optional signature

Author: Arthur Ozga

src/compiler/checker.ts

@@ -2218,7 +2218,7 @@ namespace ts {
                 indexInfoToIndexSignatureDeclaration: (indexInfo: IndexInfo, kind: IndexKind, enclosingDeclaration?: Node, flags?: NodeBuilderFlags) => {
                     Debug.assert(encounteredError === false, "Nested call into nodeBuilder are forbidden.");
                     encounteredError = false;
-                    const resultingNode = indexInfoToIndexSignatureDeclarationHelper(indexInfo, kind, enclosingDeclaration, flags)
+                    const resultingNode = indexInfoToIndexSignatureDeclarationHelper(indexInfo, kind, enclosingDeclaration, flags);
                     const result = encounteredError ? undefined : resultingNode;
                     encounteredError = false;
                     return result;
@@ -2568,8 +2568,8 @@ namespace ts {
 
             function indexInfoToIndexSignatureDeclarationHelper(indexInfo: IndexInfo, kind: IndexKind, enclosingDeclaration: Node, flags: NodeBuilderFlags): IndexSignatureDeclaration {
                 const indexerTypeNode = createKeywordTypeNode(kind === IndexKind.String ? SyntaxKind.StringKeyword : SyntaxKind.NumberKeyword);
-
                 const name = getNameFromIndexInfo(indexInfo);
+
                 const indexingParameter = createParameter(
                 /*decorators*/ undefined,
                 /*modifiers*/ undefined,

src/services/codefixes/helpers.ts

@@ -67,6 +67,7 @@ namespace ts.codefix {
         const visibilityModifier = createVisibilityModifier(getModifierFlags(declaration));
         const modifiers = visibilityModifier ? createNodeArray([visibilityModifier]) : undefined;
         const type = checker.getWidenedType(checker.getTypeOfSymbolAtLocation(symbol, enclosingDeclaration));
+        const optional = !!(symbol.flags & SymbolFlags.Optional);
 
         switch (declaration.kind) {
             case SyntaxKind.GetAccessor:
@@ -78,7 +79,7 @@ namespace ts.codefix {
                     /*decorators*/undefined,
                     modifiers,
                     name,
-                    /*questionToken*/ undefined,
+                    optional ? createToken(SyntaxKind.QuestionToken) : undefined,
                     typeNode,
                     /*initializer*/ undefined);
                 return property;
@@ -96,36 +97,27 @@ namespace ts.codefix {
                     return undefined;
                 }
 
-                const optional = !!(symbol.flags & SymbolFlags.Optional);
                 if (declarations.length === 1) {
                     Debug.assert(signatures.length === 1);
                     const signature = signatures[0];
-                    const signatureDeclaration = <MethodDeclaration>checker.signatureToSignatureDeclaration(signature, SyntaxKind.MethodDeclaration, enclosingDeclaration);
-                    signatureDeclaration.modifiers = modifiers;
-                    signatureDeclaration.name = name;
-                    signatureDeclaration.questionToken = optional ? createToken(SyntaxKind.QuestionToken) : undefined;
-                    signatureDeclaration.body = createStubbedMethodBody();
-                    return signatureDeclaration;
+                    return signatureToMethodDeclaration(signature, enclosingDeclaration, createStubbedMethodBody());
                 }
 
                 const signatureDeclarations = [];
                 for (let i = 0; i < signatures.length; i++) {
                     const signature = signatures[i];
-                    const signatureDeclaration = <MethodDeclaration>checker.signatureToSignatureDeclaration(signature, SyntaxKind.MethodDeclaration, enclosingDeclaration);
-                    signatureDeclaration.modifiers = modifiers;
-                    signatureDeclaration.name = name;
-                    signatureDeclaration.questionToken = optional ? createToken(SyntaxKind.QuestionToken) : undefined;
-                    signatureDeclarations.push(signatureDeclaration);
+                    const methodDeclaration = signatureToMethodDeclaration(signature, enclosingDeclaration);
+                    if (methodDeclaration) {
+                        signatureDeclarations.push(methodDeclaration);
+                    }
                 }
 
                 if (declarations.length > signatures.length) {
                     const signature = checker.getSignatureFromDeclaration(declarations[declarations.length - 1] as SignatureDeclaration);
-                    const signatureDeclaration = <MethodDeclaration>checker.signatureToSignatureDeclaration(signature, SyntaxKind.MethodDeclaration, enclosingDeclaration);
-                    signatureDeclaration.modifiers = modifiers;
-                    signatureDeclaration.name = name;
-                    signatureDeclaration.questionToken = optional ? createToken(SyntaxKind.QuestionToken) : undefined;
-                    signatureDeclaration.body = createStubbedMethodBody();
-                    signatureDeclarations.push(signatureDeclaration);
+                    const methodDeclaration = signatureToMethodDeclaration(signature, enclosingDeclaration, createStubbedMethodBody());
+                    if (methodDeclaration) {
+                        signatureDeclarations.push(methodDeclaration);
+                    }
                 }
                 else {
                     Debug.assert(declarations.length === signatures.length);
@@ -136,6 +128,17 @@ namespace ts.codefix {
             default:
                 return undefined;
         }
+
+        function signatureToMethodDeclaration(signature: Signature, enclosingDeclaration: Node, body?: Block) {
+            const signatureDeclaration = <MethodDeclaration>checker.signatureToSignatureDeclaration(signature, SyntaxKind.MethodDeclaration, enclosingDeclaration);
+            if (signatureDeclaration) {
+                signatureDeclaration.modifiers = modifiers;
+                signatureDeclaration.name = name;
+                signatureDeclaration.questionToken = optional ? createToken(SyntaxKind.QuestionToken) : undefined;
+                signatureDeclaration.body = body;
+            }
+            return signatureDeclaration;
+        }
     }
 
     function createMethodImplementingSignatures(signatures: Signature[], name: PropertyName, optional: boolean, modifiers: Modifier[] | undefined): MethodDeclaration {

tests/cases/fourslash/codeFixClassImplementClassMemberAnonymousClass.ts

@@ -10,11 +10,4 @@
 //// }
 //// class C implements A {[| |]}
 
-verify.rangeAfterCodeFix(`
-    foo() {
-        throw new Error("Method not implemented.");
-    }
-    bar() {
-        throw new Error("Method not implemented.");
-    }
-`);
+verify.not.codeFixAvailable();