test-utils: add const type parameter modifier to TestApiProvider and TestApiRegistry.from

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

.changeset/fix-test-api-provider-const.md

@@ -0,0 +1,5 @@
+---
+'@backstage/test-utils': patch
+---
+
+Added `const` type parameter modifier to `TestApiProvider` and `TestApiRegistry.from` for improved type inference of API pairs.

packages/test-utils/report.api.md

@@ -340,7 +340,7 @@ export function setupRequestMockHandlers(worker: {
 export type SyncLogCollector = () => void;
 
 // @public
-export const TestApiProvider: <T extends any[]>(
+export const TestApiProvider: <const T extends any[]>(
   props: TestApiProviderProps<T>,
 ) => JSX_2.Element;
 
@@ -352,7 +352,7 @@ export type TestApiProviderProps<TApiPairs extends any[]> = {
 
 // @public
 export class TestApiRegistry implements ApiHolder {
-  static from<TApiPairs extends any[]>(
+  static from<const TApiPairs extends any[]>(
     ...apis: readonly [...TestApiProviderPropsApiPairs<TApiPairs>]
   ): TestApiRegistry;
   get<T>(api: ApiRef<T>): T | undefined;

packages/test-utils/src/testUtils/TestApiProvider.tsx

@@ -63,7 +63,7 @@ export class TestApiRegistry implements ApiHolder {
    * @public
    * @param apis - A list of pairs mapping an ApiRef to its respective implementation.
    */
-  static from<TApiPairs extends any[]>(
+  static from<const TApiPairs extends any[]>(
     ...apis: readonly [...TestApiProviderPropsApiPairs<TApiPairs>]
   ) {
     return new TestApiRegistry(
@@ -124,7 +124,7 @@ export class TestApiRegistry implements ApiHolder {
  *
  * @public
  */
-export const TestApiProvider = <T extends any[]>(
+export const TestApiProvider = <const T extends any[]>(
   props: TestApiProviderProps<T>,
 ) => {
   return (