Add test for generic parameter inference tsdjs#142

skarab42 · Oct 22, 2022 · d6f728f · d6f728f
1 parent 55f340f
commit d6f728f
Show file tree

Hide file tree

Showing 3 changed files with 26 additions and 0 deletions.
diff --git a/source/test/fixtures/jest-like-api/identical-to/index.test-d.ts b/source/test/fixtures/jest-like-api/identical-to/index.test-d.ts
@@ -14,3 +14,14 @@ assertType<string>().identicalTo<number>();
 assertType<number>().identicalTo(fooString);
 assertType(fooString).identicalTo<number>();
 assertType(fooString).identicalTo(fooNumber);
+
+// Should handle generic, see https://github.com/SamVerschueren/tsd/issues/142
+declare const inferrable: <T = 'foo'>() => T;
+
+// Should pass
+assertType<'foo'>().identicalTo(inferrable());
+assertType(inferrable()).identicalTo('foo');
+
+// Should fail
+assertType<string>().identicalTo(inferrable());
+assertType(inferrable()).identicalTo(fooString);
diff --git a/source/test/fixtures/jest-like-api/not-identical-to/index.test-d.ts b/source/test/fixtures/jest-like-api/not-identical-to/index.test-d.ts
@@ -14,3 +14,14 @@ assertType<string>().not.identicalTo<string>();
 assertType<string>().not.identicalTo(fooString);
 assertType(fooString).not.identicalTo<string>();
 assertType(fooString).not.identicalTo(fooString);
+
+// Should handle generic, see https://github.com/SamVerschueren/tsd/issues/142
+declare const inferrable: <T = 'foo'>() => T;
+
+// Should pass
+assertType<string>().not.identicalTo(inferrable());
+assertType(inferrable()).not.identicalTo(fooString);
+
+// Should fail
+assertType<'foo'>().not.identicalTo(inferrable());
+assertType(inferrable()).not.identicalTo('foo');
diff --git a/source/test/jest-like-api.ts b/source/test/jest-like-api.ts
@@ -30,6 +30,8 @@ test('identical-to', async t => {
 		[14, 0, 'error', 'Parameter type `number` is not identical to argument type `string`.'],
 		[15, 0, 'error', 'Parameter type `string` is not identical to argument type `number`.'],
 		[16, 0, 'error', 'Parameter type `string` is not identical to argument type `number`.'],
+		[26, 0, 'error', 'Parameter type `string` is not identical to argument type `"foo"`.'],
+		[27, 0, 'error', 'Parameter type `"foo"` is not identical to argument type `string`.'],
 	]);
 });
 
@@ -41,6 +43,8 @@ test('not-identical-to', async t => {
 		[14, 0, 'error', 'Parameter type `string` is identical to argument type `string`.'],
 		[15, 0, 'error', 'Parameter type `string` is identical to argument type `string`.'],
 		[16, 0, 'error', 'Parameter type `string` is identical to argument type `string`.'],
+		[26, 0, 'error', 'Parameter type `"foo"` is identical to argument type `"foo"`.'],
+		[27, 0, 'error', 'Parameter type `"foo"` is identical to argument type `"foo"`.'],
 	]);
 });