From adefdc79538d171435ddb8a37f5a543556803495 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <nathansa@microsoft.com>
Date: Tue, 18 Apr 2017 14:56:11 -0700
Subject: [PATCH 1/2] Unknown properties are assignable to Object unions

For the last week or so they have been treated as excess properties when
assigning to a union type containing Object, but not when assigning directly
to Object type.
---
 src/compiler/checker.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 353356c208b..c0e3c490831 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -8708,7 +8708,7 @@ namespace ts {
                 if (maybeTypeOfKind(target, TypeFlags.Object) && !(getObjectFlags(target) & ObjectFlags.ObjectLiteralPatternWithComputedProperties)) {
                     const isComparingJsxAttributes = !!(source.flags & TypeFlags.JsxAttributes);
                     if ((relation === assignableRelation || relation === comparableRelation) &&
-                        (target === globalObjectType || (!isComparingJsxAttributes && isEmptyObjectType(target)))) {
+                        (isTypeSubsetOf(globalObjectType, target) || (!isComparingJsxAttributes && isEmptyObjectType(target)))) {
                         return false;
                     }
                     for (const prop of getPropertiesOfObjectType(source)) {

From 8ab22217c133abb805cd4df18b9e5848766e9582 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <nathansa@microsoft.com>
Date: Tue, 18 Apr 2017 14:58:27 -0700
Subject: [PATCH 2/2] Test:Unknown properties are assignable to Object in union

Add test and accept baselines
---
 ...unknownPropertiesAreAssignableToObjectUnion.js |  8 ++++++++
 ...wnPropertiesAreAssignableToObjectUnion.symbols | 11 +++++++++++
 ...nownPropertiesAreAssignableToObjectUnion.types | 15 +++++++++++++++
 ...unknownPropertiesAreAssignableToObjectUnion.ts |  3 +++
 4 files changed, 37 insertions(+)
 create mode 100644 tests/baselines/reference/unknownPropertiesAreAssignableToObjectUnion.js
 create mode 100644 tests/baselines/reference/unknownPropertiesAreAssignableToObjectUnion.symbols
 create mode 100644 tests/baselines/reference/unknownPropertiesAreAssignableToObjectUnion.types
 create mode 100644 tests/cases/compiler/unknownPropertiesAreAssignableToObjectUnion.ts

diff --git a/tests/baselines/reference/unknownPropertiesAreAssignableToObjectUnion.js b/tests/baselines/reference/unknownPropertiesAreAssignableToObjectUnion.js
new file mode 100644
index 00000000000..7140f13cb7b
--- /dev/null
+++ b/tests/baselines/reference/unknownPropertiesAreAssignableToObjectUnion.js
@@ -0,0 +1,8 @@
+//// [unknownPropertiesAreAssignableToObjectUnion.ts]
+const x: Object | string = { x: 0 };
+const y: Object | undefined = { x: 0 };
+
+
+//// [unknownPropertiesAreAssignableToObjectUnion.js]
+var x = { x: 0 };
+var y = { x: 0 };
diff --git a/tests/baselines/reference/unknownPropertiesAreAssignableToObjectUnion.symbols b/tests/baselines/reference/unknownPropertiesAreAssignableToObjectUnion.symbols
new file mode 100644
index 00000000000..f9c0b09c987
--- /dev/null
+++ b/tests/baselines/reference/unknownPropertiesAreAssignableToObjectUnion.symbols
@@ -0,0 +1,11 @@
+=== tests/cases/compiler/unknownPropertiesAreAssignableToObjectUnion.ts ===
+const x: Object | string = { x: 0 };
+>x : Symbol(x, Decl(unknownPropertiesAreAssignableToObjectUnion.ts, 0, 5))
+>Object : Symbol(Object, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>x : Symbol(x, Decl(unknownPropertiesAreAssignableToObjectUnion.ts, 0, 28))
+
+const y: Object | undefined = { x: 0 };
+>y : Symbol(y, Decl(unknownPropertiesAreAssignableToObjectUnion.ts, 1, 5))
+>Object : Symbol(Object, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>x : Symbol(x, Decl(unknownPropertiesAreAssignableToObjectUnion.ts, 1, 31))
+
diff --git a/tests/baselines/reference/unknownPropertiesAreAssignableToObjectUnion.types b/tests/baselines/reference/unknownPropertiesAreAssignableToObjectUnion.types
new file mode 100644
index 00000000000..d242cb8805c
--- /dev/null
+++ b/tests/baselines/reference/unknownPropertiesAreAssignableToObjectUnion.types
@@ -0,0 +1,15 @@
+=== tests/cases/compiler/unknownPropertiesAreAssignableToObjectUnion.ts ===
+const x: Object | string = { x: 0 };
+>x : string | Object
+>Object : Object
+>{ x: 0 } : { x: number; }
+>x : number
+>0 : 0
+
+const y: Object | undefined = { x: 0 };
+>y : Object | undefined
+>Object : Object
+>{ x: 0 } : { x: number; }
+>x : number
+>0 : 0
+
diff --git a/tests/cases/compiler/unknownPropertiesAreAssignableToObjectUnion.ts b/tests/cases/compiler/unknownPropertiesAreAssignableToObjectUnion.ts
new file mode 100644
index 00000000000..eb4209509de
--- /dev/null
+++ b/tests/cases/compiler/unknownPropertiesAreAssignableToObjectUnion.ts
@@ -0,0 +1,3 @@
+// @strictNullChecks: true
+const x: Object | string = { x: 0 };
+const y: Object | undefined = { x: 0 };