Strongly typecheck unions of intrinsic tag names (microsoft#28557)

Author: weswigham

src/compiler/checker.ts

@@ -18355,16 +18355,31 @@ namespace ts {
             return getNameFromJsxElementAttributesContainer(JsxNames.ElementChildrenAttributeNameContainer, jsxNamespace);
         }
 
-        function getUninstantiatedJsxSignaturesOfType(elementType: Type): ReadonlyArray<Signature> {
+        function getUninstantiatedJsxSignaturesOfType(elementType: Type, caller: JsxOpeningLikeElement): ReadonlyArray<Signature> {
+            if (elementType.flags & TypeFlags.String) {
+                return [anySignature];
+            }
+            else if (elementType.flags & TypeFlags.StringLiteral) {
+                const intrinsicType = getIntrinsicAttributesTypeFromStringLiteralType(elementType as StringLiteralType, caller);
+                if (!intrinsicType) {
+                    error(caller, Diagnostics.Property_0_does_not_exist_on_type_1, (elementType as StringLiteralType).value, "JSX." + JsxNames.IntrinsicElements);
+                    return emptyArray;
+                }
+                else {
+                    const fakeSignature = createSignatureForJSXIntrinsic(caller, intrinsicType);
+                    return [fakeSignature];
+                }
+            }
+            const apparentElemType = getApparentType(elementType);
             // Resolve the signatures, preferring constructor
-            let signatures = getSignaturesOfType(elementType, SignatureKind.Construct);
+            let signatures = getSignaturesOfType(apparentElemType, SignatureKind.Construct);
             if (signatures.length === 0) {
                 // No construct signatures, try call signatures
-                signatures = getSignaturesOfType(elementType, SignatureKind.Call);
+                signatures = getSignaturesOfType(apparentElemType, SignatureKind.Call);
             }
-            if (signatures.length === 0 && elementType.flags & TypeFlags.Union) {
+            if (signatures.length === 0 && apparentElemType.flags & TypeFlags.Union) {
                 // If each member has some combination of new/call signatures; make a union signature list for those
-                signatures = getUnionSignatures(map((elementType as UnionType).types, getUninstantiatedJsxSignaturesOfType));
+                signatures = getUnionSignatures(map((apparentElemType as UnionType).types, t => getUninstantiatedJsxSignaturesOfType(t, caller)));
             }
             return signatures;
         }
@@ -20547,21 +20562,8 @@ namespace ts {
                 return resolveErrorCall(node);
             }
 
-            if (exprTypes.flags & TypeFlags.StringLiteral) {
-                const intrinsicType = getIntrinsicAttributesTypeFromStringLiteralType(exprTypes as StringLiteralType, node);
-                if (!intrinsicType) {
-                    error(node, Diagnostics.Property_0_does_not_exist_on_type_1, (exprTypes as StringLiteralType).value, "JSX." + JsxNames.IntrinsicElements);
-                    return resolveUntypedCall(node);
-                }
-                else {
-                    const fakeSignature = createSignatureForJSXIntrinsic(node, intrinsicType);
-                    checkTypeAssignableToAndOptionallyElaborate(checkExpressionWithContextualType(node.attributes, getEffectiveFirstArgumentForJsxSignature(fakeSignature, node), /*mapper*/ undefined), intrinsicType, node.tagName, node.attributes);
-                    return fakeSignature;
-                }
-            }
-
-            const signatures = getUninstantiatedJsxSignaturesOfType(apparentType);
-            if (exprTypes.flags & TypeFlags.String || isUntypedFunctionCall(exprTypes, apparentType, signatures.length, /*constructSignatures*/ 0)) {
+            const signatures = getUninstantiatedJsxSignaturesOfType(exprTypes, node);
+            if (isUntypedFunctionCall(exprTypes, apparentType, signatures.length, /*constructSignatures*/ 0)) {
                 return resolveUntypedCall(node);
             }
 

tests/baselines/reference/jsxIntrinsicUnions.js

@@ -0,0 +1,17 @@
+//// [jsxIntrinsicUnions.tsx]
+/// <reference path="/.lib/react16.d.ts" />
+
+import * as React from "react";
+
+const El = Math.random() ? 'h1' : 'h2';
+
+const tag = <El className="ok" key="key">{"Title"}</El>;
+
+
+//// [jsxIntrinsicUnions.js]
+"use strict";
+/// <reference path="react16.d.ts" />
+exports.__esModule = true;
+var React = require("react");
+var El = Math.random() ? 'h1' : 'h2';
+var tag = React.createElement(El, { className: "ok", key: "key" }, "Title");

tests/baselines/reference/jsxIntrinsicUnions.symbols

@@ -0,0 +1,19 @@
+=== tests/cases/compiler/jsxIntrinsicUnions.tsx ===
+/// <reference path="react16.d.ts" />
+
+import * as React from "react";
+>React : Symbol(React, Decl(jsxIntrinsicUnions.tsx, 2, 6))
+
+const El = Math.random() ? 'h1' : 'h2';
+>El : Symbol(El, Decl(jsxIntrinsicUnions.tsx, 4, 5))
+>Math.random : Symbol(Math.random, Decl(lib.es5.d.ts, --, --))
+>Math : Symbol(Math, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>random : Symbol(Math.random, Decl(lib.es5.d.ts, --, --))
+
+const tag = <El className="ok" key="key">{"Title"}</El>;
+>tag : Symbol(tag, Decl(jsxIntrinsicUnions.tsx, 6, 5))
+>El : Symbol(El, Decl(jsxIntrinsicUnions.tsx, 4, 5))
+>className : Symbol(className, Decl(jsxIntrinsicUnions.tsx, 6, 15))
+>key : Symbol(key, Decl(jsxIntrinsicUnions.tsx, 6, 30))
+>El : Symbol(El, Decl(jsxIntrinsicUnions.tsx, 4, 5))
+

tests/baselines/reference/jsxIntrinsicUnions.types

@@ -0,0 +1,25 @@
+=== tests/cases/compiler/jsxIntrinsicUnions.tsx ===
+/// <reference path="react16.d.ts" />
+
+import * as React from "react";
+>React : typeof React
+
+const El = Math.random() ? 'h1' : 'h2';
+>El : "h1" | "h2"
+>Math.random() ? 'h1' : 'h2' : "h1" | "h2"
+>Math.random() : number
+>Math.random : () => number
+>Math : Math
+>random : () => number
+>'h1' : "h1"
+>'h2' : "h2"
+
+const tag = <El className="ok" key="key">{"Title"}</El>;
+>tag : JSX.Element
+><El className="ok" key="key">{"Title"}</El> : JSX.Element
+>El : "h1" | "h2"
+>className : string
+>key : string
+>"Title" : "Title"
+>El : "h1" | "h2"
+

tests/baselines/reference/tsxDynamicTagName3.errors.txt

@@ -1,7 +1,8 @@
 tests/cases/conformance/jsx/tsxDynamicTagName3.tsx(9,1): error TS2339: Property 'h1' does not exist on type 'JSX.IntrinsicElements'.
+tests/cases/conformance/jsx/tsxDynamicTagName3.tsx(9,2): error TS2604: JSX element type 'CustomTag' does not have any construct or call signatures.
 
 
-==== tests/cases/conformance/jsx/tsxDynamicTagName3.tsx (1 errors) ====
+==== tests/cases/conformance/jsx/tsxDynamicTagName3.tsx (2 errors) ====
     declare module JSX {
     	interface Element { }
     	interface IntrinsicElements {
@@ -12,4 +13,6 @@ tests/cases/conformance/jsx/tsxDynamicTagName3.tsx(9,1): error TS2339: Property
     var CustomTag: "h1" = "h1";
     <CustomTag> Hello World </CustomTag>  // This should be an error. we will try look up string literal type in JSX.IntrinsicElements
     ~~~~~~~~~~~
-!!! error TS2339: Property 'h1' does not exist on type 'JSX.IntrinsicElements'.
+!!! error TS2339: Property 'h1' does not exist on type 'JSX.IntrinsicElements'.
+     ~~~~~~~~~
+!!! error TS2604: JSX element type 'CustomTag' does not have any construct or call signatures.

tests/cases/compiler/jsxIntrinsicUnions.tsx

@@ -0,0 +1,8 @@
+// @jsx: react
+/// <reference path="/.lib/react16.d.ts" />
+
+import * as React from "react";
+
+const El = Math.random() ? 'h1' : 'h2';
+
+const tag = <El className="ok" key="key">{"Title"}</El>;