From afa94c527cd407fb0eed815d070f66406485a03d Mon Sep 17 00:00:00 2001
From: Andy <anhans@microsoft.com>
Date: Mon, 22 Oct 2018 11:18:56 -0700
Subject: [PATCH] Un-consolidate overloads for Map and WeakMap (#28052)

---
 src/lib/es2015.collection.d.ts              | 3 ++-
 src/lib/es2015.iterable.d.ts                | 2 +-
 tests/baselines/reference/newMap.errors.txt | 8 ++++++++
 tests/baselines/reference/newMap.js         | 6 ++++++
 tests/baselines/reference/newMap.symbols    | 4 ++++
 tests/baselines/reference/newMap.types      | 5 +++++
 tests/cases/compiler/newMap.ts              | 2 ++
 7 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100644 tests/baselines/reference/newMap.errors.txt
 create mode 100644 tests/baselines/reference/newMap.js
 create mode 100644 tests/baselines/reference/newMap.symbols
 create mode 100644 tests/baselines/reference/newMap.types
 create mode 100644 tests/cases/compiler/newMap.ts

diff --git a/src/lib/es2015.collection.d.ts b/src/lib/es2015.collection.d.ts
index 46bb7af0c8fc7..34afa3d1b2b24 100644
--- a/src/lib/es2015.collection.d.ts
+++ b/src/lib/es2015.collection.d.ts
@@ -9,7 +9,8 @@ interface Map<K, V> {
 }
 
 interface MapConstructor {
-    new <K = any, V = any>(entries?: ReadonlyArray<[K, V]> | null): Map<K, V>;
+    new(): Map<any, any>;
+    new<K, V>(entries?: ReadonlyArray<[K, V]> | null): Map<K, V>;
     readonly prototype: Map<any, any>;
 }
 declare var Map: MapConstructor;
diff --git a/src/lib/es2015.iterable.d.ts b/src/lib/es2015.iterable.d.ts
index 568d3596ddae3..f0a38dff3fe02 100644
--- a/src/lib/es2015.iterable.d.ts
+++ b/src/lib/es2015.iterable.d.ts
@@ -135,7 +135,7 @@ interface MapConstructor {
 interface WeakMap<K extends object, V> { }
 
 interface WeakMapConstructor {
-    new <K extends object = object, V = any>(iterable: Iterable<[K, V]>): WeakMap<K, V>;
+    new <K extends object, V>(iterable: Iterable<[K, V]>): WeakMap<K, V>;
 }
 
 interface Set<T> {
diff --git a/tests/baselines/reference/newMap.errors.txt b/tests/baselines/reference/newMap.errors.txt
new file mode 100644
index 0000000000000..46668890b0714
--- /dev/null
+++ b/tests/baselines/reference/newMap.errors.txt
@@ -0,0 +1,8 @@
+tests/cases/compiler/newMap.ts(1,9): error TS2558: Expected 0-2 type arguments, but got 1.
+
+
+==== tests/cases/compiler/newMap.ts (1 errors) ====
+    new Map<string>();
+            ~~~~~~
+!!! error TS2558: Expected 0-2 type arguments, but got 1.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/newMap.js b/tests/baselines/reference/newMap.js
new file mode 100644
index 0000000000000..9ab99fc7242c5
--- /dev/null
+++ b/tests/baselines/reference/newMap.js
@@ -0,0 +1,6 @@
+//// [newMap.ts]
+new Map<string>();
+
+
+//// [newMap.js]
+new Map();
diff --git a/tests/baselines/reference/newMap.symbols b/tests/baselines/reference/newMap.symbols
new file mode 100644
index 0000000000000..1ce51df496927
--- /dev/null
+++ b/tests/baselines/reference/newMap.symbols
@@ -0,0 +1,4 @@
+=== tests/cases/compiler/newMap.ts ===
+new Map<string>();
+>Map : Symbol(Map, Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+
diff --git a/tests/baselines/reference/newMap.types b/tests/baselines/reference/newMap.types
new file mode 100644
index 0000000000000..d3fab45ccc0fd
--- /dev/null
+++ b/tests/baselines/reference/newMap.types
@@ -0,0 +1,5 @@
+=== tests/cases/compiler/newMap.ts ===
+new Map<string>();
+>new Map<string>() : any
+>Map : MapConstructor
+
diff --git a/tests/cases/compiler/newMap.ts b/tests/cases/compiler/newMap.ts
new file mode 100644
index 0000000000000..ab7040e11d98b
--- /dev/null
+++ b/tests/cases/compiler/newMap.ts
@@ -0,0 +1,2 @@
+// @lib: es6
+new Map<string>();