feat: add migration schematic for function-based providers

jest.config.js

@@ -12,5 +12,9 @@ module.exports = {
 
   coverageDirectory: '<rootDir>/coverage/jest',
   coverageReporters: ['json', 'text'],
-  collectCoverageFrom: ['<rootDir>/**/*.ts', '!**/testing/**'],
+  collectCoverageFrom: [
+    '<rootDir>/**/*.ts',
+    '!**/testing/**',
+    '!**/external-utils/**',
+  ],
 }

projects/ngx-meta/schematics/external-utils/README.md

@@ -0,0 +1,19 @@
+# Why is this needed
+
+May schematic utilities are deep imports, hence not part of [Angular's public API surface](https://github.com/angular/angular/blob/main/contributing-docs/public-api-surface.md)
+
+> A deep import is an import deeper than one of the package's entry point. For instance `@angular/core` is a regular import. But `@angular/core/src/utils` is a deep import.
+
+For instance:
+
+- `@schematics/angular/utility`
+- `@angular-devkit/core/src/utils`
+
+So the files needed from there are copy / pasted in here to avoid coupling to non-public APIs which can be dangerous (for instance breaking changes)
+
+Indeed, [some `@angular/core` schematic utils mysteriously disappeared in v15.1](https://stackoverflow.com/a/79123753/3263250)
+
+Existing `npm` libraries with exported utils aren't very popular or maintained at the moment of writing this. For instance:
+
+- [`schematics-utilities`](https://www.npmjs.com/package/schematics-utilities). Most popular one. Exports copy/pasted utils from Angular's schematics package and Angular Material package. [Latest release is from 2021 (3+ years ago)](https://github.com/nitayneeman/schematics-utilities/releases/tag/v2.0.3). [Depends on Angular v8 and Typescript v3](https://github.com/nitayneeman/schematics-utilities/blob/v2.0.3/package.json#L38-L41)
+- [`@hug/ngx-schematics-utilities`](https://www.npmjs.com/package/@hug/ngx-schematics-utilities). Modern schematics with a builder-like pattern. It's updated: [latest release was last month](https://github.com/DSI-HUG/ngx-schematics-utilities/releases/tag/10.1.4). [Depends with peer dependencies (yay!) on Angular > v17](https://github.com/DSI-HUG/ngx-schematics-utilities/blob/10.1.4/projects/lib/package.json#L53-L58). Not very popular though. So prefer copy/pasting for now.

projects/ngx-meta/schematics/external-utils/angular-devkit/core/src/utils/strings.ts

@@ -0,0 +1,69 @@
+// Partial extraction from
+// https://github.com/angular/angular-cli/blob/18.2.10/packages/angular_devkit/core/src/utils/strings.ts
+const STRING_CAMELIZE_REGEXP = /(-|_|\.|\s)+(.)?/g
+
+/**
+ Returns the lowerCamelCase form of a string.
+
+ ```javascript
+ camelize('innerHTML');          // 'innerHTML'
+ camelize('action_name');        // 'actionName'
+ camelize('css-class-name');     // 'cssClassName'
+ camelize('my favorite items');  // 'myFavoriteItems'
+ camelize('My Favorite Items');  // 'myFavoriteItems'
+ ```
+
+ @method camelize
+ @param {String} str The string to camelize.
+ @return {String} the camelized string.
+ */
+export function camelize(str: string): string {
+  return str
+    .replace(
+      STRING_CAMELIZE_REGEXP,
+      (_match: string, _separator: string, chr: string) => {
+        return chr ? chr.toUpperCase() : ''
+      },
+    )
+    .replace(/^([A-Z])/, (match: string) => match.toLowerCase())
+}
+
+/**
+ Returns the UpperCamelCase form of a string.
+
+ @example
+ ```javascript
+ 'innerHTML'.classify();          // 'InnerHTML'
+ 'action_name'.classify();        // 'ActionName'
+ 'css-class-name'.classify();     // 'CssClassName'
+ 'my favorite items'.classify();  // 'MyFavoriteItems'
+ 'app.component'.classify();      // 'AppComponent'
+ ```
+ @method classify
+ @param {String} str the string to classify
+ @return {String} the classified string
+ */
+export function classify(str: string): string {
+  return str
+    .split('.')
+    .map((part) => capitalize(camelize(part)))
+    .join('')
+}
+
+/**
+ Returns the Capitalized form of a string
+
+ ```javascript
+ 'innerHTML'.capitalize()         // 'InnerHTML'
+ 'action_name'.capitalize()       // 'Action_name'
+ 'css-class-name'.capitalize()    // 'Css-class-name'
+ 'my favorite items'.capitalize() // 'My favorite items'
+ ```
+
+ @method capitalize
+ @param {String} str The string to capitalize.
+ @return {String} The capitalized string.
+ */
+export function capitalize(str: string): string {
+  return str.charAt(0).toUpperCase() + str.slice(1)
+}

projects/ngx-meta/schematics/external-utils/schematics/angular/utility/change.ts

@@ -0,0 +1,114 @@
+// Partial extraction from
+// https://github.com/angular/angular-cli/blob/18.2.10/packages/schematics/angular/utility/change.ts
+/**
+ * @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.dev/license
+ */
+
+import { UpdateRecorder } from '@angular-devkit/schematics'
+
+export interface Change {
+  // The file this change should be applied to. Some changes might not apply to
+  // a file (maybe the config).
+  readonly path: string | null
+
+  // The order this change should be applied. Normally the position inside the file.
+  // Changes are applied from the bottom of a file to the top.
+  readonly order: number
+
+  // The description of this change. This will be outputted in a dry or verbose run.
+  readonly description: string
+}
+
+/**
+ * An operation that does nothing.
+ */
+export class NoopChange implements Change {
+  description = 'No operation.'
+  order = Infinity
+  path = null
+}
+
+/**
+ * Will add text to the source code.
+ */
+export class InsertChange implements Change {
+  order: number
+  description: string
+
+  constructor(
+    public path: string,
+    public pos: number,
+    public toAdd: string,
+  ) {
+    if (pos < 0) {
+      throw new Error('Negative positions are invalid')
+    }
+    this.description = `Inserted ${toAdd} into position ${pos} of ${path}`
+    this.order = pos
+  }
+}
+
+/**
+ * Will remove text from the source code.
+ */
+export class RemoveChange implements Change {
+  order: number
+  description: string
+
+  constructor(
+    public path: string,
+    pos: number,
+    public toRemove: string,
+  ) {
+    if (pos < 0) {
+      throw new Error('Negative positions are invalid')
+    }
+    this.description = `Removed ${toRemove} into position ${pos} of ${path}`
+    this.order = pos
+  }
+}
+
+/**
+ * Will replace text from the source code.
+ */
+export class ReplaceChange implements Change {
+  order: number
+  description: string
+
+  constructor(
+    public path: string,
+    pos: number,
+    public oldText: string,
+    public newText: string,
+  ) {
+    if (pos < 0) {
+      throw new Error('Negative positions are invalid')
+    }
+    this.description = `Replaced ${oldText} into position ${pos} of ${path} with ${newText}`
+    this.order = pos
+  }
+}
+
+export function applyToUpdateRecorder(
+  recorder: UpdateRecorder,
+  changes: Change[],
+): void {
+  for (const change of changes) {
+    if (change instanceof InsertChange) {
+      recorder.insertLeft(change.pos, change.toAdd)
+    } else if (change instanceof RemoveChange) {
+      recorder.remove(change.order, change.toRemove.length)
+    } else if (change instanceof ReplaceChange) {
+      recorder.remove(change.order, change.oldText.length)
+      recorder.insertLeft(change.order, change.newText)
+    } else if (!(change instanceof NoopChange)) {
+      throw new Error(
+        'Unknown Change type encountered when updating a recorder.',
+      )
+    }
+  }
+}

projects/ngx-meta/schematics/migrations.json

@@ -0,0 +1,10 @@
+{
+  "$schema": "../../../node_modules/@angular-devkit/schematics/collection-schema.json",
+  "schematics": {
+    "const-to-function-manager-providers": {
+      "version": "1.0.0-beta.35",
+      "description": "Changes `const`-based metadata manager providers by `function`-based ones for tree shaking and extensibility purposes. See https://ngx-meta.dev/migrations/const-to-function-manager-providers/",
+      "factory": "./migrations/const-to-function-manager-providers/index#migrate"
+    }
+  }
+}