[gjs/wip/ptomato/mozjs38: 24/27] js: Various SpiderMonkey 38 improvements

[Philip Chimento <pchimento src gnome org>]

commit fb617ddd69b1de1ad864967bb57cc4b3e8cac496
Author: Philip Chimento <philip endlessm com>
Date:   Thu Jan 26 16:19:53 2017 -0800

    js: Various SpiderMonkey 38 improvements
    
    Here are three places where SpiderMonkey 38 offers a better API than the
    one we were using.
    
    The fourth spot, we could use JS::CallArgs::requireAtLeast(), but there is
    an issue with the visibility of that symbol in the shared library. Add a
    link to the Mozilla bug for that.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=777962

 gi/object.cpp                   |    8 +-------
 gjs/jsapi-constructor-proxy.cpp |    3 +--
 gjs/jsapi-util-args.h           |    3 ++-
 installed-tests/js/testGDBus.js |   11 +++--------
 4 files changed, 7 insertions(+), 18 deletions(-)
---
diff --git a/gi/object.cpp b/gi/object.cpp
index 96b5be9..721d197 100644
--- a/gi/object.cpp
+++ b/gi/object.cpp
@@ -1735,13 +1735,7 @@ real_connect_func(JSContext *context,
         return false;
     }
 
-    /* Best I can tell, there is no way to know if argv[1] is really
-     * callable other than to just try it. Checking whether it's a
-     * function will not detect native objects that provide
-     * JSClass::call, for example.
-     */
-
-    if (argc != 2 || !argv[0].isString() || !argv[1].isObject()) {
+    if (argc != 2 || !argv[0].isString() || !JS::IsCallable(&argv[1].toObject())) {
         gjs_throw(context, "connect() takes two args, the signal name and the callback");
         return false;
     }
diff --git a/gjs/jsapi-constructor-proxy.cpp b/gjs/jsapi-constructor-proxy.cpp
index 02dc1a1..aede3c3 100644
--- a/gjs/jsapi-constructor-proxy.cpp
+++ b/gjs/jsapi-constructor-proxy.cpp
@@ -144,8 +144,7 @@ create_gjs_constructor_proxy(JSContext *cx,
         return false;
     }
 
-    if (!args[0].isObject() || !JS_ObjectIsFunction(cx, &args[0].toObject())) {
-        /* COMPAT: Use JS::IsConstructor() in mozjs38 */
+    if (!args[0].isObject() || !JS::IsConstructor(&args[0].toObject())) {
         gjs_throw(cx, "First argument must be a constructor");
         return false;
     }
diff --git a/gjs/jsapi-util-args.h b/gjs/jsapi-util-args.h
index 3229350..665aeb6 100644
--- a/gjs/jsapi-util-args.h
+++ b/gjs/jsapi-util-args.h
@@ -394,7 +394,8 @@ gjs_parse_call_args(JSContext    *cx,
 
     JSAutoRequest ar(cx);
 
-    /* COMPAT: In future, use args.requireAtLeast() */
+    /* COMPAT: In future, use args.requireAtLeast()
+     * https://bugzilla.mozilla.org/show_bug.cgi?id=1334338 */
     if (args.length() < n_required ||
         (args.length() > n_total && !ignore_trailing_args)) {
         if (n_required == n_total) {
diff --git a/installed-tests/js/testGDBus.js b/installed-tests/js/testGDBus.js
index 28e1f15..ab21585 100644
--- a/installed-tests/js/testGDBus.js
+++ b/installed-tests/js/testGDBus.js
@@ -158,7 +158,7 @@ Test.prototype = {
     },
 
     arrayOutBadSig: function() {
-        return [ "Hello", "World", "!" ];
+        return Symbol('Hello World!');
     },
 
     byteArrayEcho: function(binaryString) {
@@ -375,19 +375,14 @@ describe('Exported DBus object', function () {
         loop.run();
     });
 
-    /* COMPAT: This test should test what happens when a TypeError is thrown
-     * during argument marshalling, but conversions don't throw TypeErrors
-     * anymore, so we can't test that ... until we upgrade to mozjs38 which has
-     * Symbols. Converting a Symbol to an int32 or string will throw a TypeError.
-     */
-    xit('handles a bad signature by throwing an exception', function () {
+    it('handles a bad signature by throwing an exception', function () {
         proxy.arrayOutBadSigRemote(function(result, excp) {
             expect(result).toBeNull();
             expect(excp).not.toBeNull();
             loop.quit();
         });
         loop.run();
-    }).pend('currently cannot throw TypeError during conversion');
+    });
 
     it('can call a remote method that is implemented asynchronously', function () {
         let someString = "Hello world!";