Allow projects in TypeScript Config to be an array of ProjectConfig

CHANGELOG.md

@@ -70,6 +70,7 @@
 - `[jest-transform]` Show enhanced `SyntaxError` message for all `SyntaxError`s ([#10749](https://github.com/facebook/jest/pull/10749))
 - `[jest-transform]` [**BREAKING**] Refactor API to pass an options bag around rather than multiple boolean options ([#10753](https://github.com/facebook/jest/pull/10753))
 - `[jest-transform]` [**BREAKING**] Refactor API of transformers to pass an options bag rather than separate `config` and other options ([#10834](https://github.com/facebook/jest/pull/10834))
+- `[jest-types]` Fix `Config.ts` `projects` types ([#11285](https://github.com/facebook/jest/pull/11285))
 - `[jest-worker]` [**BREAKING**] Use named exports ([#10623](https://github.com/facebook/jest/pull/10623))
 - `[jest-worker]` Do not swallow errors during serialization ([#10984](https://github.com/facebook/jest/pull/10984))
 - `[jest-worker]` Handle `ERR_IPC_CHANNEL_CLOSED` errors properly ([#11143](https://github.com/facebook/jest/pull/11143))

packages/jest-config/src/normalize.ts

@@ -821,14 +821,19 @@ export default async function normalize(
               ? _replaceRootDirTags(options.rootDir, project)
               : project,
           )
-          .reduce<Array<string>>((projects, project) => {
-            // Project can be specified as globs. If a glob matches any files,
-            // We expand it to these paths. If not, we keep the original path
-            // for the future resolution.
-            const globMatches =
-              typeof project === 'string' ? glob(project) : [];
-            return projects.concat(globMatches.length ? globMatches : project);
-          }, []);
+          .reduce<Array<string | Config.InitialProjectOptions>>(
+            (projects, project) => {
+              // Project can be specified as globs. If a glob matches any files,
+              // We expand it to these paths. If not, we keep the original path
+              // for the future resolution.
+              const globMatches =
+                typeof project === 'string' ? glob(project) : [];
+              return projects.concat(
+                globMatches.length ? globMatches : project,
+              );
+            },
+            [],
+          );
         break;
       case 'moduleDirectories':
       case 'testMatch':

packages/jest-types/src/Config.ts

@@ -124,6 +124,11 @@ export type DisplayName = {
 export type InitialOptionsWithRootDir = InitialOptions &
   Required<Pick<InitialOptions, 'rootDir'>>;
 
+export type InitialProjectOptions = Pick<
+  InitialOptions & {cwd?: string},
+  keyof ProjectConfig
+>;
+
 export type InitialOptions = Partial<{
   automock: boolean;
   bail: boolean | number;
@@ -184,7 +189,7 @@ export type InitialOptions = Partial<{
   preprocessorIgnorePatterns: Array<Glob>;
   preset: string | null | undefined;
   prettierPath: string | null | undefined;
-  projects: Array<Glob>;
+  projects: Array<Glob | InitialProjectOptions>;
   replname: string | null | undefined;
   resetMocks: boolean;
   resetModules: boolean;

test-types/top-level-config.test.ts

@@ -32,4 +32,12 @@ expectAssignable<Config.InitialOptions>({
       statements: 50,
     },
   },
+  projects: [
+    // projects can be globs or objects
+    './src/**',
+    {
+      displayName: 'A Project',
+      rootDir: './src/components',
+    },
+  ],
 });