Pass original dependency specifier into the resolver

Summary:
Changelog:
* **[Breaking]**: `DependencyGraph.resolveDependency` now takes a dependency object instead of a string.
* **[Feature]**: Custom resolvers may access the original dependency descriptor for diagnostic purposes.

Makes the full `TransformResultDependency` object ( = dependency descriptor extracted by `collectDependencies`) available to Metro's resolver, including custom resolvers. For the time being, this infrastructure will be used for improved diagnostics and explicitly *not* for any change to resolution semantics. We will likely loosen this restriction in the future (e.g. to introduce Node-compatible ESM/CJS resolution, more compliant `exports`, etc).

The improved diagnostics themselves are coming in a separate diff for ease of review.

Reviewed By: GijsWeterings

Differential Revision: D47453640

fbshipit-source-id: a743875ec1238c9fd50a14bd250aeae2973c12ab

docs/Resolution.md

@@ -267,6 +267,32 @@ When calling the default resolver with a non-null `resolveRequest` function, it
 
 Inside a custom resolver, `resolveRequest` is set to the default resolver function, for easy chaining and customization.
 
+#### `dependency: ?Dependency`
+
+A dependency descriptor corresponding to the current resolution request. This is provided for diagnostic purposes *only* and may not be used for semantic purposes. See the [Caching](#caching) section for more information.
+
+```flow
+type Dependency = {
+  // The literal name provided to a require or import call. For example 'foo' in
+  // case of `require('foo')`.
+  name: string,
+
+  data: {
+    // A locally unique key for this dependency within the origin module.
+    key: string,
+
+    // Source locations from the Babel AST, relative to the origin module, where
+    // this dependency was encountered. This may be an empty array.
+    locs: $ReadOnlyArray<BabelSourceLocation>,
+
+    asyncType: 'async' | 'prefetch' | 'weak' | null,
+
+    // Other properties are considered internal and may change in the future.
+    ...
+  },
+};
+```
+
 ## Caching
 
 Resolver results may be cached under the following conditions:

packages/metro-resolver/package.json

@@ -14,5 +14,8 @@
   "license": "MIT",
   "engines": {
     "node": ">=18"
+  },
+  "devDependencies": {
+    "metro": "0.77.0"
   }
 }

packages/metro-resolver/src/PackageExportsResolve.js

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow strict
+ * @flow strict-local
  * @format
  * @oncall react_native
  */

packages/metro-resolver/src/PackageResolve.js

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow strict
+ * @flow strict-local
  * @format
  * @oncall react_native
  */

packages/metro-resolver/src/createDefaultContext.js

@@ -9,6 +9,7 @@
  * @oncall react_native
  */
 
+import type {TransformResultDependency} from 'metro/src/DeltaBundler/types.flow';
 import type {ResolutionContext} from './types';
 
 import {redirectModulePath} from './PackageResolve';
@@ -23,10 +24,14 @@ type PartialContext = $ReadOnly<{
  * As context values can be overridden by callers, this occurs externally to
  * `resolve.js`.
  */
-function createDefaultContext(context: PartialContext): ResolutionContext {
+function createDefaultContext(
+  context: PartialContext,
+  dependency: TransformResultDependency,
+): ResolutionContext {
   return {
     redirectModulePath: (modulePath: string) =>
       redirectModulePath(context, modulePath),
+    dependency,
     ...context,
   };
 }

packages/metro-resolver/src/errors/FailedToResolvePathError.js

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow strict
+ * @flow strict-local
  * @format
  * @oncall react_native
  */

packages/metro-resolver/src/errors/InvalidPackageError.js

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow strict
+ * @flow strict-local
  * @format
  * @oncall react_native
  */

packages/metro-resolver/src/errors/formatFileCandidates.js

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow strict
+ * @flow strict-local
  * @format
  * @oncall react_native
  */

packages/metro-resolver/src/resolveAsset.js

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow strict
+ * @flow strict-local
  * @format
  * @oncall react_native
  */

packages/metro-resolver/src/types.js

@@ -4,13 +4,15 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow strict
+ * @flow strict-local
  * @format
  * @oncall react_native
  */
 
 'use strict';
 
+import type {TransformResultDependency} from 'metro/src/DeltaBundler/types.flow';
+
 export type Result<+TResolution, +TCandidates> =
   | {+type: 'resolved', +resolution: TResolution}
   | {+type: 'failed', +candidates: TCandidates};
@@ -123,6 +125,13 @@ export type ResolutionContext = $ReadOnly<{
    */
   getPackageForModule: (modulePath: string) => ?PackageInfo,
 
+  /**
+   * The dependency descriptor, within the origin module, corresponding to the
+   * current resolution request. This is provided for diagnostic purposes ONLY
+   * and may not be used for resolution purposes.
+   */
+  dependency?: TransformResultDependency,
+
   /**
    * The ordered list of fields to read in `package.json` to resolve a main
    * entry point based on the "browser" field spec.
@@ -131,7 +140,8 @@ export type ResolutionContext = $ReadOnly<{
 
   /**
    * Full path of the module that is requiring or importing the module to be
-   * resolved.
+   * resolved. This may not be the only place this dependency was found,
+   * as resolutions can be cached.
    */
   originModulePath: string,
 

packages/metro-resolver/types/types.d.ts

@@ -8,6 +8,8 @@
  * @oncall react_native
  */
 
+import {TransformResultDependency} from 'metro';
+
 export type Result<TResolution, TCandidates> =
   | {readonly type: 'resolved'; readonly resolution: TResolution}
   | {readonly type: 'failed'; readonly candidates: TCandidates};
@@ -102,6 +104,13 @@ export interface ResolutionContext {
    */
   readonly getPackageForModule: (modulePath: string) => PackageInfo | null;
 
+  /**
+   * The dependency descriptor, within the origin module, corresponding to the
+   * current resolution request. This is provided for diagnostic purposes ONLY
+   * and may not be used for resolution purposes.
+   */
+  readonly dependency?: TransformResultDependency;
+
   /**
    * The ordered list of fields to read in `package.json` to resolve a main
    * entry point based on the "browser" field spec.
@@ -110,7 +119,8 @@ export interface ResolutionContext {
 
   /**
    * Full path of the module that is requiring or importing the module to be
-   * resolved.
+   * resolved. This may not be the only place this dependency was found,
+   * as resolutions can be cached.
    */
   readonly originModulePath: string;
 

packages/metro/src/DeltaBundler/Graph.js

@@ -574,7 +574,7 @@ export class Graph<T = MixedOutput> {
       } else {
         try {
           resolvedDep = {
-            absolutePath: options.resolve(parentPath, dep.name).filePath,
+            absolutePath: options.resolve(parentPath, dep).filePath,
             data: dep,
           };
 

packages/metro/src/DeltaBundler/__tests__/DeltaBundler-test.js

@@ -11,6 +11,8 @@
 
 'use strict';
 
+import type {TransformResultDependency} from '../types.flow';
+
 jest.mock('../DeltaCalculator');
 
 const DeltaBundler = require('../../DeltaBundler');
@@ -33,7 +35,7 @@ describe('DeltaBundler', () => {
     unstable_enablePackageExports: false,
     lazy: false,
     onProgress: null,
-    resolve: (from: string, to: string) => {
+    resolve: (from: string, dependency: TransformResultDependency) => {
       throw new Error('Never called');
     },
     shallow: false,

packages/metro/src/DeltaBundler/__tests__/DeltaCalculator-context-test.js

@@ -11,7 +11,7 @@
 
 'use strict';
 
-import type {Options} from '../types.flow';
+import type {Options, TransformResultDependency} from '../types.flow';
 import type {Result} from '../Graph';
 import CountingSet from '../../lib/CountingSet';
 import {Graph} from '../Graph';
@@ -41,7 +41,7 @@ describe('DeltaCalculator + require.context', () => {
     unstable_enablePackageExports: false,
     lazy: false,
     onProgress: null,
-    resolve: (from: string, to: string) => {
+    resolve: (from: string, to: TransformResultDependency) => {
       throw new Error('Never called');
     },
     shallow: false,

packages/metro/src/DeltaBundler/__tests__/DeltaCalculator-test.js

@@ -9,7 +9,12 @@
  * @oncall react_native
  */
 
-import type {Module, Options, Dependency} from '../types.flow';
+import type {
+  Module,
+  Options,
+  Dependency,
+  TransformResultDependency,
+} from '../types.flow';
 import type {Graph as GraphType, Result} from '../Graph';
 
 import path from 'path';
@@ -34,7 +39,7 @@ describe.each(['linux', 'win32'])('DeltaCalculator (%s)', osPlatform => {
     unstable_enablePackageExports: true,
     lazy: false,
     onProgress: null,
-    resolve: (from: string, to: string) => {
+    resolve: (from: string, to: TransformResultDependency) => {
       throw new Error('Never called');
     },
     shallow: false,

packages/metro/src/DeltaBundler/__tests__/Graph-test.js

@@ -348,9 +348,9 @@ beforeEach(async () => {
     unstable_enablePackageExports: false,
     lazy: false,
     onProgress: null,
-    resolve: (from: string, to: string) => {
+    resolve: (from: string, to: TransformResultDependency) => {
       const deps = getMockDependency(from);
-      const {path} = deps.filter(dep => dep.name === to)[0];
+      const {path} = deps.filter(dep => dep.name === to.name)[0];
 
       if (!mockedDependencies.has(path)) {
         throw new Error(`Dependency not found: ${from} -> ${path}`);