Create a few (failing) test cases of microsoft#58449

Author: blickly

tests/cases/fourslash/codeFixMissingTypeAnnotationOnExports50-generics-with-default.ts

@@ -0,0 +1,17 @@
+/// <reference path='fourslash.ts'/>
+
+// @isolatedDeclarations: true
+// @declaration: true
+// @file lib.d.ts
+////interface MyIterator<T, TReturn = any, TNext = undefined> {}
+////let x: MyIterator<number>;
+////export const y = x;
+
+verify.codeFix({
+    description: "Add annotation of type 'MyIterator<number>'",
+    index: 0,
+    newFileContent:
+`interface MyIterator<T, TReturn = any, TNext = undefined> {}
+let x: MyIterator<number>;
+export const y: MyIterator<number> = x;`,
+});

tests/cases/fourslash/codeFixMissingTypeAnnotationOnExports51-slightly-more-complex-generics-with-default.ts

@@ -0,0 +1,19 @@
+/// <reference path='fourslash.ts'/>
+
+// @isolatedDeclarations: true
+// @declaration: true
+
+////export interface Foo<T, U = T[]> {}
+////export function foo(x: Foo<string>) {
+////    return x;
+////}
+
+verify.codeFix({
+    description: "Add return type 'Foo<string>'",
+    index: 0,
+    newFileContent:
+`export interface Foo<T, U = T[]> {}
+export function foo(x: Foo<string>): Foo<string> {
+    return x;
+}`,
+});