fix(ngcc): correctly retrieve a package's version from its `package.json` (#37040)

In order to retrieve the ngcc configuration (if any) for an entry-point,
ngcc has to detect the containing package's version.

Previously, ngcc would try to read the version from the entry-point's
`package.json` file, which was different than the package's top-level
`package.json` for secondary entry-points. For example, it would try to
read it from `node_modules/@angular/common/http/package.json` for
entry-point `@angular/common/http`. However, the `package.json` files
for secondary entry-points are not guaranteed to include a `version`
property.

This commit fixes this by first trying to read the version from the
_package's_ `package.json` (falling back to the entry-point's
`package.json`). For example, it will first try to read it from
`@angular/common/package.json` for entry-point `@angular/common/http`.

PR Close #37040

packages/compiler-cli/ngcc/src/packages/entry_point.ts

@@ -125,21 +125,25 @@ export type GetEntryPointResult =
 export function getEntryPointInfo(
     fs: FileSystem, config: NgccConfiguration, logger: Logger, packagePath: AbsoluteFsPath,
     entryPointPath: AbsoluteFsPath): GetEntryPointResult {
-  const packageJsonPath = resolve(entryPointPath, 'package.json');
+  const packagePackageJsonPath = resolve(packagePath, 'package.json');
-  const loadedEntryPointPackageJson = loadPackageJson(fs, packageJsonPath);
+  const entryPointPackageJsonPath = resolve(entryPointPath, 'package.json');
-  const packageVersion = getPackageVersion(loadedEntryPointPackageJson);
+  const loadedPackagePackageJson = loadPackageJson(fs, packagePackageJsonPath);
+  const loadedEntryPointPackageJson = (packagePackageJsonPath === entryPointPackageJsonPath) ?
+      loadedPackagePackageJson :
+      loadPackageJson(fs, entryPointPackageJsonPath);
+  const packageVersion = getPackageVersion(loadedPackagePackageJson);
   const entryPointConfig =
       config.getPackageConfig(packagePath, packageVersion).entryPoints[entryPointPath];
   let entryPointPackageJson: EntryPointPackageJson;
 
   if (entryPointConfig === undefined) {
-    if (!fs.exists(packageJsonPath)) {
+    if (!fs.exists(entryPointPackageJsonPath)) {
       // No `package.json` and no config.
       return NO_ENTRY_POINT;
     } else if (loadedEntryPointPackageJson === null) {
       // `package.json` exists but could not be parsed and there is no redeeming config.
-      logger.warn(
+      logger.warn(`Failed to read entry point info from invalid 'package.json' file: ${
-          `Failed to read entry point info from invalid 'package.json' file: ${packageJsonPath}`);
+          entryPointPackageJsonPath}`);
 
       return INCOMPATIBLE_ENTRY_POINT;
     } else {
@@ -302,13 +306,12 @@ function guessTypingsFromPackageJson(
 /**
  * Find the version of the package at `packageJsonPath`.
  *
- * The version is read off of the `version` property of `packageJson`. It is assumed that even if
+ * The version is read off of the `version` property of the package's `package.json` file (if
- * `packageJson` corresponds to a secondary entry-point (e.g. `@angular/common/http`) it will still
+ * available).
- * contain the same version as the main package (e.g. `@angular/common`).
  *
- * @param packageJson the parsed `package.json` of the package or one of its entry-points (if
+ * @param packageJson the parsed `package.json` of the package (if available).
- *     available).
+ * @returns the version string or `null` if the `pckage.json` file is missing or doesn't contain a
- * @returns the version string or `null` if the `package.json` is not available.
+ *     version.
  */
 function getPackageVersion(packageJson: EntryPointPackageJson|null): string|null {
   return packageJson?.version ?? null;

packages/compiler-cli/ngcc/test/packages/entry_point_spec.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {absoluteFrom, AbsoluteFsPath, FileSystem, getFileSystem} from '../../../src/ngtsc/file_system';
+import {absoluteFrom, AbsoluteFsPath, FileSystem, getFileSystem, join} from '../../../src/ngtsc/file_system';
 import {runInEachFileSystem} from '../../../src/ngtsc/file_system/testing';
 import {loadTestFiles} from '../../../test/helpers';
 import {NgccConfiguration} from '../../src/packages/configuration';
@@ -77,6 +77,92 @@ runInEachFileSystem(() => {
       expect(entryPoint).toBe(IGNORED_ENTRY_POINT);
     });
 
+    it('should retrieve the entry-point\'s version from the package\'s `package.json`', () => {
+      const entryPointPath = join(SOME_PACKAGE, 'valid_entry_point');
+
+      loadTestFiles([
+        {
+          name: _('/project/ngcc.config.js'),
+          contents: `
+            module.exports = {
+              packages: {
+                'some_package@3': {
+                  entryPoints: {valid_entry_point: {override: {packageVersion: '3'}}},
+                },
+                'some_package@2': {
+                  entryPoints: {valid_entry_point: {override: {packageVersion: '2'}}},
+                },
+                'some_package@1': {
+                  entryPoints: {valid_entry_point: {override: {packageVersion: '1'}}},
+                },
+              },
+            };
+          `,
+        },
+        {
+          name: join(SOME_PACKAGE, 'package.json'),
+          contents: createPackageJson('', {version: '1.0.0'}),
+        },
+        {
+          name: join(entryPointPath, 'package.json'),
+          contents: createPackageJson('valid_entry_point', {version: '2.0.0'}),
+        },
+        {
+          name: join(entryPointPath, 'valid_entry_point.metadata.json'),
+          contents: 'some meta data',
+        },
+      ]);
+
+      const config = new NgccConfiguration(fs, _('/project'));
+      const info: EntryPoint =
+          getEntryPointInfo(fs, config, new MockLogger(), SOME_PACKAGE, entryPointPath) as any;
+
+      expect(info.packageJson).toEqual(jasmine.objectContaining({packageVersion: '1'}));
+    });
+
+    it('should use `null` for version if it cannot be retrieved from a `package.json`', () => {
+      const entryPointPath = join(SOME_PACKAGE, 'valid_entry_point');
+
+      loadTestFiles([
+        {
+          name: _('/project/ngcc.config.js'),
+          contents: `
+            module.exports = {
+              packages: {
+                'some_package@3': {
+                  entryPoints: {valid_entry_point: {override: {packageVersion: '3'}}},
+                },
+                'some_package@2': {
+                  entryPoints: {valid_entry_point: {override: {packageVersion: '2'}}},
+                },
+                'some_package@1': {
+                  entryPoints: {valid_entry_point: {override: {packageVersion: '1'}}},
+                },
+              },
+            };
+          `,
+        },
+        {
+          name: join(SOME_PACKAGE, 'package.json'),
+          contents: createPackageJson(''),
+        },
+        {
+          name: join(entryPointPath, 'package.json'),
+          contents: createPackageJson('valid_entry_point'),
+        },
+        {
+          name: join(entryPointPath, 'valid_entry_point.metadata.json'),
+          contents: 'some meta data',
+        },
+      ]);
+
+      const config = new NgccConfiguration(fs, _('/project'));
+      const info: EntryPoint =
+          getEntryPointInfo(fs, config, new MockLogger(), SOME_PACKAGE, entryPointPath) as any;
+
+      expect(info.packageJson).toEqual(jasmine.objectContaining({packageVersion: '3'}));
+    });
+
     it('should override the properties on package.json if the entry-point is configured', () => {
       loadTestFiles([
         {
@@ -514,19 +600,23 @@ runInEachFileSystem(() => {
 });
 
 export function createPackageJson(
-    packageName: string,
+    entryPointName: string, {excludes, typingsProp = 'typings', typingsIsArray, version}: {
-    {excludes, typingsProp = 'typings', typingsIsArray}:
+      excludes?: string[],
-        {excludes?: string[], typingsProp?: string, typingsIsArray?: boolean} = {}): string {
+      typingsProp?: string,
+      typingsIsArray?: boolean,
+      version?: string
+    } = {}): string {
   const packageJson: any = {
-    name: `some_package/${packageName}`,
+    name: (entryPointName === '') ? 'some_package' : `some_package/${entryPointName}`,
-    [typingsProp]: typingsIsArray ? [`./${packageName}.d.ts`] : `./${packageName}.d.ts`,
+    version,
-    fesm2015: `./fesm2015/${packageName}.js`,
+    [typingsProp]: typingsIsArray ? [`./${entryPointName}.d.ts`] : `./${entryPointName}.d.ts`,
-    esm2015: `./esm2015/${packageName}.js`,
+    fesm2015: `./fesm2015/${entryPointName}.js`,
-    es2015: `./es2015/${packageName}.js`,
+    esm2015: `./esm2015/${entryPointName}.js`,
-    fesm5: `./fesm5/${packageName}.js`,
+    es2015: `./es2015/${entryPointName}.js`,
-    esm5: `./esm5/${packageName}.js`,
+    fesm5: `./fesm5/${entryPointName}.js`,
-    main: `./bundles/${packageName}/index.js`,
+    esm5: `./esm5/${entryPointName}.js`,
-    browser: `./bundles/${packageName}/index.js`,
+    main: `./bundles/${entryPointName}/index.js`,
+    browser: `./bundles/${entryPointName}/index.js`,
     module: './index.js',
   };
   if (excludes) {