fix(material/schematics): incorrect partial migration after typography hierarchy inclusion

Fixes that the `isPartialMigration` check wasn't working correctly after hardcoding in the `typography-hierarchy` migration.

(cherry picked from commit 25bcfeb)

Author: crisbeto

src/material/schematics/ng-generate/mdc-migration/index.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {ComponentMigrator, MIGRATORS} from './rules';
+import {ComponentMigrator, MIGRATORS, PERMANENT_MIGRATORS} from './rules';
 import {
   DevkitFileSystem,
   UpdateProject,
@@ -21,8 +21,6 @@ import {RuntimeCodeMigration} from './rules/ts-migration/runtime-migration';
 import {Schema} from './schema';
 import {TemplateMigration} from './rules/template-migration';
 import {ThemingStylesMigration} from './rules/theming-styles';
-import {TypographyHierarchyTemplateMigrator} from './rules/components/typography-hierarchy/typography-hierarchy-template';
-import {TypographyHierarchyStylesMigrator} from './rules/components/typography-hierarchy/typography-hierarchy-styles';
 
 /** Groups of components that must be migrated together. */
 const migrationGroups = [
@@ -46,12 +44,6 @@ const migrationGroups = [
   ['tooltip'],
 ];
 
-const TYPOGRAPHY_HIERARCHY_MIGRATOR: ComponentMigrator = {
-  component: 'typography-hierarchy',
-  template: new TypographyHierarchyTemplateMigrator(),
-  styles: new TypographyHierarchyStylesMigrator(),
-};
-
 function getComponentsToMigrate(requested: string[]): Set<string> {
   const componentsToMigrate = new Set<string>(requested);
   if (componentsToMigrate.has('all')) {
@@ -102,10 +94,10 @@ export default function (options: Schema): Rule {
     const fileSystem = new DevkitFileSystem(tree);
     const analyzedFiles = new Set<WorkspacePath>();
     const componentsToMigrate = getComponentsToMigrate(options.components);
-    const migrators = MIGRATORS.filter(m => componentsToMigrate.has(m.component)).concat(
-      // The typography hierarchy should always be migrated.
-      TYPOGRAPHY_HIERARCHY_MIGRATOR,
-    );
+    const migrators = [
+      ...MIGRATORS.filter(m => componentsToMigrate.has(m.component)),
+      ...PERMANENT_MIGRATORS,
+    ];
     let success = true;
 
     if (options.directory) {

src/material/schematics/ng-generate/mdc-migration/rules/index.ts

@@ -36,6 +36,8 @@ import {OptgroupStylesMigrator} from './components/optgroup/optgroup-styles';
 import {OptionStylesMigrator} from './components/option/option-styles';
 import {FormFieldTemplateMigrator} from './components/form-field/form-field-template';
 import {SliderTemplateMigrator} from './components/slider/slider-template';
+import {TypographyHierarchyTemplateMigrator} from './components/typography-hierarchy/typography-hierarchy-template';
+import {TypographyHierarchyStylesMigrator} from './components/typography-hierarchy/typography-hierarchy-styles';
 
 /** Contains the migrators to migrate a single component. */
 export interface ComponentMigrator {
@@ -191,3 +193,13 @@ export const MIGRATORS: ComponentMigrator[] = [
     styles: new TooltipStylesMigrator(),
   },
 ];
+
+export const PERMANENT_MIGRATORS: ComponentMigrator[] = [
+  {
+    // The typography hierarchy used to always be included
+    // with `mat.core` so it always has to be migrated.
+    component: 'typography-hierarchy',
+    template: new TypographyHierarchyTemplateMigrator(),
+    styles: new TypographyHierarchyStylesMigrator(),
+  },
+];

src/material/schematics/ng-generate/mdc-migration/rules/theming-styles.ts

@@ -10,7 +10,7 @@ import {Migration, ResolvedResource} from '@angular/cdk/schematics';
 import {SchematicContext} from '@angular-devkit/schematics';
 import * as postcss from 'postcss';
 import * as scss from 'postcss-scss';
-import {ComponentMigrator, MIGRATORS} from '.';
+import {ComponentMigrator, MIGRATORS, PERMANENT_MIGRATORS} from '.';
 import {RENAMED_TYPOGRAPHY_LEVELS} from './components/typography-hierarchy/constants';
 
 const COMPONENTS_MIXIN_NAME = /\.([^(;]*)/;
@@ -95,7 +95,7 @@ export class ThemingStylesMigration extends Migration<ComponentMigrator[], Schem
   }
 
   isPartialMigration() {
-    return this.upgradeData.length !== MIGRATORS.length;
+    return this.upgradeData.length !== MIGRATORS.length + PERMANENT_MIGRATORS.length;
   }
 
   ruleHandler(rule: postcss.Rule) {