3 files changed, 74 insertions, 0 deletions
diff --git a/Libraries/LibJS/Runtime/ArrayPrototype.cpp b/Libraries/LibJS/Runtime/ArrayPrototype.cpp
index 0cd228cf6a..1d3c563d42 100644
--- a/Libraries/LibJS/Runtime/ArrayPrototype.cpp
+++ b/Libraries/LibJS/Runtime/ArrayPrototype.cpp
@@ -61,6 +61,7 @@ ArrayPrototype::ArrayPrototype()
     put_native_function("includes", includes, 1, attr);
     put_native_function("find", find, 1, attr);
     put_native_function("findIndex", find_index, 1, attr);
+    put_native_function("some", some, 1, attr);
     put("length", Value(0), Attribute::Configurable);
 }
 
@@ -501,4 +502,41 @@ Value ArrayPrototype::find_index(Interpreter& interpreter)
     return Value(-1);
 }
 
+Value ArrayPrototype::some(Interpreter& interpreter)
+{
+    auto* array = array_from(interpreter);
+    if (!array)
+        return {};
+
+    auto* callback = callback_from_args(interpreter, "some");
+    if (!callback)
+        return {};
+
+    auto this_value = interpreter.argument(1);
+    auto array_size = array->elements().size();
+
+    for (size_t i = 0; i < array_size; ++i) {
+        if (i >= array->elements().size())
+            break;
+
+        auto value = array->elements().at(i);
+        if (value.is_empty())
+            continue;
+
+        MarkedValueList arguments(interpreter.heap());
+        arguments.append(value);
+        arguments.append(Value((i32)i));
+        arguments.append(array);
+
+        auto result = interpreter.call(callback, this_value, move(arguments));
+        if (interpreter.exception())
+            return {};
+
+        if (result.to_boolean())
+            return Value(true);
+    }
+
+    return Value(false);
+}
+
 }
diff --git a/Libraries/LibJS/Runtime/ArrayPrototype.h b/Libraries/LibJS/Runtime/ArrayPrototype.h
index 30f4c6f000..70802e9cfa 100644
--- a/Libraries/LibJS/Runtime/ArrayPrototype.h
+++ b/Libraries/LibJS/Runtime/ArrayPrototype.h
@@ -56,5 +56,7 @@ private:
     static Value includes(Interpreter&);
     static Value find(Interpreter&);
     static Value find_index(Interpreter&);
+    static Value some(Interpreter&);
 };
+
 }
diff --git a/Libraries/LibJS/Tests/Array.prototype.some.js b/Libraries/LibJS/Tests/Array.prototype.some.js
new file mode 100644
index 0000000000..28d5676d35
--- /dev/null
+++ b/Libraries/LibJS/Tests/Array.prototype.some.js
@@ -0,0 +1,34 @@
+load("test-common.js");
+
+try {
+    assert(Array.prototype.some.length === 1);
+
+    assertThrowsError(() => {
+        [].some(undefined);
+    }, {
+        error: TypeError,
+        message: "undefined is not a function"
+    });
+
+    var array = ["hello", "friends", 1, 2, false, -42, { name: "serenityos"}];
+
+    assert(array.some(value => value === "hello") === true);
+    assert(array.some(value => value === "serenity") === false);
+    assert(array.some((value, index, arr) => index === 1) === true);
+    assert(array.some(value => value == "1") === true);
+    assert(array.some(value => value === 1) === true);
+    assert(array.some(value => value === 13) === false);
+    assert(array.some(value => typeof(value) !== "string") === true);
+    assert(array.some(value => typeof(value) === "boolean") === true);
+    assert(array.some(value => value > 1) === true);
+    assert(array.some(value => value > 1 && value < 3) === true);
+    assert(array.some(value => value > 100) === false);
+    assert(array.some(value => value < 0) === true);
+    assert(array.some(value => array.pop()) === true);
+    assert(["", "hello", "friends", "serenity"].some(value => value.length === 0) === true);
+    assert([].some(value => value === 1) === false);
+
+    console.log("PASS");
+} catch (e) {
+    console.log("FAIL: " + e);
+}