feat(core): add migration for `XhrFactory` import (#41313)

Automatically migrates `XhrFactory` from `@angular/common/http` to `@angular/common`.

PR Close #41313

packages/core/schematics/BUILD.bazel

@@ -28,5 +28,6 @@ pkg_npm(
         "//packages/core/schematics/migrations/undecorated-classes-with-decorated-fields",
         "//packages/core/schematics/migrations/undecorated-classes-with-di",
         "//packages/core/schematics/migrations/wait-for-async",
+        "//packages/core/schematics/migrations/xhr-factory",
     ],
 )

packages/core/schematics/migrations.json

@@ -89,6 +89,11 @@
       "version": "12.0.0-beta",
       "description": "In Angular version 12, the type of ActivatedRouteSnapshot.fragment is nullable. This migration automatically adds non-null assertions to it.",
       "factory": "./migrations/activated-route-snapshot-fragment/index"
+    },
+    "migration-v12-xhr-factory": {
+      "version": "12.0.0-next.6",
+      "description": "`XhrFactory` has been moved from `@angular/common/http` to `@angular/common`.",
+      "factory": "./migrations/xhr-factory/index"
     }
   }
 }

packages/core/schematics/migrations/xhr-factory/BUILD.bazel

@@ -0,0 +1,17 @@
+load("//tools:defaults.bzl", "ts_library")
+
+ts_library(
+    name = "xhr-factory",
+    srcs = glob(["**/*.ts"]),
+    tsconfig = "//packages/core/schematics:tsconfig.json",
+    visibility = [
+        "//packages/core/schematics:__pkg__",
+        "//packages/core/schematics/test:__pkg__",
+    ],
+    deps = [
+        "//packages/core/schematics/utils",
+        "@npm//@angular-devkit/schematics",
+        "@npm//@types/node",
+        "@npm//typescript",
+    ],
+)

packages/core/schematics/migrations/xhr-factory/README.md

@@ -0,0 +1,13 @@
+## XhrFactory migration
+
+Automatically migrates `XhrFactory` from `@angular/common/http` to `@angular/common`.
+
+#### Before
+```ts
+import { XhrFactory } from '@angular/common/http';
+```
+
+#### After
+```ts
+import { XhrFactory } from '@angular/common';
+```

packages/core/schematics/migrations/xhr-factory/index.ts

@@ -0,0 +1,132 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import {DirEntry, Rule, UpdateRecorder} from '@angular-devkit/schematics';
+import * as ts from 'typescript';
+import {findImportSpecifier} from '../../utils/typescript/imports';
+
+function* visit(directory: DirEntry): IterableIterator<ts.SourceFile> {
+  for (const path of directory.subfiles) {
+    if (path.endsWith('.ts') && !path.endsWith('.d.ts')) {
+      const entry = directory.file(path);
+      if (entry) {
+        const content = entry.content;
+        if (content.includes('XhrFactory')) {
+          const source = ts.createSourceFile(
+              entry.path,
+              content.toString().replace(/^\uFEFF/, ''),
+              ts.ScriptTarget.Latest,
+              true,
+          );
+
+          yield source;
+        }
+      }
+    }
+  }
+
+  for (const path of directory.subdirs) {
+    if (path === 'node_modules' || path.startsWith('.')) {
+      continue;
+    }
+
+    yield* visit(directory.dir(path));
+  }
+}
+
+export default function(): Rule {
+  return tree => {
+    const printer = ts.createPrinter({newLine: ts.NewLineKind.LineFeed});
+
+    for (const sourceFile of visit(tree.root)) {
+      let recorder: UpdateRecorder|undefined;
+
+      const allImportDeclarations =
+          sourceFile.statements.filter(n => ts.isImportDeclaration(n)) as ts.ImportDeclaration[];
+      if (allImportDeclarations.length === 0) {
+        continue;
+      }
+
+      const httpCommonImport = findImportDeclaration('@angular/common/http', allImportDeclarations);
+      if (!httpCommonImport) {
+        continue;
+      }
+
+      const commonHttpNamedBinding = getNamedImports(httpCommonImport);
+      if (commonHttpNamedBinding) {
+        const commonHttpNamedImports = commonHttpNamedBinding.elements;
+        const xhrFactorySpecifier = findImportSpecifier(commonHttpNamedImports, 'XhrFactory');
+
+        if (!xhrFactorySpecifier) {
+          continue;
+        }
+
+        recorder = tree.beginUpdate(sourceFile.fileName);
+
+        // Remove 'XhrFactory' from '@angular/common/http'
+        if (commonHttpNamedImports.length > 1) {
+          // Remove 'XhrFactory' named import
+          const index = commonHttpNamedBinding.getStart();
+          const length = commonHttpNamedBinding.getWidth();
+
+          const newImports = printer.printNode(
+              ts.EmitHint.Unspecified,
+              ts.factory.updateNamedImports(
+                  commonHttpNamedBinding,
+                  commonHttpNamedBinding.elements.filter(e => e !== xhrFactorySpecifier)),
+              sourceFile);
+          recorder.remove(index, length).insertLeft(index, newImports);
+        } else {
+          // Remove '@angular/common/http' import
+          const index = httpCommonImport.getFullStart();
+          const length = httpCommonImport.getFullWidth();
+          recorder.remove(index, length);
+        }
+
+        // Import XhrFactory from @angular/common
+        const commonImport = findImportDeclaration('@angular/common', allImportDeclarations);
+        const commonNamedBinding = getNamedImports(commonImport);
+        if (commonNamedBinding) {
+          // Already has an import for '@angular/common', just add the named import.
+          const index = commonNamedBinding.getStart();
+          const length = commonNamedBinding.getWidth();
+          const newImports = printer.printNode(
+              ts.EmitHint.Unspecified,
+              ts.factory.updateNamedImports(
+                  commonNamedBinding, [...commonNamedBinding.elements, xhrFactorySpecifier]),
+              sourceFile);
+
+          recorder.remove(index, length).insertLeft(index, newImports);
+        } else {
+          // Add import to '@angular/common'
+          const index = httpCommonImport.getFullStart();
+          recorder.insertLeft(index, `\nimport { XhrFactory } from '@angular/common';`);
+        }
+      }
+
+      if (recorder) {
+        tree.commitUpdate(recorder);
+      }
+    }
+  };
+}
+
+function findImportDeclaration(moduleSpecifier: string, importDeclarations: ts.ImportDeclaration[]):
+    ts.ImportDeclaration|undefined {
+  return importDeclarations.find(
+      n => ts.isStringLiteral(n.moduleSpecifier) && n.moduleSpecifier.text === moduleSpecifier);
+}
+
+function getNamedImports(importDeclaration: ts.ImportDeclaration|undefined): ts.NamedImports|
+    undefined {
+  const namedBindings = importDeclaration?.importClause?.namedBindings;
+  if (namedBindings && ts.isNamedImports(namedBindings)) {
+    return namedBindings;
+  }
+
+  return undefined;
+}

packages/core/schematics/test/BUILD.bazel

@@ -26,6 +26,7 @@ ts_library(
         "//packages/core/schematics/migrations/undecorated-classes-with-decorated-fields",
         "//packages/core/schematics/migrations/undecorated-classes-with-di",
         "//packages/core/schematics/migrations/wait-for-async",
+        "//packages/core/schematics/migrations/xhr-factory",
         "//packages/core/schematics/utils",
         "@npm//@angular-devkit/core",
         "@npm//@angular-devkit/schematics",

packages/core/schematics/test/xhr_factory_spec.ts

@@ -0,0 +1,79 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {tags} from '@angular-devkit/core';
+import {EmptyTree} from '@angular-devkit/schematics';
+import {SchematicTestRunner, UnitTestTree} from '@angular-devkit/schematics/testing';
+
+describe('XhrFactory migration', () => {
+  let tree: UnitTestTree;
+  const runner = new SchematicTestRunner('test', require.resolve('../migrations.json'));
+
+  beforeEach(() => {
+    tree = new UnitTestTree(new EmptyTree());
+  });
+
+  it(`should replace 'XhrFactory' from '@angular/common/http' to '@angular/common'`, async () => {
+    tree.create('/index.ts', tags.stripIndents`
+      import { HttpClient } from '@angular/common';
+      import { HttpErrorResponse, HttpResponse, XhrFactory } from '@angular/common/http';
+    `);
+
+    await runMigration();
+    expect(tree.readContent('/index.ts')).toBe(tags.stripIndents`
+      import { HttpClient, XhrFactory } from '@angular/common';
+      import { HttpErrorResponse, HttpResponse } from '@angular/common/http';
+    `);
+  });
+
+  it(`should replace import for 'XhrFactory' to '@angular/common'`, async () => {
+    tree.create('/index.ts', tags.stripIndents`
+      import { Injecable } from '@angular/core';
+      import { XhrFactory } from '@angular/common/http';
+      import { BrowserModule } from '@angular/platform-browser';
+    `);
+
+    await runMigration();
+    expect(tree.readContent('/index.ts')).toBe(tags.stripIndents`
+      import { Injecable } from '@angular/core';
+      import { XhrFactory } from '@angular/common';
+      import { BrowserModule } from '@angular/platform-browser';
+    `);
+  });
+
+  it(`should remove http import when 'XhrFactory' is the only imported symbol`, async () => {
+    tree.create('/index.ts', tags.stripIndents`
+      import { HttpClient } from '@angular/common';
+      import { XhrFactory as XhrFactory2 } from '@angular/common/http';
+      import { Injecable } from '@angular/core';
+    `);
+
+    await runMigration();
+    expect(tree.readContent('/index.ts')).toBe(tags.stripIndents`
+      import { HttpClient, XhrFactory as XhrFactory2 } from '@angular/common';
+      import { Injecable } from '@angular/core';
+    `);
+  });
+
+  it(`should add named import when '@angular/common' is a namespace import`, async () => {
+    tree.create('/index.ts', tags.stripIndents`
+      import * as common from '@angular/common';
+      import { XhrFactory } from '@angular/common/http';
+    `);
+
+    await runMigration();
+    expect(tree.readContent('/index.ts')).toBe(tags.stripIndents`
+      import * as common from '@angular/common';
+      import { XhrFactory } from '@angular/common';
+    `);
+  });
+
+  async function runMigration(): Promise<void> {
+    await runner.runSchematicAsync('migration-v12-xhr-factory', {}, tree).toPromise();
+  }
+});

packages/core/schematics/tsconfig.json

@@ -3,7 +3,9 @@
     "noImplicitReturns": true,
     "noFallthroughCasesInSwitch": true,
     "strict": true,
-    "lib": ["es2015"],
+    "moduleResolution": "node",
+    "target": "es2019",
+    "lib": ["es2019"],
     "types": ["jasmine"],
     "baseUrl": ".",
     "paths": {

packages/core/schematics/utils/typescript/imports.ts

@@ -110,7 +110,7 @@ export function replaceImport(
 
 
 /** Finds an import specifier with a particular name. */
-function findImportSpecifier(
+export function findImportSpecifier(
     nodes: ts.NodeArray<ts.ImportSpecifier>, specifierName: string): ts.ImportSpecifier|undefined {
   return nodes.find(element => {
     const {name, propertyName} = element;