Bug 279158 - nsIDNSRecord::canonicalName should document what it does for IDN r=valentin

Differential Revision: https://phabricator.services.mozilla.com/D72651

netwerk/dns/nsIDNSRecord.idl

@@ -32,6 +32,9 @@ interface nsIDNSRecord : nsISupports
      * the record was not fetched with the RESOLVE_CANONICAL_NAME flag.
      *
      * e.g., www.mozilla.org --> rheet.mozilla.org
+     *
+     * That the result, if IDN will be returned as punycode.
+     * e.g., élève.w3c-test.org --> xn--lve-6lad.w3c-test.org
      */
     readonly attribute ACString canonicalName;
 

netwerk/test/unit/test_dns_service.js

@@ -1,24 +1,41 @@
 "use strict";
 
-var dns = Cc["@mozilla.org/network/dns-service;1"].getService(Ci.nsIDNSService);
-
-var listener = {
-  onLookupComplete(inRequest, inRecord, inStatus) {
-    var answer = inRecord.getNextAddrAsString();
-    Assert.ok(answer == "127.0.0.1" || answer == "::1");
-
-    do_test_finished();
-  },
-  QueryInterface: ChromeUtils.generateQI(["nsIDNSListener"]),
-};
-
+const dns = Cc["@mozilla.org/network/dns-service;1"].getService(
+  Ci.nsIDNSService
+);
 const defaultOriginAttributes = {};
+const threadManager = Cc["@mozilla.org/thread-manager;1"].getService(
+  Ci.nsIThreadManager
+);
+const mainThread = threadManager.currentThread;
 
-function run_test() {
-  var threadManager = Cc["@mozilla.org/thread-manager;1"].getService(
-    Ci.nsIThreadManager
-  );
-  var mainThread = threadManager.currentThread;
+class Listener {
+  constructor() {
+    this.promise = new Promise(resolve => {
+      this.resolve = resolve;
+    });
+  }
+
+  onLookupComplete(inRequest, inRecord, inStatus) {
+    this.resolve([inRequest, inRecord, inStatus]);
+  }
+
+  then() {
+    return this.promise.then.apply(this.promise, arguments);
+  }
+}
+
+Listener.prototype.QueryInterface = ChromeUtils.generateQI(["nsIDNSListener"]);
+
+const DOMAIN_IDN = "bücher.org";
+const ACE_IDN = "xn--bcher-kva.org";
+
+const DOMAIN = "localhost";
+const ADDR1 = "127.0.0.1";
+const ADDR2 = "::1";
+
+add_task(async function test_dns_localhost() {
+  let listener = new Listener();
   dns.asyncResolve(
     "localhost",
     0,
@@ -26,6 +43,21 @@ function run_test() {
     mainThread,
     defaultOriginAttributes
   );
+  let [inRequest, inRecord, inStatus] = await listener;
 
-  do_test_pending();
-}
+  let answer = inRecord.getNextAddrAsString();
+  Assert.ok(answer == ADDR1 || answer == ADDR2);
+});
+
+add_task(async function test_idn_cname() {
+  let listener = new Listener();
+  dns.asyncResolve(
+    DOMAIN_IDN,
+    Ci.nsIDNSService.RESOLVE_CANONICAL_NAME,
+    listener,
+    mainThread,
+    defaultOriginAttributes
+  );
+  let [inRequest, inRecord, inStatus] = await listener;
+  Assert.equal(inRecord.canonicalName, ACE_IDN, "IDN is returned as punycode");
+});