LibJS: Simplify various StringPrototype functions

1 files changed, 31 insertions, 62 deletions

diff --git a/Libraries/LibJS/Runtime/StringPrototype.cpp b/Libraries/LibJS/Runtime/StringPrototype.cpp
index 0062a22263..bc54c5823d 100644
--- a/Libraries/LibJS/Runtime/StringPrototype.cpp
+++ b/Libraries/LibJS/Runtime/StringPrototype.cpp
@@ -113,9 +113,9 @@ Value StringPrototype::repeat(Interpreter& interpreter)
         return interpreter.throw_exception<RangeError>("repeat count must be a positive number");
     if (count_value.is_infinity())
         return interpreter.throw_exception<RangeError>("repeat count must be a finite number");
-    auto count = count_value.to_i32();
+    auto count = count_value.to_size_t();
     StringBuilder builder;
-    for (i32 i = 0; i < count; ++i)
+    for (size_t i = 0; i < count; ++i)
         builder.append(string);
     return js_string(interpreter, builder.to_string());
 }
@@ -130,15 +130,14 @@ Value StringPrototype::starts_with(Interpreter& interpreter)
     auto search_string = interpreter.argument(0).to_string(interpreter);
     if (interpreter.exception())
         return {};
-    auto search_string_length = static_cast<i32>(search_string.length());
-    i32 position = 0;
+    auto string_length = string.length();
+    auto search_string_length = search_string.length();
+    size_t start = 0;
     if (interpreter.argument_count() > 1) {
         auto number = interpreter.argument(1).to_number();
         if (!number.is_nan())
-            position = number.to_i32();
+            start = min(number.to_size_t(), string_length);
     }
-    auto string_length = static_cast<i32>(string.length());
-    auto start = min(max(position, 0), string_length);
     if (start + search_string_length > string_length)
         return Value(false);
     if (search_string_length == 0)
@@ -151,10 +150,7 @@ Value StringPrototype::index_of(Interpreter& interpreter)
     auto string = string_from(interpreter);
     if (string.is_null())
         return {};
-    Value needle_value = js_undefined();
-    if (interpreter.argument_count() >= 1)
-        needle_value = interpreter.argument(0);
-    auto needle = needle_value.to_string(interpreter);
+    auto needle = interpreter.argument(0).to_string(interpreter);
     if (interpreter.exception())
         return {};
     return Value((i32)string.index_of(needle).value_or(-1));
@@ -199,11 +195,7 @@ enum class PadPlacement {
 
 static Value pad_string(Interpreter& interpreter, const String& string, PadPlacement placement)
 {
-    auto max_length_value = interpreter.argument(0).to_number();
-    if (max_length_value.is_nan() || max_length_value.is_undefined() || max_length_value.as_double() < 0)
-        return js_string(interpreter, string);
-
-    auto max_length = static_cast<size_t>(max_length_value.to_i32());
+    auto max_length = interpreter.argument(0).to_size_t();
     if (max_length <= string.length())
         return js_string(interpreter, string);
 
@@ -212,9 +204,9 @@ static Value pad_string(Interpreter& interpreter, const String& string, PadPlace
         fill_string = interpreter.argument(1).to_string(interpreter);
         if (interpreter.exception())
             return {};
+        if (fill_string.is_empty())
+            return js_string(interpreter, string);
     }
-    if (fill_string.is_empty())
-        return js_string(interpreter, string);
 
     auto fill_length = max_length - string.length();
 
@@ -292,35 +284,22 @@ Value StringPrototype::substring(Interpreter& interpreter)
     if (interpreter.argument_count() == 0)
         return js_string(interpreter, string);
 
-    i32 string_length = static_cast<i32>(string.length());
-    i32 index_start = interpreter.argument(0).to_number().to_i32();
-    i32 index_end = string_length;
-
-    if (index_start > string_length)
-        index_start = string_length;
-    else if (index_start < 0)
-        index_start = 0;
+    auto string_length = string.length();
+    auto index_start = min(interpreter.argument(0).to_size_t(), string_length);
+    auto index_end = string_length;
 
-    if (interpreter.argument_count() >= 2) {
-        index_end = interpreter.argument(1).to_number().to_i32();
-
-        if (index_end > string_length)
-            index_end = string_length;
-        else if (index_end < 0)
-            index_end = 0;
-    }
+    if (interpreter.argument_count() >= 2)
+        index_end = min(interpreter.argument(1).to_size_t(), string_length);
 
     if (index_start == index_end)
         return js_string(interpreter, String(""));
 
     if (index_start > index_end) {
-        if (interpreter.argument_count() == 1) {
+        if (interpreter.argument_count() == 1)
             return js_string(interpreter, String(""));
-        } else {
-            i32 temp_index_start = index_start;
-            index_start = index_end;
-            index_end = temp_index_start;
-        }
+        auto temp_index_start = index_start;
+        index_start = index_end;
+        index_end = temp_index_start;
     }
 
     auto part_length = index_end - index_start;
@@ -336,16 +315,12 @@ Value StringPrototype::includes(Interpreter& interpreter)
     auto search_string = interpreter.argument(0).to_string(interpreter);
     if (interpreter.exception())
         return {};
-    i32 position = 0;
 
+    size_t position = 0;
     if (interpreter.argument_count() >= 2) {
-        position = interpreter.argument(1).to_i32();
-
-        if (position >= static_cast<i32>(string.length()))
+        position = interpreter.argument(1).to_size_t();
+        if (position >= string.length())
             return Value(false);
-
-        if (position < 0)
-            position = 0;
     }
 
     if (position == 0)
@@ -365,9 +340,9 @@ Value StringPrototype::slice(Interpreter& interpreter)
     if (interpreter.argument_count() == 0)
         return js_string(interpreter, string);
 
-    i32 string_length = static_cast<i32>(string.length());
-    i32 index_start = interpreter.argument(0).to_i32();
-    i32 index_end = string_length;
+    auto string_length = static_cast<i32>(string.length());
+    auto index_start = interpreter.argument(0).to_i32();
+    auto index_end = string_length;
 
     auto negative_min_index = -(string_length - 1);
     if (index_start < negative_min_index)
@@ -410,21 +385,15 @@ Value StringPrototype::last_index_of(Interpreter& interpreter)
     if (search_string.length() > string.length())
         return Value(-1);
 
-    ssize_t max_index = string.length() - search_string.length();
-    ssize_t from_index = max_index;
-    if (interpreter.argument_count() >= 2) {
-        from_index = static_cast<ssize_t>(interpreter.argument(1).to_i32());
-
-        if (from_index < 0)
-            from_index = 0;
-        if (from_index > max_index)
-            from_index = max_index;
-    }
+    auto max_index = string.length() - search_string.length();
+    auto from_index = max_index;
+    if (interpreter.argument_count() >= 2)
+        from_index = min(interpreter.argument(1).to_size_t(), max_index);
 
-    for (ssize_t i = from_index; i >= 0; --i) {
+    for (i32 i = from_index; i >= 0; --i) {
         auto part_view = string.substring_view(i, search_string.length());
         if (part_view == search_string)
-            return Value((i32)i);
+            return Value(i);
     }
 
     return Value(-1);