Fix crash when the element instance type was undefined

src/compiler/checker.ts

@@ -4363,11 +4363,11 @@ namespace ts {
                         return getInferredType(context, i);
                     }
                 }
-                return t;
+                return t;
             };
 
             mapper.context = context;
-            return mapper;
+            return mapper;
         }
 
         function identityMapper(type: Type): Type {
@@ -7323,10 +7323,9 @@ namespace ts {
          * For example, in the element <MyClass>, the element instance type is `MyClass` (not `typeof MyClass`).
          */
         function getJsxElementInstanceType(node: JsxOpeningLikeElement) {
-            if (!(getNodeLinks(node).jsxFlags & JsxFlags.ClassElement)) {
-                // There is no such thing as an instance type for a non-class element
-                return undefined;
-            }
+            // There is no such thing as an instance type for a non-class element. This
+            // line shouldn't be hit.
+            Debug.assert(!!(getNodeLinks(node).jsxFlags & JsxFlags.ClassElement), 'Should not call getJsxElementInstanceType on non-class Element');
 
             let classSymbol = getJsxElementTagSymbol(node);
             if (classSymbol === unknownSymbol) {
@@ -7349,16 +7348,11 @@ namespace ts {
                 if (signatures.length === 0) {
                     // We found no signatures at all, which is an error
                     error(node.tagName, Diagnostics.JSX_element_type_0_does_not_have_any_construct_or_call_signatures, getTextOfNode(node.tagName));
-                    return undefined;
+                    return unknownType;
                 }
             }
 
-            // Check that the constructor/factory returns an object type
-            let returnType = getUnionType(signatures.map(s => getReturnTypeOfSignature(s)));
-            if (!isTypeAny(returnType) && !(returnType.flags & TypeFlags.ObjectType)) {
-                error(node.tagName, Diagnostics.The_return_type_of_a_JSX_element_constructor_must_return_an_object_type);
-                return undefined;
-            }
+            let returnType = getUnionType(signatures.map(getReturnTypeOfSignature));
 
             // Issue an error if this return type isn't assignable to JSX.ElementClass
             let elemClassType = getJsxGlobalElementClassType();
@@ -7419,7 +7413,7 @@ namespace ts {
                     let elemInstanceType = getJsxElementInstanceType(node);
 
                     if (isTypeAny(elemInstanceType)) {
-                        return links.resolvedJsxType = anyType;
+                        return links.resolvedJsxType = elemInstanceType;
                     }
 
                     let propsName = getJsxElementPropertiesName();

tests/baselines/reference/jsxViaImport.errors.txt

@@ -0,0 +1,27 @@
+tests/cases/compiler/consumer.tsx(5,17): error TS2604: JSX element type 'BaseComponent' does not have any construct or call signatures.
+
+
+==== tests/cases/compiler/consumer.tsx (1 errors) ====
+    /// <reference path="component.d.ts" />
+    import BaseComponent = require('BaseComponent');
+    class TestComponent extends React.Component<any, {}> {
+        render() {
+            return <BaseComponent />;
+                    ~~~~~~~~~~~~~
+!!! error TS2604: JSX element type 'BaseComponent' does not have any construct or call signatures.
+        }
+    }
+
+==== tests/cases/compiler/component.d.ts (0 errors) ====
+
+    declare module JSX {
+      interface ElementAttributesProperty { props; }
+    }
+    declare module React {
+      class Component<T, U> { }
+    }
+    declare module "BaseComponent" {
+        var base: React.Component<any, {}>;
+        export = base;
+    }
+

tests/baselines/reference/jsxViaImport.js

@@ -0,0 +1,43 @@
+//// [tests/cases/compiler/jsxViaImport.tsx] ////
+
+//// [component.d.ts]
+
+declare module JSX {
+  interface ElementAttributesProperty { props; }
+}
+declare module React {
+  class Component<T, U> { }
+}
+declare module "BaseComponent" {
+    var base: React.Component<any, {}>;
+    export = base;
+}
+
+//// [consumer.tsx]
+/// <reference path="component.d.ts" />
+import BaseComponent = require('BaseComponent');
+class TestComponent extends React.Component<any, {}> {
+    render() {
+        return <BaseComponent />;
+    }
+}
+
+
+//// [consumer.jsx]
+var __extends = (this && this.__extends) || function (d, b) {
+    for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
+    function __() { this.constructor = d; }
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
+};
+/// <reference path="component.d.ts" />
+var BaseComponent = require('BaseComponent');
+var TestComponent = (function (_super) {
+    __extends(TestComponent, _super);
+    function TestComponent() {
+        _super.apply(this, arguments);
+    }
+    TestComponent.prototype.render = function () {
+        return <BaseComponent />;
+    };
+    return TestComponent;
+})(React.Component);

tests/baselines/reference/tsxElementResolution8.errors.txt

@@ -1,10 +1,8 @@
 tests/cases/conformance/jsx/tsxElementResolution8.tsx(8,2): error TS2604: JSX element type 'Div' does not have any construct or call signatures.
-tests/cases/conformance/jsx/tsxElementResolution8.tsx(16,2): error TS2601: The return type of a JSX element constructor must return an object type.
-tests/cases/conformance/jsx/tsxElementResolution8.tsx(29,2): error TS2601: The return type of a JSX element constructor must return an object type.
 tests/cases/conformance/jsx/tsxElementResolution8.tsx(34,2): error TS2604: JSX element type 'Obj3' does not have any construct or call signatures.
 
 
-==== tests/cases/conformance/jsx/tsxElementResolution8.tsx (4 errors) ====
+==== tests/cases/conformance/jsx/tsxElementResolution8.tsx (2 errors) ====
     declare module JSX {
     	interface Element { }
     	interface IntrinsicElements { }
@@ -23,8 +21,6 @@ tests/cases/conformance/jsx/tsxElementResolution8.tsx(34,2): error TS2604: JSX e
     // Error
     function Fnum(): number{ return 42; }
     <Fnum />
-     ~~~~
-!!! error TS2601: The return type of a JSX element constructor must return an object type.
 
     interface Obj1 {
     	new(): {};
@@ -38,8 +34,6 @@ tests/cases/conformance/jsx/tsxElementResolution8.tsx(34,2): error TS2604: JSX e
     }
     var Obj2: Obj2;
     <Obj2 />; // Error
-     ~~~~
-!!! error TS2601: The return type of a JSX element constructor must return an object type.
 
     interface Obj3 {
     }

tests/baselines/reference/tsxElementResolution9.symbols

@@ -0,0 +1,67 @@
+=== tests/cases/conformance/jsx/tsxElementResolution9.tsx ===
+declare module JSX {
+>JSX : Symbol(JSX, Decl(tsxElementResolution9.tsx, 0, 0))
+
+	interface Element { }
+>Element : Symbol(Element, Decl(tsxElementResolution9.tsx, 0, 20))
+
+	interface IntrinsicElements { }
+>IntrinsicElements : Symbol(IntrinsicElements, Decl(tsxElementResolution9.tsx, 1, 22))
+}
+
+interface Obj1 {
+>Obj1 : Symbol(Obj1, Decl(tsxElementResolution9.tsx, 3, 1), Decl(tsxElementResolution9.tsx, 9, 3))
+
+	new(n: string): { x: number };
+>n : Symbol(n, Decl(tsxElementResolution9.tsx, 6, 5))
+>x : Symbol(x, Decl(tsxElementResolution9.tsx, 6, 18))
+
+	new(n: number): { y: string };
+>n : Symbol(n, Decl(tsxElementResolution9.tsx, 7, 5))
+>y : Symbol(y, Decl(tsxElementResolution9.tsx, 7, 18))
+}
+var Obj1: Obj1;
+>Obj1 : Symbol(Obj1, Decl(tsxElementResolution9.tsx, 3, 1), Decl(tsxElementResolution9.tsx, 9, 3))
+>Obj1 : Symbol(Obj1, Decl(tsxElementResolution9.tsx, 3, 1), Decl(tsxElementResolution9.tsx, 9, 3))
+
+<Obj1 />; // Error, return type is not an object type
+>Obj1 : Symbol(Obj1, Decl(tsxElementResolution9.tsx, 3, 1), Decl(tsxElementResolution9.tsx, 9, 3))
+
+interface Obj2 {
+>Obj2 : Symbol(Obj2, Decl(tsxElementResolution9.tsx, 10, 9), Decl(tsxElementResolution9.tsx, 16, 3))
+
+	(n: string): { x: number };
+>n : Symbol(n, Decl(tsxElementResolution9.tsx, 13, 2))
+>x : Symbol(x, Decl(tsxElementResolution9.tsx, 13, 15))
+
+	(n: number): { y: string };
+>n : Symbol(n, Decl(tsxElementResolution9.tsx, 14, 2))
+>y : Symbol(y, Decl(tsxElementResolution9.tsx, 14, 15))
+}
+var Obj2: Obj2;
+>Obj2 : Symbol(Obj2, Decl(tsxElementResolution9.tsx, 10, 9), Decl(tsxElementResolution9.tsx, 16, 3))
+>Obj2 : Symbol(Obj2, Decl(tsxElementResolution9.tsx, 10, 9), Decl(tsxElementResolution9.tsx, 16, 3))
+
+<Obj2 />; // Error, return type is not an object type
+>Obj2 : Symbol(Obj2, Decl(tsxElementResolution9.tsx, 10, 9), Decl(tsxElementResolution9.tsx, 16, 3))
+
+interface Obj3 {
+>Obj3 : Symbol(Obj3, Decl(tsxElementResolution9.tsx, 17, 9), Decl(tsxElementResolution9.tsx, 23, 3))
+
+	(n: string): { x: number };
+>n : Symbol(n, Decl(tsxElementResolution9.tsx, 20, 2))
+>x : Symbol(x, Decl(tsxElementResolution9.tsx, 20, 15))
+
+	(n: number): { x: number; y: string };
+>n : Symbol(n, Decl(tsxElementResolution9.tsx, 21, 2))
+>x : Symbol(x, Decl(tsxElementResolution9.tsx, 21, 15))
+>y : Symbol(y, Decl(tsxElementResolution9.tsx, 21, 26))
+}
+var Obj3: Obj3;
+>Obj3 : Symbol(Obj3, Decl(tsxElementResolution9.tsx, 17, 9), Decl(tsxElementResolution9.tsx, 23, 3))
+>Obj3 : Symbol(Obj3, Decl(tsxElementResolution9.tsx, 17, 9), Decl(tsxElementResolution9.tsx, 23, 3))
+
+<Obj3 x={42} />; // OK
+>Obj3 : Symbol(Obj3, Decl(tsxElementResolution9.tsx, 17, 9), Decl(tsxElementResolution9.tsx, 23, 3))
+>x : Symbol(unknown)
+

tests/baselines/reference/tsxElementResolution9.types

@@ -0,0 +1,70 @@
+=== tests/cases/conformance/jsx/tsxElementResolution9.tsx ===
+declare module JSX {
+>JSX : any
+
+	interface Element { }
+>Element : Element
+
+	interface IntrinsicElements { }
+>IntrinsicElements : IntrinsicElements
+}
+
+interface Obj1 {
+>Obj1 : Obj1
+
+	new(n: string): { x: number };
+>n : string
+>x : number
+
+	new(n: number): { y: string };
+>n : number
+>y : string
+}
+var Obj1: Obj1;
+>Obj1 : Obj1
+>Obj1 : Obj1
+
+<Obj1 />; // Error, return type is not an object type
+><Obj1 /> : JSX.Element
+>Obj1 : Obj1
+
+interface Obj2 {
+>Obj2 : Obj2
+
+	(n: string): { x: number };
+>n : string
+>x : number
+
+	(n: number): { y: string };
+>n : number
+>y : string
+}
+var Obj2: Obj2;
+>Obj2 : Obj2
+>Obj2 : Obj2
+
+<Obj2 />; // Error, return type is not an object type
+><Obj2 /> : JSX.Element
+>Obj2 : Obj2
+
+interface Obj3 {
+>Obj3 : Obj3
+
+	(n: string): { x: number };
+>n : string
+>x : number
+
+	(n: number): { x: number; y: string };
+>n : number
+>x : number
+>y : string
+}
+var Obj3: Obj3;
+>Obj3 : Obj3
+>Obj3 : Obj3
+
+<Obj3 x={42} />; // OK
+><Obj3 x={42} /> : JSX.Element
+>Obj3 : Obj3
+>x : any
+

tests/cases/compiler/jsxViaImport.tsx

@@ -0,0 +1,23 @@
+//@jsx: preserve
+//@module: commonjs
+
+//@filename: component.d.ts
+declare module JSX {
+  interface ElementAttributesProperty { props; }
+}
+declare module React {
+  class Component<T, U> { }
+}
+declare module "BaseComponent" {
+    var base: React.Component<any, {}>;
+    export = base;
+}
+
+//@filename: consumer.tsx
+/// <reference path="component.d.ts" />
+import BaseComponent = require('BaseComponent');
+class TestComponent extends React.Component<any, {}> {
+    render() {
+        return <BaseComponent />;
+    }
+}