Changes to enable the module conversion script

* shorthand -> long for `factory` since the typeformer script doesn't
  know how to handle it.

* Use setter to change `ts.sys` (similar to microsoft#35399).

* Fix `loggedIO` with empty namespaces to indicate dependency
  (similar to 50603ed).

* Move `Map` / `Set` stuff from `core.ts` to `corePublic.ts` since the
  types are there.

Author: elibarzilay

src/compiler/core.ts

@@ -1,25 +1,5 @@
 /* @internal */
 namespace ts {
-    type GetIteratorCallback = <I extends readonly any[] | ReadonlySet<any> | ReadonlyESMap<any, any> | undefined>(iterable: I) => Iterator<
-        I extends ReadonlyESMap<infer K, infer V> ? [K, V] :
-        I extends ReadonlySet<infer T> ? T :
-        I extends readonly (infer T)[] ? T :
-        I extends undefined ? undefined :
-        never>;
-
-    function getCollectionImplementation<
-        K1 extends MatchingKeys<typeof NativeCollections, () => any>,
-        K2 extends MatchingKeys<typeof ShimCollections, (getIterator?: GetIteratorCallback) => ReturnType<(typeof NativeCollections)[K1]>>
-    >(name: string, nativeFactory: K1, shimFactory: K2): NonNullable<ReturnType<(typeof NativeCollections)[K1]>> {
-        // NOTE: ts.ShimCollections will be defined for typescriptServices.js but not for tsc.js, so we must test for it.
-        const constructor = NativeCollections[nativeFactory]() ?? ShimCollections?.[shimFactory](getIterator);
-        if (constructor) return constructor as NonNullable<ReturnType<(typeof NativeCollections)[K1]>>;
-        throw new Error(`TypeScript requires an environment that provides a compatible native ${name} implementation.`);
-    }
-
-    export const Map = getCollectionImplementation("Map", "tryGetNativeMap", "createMapShim");
-    export const Set = getCollectionImplementation("Set", "tryGetNativeSet", "createSetShim");
-
     export function getIterator<I extends readonly any[] | ReadonlySet<any> | ReadonlyESMap<any, any> | undefined>(iterable: I): Iterator<
         I extends ReadonlyESMap<infer K, infer V> ? [K, V] :
         I extends ReadonlySet<infer T> ? T :

src/compiler/corePublic.ts

@@ -113,7 +113,7 @@ namespace ts {
     }
 
     /* @internal */
-    export namespace NativeCollections {
+    namespace NativeCollections {
         declare const Map: MapConstructor | undefined;
         declare const Set: SetConstructor | undefined;
 
@@ -135,4 +135,28 @@ namespace ts {
             return typeof Set !== "undefined" && "entries" in Set.prototype && new Set([0]).size === 1 ? Set : undefined;
         }
     }
-}
+
+    /* @internal */
+    export const Map = getCollectionImplementation("Map", "tryGetNativeMap", "createMapShim");
+    /* @internal */
+    export const Set = getCollectionImplementation("Set", "tryGetNativeSet", "createSetShim");
+
+    /* @internal */
+    type GetIteratorCallback = <I extends readonly any[] | ReadonlySet<any> | ReadonlyESMap<any, any> | undefined>(iterable: I) => Iterator<
+        I extends ReadonlyESMap<infer K, infer V> ? [K, V] :
+        I extends ReadonlySet<infer T> ? T :
+        I extends readonly (infer T)[] ? T :
+        I extends undefined ? undefined :
+        never>;
+
+    /* @internal */
+    function getCollectionImplementation<
+        K1 extends MatchingKeys<typeof NativeCollections, () => any>,
+        K2 extends MatchingKeys<typeof ShimCollections, (getIterator?: GetIteratorCallback) => ReturnType<(typeof NativeCollections)[K1]>>
+    >(name: string, nativeFactory: K1, shimFactory: K2): NonNullable<ReturnType<(typeof NativeCollections)[K1]>> {
+        // NOTE: ts.ShimCollections will be defined for typescriptServices.js but not for tsc.js, so we must test for it.
+        const constructor = NativeCollections[nativeFactory]() ?? ShimCollections?.[shimFactory](getIterator);
+        if (constructor) return constructor as NonNullable<ReturnType<(typeof NativeCollections)[K1]>>;
+        throw new Error(`TypeScript requires an environment that provides a compatible native ${name} implementation.`);
+    }
+}

src/compiler/sys.ts

@@ -1900,6 +1900,11 @@ namespace ts {
         return sys!;
     })();
 
+    /*@internal*/
+    export function setSys(s: System) {
+        sys = s;
+    }
+
     if (sys && sys.getEnvironmentVariable) {
         setCustomPollingValues(sys);
         Debug.setAssertionLevel(/^development$/i.test(sys.getEnvironmentVariable("NODE_ENV"))

src/compiler/transformer.ts

@@ -566,7 +566,7 @@ namespace ts {
     }
 
     export const nullTransformationContext: TransformationContext = {
-        factory,
+        factory: factory, // eslint-disable-line object-shorthand
         getCompilerOptions: () => ({}),
         getEmitResolver: notImplemented,
         getEmitHost: notImplemented,

src/loggedIO/loggedIO.ts

@@ -1,4 +1,4 @@
-namespace Playback {
+namespace Playback { // eslint-disable-line one-namespace-per-file
     interface FileInformation {
         contents?: string;
         contentsPath?: string;
@@ -445,3 +445,7 @@ namespace Playback {
         return wrapper;
     }
 }
+
+// empty modules for the module migration script
+namespace ts.server { } // eslint-disable-line one-namespace-per-file
+namespace Harness { } // eslint-disable-line one-namespace-per-file

src/tsserver/webServer.ts

@@ -78,7 +78,7 @@ namespace ts.server {
         };
         // Do this after sys has been set as findArguments is going to work only then
         const sys = server.createWebSystem(webHost, args, () => findArgument("--executingFilePath") || location + "");
-        ts.sys = sys;
+        setSys(sys);
         const localeStr = findArgument("--locale");
         if (localeStr) {
             validateLocaleAndSetLanguage(localeStr, sys);