Verify JS function is constructor

Author: rbuckton

Jakefile.js

@@ -802,7 +802,8 @@ function runConsoleTests(defaultReporter, runInParallel) {
 
     var debug = process.env.debug || process.env.d;
     var inspect = process.env.inspect;
-    tests = process.env.test || process.env.tests || process.env.t;
+    var testTimeout = process.env.timeout || defaultTestTimeout;
+    var tests = process.env.test || process.env.tests || process.env.t;
     var light = process.env.light || false;
     var stackTraceLimit = process.env.stackTraceLimit;
     var testConfigFile = 'test.config';
@@ -820,7 +821,7 @@ function runConsoleTests(defaultReporter, runInParallel) {
         } while (fs.existsSync(taskConfigsFolder));
         fs.mkdirSync(taskConfigsFolder);
 
-        workerCount = process.env.workerCount || os.cpus().length;
+        workerCount = process.env.workerCount || process.env.p || os.cpus().length;
     }
 
     if (tests || light || taskConfigsFolder) {
@@ -925,7 +926,7 @@ function runConsoleTests(defaultReporter, runInParallel) {
     }
 }
 
-var testTimeout = 20000;
+var defaultTestTimeout = 20000;
 desc("Runs all the tests in parallel using the built run.js file. Optional arguments are: t[ests]=category1|category2|... d[ebug]=true.");
 task("runtests-parallel", ["build-rules", "tests", builtLocalDirectory], function () {
     runConsoleTests('min', /*runInParallel*/ true);

src/compiler/checker.ts

@@ -15892,7 +15892,7 @@ namespace ts {
             const callSignatures = getSignaturesOfType(expressionType, SignatureKind.Call);
             if (callSignatures.length) {
                 const signature = resolveCall(node, callSignatures, candidatesOutArray);
-                if (!isInJavaScriptFile(signature.declaration) && getReturnTypeOfSignature(signature) !== voidType) {
+                if (!isJavaScriptConstructor(signature.declaration) && getReturnTypeOfSignature(signature) !== voidType) {
                     error(node, Diagnostics.Only_a_void_function_can_be_called_with_the_new_keyword);
                 }
                 if (getThisTypeOfSignature(signature) === voidType) {
@@ -16119,6 +16119,26 @@ namespace ts {
             return getNodeLinks(node).resolvedSignature === resolvingSignature ? resolvingSignature : getResolvedSignature(node);
         }
 
+        /**
+         * Indicates whether a declaration can be treated as a constructor in a JavaScript
+         * file.
+         */
+        function isJavaScriptConstructor(node: Declaration): boolean {
+            if (isInJavaScriptFile(node)) {
+                // If the node has a @class tag, treat it like a constructor.
+                if (getJSDocClassTag(node)) return true;
+
+                // If the symbol of the node has members, treat it like a constructor.
+                const symbol = isFunctionDeclaration(node) || isFunctionExpression(node) ? getSymbolOfNode(node) :
+                     isVariableDeclaration(node) && isFunctionExpression(node.initializer) ? getSymbolOfNode(node.initializer) :
+                     undefined;
+
+                return symbol && symbol.members !== undefined;
+            }
+
+            return false;
+        }
+
         function getInferredClassType(symbol: Symbol) {
             const links = getSymbolLinks(symbol);
             if (!links.inferredClassType) {

src/compiler/parser.ts

@@ -6533,6 +6533,10 @@ namespace ts {
                             case "augments":
                                 tag = parseAugmentsTag(atToken, tagName);
                                 break;
+                            case "class":
+                            case "constructor":
+                                tag = parseClassTag(atToken, tagName);
+                                break;
                             case "arg":
                             case "argument":
                             case "param":
@@ -6752,6 +6756,13 @@ namespace ts {
                     return finishNode(result);
                 }
 
+                function parseClassTag(atToken: AtToken, tagName: Identifier): JSDocClassTag {
+                    const tag = <JSDocClassTag>createNode(SyntaxKind.JSDocClassTag, atToken.pos);
+                    tag.atToken = atToken;
+                    tag.tagName = tagName;
+                    return finishNode(tag);
+                }
+
                 function parseTypedefTag(atToken: AtToken, tagName: Identifier): JSDocTypedefTag {
                     const typeExpression = tryParseTypeExpression();
                     skipWhitespace();

src/compiler/types.ts

@@ -374,6 +374,7 @@ namespace ts {
         JSDocComment,
         JSDocTag,
         JSDocAugmentsTag,
+        JSDocClassTag,
         JSDocParameterTag,
         JSDocReturnTag,
         JSDocTypeTag,
@@ -2132,6 +2133,10 @@ namespace ts {
         typeExpression: JSDocTypeExpression;
     }
 
+    export interface JSDocClassTag extends JSDocTag {
+        kind: SyntaxKind.JSDocClassTag;
+    }
+
     export interface JSDocTemplateTag extends JSDocTag {
         kind: SyntaxKind.JSDocTemplateTag;
         typeParameters: NodeArray<TypeParameterDeclaration>;

src/compiler/utilities.ts

@@ -1562,6 +1562,10 @@ namespace ts {
         return getFirstJSDocTag(node, SyntaxKind.JSDocAugmentsTag) as JSDocAugmentsTag;
     }
 
+    export function getJSDocClassTag(node: Node): JSDocClassTag {
+        return getFirstJSDocTag(node, SyntaxKind.JSDocClassTag) as JSDocClassTag;
+    }
+
     export function getJSDocReturnTag(node: Node): JSDocReturnTag {
         return getFirstJSDocTag(node, SyntaxKind.JSDocReturnTag) as JSDocReturnTag;
     }