Implement Array.prototype.with (#45)

Author: bnoordhuis

quickjs.c

@@ -35936,6 +35936,80 @@ static JSValue js_array_at(JSContext *ctx, JSValueConst this_val,
     return ret;
 }
 
+static JSValue js_array_with(JSContext *ctx, JSValueConst this_val,
+                             int argc, JSValueConst *argv)
+{
+    JSValue arr, obj, ret, *arrp, *pval;
+    JSObject *p;
+    int64_t i, len, idx;
+    uint32_t count32;
+
+    ret = JS_EXCEPTION;
+    arr = JS_UNDEFINED;
+    obj = JS_ToObject(ctx, this_val);
+    if (js_get_length64(ctx, &len, obj))
+        goto exception;
+
+    if (len > UINT32_MAX) {
+        JS_ThrowRangeError(ctx, "invalid array length");
+        goto exception;
+    }
+
+    if (JS_ToInt64Sat(ctx, &idx, argv[0]))
+        goto exception;
+
+    if (idx < 0)
+        idx = len + idx;
+
+    if (idx < 0 || idx >= len) {
+        JS_ThrowRangeError(ctx, "invalid array index: %" PRId64, idx);
+        goto exception;
+    }
+
+    arr = JS_NewArray(ctx);
+    if (JS_IsException(arr))
+        goto exception;
+
+    p = JS_VALUE_GET_OBJ(arr);
+    if (expand_fast_array(ctx, p, len) < 0)
+        goto exception;
+    p->u.array.count = len;
+
+    i = 0;
+    pval = p->u.array.u.values;
+    if (js_get_fast_array(ctx, obj, &arrp, &count32) && count32 == len) {
+        for (; i < idx; i++, pval++)
+            *pval = JS_DupValue(ctx, arrp[i]);
+        *pval = JS_DupValue(ctx, argv[1]);
+        for (i++, pval++; i < len; i++, pval++)
+            *pval = JS_DupValue(ctx, arrp[i]);
+    } else {
+        for (; i < idx; i++, pval++)
+            if (-1 == JS_TryGetPropertyInt64(ctx, obj, i, pval))
+                goto fill_and_fail;
+        *pval = JS_DupValue(ctx, argv[1]);
+        for (i++, pval++; i < len; i++, pval++) {
+            if (-1 == JS_TryGetPropertyInt64(ctx, obj, i, pval)) {
+            fill_and_fail:
+                for (; i < len; i++, pval++)
+                    *pval = JS_UNDEFINED;
+                goto exception;
+            }
+        }
+    }
+
+    if (JS_SetProperty(ctx, arr, JS_ATOM_length, JS_NewInt64(ctx, len)) < 0)
+        goto exception;
+
+    ret = arr;
+    arr = JS_UNDEFINED;
+
+exception:
+    JS_FreeValue(ctx, arr);
+    JS_FreeValue(ctx, obj);
+    return ret;
+}
+
 static JSValue js_array_concat(JSContext *ctx, JSValueConst this_val,
                                int argc, JSValueConst *argv)
 {
@@ -37432,6 +37506,7 @@ static const JSCFunctionListEntry js_iterator_proto_funcs[] = {
 
 static const JSCFunctionListEntry js_array_proto_funcs[] = {
     JS_CFUNC_DEF("at", 1, js_array_at ),
+    JS_CFUNC_DEF("with", 2, js_array_with ),
     JS_CFUNC_DEF("concat", 1, js_array_concat ),
     JS_CFUNC_MAGIC_DEF("every", 1, js_array_every, special_every ),
     JS_CFUNC_MAGIC_DEF("some", 1, js_array_every, special_some ),

test262_errors.txt

@@ -59,42 +59,6 @@ test262/test/built-ins/Array/prototype/toSpliced/this-value-boolean.js:18: TypeE
 test262/test/built-ins/Array/prototype/toSpliced/this-value-boolean.js:18: strict mode: TypeError: cannot read property 'call' of undefined
 test262/test/built-ins/Array/prototype/toSpliced/unmodified.js:13: TypeError: not a function
 test262/test/built-ins/Array/prototype/toSpliced/unmodified.js:13: strict mode: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/frozen-this-value.js:13: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/frozen-this-value.js:13: strict mode: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/holes-not-preserved.js:27: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/holes-not-preserved.js:27: strict mode: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/ignores-species.js:21: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/ignores-species.js:21: strict mode: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/immutable.js:13: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/immutable.js:13: strict mode: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/index-bigger-or-eq-than-length.js:21: Test262Error: Expected a RangeError but got a TypeError
-test262/test/built-ins/Array/prototype/with/index-bigger-or-eq-than-length.js:21: strict mode: Test262Error: Expected a RangeError but got a TypeError
-test262/test/built-ins/Array/prototype/with/index-casted-to-number.js:23: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/index-casted-to-number.js:23: strict mode: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/index-negative.js:23: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/index-negative.js:23: strict mode: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/index-smaller-than-minus-length.js:21: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/index-smaller-than-minus-length.js:21: strict mode: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/length-decreased-while-iterating.js:32: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/length-decreased-while-iterating.js:32: strict mode: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/length-exceeding-array-length-limit.js:26: Test262Error: Expected a RangeError but got a TypeError
-test262/test/built-ins/Array/prototype/with/length-exceeding-array-length-limit.js:26: strict mode: Test262Error: Expected a RangeError but got a TypeError
-test262/test/built-ins/Array/prototype/with/length-increased-while-iterating.js:32: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/length-increased-while-iterating.js:32: strict mode: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/length-tolength.js:19: TypeError: cannot read property 'call' of undefined
-test262/test/built-ins/Array/prototype/with/length-tolength.js:19: strict mode: TypeError: cannot read property 'call' of undefined
-test262/test/built-ins/Array/prototype/with/metadata/length.js:30: TypeError: cannot convert to object
-test262/test/built-ins/Array/prototype/with/metadata/length.js:30: strict mode: TypeError: cannot convert to object
-test262/test/built-ins/Array/prototype/with/metadata/name.js:28: TypeError: cannot convert to object
-test262/test/built-ins/Array/prototype/with/metadata/name.js:28: strict mode: TypeError: cannot convert to object
-test262/test/built-ins/Array/prototype/with/metadata/property-descriptor.js:18: Test262Error: typeof Expected SameValue(«undefined», «function») to be true
-test262/test/built-ins/Array/prototype/with/metadata/property-descriptor.js:18: strict mode: Test262Error: typeof Expected SameValue(«undefined», «function») to be true
-test262/test/built-ins/Array/prototype/with/no-get-replaced-index.js:29: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/no-get-replaced-index.js:29: strict mode: TypeError: not a function
-test262/test/built-ins/Array/prototype/with/not-a-constructor.js:30: Test262Error: isConstructor invoked with a non-function value
-test262/test/built-ins/Array/prototype/with/not-a-constructor.js:30: strict mode: Test262Error: isConstructor invoked with a non-function value
-test262/test/built-ins/Array/prototype/with/this-value-boolean.js:22: TypeError: cannot read property 'call' of undefined
-test262/test/built-ins/Array/prototype/with/this-value-boolean.js:22: strict mode: TypeError: cannot read property 'call' of undefined
 test262/test/built-ins/AsyncGeneratorPrototype/return/return-state-completed-broken-promise.js:53: TypeError: $DONE() not called
 test262/test/built-ins/AsyncGeneratorPrototype/return/return-state-completed-broken-promise.js:53: strict mode: TypeError: $DONE() not called
 test262/test/built-ins/AsyncGeneratorPrototype/return/return-suspendedStart-broken-promise.js:34: TypeError: $DONE() not called