Bug 1102219 - Part 1: Add `String.prototype.includes`; keep `String.prototype.contains` around as an alias with a (non-release builds only) warning. r=till

js/src/js.msg

@@ -124,6 +124,7 @@ MSG_DEF(JSMSG_INVALID_NORMALIZE_FORM,  0, JSEXN_RANGEERR, "form must be one of '
 MSG_DEF(JSMSG_NEGATIVE_REPETITION_COUNT, 0, JSEXN_RANGEERR, "repeat count must be non-negative")
 MSG_DEF(JSMSG_NOT_A_CODEPOINT,         1, JSEXN_RANGEERR, "{0} is not a valid code point")
 MSG_DEF(JSMSG_RESULTING_STRING_TOO_LARGE, 0, JSEXN_RANGEERR, "repeat count must be less than infinity and not overflow maximum string size")
+MSG_DEF(JSMSG_DEPRECATED_STRING_CONTAINS, 0, JSEXN_NONE, "String.prototype.contains() is deprecated and will be removed in a future release; use String.prototype.includes() instead")
 
 // Number
 MSG_DEF(JSMSG_BAD_RADIX,               0, JSEXN_RANGEERR, "radix must be an integer at least 2 and no greater than 36")

js/src/jsstr.cpp

@@ -1517,9 +1517,9 @@ RopeMatch(JSContext* cx, JSRope* text, JSLinearString* pat, int* match)
     return true;
 }
 
-/* ES6 draft rc3 21.1.3.7. */
+/* ES6 draft rc4 21.1.3.7. */
 static bool
-str_contains(JSContext* cx, unsigned argc, Value* vp)
+str_includes(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
 
@@ -1574,6 +1574,19 @@ str_contains(JSContext* cx, unsigned argc, Value* vp)
     return true;
 }
 
+/* TODO: remove String.prototype.contains (bug 1103588) */
+static bool
+str_contains(JSContext *cx, unsigned argc, Value *vp)
+{
+#ifndef RELEASE_BUILD
+    CallArgs args = CallArgsFromVp(argc, vp);
+    RootedObject callee(cx, &args.callee());
+    if (!GlobalObject::warnOnceAboutStringContains(cx, callee))
+        return false;
+#endif
+    return str_includes(cx, argc, vp);
+}
+
 /* ES6 20120927 draft 15.5.4.7. */
 bool
 js::str_indexOf(JSContext* cx, unsigned argc, Value* vp)
@@ -3985,6 +3998,7 @@ static const JSFunctionSpec string_methods[] = {
     JS_FN("charCodeAt",        str_charCodeAt,        1,JSFUN_GENERIC_NATIVE),
     JS_SELF_HOSTED_FN("substring", "String_substring", 2,0),
     JS_SELF_HOSTED_FN("codePointAt", "String_codePointAt", 1,0),
+    JS_FN("includes",          str_includes,          1,JSFUN_GENERIC_NATIVE),
     JS_FN("contains",          str_contains,          1,JSFUN_GENERIC_NATIVE),
     JS_FN("indexOf",           str_indexOf,           1,JSFUN_GENERIC_NATIVE),
     JS_FN("lastIndexOf",       str_lastIndexOf,       1,JSFUN_GENERIC_NATIVE),

js/src/vm/GlobalObject.h

@@ -121,7 +121,8 @@ class GlobalObject : public NativeObject
 
     enum WarnOnceFlag : int32_t {
         WARN_WATCH_DEPRECATED = 0x00000001,
-        WARN_PROTO_SETTING_SLOW = 0x00000002
+        WARN_PROTO_SETTING_SLOW = 0x00000002,
+        WARN_STRING_CONTAINS_DEPRECATED = 0x00000004
     };
 
     // Emit the specified warning if the given slot in |obj|'s global isn't
@@ -658,6 +659,12 @@ class GlobalObject : public NativeObject
         return warnOnceAbout(cx, protoSetter, WARN_PROTO_SETTING_SLOW, JSMSG_PROTO_SETTING_SLOW);
     }
 
+    // Warn about use of the deprecated String.prototype.contains method
+    static bool warnOnceAboutStringContains(JSContext *cx, HandleObject strContains) {
+        return warnOnceAbout(cx, strContains, WARN_STRING_CONTAINS_DEPRECATED,
+                             JSMSG_DEPRECATED_STRING_CONTAINS);
+    }
+
     static bool getOrCreateEval(JSContext* cx, Handle<GlobalObject*> global,
                                 MutableHandleObject eval);
 

js/src/vm/Xdr.h

@@ -33,7 +33,7 @@ static const uint32_t XDR_BYTECODE_VERSION_SUBTRAHEND = 281;
 static const uint32_t XDR_BYTECODE_VERSION =
     uint32_t(0xb973c0de - XDR_BYTECODE_VERSION_SUBTRAHEND);
 
-static_assert(JSErr_Limit == 392,
+static_assert(JSErr_Limit == 393,
               "GREETINGS, POTENTIAL SUBTRAHEND INCREMENTER! If you added or "
               "removed MSG_DEFs from js.msg, you should increment "
               "XDR_BYTECODE_VERSION_SUBTRAHEND and update this assertion's "