Adding test

tests/baselines/reference/typeParameterConstraintInstantiation.js

@@ -0,0 +1,15 @@
+//// [typeParameterConstraintInstantiation.ts]
+// Check that type parameter constraints are properly instantiated
+
+interface Mapper<T> {
+    map<U extends T, V extends U[]>(f: (item: T) => U): V;
+}
+
+var m: Mapper<string>;
+var a = m.map((x: string) => x);  // string[]
+
+
+//// [typeParameterConstraintInstantiation.js]
+// Check that type parameter constraints are properly instantiated
+var m;
+var a = m.map(function (x) { return x; }); // string[]

tests/baselines/reference/typeParameterConstraintInstantiation.symbols

@@ -0,0 +1,32 @@
+=== tests/cases/compiler/typeParameterConstraintInstantiation.ts ===
+// Check that type parameter constraints are properly instantiated
+
+interface Mapper<T> {
+>Mapper : Symbol(Mapper, Decl(typeParameterConstraintInstantiation.ts, 0, 0))
+>T : Symbol(T, Decl(typeParameterConstraintInstantiation.ts, 2, 17))
+
+    map<U extends T, V extends U[]>(f: (item: T) => U): V;
+>map : Symbol(map, Decl(typeParameterConstraintInstantiation.ts, 2, 21))
+>U : Symbol(U, Decl(typeParameterConstraintInstantiation.ts, 3, 8))
+>T : Symbol(T, Decl(typeParameterConstraintInstantiation.ts, 2, 17))
+>V : Symbol(V, Decl(typeParameterConstraintInstantiation.ts, 3, 20))
+>U : Symbol(U, Decl(typeParameterConstraintInstantiation.ts, 3, 8))
+>f : Symbol(f, Decl(typeParameterConstraintInstantiation.ts, 3, 36))
+>item : Symbol(item, Decl(typeParameterConstraintInstantiation.ts, 3, 40))
+>T : Symbol(T, Decl(typeParameterConstraintInstantiation.ts, 2, 17))
+>U : Symbol(U, Decl(typeParameterConstraintInstantiation.ts, 3, 8))
+>V : Symbol(V, Decl(typeParameterConstraintInstantiation.ts, 3, 20))
+}
+
+var m: Mapper<string>;
+>m : Symbol(m, Decl(typeParameterConstraintInstantiation.ts, 6, 3))
+>Mapper : Symbol(Mapper, Decl(typeParameterConstraintInstantiation.ts, 0, 0))
+
+var a = m.map((x: string) => x);  // string[]
+>a : Symbol(a, Decl(typeParameterConstraintInstantiation.ts, 7, 3))
+>m.map : Symbol(Mapper.map, Decl(typeParameterConstraintInstantiation.ts, 2, 21))
+>m : Symbol(m, Decl(typeParameterConstraintInstantiation.ts, 6, 3))
+>map : Symbol(Mapper.map, Decl(typeParameterConstraintInstantiation.ts, 2, 21))
+>x : Symbol(x, Decl(typeParameterConstraintInstantiation.ts, 7, 15))
+>x : Symbol(x, Decl(typeParameterConstraintInstantiation.ts, 7, 15))
+

tests/baselines/reference/typeParameterConstraintInstantiation.types

@@ -0,0 +1,34 @@
+=== tests/cases/compiler/typeParameterConstraintInstantiation.ts ===
+// Check that type parameter constraints are properly instantiated
+
+interface Mapper<T> {
+>Mapper : Mapper<T>
+>T : T
+
+    map<U extends T, V extends U[]>(f: (item: T) => U): V;
+>map : <U extends T, V extends U[]>(f: (item: T) => U) => V
+>U : U
+>T : T
+>V : V
+>U : U
+>f : (item: T) => U
+>item : T
+>T : T
+>U : U
+>V : V
+}
+
+var m: Mapper<string>;
+>m : Mapper<string>
+>Mapper : Mapper<T>
+
+var a = m.map((x: string) => x);  // string[]
+>a : string[]
+>m.map((x: string) => x) : string[]
+>m.map : <U extends string, V extends U[]>(f: (item: string) => U) => V
+>m : Mapper<string>
+>map : <U extends string, V extends U[]>(f: (item: string) => U) => V
+>(x: string) => x : (x: string) => string
+>x : string
+>x : string
+

tests/cases/compiler/typeParameterConstraintInstantiation.ts

@@ -0,0 +1,8 @@
+// Check that type parameter constraints are properly instantiated
+
+interface Mapper<T> {
+    map<U extends T, V extends U[]>(f: (item: T) => U): V;
+}
+
+var m: Mapper<string>;
+var a = m.map((x: string) => x);  // string[]