Merge pull request microsoft#5294 from Microsoft/fixDecoratorSwitch

Fixes an issue with decorators when compiling using tsc.exe

Author: rbuckton

src/compiler/checker.ts

@@ -8646,39 +8646,36 @@ namespace ts {
  */
  function getEffectiveDecoratorFirstArgumentType(node: Node): Type {
  // The first argument to a decorator is its `target`.
- switch (node.kind) {
- case SyntaxKind.ClassDeclaration:
- case SyntaxKind.ClassExpression:
- // For a class decorator, the `target` is the type of the class (e.g. the
- // "static" or "constructor" side of the class)
+ if (node.kind === SyntaxKind.ClassDeclaration) {
+ // For a class decorator, the `target` is the type of the class (e.g. the
+ // "static" or "constructor" side of the class)
+ let classSymbol = getSymbolOfNode(node);
+ return getTypeOfSymbol(classSymbol);
+ }
+
+ if (node.kind === SyntaxKind.Parameter) {
+ // For a parameter decorator, the `target` is the parent type of the
+ // parameter's containing method.
+ node = node.parent;
+ if (node.kind === SyntaxKind.Constructor) {
  let classSymbol = getSymbolOfNode(node);
  return getTypeOfSymbol(classSymbol);
+ }
+ }
 
- case SyntaxKind.Parameter:
- // For a parameter decorator, the `target` is the parent type of the
- // parameter's containing method.
- node = node.parent;
- if (node.kind === SyntaxKind.Constructor) {
- let classSymbol = getSymbolOfNode(node);
- return getTypeOfSymbol(classSymbol);
- }
-
- // fall-through
-
- case SyntaxKind.PropertyDeclaration:
- case SyntaxKind.MethodDeclaration:
- case SyntaxKind.GetAccessor:
- case SyntaxKind.SetAccessor:
- // For a property or method decorator, the `target` is the
- // "static"-side type of the parent of the member if the member is
- // declared "static"; otherwise, it is the "instance"-side type of the
- // parent of the member.
- return getParentTypeOfClassElement(<ClassElement>node);
-
- default:
- Debug.fail("Unsupported decorator target.");
- return unknownType;
+ if (node.kind === SyntaxKind.PropertyDeclaration ||
+ node.kind === SyntaxKind.MethodDeclaration ||
+ node.kind === SyntaxKind.GetAccessor ||
+ node.kind === SyntaxKind.SetAccessor) {
+ // For a property or method decorator, the `target` is the
+ // "static"-side type of the parent of the member if the member is
+ // declared "static"; otherwise, it is the "instance"-side type of the
+ // parent of the member.
+ return getParentTypeOfClassElement(<ClassElement>node);
  }
+
+ Debug.fail("Unsupported decorator target.");
+ return unknownType;
  }
 
  /**
@@ -8698,57 +8695,54 @@ namespace ts {
  */
  function getEffectiveDecoratorSecondArgumentType(node: Node) {
  // The second argument to a decorator is its `propertyKey`
- switch (node.kind) {
- case SyntaxKind.ClassDeclaration:
-  Debug.fail("Class decorators should not have a second synthetic argument.");
-  return unknownType;
+ if (node.kind === SyntaxKind.ClassDeclaration) {
+ Debug.fail("Class decorators should not have a second synthetic argument.");
+ return unknownType;
+ }
 
-  case SyntaxKind.Parameter:
-  node = node.parent;
-  if (node.kind === SyntaxKind.Constructor) {
-  // For a constructor parameter decorator, the `propertyKey` will be `undefined`.
-  return anyType;
-  }
+ if (node.kind === SyntaxKind.Parameter) {
+ node = node.parent;
+ if (node.kind === SyntaxKind.Constructor) {
+ // For a constructor parameter decorator, the `propertyKey` will be `undefined`.
+ return anyType;
+ }
 
  // For a non-constructor parameter decorator, the `propertyKey` will be either
  // a string or a symbol, based on the name of the parameter's containing method.
+ }
 
- // fall-through
-
- case SyntaxKind.PropertyDeclaration:
- case SyntaxKind.MethodDeclaration:
- case SyntaxKind.GetAccessor:
- case SyntaxKind.SetAccessor:
- // The `propertyKey` for a property or method decorator will be a
- // string literal type if the member name is an identifier, number, or string;
- // otherwise, if the member name is a computed property name it will
- // be either string or symbol.
- let element = <ClassElement>node;
- switch (element.name.kind) {
- case SyntaxKind.Identifier:
- case SyntaxKind.NumericLiteral:
- case SyntaxKind.StringLiteral:
- return getStringLiteralType(<StringLiteral>element.name);
-
- case SyntaxKind.ComputedPropertyName:
- let nameType = checkComputedPropertyName(<ComputedPropertyName>element.name);
- if (allConstituentTypesHaveKind(nameType, TypeFlags.ESSymbol)) {
- return nameType;
- }
- else {
- return stringType;
- }
-
- default:
- Debug.fail("Unsupported property name.");
- return unknownType;
- }
+ if (node.kind === SyntaxKind.PropertyDeclaration ||
+ node.kind === SyntaxKind.MethodDeclaration ||
+ node.kind === SyntaxKind.GetAccessor ||
+ node.kind === SyntaxKind.SetAccessor) {
+ // The `propertyKey` for a property or method decorator will be a
+ // string literal type if the member name is an identifier, number, or string;
+ // otherwise, if the member name is a computed property name it will
+ // be either string or symbol.
+ let element = <ClassElement>node;
+ switch (element.name.kind) {
+ case SyntaxKind.Identifier:
+ case SyntaxKind.NumericLiteral:
+ case SyntaxKind.StringLiteral:
+ return getStringLiteralType(<StringLiteral>element.name);
 
+ case SyntaxKind.ComputedPropertyName:
+ let nameType = checkComputedPropertyName(<ComputedPropertyName>element.name);
+ if (allConstituentTypesHaveKind(nameType, TypeFlags.ESSymbol)) {
+ return nameType;
+ }
+ else {
+ return stringType;
+ }
 
- default:
- Debug.fail("Unsupported decorator target.");
- return unknownType;
+ default:
+ Debug.fail("Unsupported property name.");
+ return unknownType;
+ }
  }
+
+ Debug.fail("Unsupported decorator target.");
+ return unknownType;
  }
 
  /**
@@ -8761,31 +8755,32 @@ namespace ts {
  function getEffectiveDecoratorThirdArgumentType(node: Node) {
  // The third argument to a decorator is either its `descriptor` for a method decorator
  // or its `parameterIndex` for a paramter decorator
- switch (node.kind) {
- case SyntaxKind.ClassDeclaration:
- Debug.fail("Class decorators should not have a third synthetic argument.");
- return unknownType;
-
- case SyntaxKind.Parameter:
- // The `parameterIndex` for a parameter decorator is always a number
- return numberType;
+ if (node.kind === SyntaxKind.ClassDeclaration) {
+ Debug.fail("Class decorators should not have a third synthetic argument.");
+ return unknownType;
+ }
 
- case SyntaxKind.PropertyDeclaration:
- Debug.fail("Property decorators should not have a third synthetic argument.");
- return unknownType;
+ if (node.kind === SyntaxKind.Parameter) {
+ // The `parameterIndex` for a parameter decorator is always a number
+ return numberType;
+ }
 
- case SyntaxKind.MethodDeclaration:
- case SyntaxKind.GetAccessor:
- case SyntaxKind.SetAccessor:
- // The `descriptor` for a method decorator will be a `TypedPropertyDescriptor<T>`
- // for the type of the member.
- let propertyType = getTypeOfNode(node);
- return createTypedPropertyDescriptorType(propertyType);
+ if (node.kind === SyntaxKind.PropertyDeclaration) {
+ Debug.fail("Property decorators should not have a third synthetic argument.");
+ return unknownType;
+ }
 
- default:
- Debug.fail("Unsupported decorator target.");
- return unknownType;
+ if (node.kind === SyntaxKind.MethodDeclaration ||
+ node.kind === SyntaxKind.GetAccessor ||
+ node.kind === SyntaxKind.SetAccessor) {
+ // The `descriptor` for a method decorator will be a `TypedPropertyDescriptor<T>`
+ // for the type of the member.
+ let propertyType = getTypeOfNode(node);
+ return createTypedPropertyDescriptorType(propertyType);
  }
+
+ Debug.fail("Unsupported decorator target.");
+ return unknownType;
  }
 
  /**