Support for --jsxFactory option

src/compiler/checker.ts

@@ -335,6 +335,7 @@ namespace ts {
         });
 
         let jsxElementType: Type;
+        let _jsxNamespace: string;
         /** Things we lazy load from the JSX namespace */
         const jsxTypes = createMap<Type>();
         const JsxNames = {
@@ -372,6 +373,22 @@ namespace ts {
 
         return checker;
 
+        function getJsxNamespace(): string {
+            if (_jsxNamespace === undefined) {
+                _jsxNamespace = "React";
+                if (compilerOptions.jsxFactory) {
+                    const jsxEntity = host.getJsxFactoryEntity();
+                    if (jsxEntity) {
+                        _jsxNamespace = getFirstIdentifier(jsxEntity).text;
+                    }
+                }
+                else if (compilerOptions.reactNamespace) {
+                    _jsxNamespace = compilerOptions.reactNamespace;
+                }
+            }
+            return _jsxNamespace;
+        }
+
         function getEmitResolver(sourceFile: SourceFile, cancellationToken: CancellationToken) {
             // Ensure we have all the type information in place for this file so that all the
             // emitter questions of this resolver will return the right information.
@@ -11337,10 +11354,10 @@ namespace ts {
         function checkJsxOpeningLikeElement(node: JsxOpeningLikeElement) {
             checkGrammarJsxElement(node);
             checkJsxPreconditions(node);
-            // The reactNamespace symbol should be marked as 'used' so we don't incorrectly elide its import. And if there
-            // is no reactNamespace symbol in scope when targeting React emit, we should issue an error.
+            // The reactNamespace/jsxFactory's root symbol should be marked as 'used' so we don't incorrectly elide its import. 
+            // And if there is no reactNamespace/jsxFactory's symbol in scope when targeting React emit, we should issue an error.
             const reactRefErr = compilerOptions.jsx === JsxEmit.React ? Diagnostics.Cannot_find_name_0 : undefined;
-            const reactNamespace = compilerOptions.reactNamespace ? compilerOptions.reactNamespace : "React";
+            const reactNamespace = getJsxNamespace();
             const reactSym = resolveName(node.tagName, reactNamespace, SymbolFlags.Value, reactRefErr, reactNamespace);
             if (reactSym) {
                 // Mark local symbol as referenced here because it might not have been marked

src/compiler/commandLineParser.ts

@@ -77,6 +77,11 @@ namespace ts {
             type: "string",
             description: Diagnostics.Specify_the_object_invoked_for_createElement_and_spread_when_targeting_react_JSX_emit
         },
+        {
+            name: "jsxFactory",
+            type: "string",
+            description: Diagnostics.Specify_the_JSX_factory_function_to_use_when_targeting_react_JSX_emit_e_g_React_createElement_or_h
+        },
         {
             name: "listFiles",
             type: "boolean",

src/compiler/diagnosticMessages.json

@@ -2381,6 +2381,10 @@
         "category": "Error",
         "code": 5066
     },
+    "Invalid value for 'jsxFactory'. '{0}' is not a valid identifier or qualified-name.": {
+        "category": "Error",
+        "code": 5067
+    },
     "Concatenate and emit output to single file.": {
         "category": "Message",
         "code": 6001
@@ -2897,6 +2901,10 @@
         "category": "Message",
         "code": 6145
     },
+    "Specify the JSX factory function to use when targeting 'react' JSX emit, e.g. 'React.createElement' or 'h'.": {
+        "category": "Message",
+        "code": 6146
+    },
     "Variable '{0}' implicitly has an '{1}' type.": {
         "category": "Error",
         "code": 7005

src/compiler/factory.ts

@@ -1628,7 +1628,34 @@ namespace ts {
         return react;
     }
 
-    export function createReactCreateElement(reactNamespace: string, tagName: Expression, props: Expression, children: Expression[], parentElement: JsxOpeningLikeElement, location: TextRange): LeftHandSideExpression {
+    function createJsxFactoryExpressionFromEntityName(jsxFactory: EntityName, parent: JsxOpeningLikeElement): Expression {
+        if (isQualifiedName(jsxFactory)) {
+            return createPropertyAccess(
+                createJsxFactoryExpressionFromEntityName(
+                    jsxFactory.left,
+                    parent
+                ),
+                setEmitFlags(
+                    getMutableClone(jsxFactory.right),
+                    EmitFlags.NoSourceMap
+                )
+            );
+        }
+        else {
+            return createReactNamespace(jsxFactory.text, parent);
+        }
+    }
+
+    function createJsxFactoryExpression(jsxFactoryEntity: EntityName, reactNamespace: string, parent: JsxOpeningLikeElement): Expression {
+        return jsxFactoryEntity ?
+            createJsxFactoryExpressionFromEntityName(jsxFactoryEntity, parent) :
+            createPropertyAccess(
+                createReactNamespace(reactNamespace, parent),
+                "createElement"
+            );
+    }
+
+    export function createExpressionForJsxElement(jsxFactoryEntity: EntityName, reactNamespace: string, tagName: Expression, props: Expression, children: Expression[], parentElement: JsxOpeningLikeElement, location: TextRange): LeftHandSideExpression {
         const argumentsList = [tagName];
         if (props) {
             argumentsList.push(props);
@@ -1651,10 +1678,7 @@ namespace ts {
         }
 
         return createCall(
-            createPropertyAccess(
-                createReactNamespace(reactNamespace, parentElement),
-                "createElement"
-            ),
+            createJsxFactoryExpression(jsxFactoryEntity, reactNamespace, parentElement),
             /*typeArguments*/ undefined,
             argumentsList,
             location

src/compiler/parser.ts

@@ -438,6 +438,10 @@ namespace ts {
         return result;
     }
 
+    export function parseIsolatedEntityName(text: string, languageVersion: ScriptTarget): EntityName {
+        return Parser.parseIsolatedEntityName(text, languageVersion);
+    }
+
     export function isExternalModule(file: SourceFile): boolean {
         return file.externalModuleIndicator !== undefined;
     }
@@ -589,6 +593,16 @@ namespace ts {
             return result;
         }
 
+        export function parseIsolatedEntityName(content: string, languageVersion: ScriptTarget): EntityName {
+            initializeState(content, languageVersion, /*syntaxCursor*/ undefined, ScriptKind.JS);
+            // Prime the scanner.
+            nextToken();
+            const entityName = parseEntityName(/*allowReservedWords*/ true);
+            const isInvalid = token() === SyntaxKind.EndOfFileToken && !parseDiagnostics.length;
+            clearState();
+            return isInvalid ? entityName : undefined;
+        }
+
         function getLanguageVariant(scriptKind: ScriptKind) {
             // .tsx and .jsx files are treated as jsx language variant.
             return scriptKind === ScriptKind.TSX || scriptKind === ScriptKind.JSX || scriptKind === ScriptKind.JS ? LanguageVariant.JSX : LanguageVariant.Standard;

src/compiler/program.ts

@@ -329,6 +329,9 @@ namespace ts {
         // Map storing if there is emit blocking diagnostics for given input
         const hasEmitBlockingDiagnostics = createFileMap<boolean>(getCanonicalFileName);
 
+        // ReactNamespace and jsxFactory information
+        let jsxFactoryEntity: EntityName;
+
         let resolveModuleNamesWorker: (moduleNames: string[], containingFile: string) => ResolvedModuleFull[];
         if (host.resolveModuleNames) {
             resolveModuleNamesWorker = (moduleNames, containingFile) => host.resolveModuleNames(moduleNames, containingFile).map(resolved => {
@@ -421,7 +424,8 @@ namespace ts {
             getFileProcessingDiagnostics: () => fileProcessingDiagnostics,
             getResolvedTypeReferenceDirectives: () => resolvedTypeReferenceDirectives,
             isSourceFileFromExternalLibrary,
-            dropDiagnosticsProducingTypeChecker
+            dropDiagnosticsProducingTypeChecker,
+            getJsxFactoryEntity: () => jsxFactoryEntity
         };
 
         verifyCompilerOptions();
@@ -727,6 +731,7 @@ namespace ts {
                 writeFile: writeFileCallback || (
                     (fileName, data, writeByteOrderMark, onError, sourceFiles) => host.writeFile(fileName, data, writeByteOrderMark, onError, sourceFiles)),
                 isEmitBlocked,
+                getJsxFactoryEntity: program.getJsxFactoryEntity,
             };
         }
 
@@ -1670,7 +1675,16 @@ namespace ts {
                 programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_cannot_be_specified_without_specifying_option_1, "emitDecoratorMetadata", "experimentalDecorators"));
             }
 
-            if (options.reactNamespace && !isIdentifierText(options.reactNamespace, languageVersion)) {
+            if (options.jsxFactory) {
+                if (options.reactNamespace) {
+                    programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_cannot_be_specified_with_option_1, "reactNamespace", "jsxFactory"));
+                }
+                jsxFactoryEntity = parseIsolatedEntityName(options.jsxFactory, languageVersion);
+                if (!jsxFactoryEntity) {
+                    programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Invalid_value_for_jsxFactory_0_is_not_a_valid_identifier_or_qualified_name, options.jsxFactory));
+                }
+            }
+            else if (options.reactNamespace && !isIdentifierText(options.reactNamespace, languageVersion)) {
                 programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Invalid_value_for_reactNamespace_0_is_not_a_valid_identifier, options.reactNamespace));
             }
 

src/compiler/transformers/jsx.ts

@@ -113,7 +113,8 @@ namespace ts {
                     || createAssignHelper(currentSourceFile.externalHelpersModuleName, segments);
             }
 
-            const element = createReactCreateElement(
+            const element = createExpressionForJsxElement(
+                context.getEmitHost().getJsxFactoryEntity(),
                 compilerOptions.reactNamespace,
                 tagName,
                 objectProperties,

src/compiler/types.ts

@@ -2177,6 +2177,7 @@ namespace ts {
         getTypeChecker(): TypeChecker;
 
         /* @internal */ getCommonSourceDirectory(): string;
+        /* @internal */ getJsxFactoryEntity(): EntityName;
 
         // For testing purposes only.  Should not be used by any other consumers (including the
         // language service).
@@ -2250,6 +2251,7 @@ namespace ts {
     /* @internal */
     export interface TypeCheckerHost {
         getCompilerOptions(): CompilerOptions;
+        getJsxFactoryEntity(): EntityName;
 
         getSourceFiles(): SourceFile[];
         getSourceFile(fileName: string): SourceFile;
@@ -3081,6 +3083,7 @@ namespace ts {
         project?: string;
         /* @internal */ pretty?: DiagnosticStyle;
         reactNamespace?: string;
+        jsxFactory?: string;
         removeComments?: boolean;
         rootDir?: string;
         rootDirs?: string[];

src/compiler/utilities.ts

@@ -34,6 +34,8 @@ namespace ts {
         /* @internal */
         isSourceFileFromExternalLibrary(file: SourceFile): boolean;
 
+        /* @internal */
+        getJsxFactoryEntity(): EntityName;
         getCommonSourceDirectory(): string;
         getCanonicalFileName(fileName: string): string;
         getNewLine(): string;

src/harness/harness.ts

@@ -1768,7 +1768,7 @@ namespace Harness {
         }
 
         // Regex for parsing options in the format "@Alpha: Value of any sort"
-        const optionRegex = /^[\/]{2}\s*@(\w+)\s*:\s*(\S*)/gm;  // multiple matches on multiple lines
+        const optionRegex = /^[\/]{2}\s*@(\w+)\s*:\s*([^\r\n]*)/gm;  // multiple matches on multiple lines
 
         function extractCompilerSettings(content: string): CompilerSettings {
             const opts: CompilerSettings = {};
@@ -1777,7 +1777,7 @@ namespace Harness {
             /* tslint:disable:no-null-keyword */
             while ((match = optionRegex.exec(content)) !== null) {
             /* tslint:enable:no-null-keyword */
-                opts[match[1]] = match[2];
+                opts[match[1]] = match[2].trim();
             }
 
             return opts;
@@ -1805,7 +1805,7 @@ namespace Harness {
                     // Comment line, check for global/file @options and record them
                     optionRegex.lastIndex = 0;
                     const metaDataName = testMetaData[1].toLowerCase();
-                    currentFileOptions[testMetaData[1]] = testMetaData[2];
+                    currentFileOptions[testMetaData[1]] = testMetaData[2].trim();
                     if (metaDataName !== "filename") {
                         continue;
                     }
@@ -1825,12 +1825,12 @@ namespace Harness {
                         // Reset local data
                         currentFileContent = undefined;
                         currentFileOptions = {};
-                        currentFileName = testMetaData[2];
+                        currentFileName = testMetaData[2].trim();
                         refs = [];
                     }
                     else {
                         // First metadata marker in the file
-                        currentFileName = testMetaData[2];
+                        currentFileName = testMetaData[2].trim();
                     }
                 }
                 else {

src/harness/unittests/transpile.ts

@@ -385,6 +385,10 @@ var x = 0;`, {
             options: { compilerOptions: { reactNamespace: "react" }, fileName: "input.js", reportDiagnostics: true }
         });
 
+        transpilesCorrectly("Supports setting 'jsxFactory'", "x;", {
+            options: { compilerOptions: { jsxFactory: "createElement" }, fileName: "input.js", reportDiagnostics: true }
+        });
+
         transpilesCorrectly("Supports setting 'removeComments'", "x;", {
             options: { compilerOptions: { removeComments: true }, fileName: "input.js", reportDiagnostics: true }
         });

tests/baselines/reference/jsxFactoryAndReactNamespace.errors.txt

@@ -0,0 +1,53 @@
+error TS5053: Option 'reactNamespace' cannot be specified with option 'jsxFactory'.
+
+
+!!! error TS5053: Option 'reactNamespace' cannot be specified with option 'jsxFactory'.
+==== tests/cases/compiler/Element.ts (0 errors) ====
+
+    declare namespace JSX {
+        interface Element {
+            name: string;
+            isIntrinsic: boolean;
+            isCustomElement: boolean;
+            toString(renderId?: number): string;
+            bindDOM(renderId?: number): number;
+            resetComponent(): void;
+            instantiateComponents(renderId?: number): number;
+            props: any;
+        }
+    }
+    export namespace Element {
+        export function isElement(el: any): el is JSX.Element {
+            return el.markAsChildOfRootElement !== undefined;
+        }
+
+        export function createElement(args: any[]) {
+
+            return {
+            }
+        }
+    }
+
+    export let createElement = Element.createElement;
+
+    function toCamelCase(text: string): string {
+        return text[0].toLowerCase() + text.substring(1);
+    }
+
+==== tests/cases/compiler/test.tsx (0 errors) ====
+    import { Element} from './Element';
+
+    let c: {
+    	a?: {
+    		b: string
+    	}
+    };
+
+    class A {
+    	view() {
+    		return [
+    			<meta content="helloworld"></meta>,
+    			<meta content={c.a!.b}></meta>
+    		];
+    	}
+    }