Merge from vscode cfc1ab4c5f816765b91fb7ead3c3427a7c8581a3

build/lib/treeshaking.ts

@@ -18,7 +18,7 @@ export const enum ShakeLevel {
 }
 
 export function toStringShakeLevel(shakeLevel: ShakeLevel): string {
-	switch(shakeLevel) {
+	switch (shakeLevel) {
 		case ShakeLevel.Files:
 			return 'Files (0)';
 		case ShakeLevel.InnerFile:
@@ -42,11 +42,6 @@ export interface ITreeShakingOptions {
 	 * Inline usages.
 	 */
 	inlineEntryPoints: string[];
-	/**
-	 * TypeScript libs.
-	 * e.g. `lib.d.ts`, `lib.es2015.collection.d.ts`
-	 */
-	libs: string[];
 	/**
 	 * Other .d.ts files
 	 */
@@ -130,11 +125,7 @@ function createTypeScriptLanguageService(options: ITreeShakingOptions): ts.Langu
 	});
 
 	// Resolve libs
-	const RESOLVED_LIBS: ILibMap = {};
-	options.libs.forEach((filename) => {
-		const filepath = path.join(TYPESCRIPT_LIB_FOLDER, filename);
-		RESOLVED_LIBS[`defaultLib:${filename}`] = fs.readFileSync(filepath).toString();
-	});
+	const RESOLVED_LIBS = processLibFiles(options);
 
 	const compilerOptions = ts.convertCompilerOptionsFromJson(options.compilerOptions, options.sourcesRoot).options;
 
@@ -205,6 +196,34 @@ function discoverAndReadFiles(options: ITreeShakingOptions): IFileMap {
 	return FILES;
 }
 
+/**
+ * Read lib files and follow lib references
+ */
+function processLibFiles(options: ITreeShakingOptions): ILibMap {
+
+	const stack: string[] = [...options.compilerOptions.lib];
+	const result: ILibMap = {};
+
+	while (stack.length > 0) {
+		const filename = `lib.${stack.shift()!.toLowerCase()}.d.ts`;
+		const key = `defaultLib:${filename}`;
+		if (!result[key]) {
+			// add this file
+			const filepath = path.join(TYPESCRIPT_LIB_FOLDER, filename);
+			const sourceText = fs.readFileSync(filepath).toString();
+			result[key] = sourceText;
+
+			// precess dependencies and "recurse"
+			const info = ts.preProcessFile(sourceText);
+			for (let ref of info.libReferenceDirectives) {
+				stack.push(ref.fileName);
+			}
+		}
+	}
+
+	return result;
+}
+
 interface ILibMap { [libName: string]: string; }
 interface IFileMap { [fileName: string]: string; }
 
@@ -317,6 +336,7 @@ function markNodes(languageService: ts.LanguageService, options: ITreeShakingOpt
 
 	const black_queue: ts.Node[] = [];
 	const gray_queue: ts.Node[] = [];
+	const export_import_queue: ts.Node[] = [];
 	const sourceFilesLoaded: { [fileName: string]: boolean } = {};
 
 	function enqueueTopLevelModuleStatements(sourceFile: ts.SourceFile): void {
@@ -332,10 +352,16 @@ function markNodes(languageService: ts.LanguageService, options: ITreeShakingOpt
 			}
 
 			if (ts.isExportDeclaration(node)) {
-				if (node.moduleSpecifier && ts.isStringLiteral(node.moduleSpecifier)) {
+				if (!node.exportClause && node.moduleSpecifier && ts.isStringLiteral(node.moduleSpecifier)) {
+					// export * from "foo";
 					setColor(node, NodeColor.Black);
 					enqueueImport(node, node.moduleSpecifier.text);
 				}
+				if (node.exportClause && ts.isNamedExports(node.exportClause)) {
+					for (const exportSpecifier of node.exportClause.elements) {
+						export_import_queue.push(exportSpecifier);
+					}
+				}
 				return;
 			}
 
@@ -475,7 +501,7 @@ function markNodes(languageService: ts.LanguageService, options: ITreeShakingOpt
 		}
 
 		if (black_queue.length === 0) {
-			for (let i = 0; i< gray_queue.length; i++) {
+			for (let i = 0; i < gray_queue.length; i++) {
 				const node = gray_queue[i];
 				const nodeParent = node.parent;
 				if ((ts.isClassDeclaration(nodeParent) || ts.isInterfaceDeclaration(nodeParent)) && nodeOrChildIsBlack(nodeParent)) {
@@ -521,6 +547,7 @@ function markNodes(languageService: ts.LanguageService, options: ITreeShakingOpt
 								|| ts.isConstructSignatureDeclaration(member)
 								|| ts.isIndexSignatureDeclaration(member)
 								|| ts.isCallSignatureDeclaration(member)
+								|| memberName === '[Symbol.iterator]'
 								|| memberName === 'toJSON'
 								|| memberName === 'toString'
 								|| memberName === 'dispose'// TODO: keeping all `dispose` methods
@@ -545,6 +572,23 @@ function markNodes(languageService: ts.LanguageService, options: ITreeShakingOpt
 		};
 		node.forEachChild(loop);
 	}
+
+	while (export_import_queue.length > 0) {
+		const node = export_import_queue.shift()!;
+		if (nodeOrParentIsBlack(node)) {
+			continue;
+		}
+		const symbol: ts.Symbol | undefined = (<any>node).symbol;
+		if (!symbol) {
+			continue;
+		}
+		const aliased = checker.getAliasedSymbol(symbol);
+		if (aliased.declarations && aliased.declarations.length > 0) {
+			if (nodeOrParentIsBlack(aliased.declarations[0]) || nodeOrChildIsBlack(aliased.declarations[0])) {
+				setColor(node, NodeColor.Black);
+			}
+		}
+	}
 }
 
 function nodeIsInItsOwnDeclaration(nodeSourceFile: ts.SourceFile, node: ts.Node, symbol: ts.Symbol): boolean {
@@ -646,6 +690,22 @@ function generateResult(languageService: ts.LanguageService, shakeLevel: ShakeLe
 				}
 			}
 
+			if (ts.isExportDeclaration(node)) {
+				if (node.exportClause && node.moduleSpecifier && ts.isNamedExports(node.exportClause)) {
+					let survivingExports: string[] = [];
+					for (const exportSpecifier of node.exportClause.elements) {
+						if (getColor(exportSpecifier) === NodeColor.Black) {
+							survivingExports.push(exportSpecifier.getFullText(sourceFile));
+						}
+					}
+					const leadingTriviaWidth = node.getLeadingTriviaWidth();
+					const leadingTrivia = sourceFile.text.substr(node.pos, leadingTriviaWidth);
+					if (survivingExports.length > 0) {
+						return write(`${leadingTrivia}export {${survivingExports.join(',')} } from${node.moduleSpecifier.getFullText(sourceFile)};`);
+					}
+				}
+			}
+
 			if (shakeLevel === ShakeLevel.ClassMembers && (ts.isClassDeclaration(node) || ts.isInterfaceDeclaration(node)) && nodeOrChildIsBlack(node)) {
 				let toWrite = node.getFullText();
 				for (let i = node.members.length - 1; i >= 0; i--) {
@@ -708,7 +768,7 @@ function getRealNodeSymbol(checker: ts.TypeChecker, node: ts.Node): [ts.Symbol |
 	//   (2) when the aliased symbol is originating from an import.
 	//
 	function shouldSkipAlias(node: ts.Node, declaration: ts.Node): boolean {
-		if (node.kind !== ts.SyntaxKind.Identifier) {
+		if (!ts.isShorthandPropertyAssignment(node) && node.kind !== ts.SyntaxKind.Identifier) {
 			return false;
 		}
 		if (node.parent === declaration) {
@@ -733,7 +793,12 @@ function getRealNodeSymbol(checker: ts.TypeChecker, node: ts.Node): [ts.Symbol |
 
 	const { parent } = node;
 
-	let symbol = checker.getSymbolAtLocation(node);
+	let symbol = (
+		ts.isShorthandPropertyAssignment(node)
+		? checker.getShorthandAssignmentValueSymbol(node)
+		: checker.getSymbolAtLocation(node)
+	);
+
 	let importNode: ts.Declaration | null = null;
 	// If this is an alias, and the request came at the declaration location
 	// get the aliased symbol instead. This allows for goto def on an import e.g.