From 0c467d095f544953f7d7e44d7d6871f07b58f7e1 Mon Sep 17 00:00:00 2001
From: Eli Barzilay <eli@barzilay.org>
Date: Thu, 19 Dec 2019 15:11:04 -0500
Subject: [PATCH] Fix `signatureToSignatureDeclarationHelper`

Even if `SuppressAnyReturnType` is on, don't supress it if it's a function.

Fixes #35508.
---
 src/compiler/checker.ts                       |  3 +-
 .../codeFixClassImplementInterfaceCallback.ts | 75 +++++++++++++++++++
 2 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 tests/cases/fourslash/codeFixClassImplementInterfaceCallback.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index dd431a50b6c..a0a1dcaad17 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -4532,7 +4532,8 @@ namespace ts {
                     const returnType = getReturnTypeOfSignature(signature);
                     returnTypeNode = returnType && typeToTypeNodeHelper(returnType, context);
                 }
-                if (context.flags & NodeBuilderFlags.SuppressAnyReturnType) {
+                if (context.flags & NodeBuilderFlags.SuppressAnyReturnType
+                    && kind !== SyntaxKind.FunctionType && kind !== SyntaxKind.ConstructorType) {
                     if (returnTypeNode && returnTypeNode.kind === SyntaxKind.AnyKeyword) {
                         returnTypeNode = undefined;
                     }
diff --git a/tests/cases/fourslash/codeFixClassImplementInterfaceCallback.ts b/tests/cases/fourslash/codeFixClassImplementInterfaceCallback.ts
new file mode 100644
index 00000000000..65692ca013b
--- /dev/null
+++ b/tests/cases/fourslash/codeFixClassImplementInterfaceCallback.ts
@@ -0,0 +1,75 @@
+/// <reference path='fourslash.ts' />
+
+// #35508
+
+////interface IFoo1 {
+////    parse(reviver: () => any): void;
+////}
+////
+////class Foo1 implements IFoo1 {
+////}
+////
+////interface IFoo2 {
+////    parse(reviver: { (): any }): void;
+////}
+////
+////class Foo2 implements IFoo2 {
+////}
+////
+////interface IFoo3 {
+////    parse(reviver: new () => any): void;
+////}
+////
+////class Foo3 implements IFoo3 {
+////}
+////
+////interface IFoo4 {
+////    parse(reviver: { new (): any }): void;
+////}
+////
+////class Foo4 implements IFoo4 {
+////}
+
+verify.codeFixAll({
+  fixAllDescription: ts.Diagnostics.Implement_all_unimplemented_interfaces.message,
+  fixId: "fixClassIncorrectlyImplementsInterface",
+  newFileContent:
+`interface IFoo1 {
+    parse(reviver: () => any): void;
+}
+
+class Foo1 implements IFoo1 {
+    parse(reviver: () => any): void {
+        throw new Error("Method not implemented.");
+    }
+}
+
+interface IFoo2 {
+    parse(reviver: { (): any }): void;
+}
+
+class Foo2 implements IFoo2 {
+    parse(reviver: () => any): void {
+        throw new Error("Method not implemented.");
+    }
+}
+
+interface IFoo3 {
+    parse(reviver: new () => any): void;
+}
+
+class Foo3 implements IFoo3 {
+    parse(reviver: new () => any): void {
+        throw new Error("Method not implemented.");
+    }
+}
+
+interface IFoo4 {
+    parse(reviver: { new (): any }): void;
+}
+
+class Foo4 implements IFoo4 {
+    parse(reviver: new () => any): void {
+        throw new Error("Method not implemented.");
+    }
+}`});