fix(typescript-estree): pass extraFileExtensions to projectService

packages/typescript-estree/src/useProgramFromProjectService.ts

@@ -1,6 +1,7 @@
 import debug from 'debug';
 import { minimatch } from 'minimatch';
 import path from 'path';
+import { ScriptKind } from 'typescript';
 
 import { createProjectProgram } from './create-program/createProjectProgram';
 import type { ProjectServiceSettings } from './create-program/createProjectService';
@@ -31,6 +32,16 @@ export function useProgramFromProjectService(
     filePathAbsolute,
   );
 
+  if (parseSettings.extraFileExtensions.length) {
+    service.setHostConfiguration({
+      extraFileExtensions: parseSettings.extraFileExtensions.map(extension => ({
+        extension,
+        isMixedContent: false,
+        scriptKind: ScriptKind.Deferred,
+      })),
+    });
+  }
+
   const opened = service.openClientFile(
     filePathAbsolute,
     parseSettings.codeFullText,

packages/typescript-estree/tests/lib/parse.test.ts

@@ -352,7 +352,6 @@ describe('parseAndGenerateServices', () => {
         range: true,
         loc: true,
         tsconfigRootDir: PROJECT_DIR,
-        project: './tsconfig.json',
       };
       const testParse =
         (filePath: string, extraFileExtensions: string[] = ['.vue']) =>
@@ -362,11 +361,26 @@ describe('parseAndGenerateServices', () => {
               ...config,
               extraFileExtensions,
               filePath: join(PROJECT_DIR, filePath),
+              project: './tsconfig.json',
             });
           } catch (error) {
             alignErrorPath(error as Error);
           }
         };
+      const testExtraFileExtensions =
+        (filePath: string, extraFileExtensions: string[]) => (): void => {
+          const result = parser.parseAndGenerateServices(code, {
+            ...config,
+            extraFileExtensions,
+            filePath: join(PROJECT_DIR, filePath),
+            projectService: true,
+          });
+          const compilerOptions = result.services.program?.getCompilerOptions();
+
+          if (!compilerOptions?.configFilePath) {
+            throw new Error('No config file found, using inferred project');
+          }
+        };
 
       describe('project includes', () => {
         it("doesn't error for matched files", () => {
@@ -479,6 +493,50 @@ describe('parseAndGenerateServices', () => {
           `);
         });
       });
+
+      describe('"parserOptions.extraFileExtensions" is non-empty and projectService is true', () => {
+        describe('the extension matches', () => {
+          it('the file is included', () => {
+            expect(
+              testExtraFileExtensions('other/included.vue', ['.vue']),
+            ).not.toThrow();
+          });
+
+          it("the file isn't included", () => {
+            expect(
+              testExtraFileExtensions('other/notIncluded.vue', ['.vue']),
+            ).toThrowErrorMatchingInlineSnapshot(
+              `"No config file found, using inferred project"`,
+            );
+          });
+
+          it('duplicate extension', () => {
+            expect(
+              testExtraFileExtensions('ts/notIncluded.ts', ['.ts']),
+            ).toThrowErrorMatchingInlineSnapshot(
+              `"No config file found, using inferred project"`,
+            );
+          });
+        });
+
+        it('invalid extension', () => {
+          expect(
+            testExtraFileExtensions('other/unknownFileType.unknown', [
+              'unknown',
+            ]),
+          ).toThrowErrorMatchingInlineSnapshot(
+            `"No config file found, using inferred project"`,
+          );
+        });
+
+        it('the extension does not match', () => {
+          expect(
+            testExtraFileExtensions('other/unknownFileType.unknown', ['.vue']),
+          ).toThrowErrorMatchingInlineSnapshot(
+            `"No config file found, using inferred project"`,
+          );
+        });
+      });
     });
 
     describe('invalid project error messages', () => {
@@ -508,7 +566,7 @@ describe('parseAndGenerateServices', () => {
 
           expect(testParse('ts/notIncluded0j1.ts'))
             .toThrowErrorMatchingInlineSnapshot(`
-            "ESLint was configured to run on \`<tsconfigRootDir>/ts/notIncluded0j1.ts\` using \`parserOptions.project\`: 
+            "ESLint was configured to run on \`<tsconfigRootDir>/ts/notIncluded0j1.ts\` using \`parserOptions.project\`:
             - <tsconfigRootDir>/tsconfig.json
             - <tsconfigRootDir>/tsconfig.extra.json
             However, none of those TSConfigs include this file. Either:

packages/typescript-estree/tests/lib/useProgramFromProjectService.test.ts

@@ -1,5 +1,6 @@
 /* eslint-disable @typescript-eslint/explicit-function-return-type -- Fancy mocks */
 import path from 'path';
+import { ScriptKind } from 'typescript';
 
 import type {
   ProjectServiceSettings,
@@ -22,6 +23,7 @@ const currentDirectory = '/repos/repo';
 
 function createMockProjectService() {
   const openClientFile = jest.fn();
+  const setHostConfiguration = jest.fn();
   const service = {
     getDefaultProjectForFile: () => ({
       getLanguageService: () => ({
@@ -33,6 +35,7 @@ function createMockProjectService() {
       getCurrentDirectory: () => currentDirectory,
     },
     openClientFile,
+    setHostConfiguration,
   };
 
   return {
@@ -43,6 +46,7 @@ function createMockProjectService() {
 
 const mockParseSettings = {
   filePath: 'path/PascalCaseDirectory/camelCaseFile.ts',
+  extraFileExtensions: [] as readonly string[],
 } as ParseSettings;
 
 const createProjectServiceSettings = <
@@ -297,4 +301,47 @@ If you absolutely need more files included, set parserOptions.projectService.max
 
     expect(actual).toBe(program);
   });
+
+  it('does not call setHostConfiguration if extraFileExtensions are not provided', () => {
+    const { service } = createMockProjectService();
+
+    useProgramFromProjectService(
+      createProjectServiceSettings({
+        allowDefaultProject: [mockParseSettings.filePath],
+        service,
+      }),
+      mockParseSettings,
+      false,
+      new Set(),
+    );
+
+    expect(service.setHostConfiguration).not.toHaveBeenCalled();
+  });
+
+  it('calls setHostConfiguration on the service to use extraFileExtensions when it is provided', () => {
+    const { service } = createMockProjectService();
+
+    useProgramFromProjectService(
+      createProjectServiceSettings({
+        allowDefaultProject: [mockParseSettings.filePath],
+        service,
+      }),
+      {
+        ...mockParseSettings,
+        extraFileExtensions: ['.vue'],
+      },
+      false,
+      new Set(),
+    );
+
+    expect(service.setHostConfiguration).toHaveBeenCalledWith({
+      extraFileExtensions: [
+        {
+          extension: '.vue',
+          isMixedContent: false,
+          scriptKind: ScriptKind.Deferred,
+        },
+      ],
+    });
+  });
 });