feat(ivy): ngcc - support targeting a start entry-point (#29092)

You can now, programmatically, specify an entry-point where
the ngcc compilation will occur.
Only this entry-point and its dependencies will be compiled.

FW-1119

PR Close #29092

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

@@ -24,6 +24,11 @@ export interface NgccOptions {
   formats: EntryPointFormat[];
   /** The path to the node_modules folder where modified files should be written. */
   baseTargetPath?: string;
+  /**
+   * The path, relative to `baseSourcePath` of the primary package to be compiled.
+   * All its dependencies will need to be compiled too.
+   */
+  targetEntryPointPath?: string;
 }
 
 /**
@@ -34,14 +39,14 @@ export interface NgccOptions {
  *
  * @param options The options telling ngcc what to compile and how.
  */
-export function mainNgcc({baseSourcePath, formats, baseTargetPath = baseSourcePath}: NgccOptions):
+export function mainNgcc({baseSourcePath, formats, baseTargetPath = baseSourcePath,
-    void {
+                          targetEntryPointPath}: NgccOptions): void {
   const transformer = new Transformer(baseSourcePath, baseTargetPath);
   const host = new DependencyHost();
   const resolver = new DependencyResolver(host);
   const finder = new EntryPointFinder(resolver);
 
-  const {entryPoints} = finder.findEntryPoints(baseSourcePath);
+  const {entryPoints} = finder.findEntryPoints(baseSourcePath, targetEntryPointPath);
   entryPoints.forEach(entryPoint => {
 
     // Are we compiling the Angular core?

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

@@ -44,7 +44,7 @@ export interface IgnoredDependency {
 }
 
 /**
- * The result of sorting the entry-points by their dependencies.
+ * A list of entry-points, sorted by their dependencies.
  *
  * The `entryPoints` array will be ordered so that no entry point depends upon an entry point that
  * appears later in the array.
@@ -67,9 +67,35 @@ export class DependencyResolver {
    * Sort the array of entry points so that the dependant entry points always come later than
    * their dependencies in the array.
    * @param entryPoints An array entry points to sort.
-   * @returns the result of sorting the entry points.
+   * @param target If provided, only return entry-points depended on by this entry-point.
+   * @returns the result of sorting the entry points by dependency.
    */
-  sortEntryPointsByDependency(entryPoints: EntryPoint[]): SortedEntryPointsInfo {
+  sortEntryPointsByDependency(entryPoints: EntryPoint[], target?: EntryPoint):
+      SortedEntryPointsInfo {
+    const {invalidEntryPoints, ignoredDependencies, graph} = this.createDependencyInfo(entryPoints);
+
+    let sortedEntryPointNodes: string[];
+    if (target) {
+      sortedEntryPointNodes = graph.dependenciesOf(target.path);
+      sortedEntryPointNodes.push(target.path);
+    } else {
+      sortedEntryPointNodes = graph.overallOrder();
+    }
+
+    return {
+      entryPoints: sortedEntryPointNodes.map(path => graph.getNodeData(path)),
+      invalidEntryPoints,
+      ignoredDependencies,
+    };
+  }
+
+  /**
+   * Computes a dependency graph of the given entry-points.
+   *
+   * The graph only holds entry-points that ngcc cares about and whose dependencies
+   * (direct and transitive) all exist.
+   */
+  private createDependencyInfo(entryPoints: EntryPoint[]) {
     const invalidEntryPoints: InvalidEntryPoint[] = [];
     const ignoredDependencies: IgnoredDependency[] = [];
     const graph = new DepGraph<EntryPoint>();
@@ -79,15 +105,10 @@ export class DependencyResolver {
 
     // Now add the dependencies between them
     entryPoints.forEach(entryPoint => {
-      const entryPointPath = entryPoint.fesm2015 || entryPoint.esm2015;
-      if (!entryPointPath) {
-        throw new Error(
-            `ESM2015 format (flat and non-flat) missing in '${entryPoint.path}' entry-point.`);
-      }
-
       const dependencies = new Set<string>();
       const missing = new Set<string>();
       const deepImports = new Set<string>();
+      const entryPointPath = getEntryPointPath(entryPoint);
       this.host.computeDependencies(entryPointPath, dependencies, missing, deepImports);
 
       if (missing.size > 0) {
@@ -119,13 +140,7 @@ export class DependencyResolver {
       }
     });
 
-    // The map now only holds entry-points that ngcc cares about and whose dependencies
+    return {invalidEntryPoints, ignoredDependencies, graph};
-    // (direct and transitive) all exist.
-    return {
-      entryPoints: graph.overallOrder().map(path => graph.getNodeData(path)),
-      invalidEntryPoints,
-      ignoredDependencies
-    };
 
     function removeNodes(entryPoint: EntryPoint, missingDependencies: string[]) {
       const nodesToRemove = [entryPoint.path, ...graph.dependantsOf(entryPoint.path)];
@@ -136,3 +151,13 @@ export class DependencyResolver {
     }
   }
 }
+
+function getEntryPointPath(entryPoint: EntryPoint): string {
+  const entryPointPath =
+      entryPoint.fesm2015 || entryPoint.fesm5 || entryPoint.esm2015 || entryPoint.esm5;
+  if (!entryPointPath) {
+    throw new Error(
+        `There is no format with import statements in '${entryPoint.path}' entry-point.`);
+  }
+  return entryPointPath;
+}

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

@@ -18,9 +18,14 @@ export class EntryPointFinder {
    * Search the given directory, and sub-directories, for Angular package entry points.
    * @param sourceDirectory An absolute path to the directory to search for entry points.
    */
-  findEntryPoints(sourceDirectory: string): SortedEntryPointsInfo {
+  findEntryPoints(sourceDirectory: string, targetEntryPointPath?: string): SortedEntryPointsInfo {
     const unsortedEntryPoints = walkDirectoryForEntryPoints(sourceDirectory);
-    return this.resolver.sortEntryPointsByDependency(unsortedEntryPoints);
+    targetEntryPointPath =
+        targetEntryPointPath && path.resolve(sourceDirectory, targetEntryPointPath);
+    const targetEntryPoint = targetEntryPointPath ?
+        unsortedEntryPoints.find(entryPoint => entryPoint.path === targetEntryPointPath) :
+        undefined;
+    return this.resolver.sortEntryPointsByDependency(unsortedEntryPoints, targetEntryPoint);
   }
 }
 

packages/compiler-cli/ngcc/test/integration/ngcc_spec.ts

@@ -33,6 +33,25 @@ describe('ngcc main()', () => {
   it('should run ngcc without errors for esm5', () => {
     expect(() => mainNgcc({baseSourcePath: '/node_modules', formats: ['esm5']})).not.toThrow();
   });
+
+  it('should only compile the given package entry-point (and its dependencies)', () => {
+    mainNgcc({
+      baseSourcePath: '/node_modules',
+      formats: ['esm2015'],
+      targetEntryPointPath: '@angular/common'
+    });
+
+    expect(loadPackage('@angular/common').__modified_by_ngcc__).toEqual({
+      esm2015: '0.0.0-PLACEHOLDER',
+      es2015: '0.0.0-PLACEHOLDER',
+    });
+    expect(loadPackage('@angular/core').__modified_by_ngcc__).toEqual({
+      esm2015: '0.0.0-PLACEHOLDER',
+      es2015: '0.0.0-PLACEHOLDER',
+    });
+    expect(loadPackage('@angular/common/testing').__modified_by_ngcc__).toBeUndefined();
+    expect(loadPackage('@angular/common/http').__modified_by_ngcc__).toBeUndefined();
+  });
 });
 
 

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

@@ -7,7 +7,7 @@
  */
 
 import {DependencyHost} from '../../src/packages/dependency_host';
-import {DependencyResolver} from '../../src/packages/dependency_resolver';
+import {DependencyResolver, SortedEntryPointsInfo} from '../../src/packages/dependency_resolver';
 import {EntryPoint} from '../../src/packages/entry_point';
 
 describe('DependencyResolver', () => {
@@ -83,7 +83,7 @@ describe('DependencyResolver', () => {
     it('should error if the entry point does not have either the fesm2015 nor esm2015 formats',
        () => {
          expect(() => resolver.sortEntryPointsByDependency([{ path: 'first' } as EntryPoint]))
-             .toThrowError(`ESM2015 format (flat and non-flat) missing in 'first' entry-point.`);
+             .toThrowError(`There is no format with import statements in 'first' entry-point.`);
        });
 
     it('should capture any dependencies that were ignored', () => {
@@ -95,6 +95,23 @@ describe('DependencyResolver', () => {
       ]);
     });
 
+    it('should only return dependencies of the target, if provided', () => {
+      spyOn(host, 'computeDependencies').and.callFake(createFakeComputeDependencies(dependencies));
+      const entryPoints = [fifth, first, fourth, second, third];
+      let sorted: SortedEntryPointsInfo;
+
+      sorted = resolver.sortEntryPointsByDependency(entryPoints, first);
+      expect(sorted.entryPoints).toEqual([fifth, fourth, third, second, first]);
+      sorted = resolver.sortEntryPointsByDependency(entryPoints, second);
+      expect(sorted.entryPoints).toEqual([fifth, fourth, third, second]);
+      sorted = resolver.sortEntryPointsByDependency(entryPoints, third);
+      expect(sorted.entryPoints).toEqual([fifth, fourth, third]);
+      sorted = resolver.sortEntryPointsByDependency(entryPoints, fourth);
+      expect(sorted.entryPoints).toEqual([fifth, fourth]);
+      sorted = resolver.sortEntryPointsByDependency(entryPoints, fifth);
+      expect(sorted.entryPoints).toEqual([fifth]);
+    });
+
     interface DepMap {
       [path: string]: {resolved: string[], missing: string[]};
     }