feat: revert .getAll removal, mark deprecated (#597)

* feat: revert `.getAll` removal, mark deprecated

* add changelog

* Update fetch.js

* fix imports

* add test

* Update slimy-seals-confess.md

.changeset/slimy-seals-confess.md

@@ -0,0 +1,5 @@
+---
+'@edge-runtime/primitives': patch
+---
+
+Reverts the removal of `Headers#getAll` introduced in #586 for compatibility reasons. It is still marked as deprecated, as `Headers.getSetCookie` is the preferred method now.

packages/integration-tests/tests/response.test.ts

@@ -12,6 +12,11 @@ test('allow to append multiple `set-cookie` header', async () => {
   response.headers.append('set-cookie', 'bar=baz')
 
   expect(response.headers.getSetCookie()).toEqual(['foo=bar', 'bar=baz'])
+
+  expect(response.headers.getAll?.('set-cookie')).toEqual([
+    'foo=bar',
+    'bar=baz',
+  ])
 })
 
 test('disallow mutate response headers for redirects', async () => {

packages/primitives/src/primitives/fetch.js

@@ -1,6 +1,8 @@
 import * as FetchSymbols from 'undici/lib/fetch/symbols'
 import * as HeadersModule from 'undici/lib/fetch/headers'
 import * as ResponseModule from 'undici/lib/fetch/response'
+import * as UtilModule from 'undici/lib/fetch/util'
+import * as WebIDLModule from 'undici/lib/fetch/webidl'
 import { Request as BaseRequest } from 'undici/lib/fetch/request'
 
 import { fetch as fetchImpl } from 'undici/lib/fetch'
@@ -43,6 +45,22 @@ HeadersModule.Headers.prototype.values = function* () {
   }
 }
 
+/**
+ * Method for retrieving all independent `set-cookie` headers that
+ * may have been appended. This will only work when getting `set-cookie`
+ * headers.
+ *
+ * @deprecated Use [`.getSetCookie()`](https://developer.mozilla.org/en-US/docs/Web/API/Headers/getSetCookie) instead.
+ */
+HeadersModule.Headers.prototype.getAll = function (name) {
+  const _name = normalizeAndValidateHeaderName(name, 'Headers.getAll')
+  if (_name !== 'set-cookie') {
+    throw new Error(`getAll can only be used with 'set-cookie'`)
+  }
+
+  return this.getSetCookie()
+}
+
 /**
  * We also must patch the error static method since it works just like
  * redirect and we need consistency.
@@ -54,6 +72,27 @@ ResponseModule.Response.error = function (...args) {
   return response
 }
 
+/**
+ * normalize header name per WHATWG spec, and validate
+ *
+ * @param {string} potentialName
+ * @param {'Header.append' | 'Headers.delete' | 'Headers.get' | 'Headers.has' | 'Header.set'} errorPrefix
+ */
+function normalizeAndValidateHeaderName(potentialName, errorPrefix) {
+  const normalizedName = potentialName.toLowerCase()
+
+  if (UtilModule.isValidHeaderName(normalizedName)) {
+    return normalizedName
+  }
+
+  // Generate an WHATWG fetch spec compliant error
+  WebIDLModule.errors.invalidArgument({
+    prefix: errorPrefix,
+    value: normalizedName,
+    type: 'header name',
+  })
+}
+
 /**
  * A global agent to be used with every fetch request. We also define a
  * couple of globals that we can hide in the runtime for advanced use.

packages/primitives/type-definitions/fetch.d.ts

@@ -1,4 +1,7 @@
-export class Headers extends globalThis.Headers {}
+export class Headers extends globalThis.Headers {
+  /** @deprecated Use [`.getSetCookie()`](https://developer.mozilla.org/en-US/docs/Web/API/Headers/getSetCookie) instead. */
+  getAll?(key: 'set-cookie'): string[]
+}
 
 export class Request extends globalThis.Request {
   readonly headers: Headers