Allow exports map entries to point at .ts source files (#48563)

* Probably works

* Add tests

* Update baselines for module option rename

tests/baselines/reference/nodeModulesExportsSourceTs(module=node16).errors.txt

@@ -0,0 +1,34 @@
+tests/cases/conformance/node/index.ts(2,23): error TS2307: Cannot find module 'inner/other' or its corresponding type declarations.
+tests/cases/conformance/node/index.ts(3,14): error TS2742: The inferred type of 'a' cannot be named without a reference to './node_modules/inner/other.js'. This is likely not portable. A type annotation is necessary.
+
+
+==== tests/cases/conformance/node/index.ts (2 errors) ====
+    // esm format file
+    import { Thing } from "inner/other";
+                          ~~~~~~~~~~~~~
+!!! error TS2307: Cannot find module 'inner/other' or its corresponding type declarations.
+    export const a = (await import("inner")).x();
+                 ~
+!!! error TS2742: The inferred type of 'a' cannot be named without a reference to './node_modules/inner/other.js'. This is likely not portable. A type annotation is necessary.
+    import {a as a2} from "package";
+==== tests/cases/conformance/node/node_modules/inner/index.ts (0 errors) ====
+    // esm format file
+    export { x } from "./other.js";
+==== tests/cases/conformance/node/node_modules/inner/other.ts (0 errors) ====
+    // esm format file
+    export interface Thing {}
+    export const x: () => Thing = null as any;
+==== tests/cases/conformance/node/package.json (0 errors) ====
+    {
+        "name": "package",
+        "private": true,
+        "type": "module",
+        "exports": "./index.ts"
+    }
+==== tests/cases/conformance/node/node_modules/inner/package.json (0 errors) ====
+    {
+        "name": "inner",
+        "private": true,
+        "type": "module",
+        "exports": "./index.ts"
+    }

tests/baselines/reference/nodeModulesExportsSourceTs(module=node16).js

@@ -0,0 +1,44 @@
+//// [tests/cases/conformance/node/nodeModulesExportsSourceTs.ts] ////
+
+//// [index.ts]
+// esm format file
+import { Thing } from "inner/other";
+export const a = (await import("inner")).x();
+import {a as a2} from "package";
+//// [index.ts]
+// esm format file
+export { x } from "./other.js";
+//// [other.ts]
+// esm format file
+export interface Thing {}
+export const x: () => Thing = null as any;
+//// [package.json]
+{
+    "name": "package",
+    "private": true,
+    "type": "module",
+    "exports": "./index.ts"
+}
+//// [package.json]
+{
+    "name": "inner",
+    "private": true,
+    "type": "module",
+    "exports": "./index.ts"
+}
+
+//// [other.js]
+export const x = null;
+//// [index.js]
+// esm format file
+export { x } from "./other.js";
+//// [index.js]
+export const a = (await import("inner")).x();
+
+
+//// [other.d.ts]
+export interface Thing {
+}
+export declare const x: () => Thing;
+//// [index.d.ts]
+export { x } from "./other.js";

tests/baselines/reference/nodeModulesExportsSourceTs(module=node16).symbols

@@ -0,0 +1,29 @@
+=== tests/cases/conformance/node/index.ts ===
+// esm format file
+import { Thing } from "inner/other";
+>Thing : Symbol(Thing, Decl(index.ts, 1, 8))
+
+export const a = (await import("inner")).x();
+>a : Symbol(a, Decl(index.ts, 2, 12))
+>(await import("inner")).x : Symbol(x, Decl(index.ts, 1, 8))
+>"inner" : Symbol("tests/cases/conformance/node/node_modules/inner/index", Decl(index.ts, 0, 0))
+>x : Symbol(x, Decl(index.ts, 1, 8))
+
+import {a as a2} from "package";
+>a : Symbol(a, Decl(index.ts, 2, 12))
+>a2 : Symbol(a2, Decl(index.ts, 3, 8))
+
+=== tests/cases/conformance/node/node_modules/inner/index.ts ===
+// esm format file
+export { x } from "./other.js";
+>x : Symbol(x, Decl(index.ts, 1, 8))
+
+=== tests/cases/conformance/node/node_modules/inner/other.ts ===
+// esm format file
+export interface Thing {}
+>Thing : Symbol(Thing, Decl(other.ts, 0, 0))
+
+export const x: () => Thing = null as any;
+>x : Symbol(x, Decl(other.ts, 2, 12))
+>Thing : Symbol(Thing, Decl(other.ts, 0, 0))
+

tests/baselines/reference/nodeModulesExportsSourceTs(module=node16).types

@@ -0,0 +1,32 @@
+=== tests/cases/conformance/node/index.ts ===
+// esm format file
+import { Thing } from "inner/other";
+>Thing : any
+
+export const a = (await import("inner")).x();
+>a : import("tests/cases/conformance/node/node_modules/inner/other").Thing
+>(await import("inner")).x() : import("tests/cases/conformance/node/node_modules/inner/other").Thing
+>(await import("inner")).x : () => import("tests/cases/conformance/node/node_modules/inner/other").Thing
+>(await import("inner")) : typeof import("tests/cases/conformance/node/node_modules/inner/index")
+>await import("inner") : typeof import("tests/cases/conformance/node/node_modules/inner/index")
+>import("inner") : Promise<typeof import("tests/cases/conformance/node/node_modules/inner/index")>
+>"inner" : "inner"
+>x : () => import("tests/cases/conformance/node/node_modules/inner/other").Thing
+
+import {a as a2} from "package";
+>a : import("tests/cases/conformance/node/node_modules/inner/other").Thing
+>a2 : import("tests/cases/conformance/node/node_modules/inner/other").Thing
+
+=== tests/cases/conformance/node/node_modules/inner/index.ts ===
+// esm format file
+export { x } from "./other.js";
+>x : () => import("tests/cases/conformance/node/node_modules/inner/other").Thing
+
+=== tests/cases/conformance/node/node_modules/inner/other.ts ===
+// esm format file
+export interface Thing {}
+export const x: () => Thing = null as any;
+>x : () => Thing
+>null as any : any
+>null : null
+

tests/baselines/reference/nodeModulesExportsSourceTs(module=nodenext).errors.txt

@@ -0,0 +1,34 @@
+tests/cases/conformance/node/index.ts(2,23): error TS2307: Cannot find module 'inner/other' or its corresponding type declarations.
+tests/cases/conformance/node/index.ts(3,14): error TS2742: The inferred type of 'a' cannot be named without a reference to './node_modules/inner/other.js'. This is likely not portable. A type annotation is necessary.
+
+
+==== tests/cases/conformance/node/index.ts (2 errors) ====
+    // esm format file
+    import { Thing } from "inner/other";
+                          ~~~~~~~~~~~~~
+!!! error TS2307: Cannot find module 'inner/other' or its corresponding type declarations.
+    export const a = (await import("inner")).x();
+                 ~
+!!! error TS2742: The inferred type of 'a' cannot be named without a reference to './node_modules/inner/other.js'. This is likely not portable. A type annotation is necessary.
+    import {a as a2} from "package";
+==== tests/cases/conformance/node/node_modules/inner/index.ts (0 errors) ====
+    // esm format file
+    export { x } from "./other.js";
+==== tests/cases/conformance/node/node_modules/inner/other.ts (0 errors) ====
+    // esm format file
+    export interface Thing {}
+    export const x: () => Thing = null as any;
+==== tests/cases/conformance/node/package.json (0 errors) ====
+    {
+        "name": "package",
+        "private": true,
+        "type": "module",
+        "exports": "./index.ts"
+    }
+==== tests/cases/conformance/node/node_modules/inner/package.json (0 errors) ====
+    {
+        "name": "inner",
+        "private": true,
+        "type": "module",
+        "exports": "./index.ts"
+    }

tests/baselines/reference/nodeModulesExportsSourceTs(module=nodenext).js

@@ -0,0 +1,44 @@
+//// [tests/cases/conformance/node/nodeModulesExportsSourceTs.ts] ////
+
+//// [index.ts]
+// esm format file
+import { Thing } from "inner/other";
+export const a = (await import("inner")).x();
+import {a as a2} from "package";
+//// [index.ts]
+// esm format file
+export { x } from "./other.js";
+//// [other.ts]
+// esm format file
+export interface Thing {}
+export const x: () => Thing = null as any;
+//// [package.json]
+{
+    "name": "package",
+    "private": true,
+    "type": "module",
+    "exports": "./index.ts"
+}
+//// [package.json]
+{
+    "name": "inner",
+    "private": true,
+    "type": "module",
+    "exports": "./index.ts"
+}
+
+//// [other.js]
+export const x = null;
+//// [index.js]
+// esm format file
+export { x } from "./other.js";
+//// [index.js]
+export const a = (await import("inner")).x();
+
+
+//// [other.d.ts]
+export interface Thing {
+}
+export declare const x: () => Thing;
+//// [index.d.ts]
+export { x } from "./other.js";

tests/baselines/reference/nodeModulesExportsSourceTs(module=nodenext).symbols

@@ -0,0 +1,29 @@
+=== tests/cases/conformance/node/index.ts ===
+// esm format file
+import { Thing } from "inner/other";
+>Thing : Symbol(Thing, Decl(index.ts, 1, 8))
+
+export const a = (await import("inner")).x();
+>a : Symbol(a, Decl(index.ts, 2, 12))
+>(await import("inner")).x : Symbol(x, Decl(index.ts, 1, 8))
+>"inner" : Symbol("tests/cases/conformance/node/node_modules/inner/index", Decl(index.ts, 0, 0))
+>x : Symbol(x, Decl(index.ts, 1, 8))
+
+import {a as a2} from "package";
+>a : Symbol(a, Decl(index.ts, 2, 12))
+>a2 : Symbol(a2, Decl(index.ts, 3, 8))
+
+=== tests/cases/conformance/node/node_modules/inner/index.ts ===
+// esm format file
+export { x } from "./other.js";
+>x : Symbol(x, Decl(index.ts, 1, 8))
+
+=== tests/cases/conformance/node/node_modules/inner/other.ts ===
+// esm format file
+export interface Thing {}
+>Thing : Symbol(Thing, Decl(other.ts, 0, 0))
+
+export const x: () => Thing = null as any;
+>x : Symbol(x, Decl(other.ts, 2, 12))
+>Thing : Symbol(Thing, Decl(other.ts, 0, 0))
+

tests/baselines/reference/nodeModulesExportsSourceTs(module=nodenext).types

@@ -0,0 +1,32 @@
+=== tests/cases/conformance/node/index.ts ===
+// esm format file
+import { Thing } from "inner/other";
+>Thing : any
+
+export const a = (await import("inner")).x();
+>a : import("tests/cases/conformance/node/node_modules/inner/other").Thing
+>(await import("inner")).x() : import("tests/cases/conformance/node/node_modules/inner/other").Thing
+>(await import("inner")).x : () => import("tests/cases/conformance/node/node_modules/inner/other").Thing
+>(await import("inner")) : typeof import("tests/cases/conformance/node/node_modules/inner/index")
+>await import("inner") : typeof import("tests/cases/conformance/node/node_modules/inner/index")
+>import("inner") : Promise<typeof import("tests/cases/conformance/node/node_modules/inner/index")>
+>"inner" : "inner"
+>x : () => import("tests/cases/conformance/node/node_modules/inner/other").Thing
+
+import {a as a2} from "package";
+>a : import("tests/cases/conformance/node/node_modules/inner/other").Thing
+>a2 : import("tests/cases/conformance/node/node_modules/inner/other").Thing
+
+=== tests/cases/conformance/node/node_modules/inner/index.ts ===
+// esm format file
+export { x } from "./other.js";
+>x : () => import("tests/cases/conformance/node/node_modules/inner/other").Thing
+
+=== tests/cases/conformance/node/node_modules/inner/other.ts ===
+// esm format file
+export interface Thing {}
+export const x: () => Thing = null as any;
+>x : () => Thing
+>null as any : any
+>null : null
+

tests/cases/conformance/node/nodeModulesExportsSourceTs.ts

@@ -0,0 +1,28 @@
+// @module: node16,nodenext
+// @declaration: true
+// @filename: index.ts
+// esm format file
+import { Thing } from "inner/other";
+export const a = (await import("inner")).x();
+import {a as a2} from "package";
+// @filename: node_modules/inner/index.ts
+// esm format file
+export { x } from "./other.js";
+// @filename: node_modules/inner/other.ts
+// esm format file
+export interface Thing {}
+export const x: () => Thing = null as any;
+// @filename: package.json
+{
+    "name": "package",
+    "private": true,
+    "type": "module",
+    "exports": "./index.ts"
+}
+// @filename: node_modules/inner/package.json
+{
+    "name": "inner",
+    "private": true,
+    "type": "module",
+    "exports": "./index.ts"
+}