feat: add request header decorator

Co-authored-by: imdudu1 <[email protected]>

Author: jbl428

lib/decorators/constants.ts

@@ -4,3 +4,4 @@ export const PATH_VARIABLE_METADATA = Symbol("PATH_VARIABLE_METADATA");
 export const REQUEST_PARAM_METADATA = Symbol("REQUEST_PARAM_METADATA");
 export const REQUEST_BODY_METADATA = Symbol("REQUEST_BODY_METADATA");
 export const REQUEST_FORM_METADATA = Symbol("REQUEST_BODY_METADATA");
+export const REQUEST_HEADER_METADATA = Symbol("REQUEST_HEADER_METADATA");

lib/decorators/request-header.decorator.spec.ts

@@ -0,0 +1,48 @@
+import { describe, test, expect } from "vitest";
+import { REQUEST_HEADER_METADATA } from "./constants";
+import {
+  RequestHeader,
+  type RequestHeaderMetadata,
+} from "./request-header.decorator";
+
+describe("RequestHeader", () => {
+  test("should set request header metadata with empty key", () => {
+    // given
+    class TestService {
+      request(@RequestHeader() query: { foo: string }): string {
+        return query.foo;
+      }
+    }
+
+    // when
+    const result: RequestHeaderMetadata = Reflect.getMetadata(
+      REQUEST_HEADER_METADATA,
+      TestService.prototype,
+      "request"
+    );
+
+    // then
+    expect(result).toHaveLength(1);
+    expect(result.get(0)).toBeUndefined();
+  });
+
+  test("should set request header metadata with key", () => {
+    // given
+    class TestService {
+      request(@RequestHeader("foo") bar: string): string {
+        return bar;
+      }
+    }
+
+    // when
+    const result: RequestHeaderMetadata = Reflect.getMetadata(
+      REQUEST_HEADER_METADATA,
+      TestService.prototype,
+      "request"
+    );
+
+    // then
+    expect(result).toHaveLength(1);
+    expect(result.get(0)).toBe("foo");
+  });
+});

lib/decorators/request-header.decorator.ts

@@ -0,0 +1,24 @@
+import { REQUEST_HEADER_METADATA } from "./constants";
+
+export type RequestHeaderMetadata = Map<number, string>;
+
+export function RequestHeader(key?: string): ParameterDecorator {
+  return (target, propertyKey, parameterIndex) => {
+    if (typeof propertyKey === "undefined") {
+      return;
+    }
+
+    const metadata =
+      Reflect.getMetadata(REQUEST_HEADER_METADATA, target, propertyKey) ??
+      new Map();
+
+    metadata.set(parameterIndex, key);
+
+    Reflect.defineMetadata(
+      REQUEST_HEADER_METADATA,
+      metadata,
+      target,
+      propertyKey
+    );
+  };
+}