refactor response create function outside of promise handler

not sure that this is favorable or not but thought that it might be and it allows for easier testing of the creation of responses and their properties.
kalisjoshua · Feb 14, 2020 · Feb 18, 2020 · Feb 19, 2020 · Feb 19, 2020 · Feb 19, 2020
commit ecfc94fe661390aa64e51eb48e05edc377de0fa1
diff --git a/.gitignore b/.gitignore
@@ -3,3 +3,4 @@ node_modules
 npm-debug.log
 .DS_Store
 /polyfill/index.js
+coverage
diff --git a/src/index.mjs b/src/index.mjs
@@ -1,37 +1,36 @@
+const regex = /^(.*?):[^\S\n]*([\s\S]*?)$/gm;
+const response = (request, headers) => ({
+	ok: (request.status/100|0) == 2,		// 200-299
+	statusText: request.statusText,
+	status: request.status,
+	url: request.responseURL,
+	text: () => Promise.resolve(request.responseText),
+	json: () => Promise.resolve(JSON.parse(request.responseText)),
+	blob: () => Promise.resolve(new Blob([request.response])),
+	clone: () => response(request, headers),
+	headers: {
+		keys: () => headers.keys,
+		entries: () => headers.all,
+		get: n => headers.raw[n.toLowerCase()],
+		has: n => n.toLowerCase() in headers.raw
+	}
+});
+
 export default function(url, options) {
 	options = options || {};
 	return new Promise( (resolve, reject) => {
 		const request = new XMLHttpRequest();
-		const keys = [];
-		const all = [];
-		const headers = {};
-
-		const response = () => ({
-			ok: (request.status/100|0) == 2,		// 200-299
-			statusText: request.statusText,
-			status: request.status,
-			url: request.responseURL,
-			text: () => Promise.resolve(request.responseText),
-			json: () => Promise.resolve(JSON.parse(request.responseText)),
-			blob: () => Promise.resolve(new Blob([request.response])),
-			clone: response,
-			headers: {
-				keys: () => keys,
-				entries: () => all,
-				get: n => headers[n.toLowerCase()],
-				has: n => n.toLowerCase() in headers
-			}
-		});
 
 		request.open(options.method || 'get', url, true);
 
 		request.onload = () => {
-			request.getAllResponseHeaders().replace(/^(.*?):[^\S\n]*([\s\S]*?)$/gm, (m, key, value) => {
-				keys.push(key = key.toLowerCase());
-				all.push([key, value]);
-				headers[key] = headers[key] ? `${headers[key]},${value}` : value;
+			const head = { all: [], keys: [], raw: {} };
+			request.getAllResponseHeaders().replace(regex, (m, key, value) => {
+				head.all.push([key, value]);
+				head.keys.push(key = key.toLowerCase());
+				head.raw[key] = head.raw[key] ? `${head.raw[key]},${value}` : value;
 			});
-			resolve(response());
+			resolve(response(request, head));
 		};
 
 		request.onerror = reject;
@@ -45,3 +44,5 @@ export default function(url, options) {
 		request.send(options.body || null);
 	});
 }
+
+export { response };
diff --git a/test/index.js b/test/index.js
@@ -1,4 +1,4 @@
-import fetch from '../src/index.mjs';
+import fetch, { response } from '../src/index.mjs';
 import fetchDist from '..';
 
 describe('unfetch', () => {
@@ -81,4 +81,33 @@ describe('unfetch', () => {
 			return p;
 		});
 	});
+
+	describe('response()', () => {
+		it('returns text()', () => response({ responseText: 'A passing test.' })
+			.text()
+			.then((text) => expect(text).toBe('A passing test.'))
+		);
+
+		it('returns blob()', () => response({ response: 'A passing test.' })
+			.blob()
+			.then((text) => expect(text.toString()).toBe(new Blob(['A passing test.']).toString()))
+		);
+
+		it('returns headers', () => {
+			const all = [['x-foo', 'bar'], ['x-baz', 'boo']];
+			const result = response({}, { all }).headers.entries();
+			expect(result).toEqual(all);
+		});
+
+		it('returns header keys', () => {
+			const result = response({}, { keys: ['x-foo'] }).headers.keys();
+			expect(result).toEqual(['x-foo']);
+		});
+
+		it('returns headers has', () => {
+			const raw = { 'x-foo': 'bar', 'x-baz': 'boo' };
+			const test = response({}, { raw }).headers;
+			expect(test.has('x-foo')).toBe(true);
+		});
+	});
 });