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ahejlsbergahejlsberg
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Parsing, binding, checking of export default with function/class
1 parent 74acbe9 commit 9af8ae4

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6 files changed

+73
-32
lines changed

6 files changed

+73
-32
lines changed

‎src/compiler/binder.ts

Lines changed: 6 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -112,10 +112,13 @@ module ts {
112112
return "__new";
113113
case SyntaxKind.IndexSignature:
114114
return "__index";
115-
case SyntaxKind.ExportAssignment:
116-
return "default";
117115
case SyntaxKind.ExportDeclaration:
118116
return "__export";
117+
case SyntaxKind.ExportAssignment:
118+
return "default";
119+
case SyntaxKind.FunctionDeclaration:
120+
case SyntaxKind.ClassDeclaration:
121+
return node.flags & NodeFlags.Default ? "default" : undefined;
119122
}
120123
}
121124

@@ -126,7 +129,7 @@ module ts {
126129
function declareSymbol(symbols: SymbolTable, parent: Symbol, node: Declaration, includes: SymbolFlags, excludes: SymbolFlags): Symbol {
127130
Debug.assert(!hasDynamicName(node));
128131

129-
var name = getDeclarationName(node);
132+
var name = node.flags & NodeFlags.Default && parent ? "default" : getDeclarationName(node);
130133
if (name !== undefined) {
131134
var symbol = hasProperty(symbols, name) ? symbols[name] : (symbols[name] = createSymbol(0, name));
132135
if (symbol.flags & excludes) {

‎src/compiler/checker.ts

Lines changed: 29 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -8268,7 +8268,7 @@ module ts {
82688268
// Do not use hasDynamicName here, because that returns false for well known symbols.
82698269
// We want to perform checkComputedPropertyName for all computed properties, including
82708270
// well known symbols.
8271-
if (node.name.kind === SyntaxKind.ComputedPropertyName) {
8271+
if (node.name && node.name.kind === SyntaxKind.ComputedPropertyName) {
82728272
// This check will account for methods in class/interface declarations,
82738273
// as well as accessors in classes/object literals
82748274
checkComputedPropertyName(<ComputedPropertyName>node.name);
@@ -8998,10 +8998,12 @@ module ts {
89988998
// Grammar checking
89998999
checkGrammarClassDeclarationHeritageClauses(node);
90009000

9001-
checkTypeNameIsReserved(node.name, Diagnostics.Class_name_cannot_be_0);
9001+
if (node.name) {
9002+
checkTypeNameIsReserved(node.name, Diagnostics.Class_name_cannot_be_0);
9003+
checkCollisionWithCapturedThisVariable(node, node.name);
9004+
checkCollisionWithRequireExportsInGeneratedCode(node, node.name);
9005+
}
90029006
checkTypeParameters(node.typeParameters);
9003-
checkCollisionWithCapturedThisVariable(node, node.name);
9004-
checkCollisionWithRequireExportsInGeneratedCode(node, node.name);
90059007
checkExportsOnMergedDeclarations(node);
90069008
var symbol = getSymbolOfNode(node);
90079009
var type = <InterfaceType>getDeclaredTypeOfSymbol(symbol);
@@ -9014,9 +9016,9 @@ module ts {
90149016
if (type.baseTypes.length) {
90159017
if (produceDiagnostics) {
90169018
var baseType = type.baseTypes[0];
9017-
checkTypeAssignableTo(type, baseType, node.name, Diagnostics.Class_0_incorrectly_extends_base_class_1);
9019+
checkTypeAssignableTo(type, baseType, node.name || node, Diagnostics.Class_0_incorrectly_extends_base_class_1);
90189020
var staticBaseType = getTypeOfSymbol(baseType.symbol);
9019-
checkTypeAssignableTo(staticType, getTypeWithoutConstructors(staticBaseType), node.name,
9021+
checkTypeAssignableTo(staticType, getTypeWithoutConstructors(staticBaseType), node.name || node,
90209022
Diagnostics.Class_static_side_0_incorrectly_extends_base_class_static_side_1);
90219023
if (baseType.symbol !== resolveEntityName(baseTypeNode.typeName, SymbolFlags.Value)) {
90229024
error(baseTypeNode, Diagnostics.Type_name_0_in_extends_clause_does_not_reference_constructor_function_for_0, typeToString(baseType));
@@ -9038,7 +9040,7 @@ module ts {
90389040
if (t !== unknownType) {
90399041
var declaredType = (t.flags & TypeFlags.Reference) ? (<TypeReference>t).target : t;
90409042
if (declaredType.flags & (TypeFlags.Class | TypeFlags.Interface)) {
9041-
checkTypeAssignableTo(type, t, node.name, Diagnostics.Class_0_incorrectly_implements_interface_1);
9043+
checkTypeAssignableTo(type, t, node.name || node, Diagnostics.Class_0_incorrectly_implements_interface_1);
90429044
}
90439045
else {
90449046
error(typeRefNode, Diagnostics.A_class_may_only_implement_another_class_or_interface);
@@ -10414,6 +10416,10 @@ module ts {
1041410416

1041510417
function generateNames(node: Node) {
1041610418
switch (node.kind) {
10419+
case SyntaxKind.FunctionDeclaration:
10420+
case SyntaxKind.ClassDeclaration:
10421+
generateNameForFunctionOrClassDeclaration(<Declaration>node);
10422+
break;
1041710423
case SyntaxKind.ModuleDeclaration:
1041810424
generateNameForModuleOrEnum(<ModuleDeclaration>node);
1041910425
generateNames((<ModuleDeclaration>node).body);
@@ -10427,6 +10433,9 @@ module ts {
1042710433
case SyntaxKind.ExportDeclaration:
1042810434
generateNameForExportDeclaration(<ExportDeclaration>node);
1042910435
break;
10436+
case SyntaxKind.ExportAssignment:
10437+
generateNameForExportAssignment(<ExportAssignment>node);
10438+
break;
1043010439
case SyntaxKind.SourceFile:
1043110440
case SyntaxKind.ModuleBlock:
1043210441
forEach((<SourceFile | ModuleBlock>node).statements, generateNames);
@@ -10464,6 +10473,12 @@ module ts {
1046410473
getNodeLinks(node).generatedName = unescapeIdentifier(name);
1046510474
}
1046610475

10476+
function generateNameForFunctionOrClassDeclaration(node: Declaration) {
10477+
if (!node.name) {
10478+
assignGeneratedName(node, makeUniqueName("default"));
10479+
}
10480+
}
10481+
1046710482
function generateNameForModuleOrEnum(node: ModuleDeclaration | EnumDeclaration) {
1046810483
if (node.name.kind === SyntaxKind.Identifier) {
1046910484
var name = node.name.text;
@@ -10490,9 +10505,15 @@ module ts {
1049010505
generateNameForImportOrExportDeclaration(node);
1049110506
}
1049210507
}
10508+
10509+
function generateNameForExportAssignment(node: ExportAssignment) {
10510+
if (node.expression.kind !== SyntaxKind.Identifier) {
10511+
assignGeneratedName(node, makeUniqueName("default"));
10512+
}
10513+
}
1049310514
}
1049410515

10495-
function getGeneratedNameForNode(node: ModuleDeclaration | EnumDeclaration | ImportDeclaration | ExportDeclaration) {
10516+
function getGeneratedNameForNode(node: Node) {
1049610517
var links = getNodeLinks(node);
1049710518
if (!links.generatedName) {
1049810519
getGeneratedNamesForSourceFile(getSourceFile(node));

‎src/compiler/emitter.ts

Lines changed: 15 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -1580,7 +1580,7 @@ module ts {
15801580
var tempParameters: Identifier[];
15811581
var externalImports: ExternalImportInfo[];
15821582
var exportSpecifiers: Map<ExportSpecifier[]>;
1583-
var exportDefault: ExportAssignment | ExportSpecifier;
1583+
var exportDefault: FunctionDeclaration | ClassDeclaration | ExportAssignment | ExportSpecifier;
15841584

15851585
/** write emitted output to disk*/
15861586
var writeEmittedFiles = writeJavaScriptFile;
@@ -3912,7 +3912,7 @@ module ts {
39123912
emitExpressionFunctionBody(node, <Expression>node.body);
39133913
}
39143914

3915-
if (node.flags & NodeFlags.Export) {
3915+
if (node.flags & NodeFlags.Export && !(node.flags & NodeFlags.Default)) {
39163916
writeLine();
39173917
emitStart(node);
39183918
emitModuleMemberName(node);
@@ -4243,11 +4243,10 @@ module ts {
42434243
emitMemberFunctions(node);
42444244
emitMemberAssignments(node, NodeFlags.Static);
42454245
writeLine();
4246-
function emitClassReturnStatement() {
4246+
emitToken(SyntaxKind.CloseBraceToken, node.members.end, () => {
42474247
write("return ");
42484248
emitNode(node.name);
4249-
}
4250-
emitToken(SyntaxKind.CloseBraceToken, node.members.end, emitClassReturnStatement);
4249+
});
42514250
write(";");
42524251
decreaseIndent();
42534252
writeLine();
@@ -4260,7 +4259,7 @@ module ts {
42604259
}
42614260
write(");");
42624261
emitEnd(node);
4263-
if (node.flags & NodeFlags.Export) {
4262+
if (node.flags & NodeFlags.Export && !(node.flags & NodeFlags.Default)) {
42644263
writeLine();
42654264
emitStart(node);
42664265
emitModuleMemberName(node);
@@ -4269,7 +4268,7 @@ module ts {
42694268
emitEnd(node);
42704269
write(";");
42714270
}
4272-
if (languageVersion < ScriptTarget.ES6 && node.parent === currentSourceFile) {
4271+
if (languageVersion < ScriptTarget.ES6 && node.parent === currentSourceFile && node.name) {
42734272
emitExportMemberAssignments(node.name);
42744273
}
42754274

@@ -4680,6 +4679,11 @@ module ts {
46804679
else if (node.kind === SyntaxKind.ExportAssignment) {
46814680
exportDefault = exportDefault || <ExportAssignment>node;
46824681
}
4682+
else if (node.kind === SyntaxKind.FunctionDeclaration || node.kind === SyntaxKind.ClassDeclaration) {
4683+
if (node.flags & NodeFlags.Export && node.flags & NodeFlags.Default) {
4684+
exportDefault = exportDefault || <FunctionDeclaration | ClassDeclaration>node;
4685+
}
4686+
}
46834687
else {
46844688
var info = createExternalImportInfo(node);
46854689
if (info) {
@@ -4788,9 +4792,12 @@ module ts {
47884792
if (exportDefault.kind === SyntaxKind.ExportAssignment) {
47894793
emit((<ExportAssignment>exportDefault).expression);
47904794
}
4791-
else {
4795+
else if (exportDefault.kind === SyntaxKind.ExportSpecifier) {
47924796
emit((<ExportSpecifier>exportDefault).propertyName);
47934797
}
4798+
else {
4799+
emit((<Declaration>exportDefault).name);
4800+
}
47944801
write(";");
47954802
emitEnd(exportDefault);
47964803
}

‎src/compiler/parser.ts

Lines changed: 12 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -358,6 +358,7 @@ module ts {
358358
case SyntaxKind.ExportKeyword: return NodeFlags.Export;
359359
case SyntaxKind.DeclareKeyword: return NodeFlags.Ambient;
360360
case SyntaxKind.ConstKeyword: return NodeFlags.Const;
361+
case SyntaxKind.DefaultKeyword: return NodeFlags.Default;
361362
}
362363
return 0;
363364
}
@@ -1501,11 +1502,13 @@ module ts {
15011502
if (token === SyntaxKind.ExportKeyword) {
15021503
nextToken();
15031504
if (token === SyntaxKind.DefaultKeyword) {
1504-
nextToken();
1505-
return token === SyntaxKind.ClassKeyword || token === SyntaxKind.FunctionKeyword;
1505+
return lookAhead(nextTokenIsClassOrFunction);
15061506
}
15071507
return token !== SyntaxKind.AsteriskToken && token !== SyntaxKind.OpenBraceToken && canFollowModifier();
15081508
}
1509+
if (token === SyntaxKind.DefaultKeyword) {
1510+
return nextTokenIsClassOrFunction();
1511+
}
15091512
nextToken();
15101513
return canFollowModifier();
15111514
}
@@ -1517,6 +1520,11 @@ module ts {
15171520
|| isLiteralPropertyName();
15181521
}
15191522

1523+
function nextTokenIsClassOrFunction(): boolean {
1524+
nextToken();
1525+
return token === SyntaxKind.ClassKeyword || token === SyntaxKind.FunctionKeyword;
1526+
}
1527+
15201528
// True if positioned at the start of a list element
15211529
function isListElement(parsingContext: ParsingContext, inErrorRecovery: boolean): boolean {
15221530
var node = currentNode(parsingContext);
@@ -4323,7 +4331,7 @@ module ts {
43234331
setModifiers(node, modifiers);
43244332
parseExpected(SyntaxKind.FunctionKeyword);
43254333
node.asteriskToken = parseOptionalToken(SyntaxKind.AsteriskToken);
4326-
node.name = parseIdentifier();
4334+
node.name = node.flags & NodeFlags.Default ? parseOptionalIdentifier() : parseIdentifier();
43274335
fillSignature(SyntaxKind.ColonToken, /*yieldAndGeneratorParameterContext:*/ !!node.asteriskToken, /*requireCompleteParameterList:*/ false, node);
43284336
node.body = parseFunctionBlockOrSemicolon(!!node.asteriskToken, Diagnostics.or_expected);
43294337
return finishNode(node);
@@ -4499,7 +4507,7 @@ module ts {
44994507
var node = <ClassDeclaration>createNode(SyntaxKind.ClassDeclaration, fullStart);
45004508
setModifiers(node, modifiers);
45014509
parseExpected(SyntaxKind.ClassKeyword);
4502-
node.name = parseIdentifier();
4510+
node.name = node.flags & NodeFlags.Default ? parseOptionalIdentifier() : parseIdentifier();
45034511
node.typeParameters = parseTypeParameters();
45044512
node.heritageClauses = parseHeritageClauses(/*isClassHeritageClause:*/ true);
45054513

‎src/compiler/types.ts

Lines changed: 10 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -298,14 +298,15 @@ module ts {
298298
Private = 0x00000020, // Property/Method
299299
Protected = 0x00000040, // Property/Method
300300
Static = 0x00000080, // Property/Method
301-
MultiLine = 0x00000100, // Multi-line array or object literal
302-
Synthetic = 0x00000200, // Synthetic node (for full fidelity)
303-
DeclarationFile = 0x00000400, // Node is a .d.ts file
304-
Let = 0x00000800, // Variable declaration
305-
Const = 0x00001000, // Variable declaration
306-
OctalLiteral = 0x00002000,
307-
308-
Modifier = Export | Ambient | Public | Private | Protected | Static,
301+
Default = 0x00000100, // Function/Class (export default declaration)
302+
MultiLine = 0x00000200, // Multi-line array or object literal
303+
Synthetic = 0x00000400, // Synthetic node (for full fidelity)
304+
DeclarationFile = 0x00000800, // Node is a .d.ts file
305+
Let = 0x00001000, // Variable declaration
306+
Const = 0x00002000, // Variable declaration
307+
OctalLiteral = 0x00004000,
308+
309+
Modifier = Export | Ambient | Public | Private | Protected | Static | Default,
309310
AccessibilityModifier = Public | Private | Protected,
310311
BlockScoped = Let | Const
311312
}
@@ -1185,7 +1186,7 @@ module ts {
11851186
}
11861187

11871188
export interface EmitResolver {
1188-
getGeneratedNameForNode(node: ModuleDeclaration | EnumDeclaration | ImportDeclaration | ExportDeclaration): string;
1189+
getGeneratedNameForNode(node: Node): string;
11891190
getExpressionNameSubstitution(node: Identifier): string;
11901191
hasExportDefaultValue(node: SourceFile): boolean;
11911192
isReferencedImportDeclaration(node: Node): boolean;

‎src/compiler/utilities.ts

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -901,6 +901,7 @@ module ts {
901901
case SyntaxKind.ExportKeyword:
902902
case SyntaxKind.DeclareKeyword:
903903
case SyntaxKind.ConstKeyword:
904+
case SyntaxKind.DefaultKeyword:
904905
return true;
905906
}
906907
return false;

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