver(path, options);
   }
 
-  const result = resolveSync(path, {
+  const resolveOptions: UpstreamResolveOptionsWithConditions = {
     ...options,
     isDirectory,
     isFile,
-    packageFilter: createPackageFilter(path, options.packageFilter),
-    pathFilter: createPathFilter(path, options.conditions, options.pathFilter),
     preserveSymlinks: false,
     readPackageSync,
     realpathSync,
-  });
+  };
+
+  const pathToResolve = getPathInModule(path, resolveOptions);
+
+  const result = isAbsolute(pathToResolve)
+    ? pathToResolve
+    : resolveSync(pathToResolve, {
+        ...resolveOptions,
+        packageFilter: createPackageFilter(pathToResolve, options),
+      });
 
   // Dereference symlinks to ensure we don't create a separate
   // module instance depending on how it was referenced.
@@ -81,65 +142,51 @@ function readPackageSync(_: unknown, file: string): PkgJson {
 
 function createPackageFilter(
   originalPath: string,
-  userFilter?: ResolverOptions['packageFilter'],
+  options: ResolverOptions,
 ): ResolverOptions['packageFilter'] {
   if (shouldIgnoreRequestForExports(originalPath)) {
-    return userFilter;
+    return options.packageFilter;
   }
 
   return function packageFilter(pkg, ...rest) {
     let filteredPkg = pkg;
 
-    if (userFilter) {
-      filteredPkg = userFilter(filteredPkg, ...rest);
+    if (options.packageFilter) {
+      filteredPkg = options.packageFilter(filteredPkg, ...rest);
     }
 
     if (filteredPkg.exports == null) {
       return filteredPkg;
     }
 
+    let resolvedMain: string | void = undefined;
+
+    try {
+      resolvedMain = resolveExports(
+        filteredPkg,
+        '.',
+        createResolveOptions(options.conditions),
+      );
+    } catch {
+      // ignore
+    }
+
     return {
       ...filteredPkg,
-      // remove `main` so `resolve` doesn't look at it and confuse the `.`
-      // loading in `pathFilter`
-      main: undefined,
+      // override `main` so `resolve` resolves it correctly while respecting
+      // `exports`.
+      main: resolvedMain,
     };
   };
 }
 
-function createPathFilter(
-  originalPath: string,
-  conditions?: Array<string>,
-  userFilter?: ResolverOptions['pathFilter'],
-): ResolverOptions['pathFilter'] {
-  if (shouldIgnoreRequestForExports(originalPath)) {
-    return userFilter;
-  }
-
-  const options: ResolveExportsOptions = conditions
+function createResolveOptions(
+  conditions: Array<string> | undefined,
+): ResolveExportsOptions {
+  return conditions
     ? {conditions, unsafe: true}
     : // no conditions were passed - let's assume this is Jest internal and it should be `require`
       {browser: false, require: true};
-
-  return function pathFilter(pkg, path, relativePath, ...rest) {
-    let pathToUse = relativePath;
-
-    if (userFilter) {
-      pathToUse = userFilter(pkg, path, relativePath, ...rest);
-    }
-
-    if (pkg.exports == null) {
-      return pathToUse;
-    }
-
-    // this `index` thing can backfire, but `resolve` adds it: https://github.com/browserify/resolve/blob/f1b51848ecb7f56f77bfb823511d032489a13eab/lib/sync.js#L192
-    const isRootRequire =
-      pathToUse === 'index' && !originalPath.endsWith('/index');
-
-    const newPath = isRootRequire ? '.' : slash(pathToUse);
-
-    return resolveExports(pkg, newPath, options) || pathToUse;
-  };
 }
 
 // if it's a relative import or an absolute path, exports are ignored