Merge branch 'master' into typeAssertionInitializers

src/compiler/checker.ts

@@ -8584,6 +8584,9 @@ namespace ts {
             }
 
             function narrowTypeByEquality(type: Type, operator: SyntaxKind, value: Expression, assumeTrue: boolean): Type {
+                if (type.flags & TypeFlags.Any) {
+                    return type;
+                }
                 if (operator === SyntaxKind.ExclamationEqualsToken || operator === SyntaxKind.ExclamationEqualsEqualsToken) {
                     assumeTrue = !assumeTrue;
                 }

src/compiler/emitter.ts

@@ -252,7 +252,9 @@ const _super = (function (geti, seti) {
 
             // Emit helpers from all the files
             if (isBundledEmit && moduleKind) {
-                forEach(sourceFiles, emitEmitHelpers);
+                for (const sourceFile of sourceFiles) {
+                    emitEmitHelpers(sourceFile);
+                }
             }
 
             // Print each transformed source file.

src/compiler/transformers/es6.ts

@@ -541,7 +541,7 @@ namespace ts {
          *
          * @param node A ClassDeclaration node.
          */
-        function visitClassDeclaration(node: ClassDeclaration): Statement {
+        function visitClassDeclaration(node: ClassDeclaration): VisitResult<Statement> {
             // [source]
             //      class C { }
             //
@@ -552,8 +552,17 @@ namespace ts {
             //          return C;
             //      }());
 
+            const modifierFlags = getModifierFlags(node);
+            const isExported = modifierFlags & ModifierFlags.Export;
+            const isDefault = modifierFlags & ModifierFlags.Default;
+
+            // Add an `export` modifier to the statement if needed (for `--target es5 --module es6`)
+            const modifiers = isExported && !isDefault
+                ? filter(node.modifiers, isExportModifier)
+                : undefined;
+
             const statement = createVariableStatement(
-                /*modifiers*/ undefined,
+                modifiers,
                 createVariableDeclarationList([
                     createVariableDeclaration(
                         getDeclarationName(node, /*allowComments*/ true),
@@ -566,9 +575,26 @@ namespace ts {
 
             setOriginalNode(statement, node);
             startOnNewLine(statement);
+
+            // Add an `export default` statement for default exports (for `--target es5 --module es6`)
+            if (isExported && isDefault) {
+                const statements: Statement[] = [statement];
+                statements.push(createExportAssignment(
+                    /*decorators*/ undefined,
+                    /*modifiers*/ undefined,
+                    /*isExportEquals*/ false,
+                    getDeclarationName(node, /*allowComments*/ false)
+                ));
+                return statements;
+            }
+
             return statement;
         }
 
+        function isExportModifier(node: Modifier) {
+            return node.kind === SyntaxKind.ExportKeyword;
+        }
+
         /**
          * Visits a ClassExpression and transforms it into an expression.
          *

src/compiler/transformers/module/module.ts

@@ -705,7 +705,7 @@ namespace ts {
                         createFunctionDeclaration(
                             /*decorators*/ undefined,
                             /*modifiers*/ undefined,
-                            /*asteriskToken*/ undefined,
+                            node.asteriskToken,
                             name,
                             /*typeParameters*/ undefined,
                             node.parameters,