Merge pull request #5 from jimmywarting/fix

fix: Correctly converted to sequence and thisArg

headers.d.ts

@@ -57,7 +57,7 @@ export class Headers {
             key: string,
             parent: Headers
         ) => void,
-        thisArg: Headers
+        thisArg: globalThis
     ): void
 
     toString(): string

headers.js

@@ -29,10 +29,19 @@ function fillHeaders (bag, object) {
 
   if (iterable) {
     // @ts-ignore
-    for (const header of object) {
+    for (let header of object) {
+      if (typeof header === 'string') {
+        throw new TypeError('The provided value cannot be converted to a sequence.')
+      }
+
+      if (header[Symbol.iterator] && !Array.isArray(header)) {
+        header = [...header]
+      }
+
       if (header.length !== 2) {
         throw new TypeError(`Invalid header. Length must be 2, but is ${header.length}`)
       }
+
       appendHeader(bag, header[0], header[1])
     }
   } else {
@@ -166,7 +175,7 @@ export class Headers {
     appendHeader(bag, name, value)
   }
 
-  forEach (callback, thisArg = this) {
+  forEach (callback, thisArg = globalThis) {
     const bag = assert(this, arguments.length, 1, 'forEach')
     if (typeof callback !== 'function') {
       throw new TypeError(

test/own-misc-test.any.js

@@ -34,27 +34,40 @@ test(() => {
   const headers = new Headers()
   bag.get(headers).guard = 'immutable'
   assert_throws_js(TypeError, () => headers.append('foo', 'bar'))
+  assert_throws_js(TypeError, () => headers.set('foo', 'bar'))
 }, 'it throws when guard is immutable')
 
 test(() => {
   const headers = new Headers([
-    ['a', 'baz'],
-    ['a', 'baz'],
-    ['a', 'bar']
+    ['a', '1'].values(),
+    new Set(['b', '2']),
   ])
-  bag.get(headers).guard = 'immutable'
-  assert_throws_js(TypeError, () => headers.append('foo', 'bar'))
-}, 'it throws when guard is immutable')
+  assert_equals(headers.get('a'), '1')
+  assert_equals(headers.get('b'), '2')
+}, 'it can convert iterables to sequence')
 
 test(() => {
-  const headers = new Headers([
-    ['a', 'baz'],
-    ['a', 'baz'],
-    ['a', 'bar']
-  ])
-  bag.get(headers).guard = 'immutable'
-  assert_throws_js(TypeError, () => headers.append('foo', 'bar'))
-}, 'it throws when guard is immutable')
+  // string is also iterable but not possible to converted to a sequence
+  assert_throws_js(TypeError, () => new Headers([ 'a1' ]))
+}, 'it cant convert string to sequence')
+
+test(() => {
+  new Headers({a: '1'}).forEach(function () {
+    assert_equals(this, globalThis)
+  })
+}, '`this` in foreach is global object')
+
+test(() => {
+  new Headers({a: '1'}).forEach(function () {
+    assert_equals(this, globalThis)
+  })
+}, '`this` in foreach is global object')
+
+test(() => {
+  new Headers({a: '1'}).forEach(function () {
+    assert_true(Array.isArray(this))
+  }, [])
+}, 'change thisArg in foreach')
 
 const headers = new Headers()
 headers[Symbol.for('nodejs.util.inspect.custom')]()