Adding test for inference with intersection type as target

Author: ahejlsberg

tests/baselines/reference/intersectionTypeInference.errors.txt

@@ -1,11 +1,10 @@
-tests/cases/conformance/types/intersection/intersectionTypeInference.ts(6,5): error TS2322: Type 'T' is not assignable to type 'T & U'.
+tests/cases/conformance/types/intersection/intersectionTypeInference.ts(5,5): error TS2322: Type 'T' is not assignable to type 'T & U'.
   Type 'T' is not assignable to type 'U'.
-tests/cases/conformance/types/intersection/intersectionTypeInference.ts(7,5): error TS2322: Type 'U' is not assignable to type 'T & U'.
+tests/cases/conformance/types/intersection/intersectionTypeInference.ts(6,5): error TS2322: Type 'U' is not assignable to type 'T & U'.
   Type 'U' is not assignable to type 'T'.
 
 
 ==== tests/cases/conformance/types/intersection/intersectionTypeInference.ts (2 errors) ====
-    
     function extend<T, U>(obj1: T, obj2: U): T & U {
         var result: T & U;
         obj1 = result;
@@ -24,4 +23,19 @@ tests/cases/conformance/types/intersection/intersectionTypeInference.ts(7,5): er
     var x = extend({ a: "hello" }, { b: 42 });
     var s = x.a;
     var n = x.b;
+    
+    interface A<T> {
+        a: T;
+    }
+    
+    interface B<U> {
+        b: U;
+    }
+    
+    function foo<T, U>(obj: A<T> & B<U>): T | U {
+        return undefined;
+    }
+    
+    var z = foo({ a: "hello", b: 42 });
+    var z: string | number;
 

tests/baselines/reference/intersectionTypeInference.js

@@ -1,5 +1,4 @@
 //// [intersectionTypeInference.ts]
-
 function extend<T, U>(obj1: T, obj2: U): T & U {
     var result: T & U;
     obj1 = result;
@@ -12,6 +11,21 @@ function extend<T, U>(obj1: T, obj2: U): T & U {
 var x = extend({ a: "hello" }, { b: 42 });
 var s = x.a;
 var n = x.b;
+
+interface A<T> {
+    a: T;
+}
+
+interface B<U> {
+    b: U;
+}
+
+function foo<T, U>(obj: A<T> & B<U>): T | U {
+    return undefined;
+}
+
+var z = foo({ a: "hello", b: 42 });
+var z: string | number;
 
 
 //// [intersectionTypeInference.js]
@@ -26,3 +40,8 @@ function extend(obj1, obj2) {
 var x = extend({ a: "hello" }, { b: 42 });
 var s = x.a;
 var n = x.b;
+function foo(obj) {
+    return undefined;
+}
+var z = foo({ a: "hello", b: 42 });
+var z;

tests/cases/conformance/types/intersection/intersectionTypeInference.ts

@@ -1,4 +1,3 @@
-
 function extend<T, U>(obj1: T, obj2: U): T & U {
     var result: T & U;
     obj1 = result;
@@ -11,3 +10,18 @@ function extend<T, U>(obj1: T, obj2: U): T & U {
 var x = extend({ a: "hello" }, { b: 42 });
 var s = x.a;
 var n = x.b;
+
+interface A<T> {
+    a: T;
+}
+
+interface B<U> {
+    b: U;
+}
+
+function foo<T, U>(obj: A<T> & B<U>): T | U {
+    return undefined;
+}
+
+var z = foo({ a: "hello", b: 42 });
+var z: string | number;