From 0fa41db6c68e550dfec9491c9f4f211f5181dab5 Mon Sep 17 00:00:00 2001
From: Oleksandr T <oleksandr.tarasiuk@outlook.com>
Date: Tue, 8 Dec 2020 00:00:46 +0200
Subject: [PATCH] fix(41827): allow infer parameters from method signature
 usage (#41836)

---
 src/services/codefixes/inferFromUsage.ts      |  1 +
 .../codeFixInferFromUsageMethodSignature.ts   | 52 +++++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 tests/cases/fourslash/codeFixInferFromUsageMethodSignature.ts

diff --git a/src/services/codefixes/inferFromUsage.ts b/src/services/codefixes/inferFromUsage.ts
index ac05ebda1d9..3721d4ea124 100644
--- a/src/services/codefixes/inferFromUsage.ts
+++ b/src/services/codefixes/inferFromUsage.ts
@@ -453,6 +453,7 @@ namespace ts.codefix {
                 break;
             case SyntaxKind.FunctionDeclaration:
             case SyntaxKind.MethodDeclaration:
+            case SyntaxKind.MethodSignature:
                 searchToken = containingFunction.name;
                 break;
         }
diff --git a/tests/cases/fourslash/codeFixInferFromUsageMethodSignature.ts b/tests/cases/fourslash/codeFixInferFromUsageMethodSignature.ts
new file mode 100644
index 00000000000..4eab7f0f56a
--- /dev/null
+++ b/tests/cases/fourslash/codeFixInferFromUsageMethodSignature.ts
@@ -0,0 +1,52 @@
+/// <reference path='fourslash.ts' />
+
+////interface Options {
+////    run(a, b, c, d, e, f): void;
+////}
+////
+////interface I {
+////    x: number;
+////}
+////
+////enum E {
+////    X
+////}
+////
+////function foo(options: Options) {
+////    const a = 1;
+////    const b = "";
+////    const c = { x: 1, y: 1 };
+////    const d = [1, 2, 3];
+////    const e: I = { x: 1 };
+////    const f: E = E.X;
+////
+////    options.run(a, b, c, d, e, f);
+////}
+
+verify.codeFixAll({
+    fixId: "inferFromUsage",
+    fixAllDescription: "Infer all types from usage",
+    newFileContent:
+`interface Options {
+    run(a: number, b: string, c: { x: number; y: number; }, d: number[], e: I, f: E): void;
+}
+
+interface I {
+    x: number;
+}
+
+enum E {
+    X
+}
+
+function foo(options: Options) {
+    const a = 1;
+    const b = "";
+    const c = { x: 1, y: 1 };
+    const d = [1, 2, 3];
+    const e: I = { x: 1 };
+    const f: E = E.X;
+
+    options.run(a, b, c, d, e, f);
+}`,
+});