feat(jest-resolve): expose PackageFilter, PathFilter and PackageJSON types

CHANGELOG.md

@@ -46,7 +46,7 @@
 - `[jest-resolve, jest-runtime]` Add support for `data:` URI import and mock ([#12392](https://github.com/facebook/jest/pull/12392))
 - `[jest-resolve, jest-runtime]` Add support for async resolver ([#11540](https://github.com/facebook/jest/pull/11540))
 - `[jest-resolve]` [**BREAKING**] Remove `browser?: boolean` from resolver options, `conditions: ['browser']` should be used instead ([#12707](https://github.com/facebook/jest/pull/12707))
-- `[jest-resolve]` Expose `JestResolver`, `AsyncResolver` and `SyncResolver` types ([#12707](https://github.com/facebook/jest/pull/12707))
+- `[jest-resolve]` Expose `JestResolver`, `AsyncResolver`, `SyncResolver`, `PackageFilter`, `PathFilter` and `PackageJSON` types ([#12707](https://github.com/facebook/jest/pull/12707), ([#12712](https://github.com/facebook/jest/pull/12712))
 - `[jest-runner]` Allow `setupFiles` module to export an async function ([#12042](https://github.com/facebook/jest/pull/12042))
 - `[jest-runner]` Allow passing `testEnvironmentOptions` via docblocks ([#12470](https://github.com/facebook/jest/pull/12470))
 - `[jest-runner]` Exposing `CallbackTestRunner`, `EmittingTestRunner` abstract classes to help typing third party runners ([#12646](https://github.com/facebook/jest/pull/12646))

docs/Configuration.md

@@ -927,8 +927,6 @@ This option allows the use of a custom resolver. This resolver must be a module
 The options object provided to resolvers has the shape:
 
 ```ts
-type PackageJson = Record<string, unknown>;
-
 type ResolverOptions = {
   /** Directory to begin resolving from. */
   basedir: string;
@@ -943,9 +941,9 @@ type ResolverOptions = {
   /** List of `require.paths` to use if nothing is found in `node_modules`. */
   paths?: Array<string>;
   /** Allows transforming parsed `package.json` contents. */
-  packageFilter?: (pkg: PackageJson, file: string, dir: string) => PackageJson;
+  packageFilter?: (pkg: PackageJSON, file: string, dir: string) => PackageJSON;
   /** Allows transforms a path within a package. */
-  pathFilter?: (pkg: PackageJson, path: string, relativePath: string) => string;
+  pathFilter?: (pkg: PackageJSON, path: string, relativePath: string) => string;
   /** Current root directory. */
   rootDir?: string;
 };

packages/jest-resolve/__typetests__/resolver.test.ts

@@ -6,19 +6,41 @@
  */
 
 import {expectAssignable, expectError, expectType} from 'tsd-lite';
-import type {AsyncResolver, JestResolver, SyncResolver} from 'jest-resolve';
-
-type PackageJson = Record<string, unknown>;
-type PackageFilter = (
-  pkg: PackageJson,
-  file: string,
-  dir: string,
-) => PackageJson;
-type PathFilter = (
-  pkg: PackageJson,
-  path: string,
-  relativePath: string,
-) => string;
+import type {
+  AsyncResolver,
+  JestResolver,
+  PackageFilter,
+  PackageJSON,
+  PathFilter,
+  SyncResolver,
+} from 'jest-resolve';
+
+// PackageJSON
+
+expectAssignable<PackageJSON>({
+  caption: 'test',
+  count: 100,
+  isTest: true,
+  location: {name: 'test', start: [1, 2], valid: false, x: 10, y: 20},
+  values: [0, 10, 20, {x: 1, y: 2}, true, 'test', ['a', 'b']],
+});
+
+expectError<PackageJSON>({
+  filter: () => {},
+});
+
+// PackageFilter
+
+const packageFilter = (pkg: PackageJSON, file: string, dir: string) => pkg;
+
+expectAssignable<PackageFilter>(packageFilter);
+
+// PathFilter
+
+const pathFilter = (pkg: PackageJSON, path: string, relativePath: string) =>
+  relativePath;
+
+expectAssignable<PathFilter>(pathFilter);
 
 // AsyncResolver
 

packages/jest-resolve/package.json

@@ -30,7 +30,7 @@
   "devDependencies": {
     "@tsd/typescript": "~4.6.2",
     "@types/graceful-fs": "^4.1.3",
-    "@types/resolve": "^1.20.0",
+    "@types/resolve": "^1.20.2",
     "tsd-lite": "^0.5.1"
   },
   "engines": {

packages/jest-resolve/src/defaultResolver.ts

@@ -13,13 +13,43 @@ import {
   resolve as resolveExports,
 } from 'resolve.exports';
 import {
-  PackageJson,
   findClosestPackageJson,
   isDirectory,
   isFile,
   readPackageCached,
   realpathSync,
 } from './fileWalkers';
+import type {PackageJSON} from './types';
+
+/**
+ * Allows transforming parsed `package.json` contents.
+ *
+ * @param pkg - Parsed `package.json` contents.
+ * @param file - Path to `package.json` file.
+ * @param dir - Directory that contains the `package.json`.
+ *
+ * @returns Transformed `package.json` contents.
+ */
+export type PackageFilter = (
+  pkg: PackageJSON,
+  file: string,
+  dir: string,
+) => PackageJSON;
+
+/**
+ * Allows transforms a path within a package.
+ *
+ * @param pkg - Parsed `package.json` contents.
+ * @param path - Path being resolved.
+ * @param relativePath - Path relative from the `package.json` location.
+ *
+ * @returns Relative path that will be joined from the `package.json` location.
+ */
+export type PathFilter = (
+  pkg: PackageJSON,
+  path: string,
+  relativePath: string,
+) => string;
 
 type ResolverOptions = {
   /** Directory to begin resolving from. */
@@ -45,9 +75,9 @@ type ResolverOptions = {
    */
   paths?: Array<string>;
   /** Allows transforming parsed `package.json` contents. */
-  packageFilter?: (pkg: PackageJson, file: string, dir: string) => PackageJson;
+  packageFilter?: PackageFilter;
   /** Allows transforms a path within a package. */
-  pathFilter?: (pkg: PackageJson, path: string, relativePath: string) => string;
+  pathFilter?: PathFilter;
   /** Current root directory. */
   rootDir?: string;
 };
@@ -79,7 +109,6 @@ const defaultResolver: SyncResolver = (path, options) => {
     return pnpResolver(path, options);
   }
 
-  // @ts-expect-error: TODO remove after merging https://github.com/DefinitelyTyped/DefinitelyTyped/pull/59990
   const resolveOptions: UpstreamResolveOptionsWithConditions = {
     ...options,
     isDirectory,
@@ -108,7 +137,7 @@ export default defaultResolver;
  * helper functions
  */
 
-function readPackageSync(_: unknown, file: string): PackageJson {
+function readPackageSync(_: unknown, file: string): PackageJSON {
   return readPackageCached(file);
 }
 

packages/jest-resolve/src/fileWalkers.ts

@@ -8,6 +8,7 @@
 import {dirname, resolve} from 'path';
 import * as fs from 'graceful-fs';
 import {tryRealpath} from 'jest-util';
+import type {PackageJSON} from './types';
 
 export function clearFsCache(): void {
   checkedPaths.clear();
@@ -71,17 +72,15 @@ function realpathCached(path: string): string {
   return result;
 }
 
-export type PackageJson = Record<string, unknown>;
-
-const packageContents = new Map<string, PackageJson>();
-export function readPackageCached(path: string): PackageJson {
+const packageContents = new Map<string, PackageJSON>();
+export function readPackageCached(path: string): PackageJSON {
   let result = packageContents.get(path);
 
   if (result != null) {
     return result;
   }
 
-  result = JSON.parse(fs.readFileSync(path, 'utf8')) as PackageJson;
+  result = JSON.parse(fs.readFileSync(path, 'utf8')) as PackageJSON;
 
   packageContents.set(path, result);
 

packages/jest-resolve/src/index.ts

@@ -7,12 +7,18 @@
 
 import Resolver from './resolver';
 
-export type {AsyncResolver, SyncResolver} from './defaultResolver';
+export type {
+  AsyncResolver,
+  SyncResolver,
+  PackageFilter,
+  PathFilter,
+} from './defaultResolver';
 export type {
   FindNodeModuleConfig,
   ResolveModuleConfig,
   ResolverObject as JestResolver,
 } from './resolver';
+export type {PackageJSON} from './types';
 export * from './utils';
 
 export default Resolver;

packages/jest-resolve/src/types.ts

@@ -21,3 +21,11 @@ type ModuleNameMapperConfig = {
   regex: RegExp;
   moduleName: string | Array<string>;
 };
+
+// https://github.com/Microsoft/TypeScript/issues/3496#issuecomment-128553540
+type JSONValue = string | number | boolean | JSONObject | Array<JSONValue>;
+interface JSONObject {
+  [key: string]: JSONValue;
+}
+
+export type PackageJSON = JSONObject;

yarn.lock

@@ -5373,10 +5373,10 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@types/resolve@npm:^1.20.0":
-  version: 1.20.1
-  resolution: "@types/resolve@npm:1.20.1"
-  checksum: d035d5aaadbd455027fa9457a4a263563d49647f088876aebd2b0388d4c35400b85c0382fdc2ec5253c35442abfc2d25431c989345b97fefe26a367811214343
+"@types/resolve@npm:^1.20.2":
+  version: 1.20.2
+  resolution: "@types/resolve@npm:1.20.2"
+  checksum: 61c2cad2499ffc8eab36e3b773945d337d848d3ac6b7b0a87c805ba814bc838ef2f262fc0f109bfd8d2e0898ff8bd80ad1025f9ff64f1f71d3d4294c9f14e5f6
   languageName: node
   linkType: hard
 
@@ -13446,7 +13446,7 @@ __metadata:
   dependencies:
     "@tsd/typescript": ~4.6.2
     "@types/graceful-fs": ^4.1.3
-    "@types/resolve": ^1.20.0
+    "@types/resolve": ^1.20.2
     chalk: ^4.0.0
     graceful-fs: ^4.2.9
     jest-haste-map: ^28.0.0-alpha.11