fix(fetch): fix headers.entries/values/forEach iteration for Set-Cookie headers (#89)

* Fix headers.entries/values/forEach handling of setCookie

* Fix headers.entries/values/forEach handling of setCookie

* Add changeset

* chore: fix changeset

---------

Co-authored-by: Matt Brophy <[email protected]>

Author: MichaelDeBoey

.changeset/good-badgers-sleep.md

@@ -0,0 +1,5 @@
+---
+"@web-std/fetch": patch
+---
+
+Fix `headers.entries`/`values`/`forEach` iteration for `Set-Cookie` headers

packages/fetch/src/headers.js

@@ -190,7 +190,14 @@ export default class Headers extends URLSearchParams {
 	 */
 	forEach(callback, thisArg = undefined) {
 		for (const name of this.keys()) {
-			Reflect.apply(callback, thisArg, [this.get(name), name, this]);
+			if (name.toLowerCase() === 'set-cookie') {
+				let cookies = this.getAll(name);
+				while (cookies.length > 0) {
+					Reflect.apply(callback, thisArg, [cookies.shift(), name, this])
+				}
+			} else {
+				Reflect.apply(callback, thisArg, [this.get(name), name, this]);
+			}
 		}
 	}
 
@@ -199,7 +206,14 @@ export default class Headers extends URLSearchParams {
 	 */
 	* values() {
 		for (const name of this.keys()) {
-			yield /** @type {string} */(this.get(name));
+			if (name.toLowerCase() === 'set-cookie') {
+				let cookies = this.getAll(name);
+				while (cookies.length > 0) {
+					yield /** @type {string} */(cookies.shift());
+				}
+			} else {
+				yield /** @type {string} */(this.get(name));
+			}
 		}
 	}
 
@@ -208,7 +222,14 @@ export default class Headers extends URLSearchParams {
 	 */
 	* entries() {
 		for (const name of this.keys()) {
-			yield [name, /** @type {string} */(this.get(name))];
+			if (name.toLowerCase() === 'set-cookie') {
+				let cookies = this.getAll(name);
+				while (cookies.length > 0) {
+					yield [name, /** @type {string} */(cookies.shift())];
+				}
+			} else {
+				yield [name, /** @type {string} */(this.get(name))];
+			}
 		}
 	}
 

packages/fetch/test/headers.js

@@ -69,6 +69,26 @@ describe('Headers', () => {
 		expect({key: 'content-type', value: 'text/html', object: headers}).to.deep.equal(results[1]);
 	});
 
+	it('should allow iterating through multiple set-cookie headers with forEach', () => {
+		let headers = new Headers([
+			['a', '1'],
+			['Set-Cookie', 'b=2']
+		]);
+		headers.append('Set-Cookie', 'c=3');
+		expect(headers.entries()).to.be.iterable;
+
+		const results = [];
+		headers.forEach((value, key, object) => {
+			results.push({value, key, object});
+		});
+
+		expect(results).to.deep.equal([
+			{ value: '1', key: 'a', object: headers },
+			{ value: 'b=2', key: 'set-cookie', object: headers },
+			{ value: 'c=3', key: 'set-cookie', object: headers },
+    ]);
+	})
+
 	it('should set "this" to undefined by default on forEach', () => {
 		const headers = new Headers({Accept: 'application/json'});
 		headers.forEach(function () {
@@ -103,8 +123,25 @@ describe('Headers', () => {
 			['b', '2, 3'],
 			['c', '4']
 		]);
+
 	});
 
+	it('should allow iterating through multiple set-cookie headers with for-of loop', () => {
+		let headers = new Headers([
+			['a', '1'],
+			['Set-Cookie', 'b=2']
+		]);
+		headers.append('Set-Cookie', 'c=3');
+		expect(headers.entries()).to.be.iterable;
+
+		const result = [];
+		for (const pair of headers) {
+			result.push(pair);
+		}
+
+		expect(result).to.deep.equal([['a', '1'], ['set-cookie', 'b=2'], ['set-cookie', 'c=3']]);
+	})
+
 	it('should allow iterating through all headers with entries()', () => {
 		const headers = new Headers([
 			['b', '2'],
@@ -121,6 +158,16 @@ describe('Headers', () => {
 			]);
 	});
 
+	it('should allow iterating through multiple set-cookie headers with entries()', ()=> {
+		let headers = new Headers([
+			['a', '1'],
+			['Set-Cookie', 'b=2']
+		]);
+		headers.append('Set-Cookie', 'c=3');
+		expect(headers.entries()).to.be.iterable
+			.and.to.deep.iterate.over([['a', '1'], ['set-cookie', 'b=2'], ['set-cookie', 'c=3']]);
+	})
+
 	it('should allow iterating through all headers with keys()', () => {
 		const headers = new Headers([
 			['b', '2'],
@@ -145,6 +192,16 @@ describe('Headers', () => {
 			.and.to.iterate.over(['1', '2, 3', '4']);
 	});
 
+	it('should allow iterating through multiple set-cookie headers with values()', ()=> {
+		let headers = new Headers([
+			['a', '1'],
+			['Set-Cookie', 'b=2']
+		]);
+		headers.append('Set-Cookie', 'c=3');
+		expect(headers.values()).to.be.iterable
+			.and.to.iterate.over(['1', 'b=2', 'c=3']);
+	})
+
 	it('should reject illegal header', () => {
 		const headers = new Headers();
 		expect(() => new Headers({'He y': 'ok'})).to.throw(TypeError);