feat(@schematics/angular): update TSConfig globals during karma to vitest migration

Automates the transition of developer test configurations from Jasmine typing providers to Vitest globals definitions.

The tool parses each collected tsconfig path and actively relocates 'vitest/globals' into the compiler options type list while removing the 'jasmine' package.

Author: clydin

packages/schematics/angular/migrations/migrate-karma-to-vitest/migration.ts

@@ -8,8 +8,10 @@
 
 import type { json } from '@angular-devkit/core';
 import { Rule, SchematicContext, Tree, chain } from '@angular-devkit/schematics';
+import { join } from 'node:path/posix';
 import { isDeepStrictEqual } from 'util';
 import { DependencyType, ExistingBehavior, addDependency } from '../../utility/dependency';
+import { JSONFile } from '../../utility/json-file';
 import { latestVersions } from '../../utility/latest-versions';
 import { TargetDefinition, allTargetOptions, updateWorkspace } from '../../utility/workspace';
 import { Builders } from '../../utility/workspace-models';
@@ -119,11 +121,45 @@ async function processTestTargetOptions(
   return needsCoverage;
 }
 
+function updateTsConfigTypes(
+  tree: Tree,
+  tsConfigsToUpdate: Set<string>,
+  context: SchematicContext,
+): void {
+  for (const tsConfigPath of tsConfigsToUpdate) {
+    if (tree.exists(tsConfigPath)) {
+      try {
+        const json = new JSONFile(tree, tsConfigPath);
+        const typesPath = ['compilerOptions', 'types'];
+        const existingTypes = (json.get(typesPath) as string[] | undefined) ?? [];
+        const newTypes = existingTypes.filter((t) => t !== 'jasmine');
+
+        if (!newTypes.includes('vitest/globals')) {
+          newTypes.push('vitest/globals');
+        }
+
+        if (
+          newTypes.length !== existingTypes.length ||
+          newTypes.some((t, i) => t !== existingTypes[i])
+        ) {
+          json.modify(typesPath, newTypes);
+        }
+      } catch (err) {
+        context.logger.warn(
+          `Failed to automatically update types in "${tsConfigPath}". ` +
+            `Please manually remove "jasmine" and add "vitest/globals" to compilerOptions.types.`,
+        );
+      }
+    }
+  }
+}
+
 function updateProjects(tree: Tree, context: SchematicContext): Rule {
   return updateWorkspace(async (workspace) => {
     let needsCoverage = false;
     const removableKarmaConfigs = new Map<string, KarmaConfigProcessingResult>();
     const migratedProjects: string[] = [];
+    const tsConfigsToUpdate = new Set<string>();
     const skippedNonApplications: string[] = [];
     const skippedMissingAppBuilder: string[] = [];
     const manualMigrationFiles: string[] = [];
@@ -169,6 +205,21 @@ function updateProjects(tree: Tree, context: SchematicContext): Rule {
         continue;
       }
 
+      // Collect tsConfig paths to perform globals updates
+      const baseTsConfig = testTarget.options?.['tsConfig'];
+      if (typeof baseTsConfig === 'string') {
+        tsConfigsToUpdate.add(baseTsConfig);
+      }
+      if (testTarget.configurations) {
+        for (const config of Object.values(testTarget.configurations)) {
+          if (typeof config?.['tsConfig'] === 'string') {
+            tsConfigsToUpdate.add(config['tsConfig']);
+          }
+        }
+      }
+      // Always include fallback to the default tsconfig.spec.json path
+      tsConfigsToUpdate.add(join(project.root, 'tsconfig.spec.json'));
+
       // Store custom build options to move to a new build configuration if needed
       const customBuildOptions: Record<string, Record<string, json.JsonValue | undefined>> = {};
 
@@ -242,6 +293,9 @@ function updateProjects(tree: Tree, context: SchematicContext): Rule {
       }
     }
 
+    // Update TSConfig files to use Vitest types instead of Jasmine
+    updateTsConfigTypes(tree, tsConfigsToUpdate, context);
+
     // Log summary
     context.logger.info('\n--- Karma to Vitest Migration Summary ---');
     context.logger.info(`Projects migrated: ${migratedProjects.length}`);

packages/schematics/angular/migrations/migrate-karma-to-vitest/migration_spec.ts

@@ -420,4 +420,26 @@ module.exports = function (config) {
     // Assert that the deletion deferred successfully until BOTH extracted the data
     expect(newTree.exists('karma.conf.js')).toBeFalse();
   });
+
+  it('should automatically transition types in referenced tsconfigs from jasmine to vitest/globals', async () => {
+    // Create a virtual tsconfig that mimics existing state
+    tree.create(
+      'tsconfig.spec.json',
+      JSON.stringify({
+        compilerOptions: {
+          outDir: './out-tsc/spec',
+          types: ['jasmine', 'node'],
+        },
+        files: ['src/test.ts'],
+        include: ['src/**/*.spec.ts', 'src/**/*.d.ts'],
+      }),
+    );
+
+    const newTree = await schematicRunner.runSchematic('migrate-karma-to-vitest', {}, tree);
+    const tsConfigJson = JSON.parse(newTree.readText('tsconfig.spec.json'));
+
+    expect(tsConfigJson.compilerOptions.types).toContain('vitest/globals');
+    expect(tsConfigJson.compilerOptions.types).not.toContain('jasmine');
+    expect(tsConfigJson.compilerOptions.types).toContain('node');
+  });
 });