feat: add Response.json static method

Signed-off-by: Logan McAnsh <[email protected]>

packages/fetch/src/response.js

@@ -12,13 +12,13 @@ const INTERNALS = Symbol('Response internals');
 
 /**
  * Response class
- * 
+ *
  * @typedef {Object} Ext
  * @property {number} [size]
  * @property {string} [url]
  * @property {number} [counter]
  * @property {number} [highWaterMark]
- * 
+ *
  * @implements {globalThis.Response}
  */
 export default class Response extends Body {
@@ -126,6 +126,23 @@ export default class Response extends Body {
 		});
 	}
 
+	/**
+	 * @param {any} data The URL that the new response is to originate from.
+	 * @param {ResponseInit} [responseInit] An optional status code for the response (e.g., 302.)
+	 * @returns {Response} A Response object.
+	 */
+	static json(data, responseInit = {}) {
+		let headers = new Headers(responseInit.headers);
+		if (!headers.has("Content-Type")) {
+			headers.set("Content-Type", "application/json; charset=utf-8");
+		}
+
+		return new Response(JSON.stringify(data), {
+			...responseInit,
+			headers,
+		});
+	}
+
 	get [Symbol.toStringTag]() {
 		return 'Response';
 	}

packages/fetch/test/response.js

@@ -198,6 +198,21 @@ describe('Response', () => {
 		const res = new Response();
 		expect(res.url).to.equal('');
 	});
+
+	it('should support json static method', () => {
+		const res = Response.json({a: 1});
+		return res.json().then(result => {
+			expect(result.a).to.equal(1);
+		});
+	})
+
+	it('should support json static method with added responseInit', () => {
+		const res = Response.json({a: 1}, { headers: { "x-foo": "bar" } });
+		expect(res.headers.get('x-foo')).to.equal('bar');
+		return res.json().then(result => {
+			expect(result.a).to.equal(1);
+		});
+	})
 });
 
 const streamFromString = text => new ReadableStream({