Cleanup displayName type

CHANGELOG.md

@@ -14,6 +14,7 @@
 ### Chore & Maintenance
 
 - `[jest-core]` 🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉 ([#10000](https://github.com/facebook/jest/pull/10000))
+- `[jest-core, jest-reporters, jest-test-result, jest-types]` Cleanup `displayName` type ([#10049](https://github.com/facebook/jest/pull/10049))
 
 ### Performance
 

packages/jest-core/src/getProjectDisplayName.ts

@@ -14,11 +14,5 @@ export default function getProjectDisplayName(
   if (!displayName) {
     return undefined;
   }
-  if (typeof displayName === 'string') {
-    return displayName;
-  }
-  if (typeof displayName === 'object') {
-    return displayName.name;
-  }
-  return undefined;
+  return displayName.name;
 }

packages/jest-reporters/src/__tests__/utils.test.ts

@@ -118,7 +118,10 @@ describe('printDisplayName', () => {
     expect(
       printDisplayName(
         makeProjectConfig({
-          displayName: 'hello',
+          displayName: {
+            color: 'white',
+            name: 'hello',
+          },
         }),
       ),
     ).toMatchSnapshot();

packages/jest-reporters/src/utils.ts

@@ -22,10 +22,6 @@ export const printDisplayName = (config: Config.ProjectConfig): string => {
     return '';
   }
 
-  if (typeof displayName === 'string') {
-    return chalk.supportsColor ? white(` ${displayName} `) : displayName;
-  }
-
   const {name, color} = displayName;
   const chosenColor = chalk.reset.inverse[color]
     ? chalk.reset.inverse[color]

packages/jest-test-result/src/helpers.ts

@@ -48,7 +48,7 @@ export const buildFailureTestResult = (
   err: SerializableError,
 ): TestResult => ({
   console: undefined,
-  displayName: '',
+  displayName: undefined,
   failureMessage: null,
   leaks: false,
   numFailingTests: 0,

packages/jest-types/src/Config.ts

@@ -84,12 +84,10 @@ export type DefaultOptions = {
   watchman: boolean;
 };
 
-export type DisplayName =
-  | string
-  | {
-      name: string;
-      color: typeof chalk.Color;
-    };
+export type DisplayName = {
+  name: string;
+  color: typeof chalk.Color;
+};
 
 export type InitialOptionsWithRootDir = InitialOptions &
   Required<Pick<InitialOptions, 'rootDir'>>;
@@ -119,7 +117,7 @@ export type InitialOptions = Partial<{
   dependencyExtractor: string;
   detectLeaks: boolean;
   detectOpenHandles: boolean;
-  displayName: DisplayName;
+  displayName: string | DisplayName;
   expand: boolean;
   extraGlobals: Array<string>;
   filter: Path;