Add regression tests documenting current behavior of #14121 (#22748)

tests/baselines/reference/exportAssignmentMembersVisibleInAugmentation.js

@@ -0,0 +1,39 @@
+//// [tests/cases/compiler/exportAssignmentMembersVisibleInAugmentation.ts] ////
+
+//// [index.d.ts]
+export = foo;
+declare namespace foo {
+    export type T = number;
+}
+
+//// [a.ts]
+import * as foo from "foo";
+declare module "foo" {
+    export function f(): T; // OK
+}
+
+//// [b.ts]
+import * as foo from "foo";
+declare module "foo" {
+    export function g(): foo.T; // OK
+}
+
+
+//// [a.js]
+"use strict";
+exports.__esModule = true;
+//// [b.js]
+"use strict";
+exports.__esModule = true;
+
+
+//// [a.d.ts]
+declare module "foo" {
+    function f(): T;
+}
+export {};
+//// [b.d.ts]
+import * as foo from "foo";
+declare module "foo" {
+    function g(): foo.T;
+}

tests/baselines/reference/exportAssignmentMembersVisibleInAugmentation.symbols

@@ -0,0 +1,36 @@
+=== /node_modules/foo/index.d.ts ===
+export = foo;
+>foo : Symbol(foo, Decl(index.d.ts, 0, 13))
+
+declare namespace foo {
+>foo : Symbol(foo, Decl(index.d.ts, 0, 13), Decl(a.ts, 0, 27), Decl(b.ts, 0, 27))
+
+    export type T = number;
+>T : Symbol(T, Decl(index.d.ts, 1, 23))
+}
+
+=== /a.ts ===
+import * as foo from "foo";
+>foo : Symbol(foo, Decl(a.ts, 0, 6))
+
+declare module "foo" {
+>"foo" : Symbol(foo, Decl(index.d.ts, 0, 13), Decl(a.ts, 0, 27), Decl(b.ts, 0, 27))
+
+    export function f(): T; // OK
+>f : Symbol(f, Decl(a.ts, 1, 22))
+>T : Symbol(T, Decl(index.d.ts, 1, 23))
+}
+
+=== /b.ts ===
+import * as foo from "foo";
+>foo : Symbol(foo, Decl(b.ts, 0, 6))
+
+declare module "foo" {
+>"foo" : Symbol(foo, Decl(index.d.ts, 0, 13), Decl(a.ts, 0, 27), Decl(b.ts, 0, 27))
+
+    export function g(): foo.T; // OK
+>g : Symbol(g, Decl(b.ts, 1, 22))
+>foo : Symbol(foo, Decl(b.ts, 0, 6))
+>T : Symbol(T, Decl(index.d.ts, 1, 23))
+}
+

tests/baselines/reference/exportAssignmentMembersVisibleInAugmentation.types

@@ -0,0 +1,36 @@
+=== /node_modules/foo/index.d.ts ===
+export = foo;
+>foo : any
+
+declare namespace foo {
+>foo : typeof foo
+
+    export type T = number;
+>T : number
+}
+
+=== /a.ts ===
+import * as foo from "foo";
+>foo : typeof foo
+
+declare module "foo" {
+>"foo" : typeof foo
+
+    export function f(): T; // OK
+>f : () => number
+>T : number
+}
+
+=== /b.ts ===
+import * as foo from "foo";
+>foo : typeof foo
+
+declare module "foo" {
+>"foo" : typeof foo
+
+    export function g(): foo.T; // OK
+>g : () => number
+>foo : any
+>T : number
+}
+

tests/cases/compiler/exportAssignmentMembersVisibleInAugmentation.ts

@@ -0,0 +1,19 @@
+// @declaration: true
+
+// @Filename: /node_modules/foo/index.d.ts
+export = foo;
+declare namespace foo {
+    export type T = number;
+}
+
+// @Filename: /a.ts
+import * as foo from "foo";
+declare module "foo" {
+    export function f(): T; // OK
+}
+
+// @Filename: /b.ts
+import * as foo from "foo";
+declare module "foo" {
+    export function g(): foo.T; // OK
+}