fix(material/core): add migration for M2 theming APIs (#28927)

Adds a migration to account for the breaking changes in #28892. The migration changes all the places where functions and variables were renamed, as well as the usages of experimental APIs that were moved into stable.

src/material/schematics/ng-update/BUILD.bazel

@@ -79,7 +79,10 @@ ts_library(
 
 spec_bundle(
     name = "spec_bundle",
-    external = ["*/paths.js"],
+    external = [
+        "*/paths.js",
+        "@angular-devkit/core/node",
+    ],
     platform = "cjs-legacy",
     target = "es2020",
     deps = [":test_lib"],

src/material/schematics/ng-update/index.ts

@@ -14,14 +14,12 @@ import {
 } from '@angular/cdk/schematics';
 
 import {materialUpgradeData} from './upgrade-data';
+import {M2ThemingMigration} from './migrations/m2-theming-v18';
 
-const materialMigrations: NullableDevkitMigration[] = [];
+const materialMigrations: NullableDevkitMigration[] = [M2ThemingMigration];
 
 /** Entry point for the migration schematics with target of Angular Material v18 */
 export function updateToV18(): Rule {
-  // We pass the v18 migration rule as a callback, instead of using `chain()`, because the
-  // legacy imports error only logs an error message, it doesn't actually interrupt the migration
-  // process and we don't want to execute migrations if there are leftover legacy imports.
   return createMigrationSchematicRule(
     TargetVersion.V18,
     materialMigrations,

src/material/schematics/ng-update/migrations/m2-theming-v18/index.ts

@@ -0,0 +1,43 @@
+/**
+ * @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 {extname} from '@angular-devkit/core';
+import {DevkitMigration, ResolvedResource, TargetVersion} from '@angular/cdk/schematics';
+import {migrateM2ThemingApiUsages} from './migration';
+
+/** Migration that updates usages of the renamed M2 theming APIs in v18. */
+export class M2ThemingMigration extends DevkitMigration<null> {
+  private _potentialThemes: ResolvedResource[] = [];
+
+  /** Whether to run this migration. */
+  enabled = this.targetVersion === TargetVersion.V18;
+
+  override visitStylesheet(stylesheet: ResolvedResource): void {
+    if (
+      extname(stylesheet.filePath) === '.scss' &&
+      // Note: intended to also capture `@angular/material-experimental`.
+      stylesheet.content.includes('@angular/material')
+    ) {
+      this._potentialThemes.push(stylesheet);
+    }
+  }
+
+  override postAnalysis(): void {
+    for (const theme of this._potentialThemes) {
+      const migrated = migrateM2ThemingApiUsages(theme.content);
+
+      if (migrated !== theme.content) {
+        this.fileSystem
+          .edit(theme.filePath)
+          .remove(0, theme.content.length)
+          .insertLeft(0, migrated);
+        this.fileSystem.commitEdits();
+      }
+    }
+  }
+}

src/material/schematics/ng-update/migrations/m2-theming-v18/migration.ts

@@ -0,0 +1,282 @@
+/**
+ * @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
+ */
+
+/** All functions whose names have been prefixed with `m2-` in v18. */
+const RENAMED_FUNCTIONS = [
+  'define-light-theme',
+  'define-dark-theme',
+  'define-palette',
+  'get-contrast-color-from-palette',
+  'get-color-from-palette',
+  'get-color-config',
+  'get-typography-config',
+  'get-density-config',
+  'define-typography-level',
+  'define-rem-typography-config',
+  'define-typography-config',
+  'define-legacy-typography-config',
+  'typography-level',
+  'font-size',
+  'line-height',
+  'font-weight',
+  'letter-spacing',
+  'font-family',
+];
+
+/** All variables whose names have been prefixed with `m2-` in v18. */
+const RENAMED_VARIABLES = [
+  'red-palette',
+  'pink-palette',
+  'indigo-palette',
+  'purple-palette',
+  'deep-purple-palette',
+  'blue-palette',
+  'light-blue-palette',
+  'cyan-palette',
+  'teal-palette',
+  'green-palette',
+  'light-green-palette',
+  'lime-palette',
+  'yellow-palette',
+  'amber-palette',
+  'orange-palette',
+  'deep-orange-palette',
+  'brown-palette',
+  'grey-palette',
+  'gray-palette',
+  'blue-grey-palette',
+  'blue-gray-palette',
+  'light-theme-background-palette',
+  'dark-theme-background-palette',
+  'light-theme-foreground-palette',
+  'dark-theme-foreground-palette',
+];
+
+/** M3 theming functions that were moved into stable. */
+const M3_FUNCTIONS = ['define-theme', 'define-colors', 'define-typography', 'define-density'];
+
+/** M3 variables that were moved into stable. */
+const M3_VARIABLES = [
+  'red-palette',
+  'green-palette',
+  'blue-palette',
+  'yellow-palette',
+  'cyan-palette',
+  'magenta-palette',
+  'orange-palette',
+  'chartreuse-palette',
+  'azure-palette',
+  'violet-palette',
+  'rose-palette',
+];
+
+/** Possible pairs of comment characters in a Sass file. */
+const COMMENT_PAIRS = new Map<string, string>([
+  ['/*', '*/'],
+  ['//', '\n'],
+]);
+
+/** Prefix for the placeholder that will be used to escape comments. */
+const COMMENT_PLACEHOLDER_START = '__<<ngM2ThemingMigrationEscapedComment';
+
+/** Suffix for the comment escape placeholder. */
+const COMMENT_PLACEHOLDER_END = '>>__';
+
+/** Replaces all usages of renamed M2 theming APIs in a file. */
+export function migrateM2ThemingApiUsages(fileContent: string): string {
+  // Strip out comments, so they don't confuse our migration.
+  let {content, placeholders} = escapeComments(fileContent);
+  const materialNamespaces = getNamespaces('@angular/material', content);
+  const experimentalNamespaces = getNamespaces('@angular/material-experimental', content);
+
+  // Migrate the APIs whose names were prefixed with `m2-`.
+  for (const namespace of materialNamespaces) {
+    for (const name of RENAMED_FUNCTIONS) {
+      content = migrateFunction(content, namespace, name, namespace, 'm2-' + name);
+    }
+
+    for (const name of RENAMED_VARIABLES) {
+      content = migrateVariable(content, namespace, name, namespace, 'm2-' + name);
+    }
+  }
+
+  // Migrate themes that were using M3 while it was still in experimental.
+  if (experimentalNamespaces.length > 0) {
+    const preExperimentalContent = content;
+    const stableNamespace = materialNamespaces.length === 0 ? 'mat' : materialNamespaces[0];
+
+    for (const namespace of experimentalNamespaces) {
+      // The only mixin that was renamed was the backwards-compatibility one.
+      content = migrateMixin(
+        content,
+        namespace,
+        'color-variants-back-compat',
+        stableNamespace,
+        'color-variants-backwards-compatibility',
+      );
+
+      // M3 functions weren't prefixed with anything
+      // so they just move over to the new namespace.
+      for (const name of M3_FUNCTIONS) {
+        content = migrateFunction(content, namespace, name, stableNamespace, name);
+      }
+
+      // Variables were all prefixed with `m3-` which needs to be stripped.
+      for (const name of M3_VARIABLES) {
+        content = migrateVariable(content, namespace, 'm3-' + name, stableNamespace, name);
+      }
+    }
+
+    // If experimental is imported, but Material isn't, insert a new import at the top.
+    // This should be rare since `@angular/material` was still required for the theme.
+    if (materialNamespaces.length === 0 && content !== preExperimentalContent) {
+      content = `@use '@angular/material' as ${stableNamespace};\n` + content;
+    }
+  }
+
+  return restoreComments(content, placeholders);
+}
+
+/** Renames all usages of a Sass function in a file. */
+function migrateFunction(
+  fileContent: string,
+  oldNamespace: string,
+  oldName: string,
+  newNamespace: string,
+  newName: string,
+): string {
+  return fileContent.replace(
+    new RegExp(`${oldNamespace}\\.${oldName}\\(`, 'g'),
+    `${newNamespace}.${newName}(`,
+  );
+}
+
+/** Renames all usages of a Sass variable in a file. */
+function migrateVariable(
+  fileContent: string,
+  oldNamespace: string,
+  oldName: string,
+  newNamespace: string,
+  newName: string,
+): string {
+  return fileContent.replace(
+    new RegExp(`${oldNamespace}\\.\\$${oldName}(?!\\s+:|[-_a-zA-Z0-9:])`, 'g'),
+    `${newNamespace}.$${newName}`,
+  );
+}
+
+/** Renames all usages of a Sass mixin in a file. */
+function migrateMixin(
+  fileContent: string,
+  oldNamespace: string,
+  oldName: string,
+  newNamespace: string,
+  newName: string,
+): string {
+  const pattern = new RegExp(`@include +${oldNamespace}\\.${oldName}`, 'g');
+  return fileContent.replace(pattern, `@include ${newNamespace}.${newName}`);
+}
+
+/**
+ * Replaces all the comments in a Sass file with placeholders and
+ * returns the list of placeholders, so they can be restored later.
+ */
+function escapeComments(content: string): {content: string; placeholders: Record<string, string>} {
+  const placeholders: Record<string, string> = {};
+  let commentCounter = 0;
+  let [openIndex, closeIndex] = findComment(content);
+
+  while (openIndex > -1 && closeIndex > -1) {
+    const placeholder = COMMENT_PLACEHOLDER_START + commentCounter++ + COMMENT_PLACEHOLDER_END;
+    placeholders[placeholder] = content.slice(openIndex, closeIndex);
+    content = content.slice(0, openIndex) + placeholder + content.slice(closeIndex);
+    [openIndex, closeIndex] = findComment(content);
+  }
+
+  return {content, placeholders};
+}
+
+/** Finds the start and end index of a comment in a file. */
+function findComment(content: string): [openIndex: number, closeIndex: number] {
+  // Add an extra new line at the end so that we can correctly capture single-line comments
+  // at the end of the file. It doesn't really matter that the end index will be out of bounds,
+  // because `String.prototype.slice` will clamp it to the string length.
+  content += '\n';
+
+  for (const [open, close] of COMMENT_PAIRS.entries()) {
+    const openIndex = content.indexOf(open);
+
+    if (openIndex > -1) {
+      const closeIndex = content.indexOf(close, openIndex + 1);
+      return closeIndex > -1 ? [openIndex, closeIndex + close.length] : [-1, -1];
+    }
+  }
+
+  return [-1, -1];
+}
+
+/** Restores the comments that have been escaped by `escapeComments`. */
+function restoreComments(content: string, placeholders: Record<string, string>): string {
+  Object.keys(placeholders).forEach(key => (content = content.replace(key, placeholders[key])));
+  return content;
+}
+
+/** Parses out the namespace from a Sass `@use` statement. */
+function extractNamespaceFromUseStatement(fullImport: string): string {
+  const closeQuoteIndex = Math.max(fullImport.lastIndexOf(`"`), fullImport.lastIndexOf(`'`));
+
+  if (closeQuoteIndex > -1) {
+    const asExpression = 'as ';
+    const asIndex = fullImport.indexOf(asExpression, closeQuoteIndex);
+
+    // If we found an ` as ` expression, we consider the rest of the text as the namespace.
+    if (asIndex > -1) {
+      return fullImport
+        .slice(asIndex + asExpression.length)
+        .split(';')[0]
+        .trim();
+    }
+
+    // Otherwise the namespace is the name of the file that is being imported.
+    const lastSlashIndex = fullImport.lastIndexOf('/', closeQuoteIndex);
+
+    if (lastSlashIndex > -1) {
+      const fileName = fullImport
+        .slice(lastSlashIndex + 1, closeQuoteIndex)
+        // Sass allows for leading underscores to be omitted and it technically supports .scss.
+        .replace(/^_|(\.import)?\.scss$|\.import$/g, '');
+
+      // Sass ignores `/index` and infers the namespace as the next segment in the path.
+      if (fileName === 'index') {
+        const nextSlashIndex = fullImport.lastIndexOf('/', lastSlashIndex - 1);
+
+        if (nextSlashIndex > -1) {
+          return fullImport.slice(nextSlashIndex + 1, lastSlashIndex);
+        }
+      } else {
+        return fileName;
+      }
+    }
+  }
+
+  throw Error(`Could not extract namespace from import "${fullImport}".`);
+}
+
+/** Gets all the namespaces that a module is available under in a specific file. */
+function getNamespaces(moduleName: string, content: string): string[] {
+  const namespaces = new Set<string>();
+  const escapedName = moduleName.replace(/([.*+?^=!:${}()|[\]\/\\])/g, '\\$1');
+  const pattern = new RegExp(`@use +['"]${escapedName}['"].*;?\n`, 'g');
+  let match: RegExpExecArray | null = null;
+
+  while ((match = pattern.exec(content))) {
+    namespaces.add(extractNamespaceFromUseStatement(match[0]));
+  }
+
+  return Array.from(namespaces);
+}