[stubs] Port String.prototype.substr to TurboFan

test/mjsunit/substr.js

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 153 matching lines @@
   assertEquals(["this", "start", "length"], log);
 }
 {
   let log = [];
   let string = {[Symbol.toPrimitive]() { log.push("this"); return "abc" }};
   let start = {[Symbol.toPrimitive]() { log.push("start"); return 0 }};
   let length = {[Symbol.toPrimitive]() { log.push("length"); return 0 }};
   assertEquals("", String.prototype.substr.call(string, start, length));
   assertEquals(["this", "start", "length"], log);
 }
+
+// Bounds edge cases.
+{
+  const str = "abc";
+  const negativeHeapNumber = -1 * 2**32;
+  const positiveHeapNumber = 2**32;
+
+  assertEquals("abc", str.substr(negativeHeapNumber));
+  assertEquals("abc", str.substr(negativeHeapNumber, str.length));
+  assertEquals("abc", str.substr(-str.length, str.length));
+  assertEquals("abc", str.substr(0, str.length));
+  assertEquals("bc", str.substr(-2, str.length));
+  assertEquals("c", str.substr(-1, str.length));
+
+  assertEquals("", str.substr(str.length));
+  assertEquals("", str.substr(4));
+  assertEquals("", str.substr(positiveHeapNumber));
+
+  assertEquals("abc", str.substr(negativeHeapNumber, positiveHeapNumber));
+  assertEquals("abc", str.substr(negativeHeapNumber, positiveHeapNumber));
+  assertEquals("abc", str.substr(-str.length, positiveHeapNumber));
+  assertEquals("abc", str.substr(0, positiveHeapNumber));
+  assertEquals("bc", str.substr(-2, positiveHeapNumber));
+  assertEquals("c", str.substr(-1, positiveHeapNumber));
+
+  assertEquals("", str.substr(str.length, positiveHeapNumber));
+  assertEquals("", str.substr(4, positiveHeapNumber));
+  assertEquals("", str.substr(positiveHeapNumber, positiveHeapNumber));
+
+  assertEquals("", str.substr(negativeHeapNumber, negativeHeapNumber));
+  assertEquals("", str.substr(negativeHeapNumber, negativeHeapNumber));
+  assertEquals("", str.substr(-str.length, negativeHeapNumber));
+  assertEquals("", str.substr(0, negativeHeapNumber));
+  assertEquals("", str.substr(-2, negativeHeapNumber));
+  assertEquals("", str.substr(-1, negativeHeapNumber));
+
+  assertEquals("", str.substr(str.length, negativeHeapNumber));
+  assertEquals("", str.substr(4, negativeHeapNumber));
+  assertEquals("", str.substr(positiveHeapNumber, negativeHeapNumber));
+
+  assertEquals("", str.substr(negativeHeapNumber, -1));
+  assertEquals("", str.substr(negativeHeapNumber, -1));
+  assertEquals("", str.substr(-str.length, -1));
+  assertEquals("", str.substr(0, -1));
+  assertEquals("", str.substr(-2, -1));
+  assertEquals("", str.substr(-1, -1));
+
+  assertEquals("", str.substr(str.length, -1));
+  assertEquals("", str.substr(4, -1));
+  assertEquals("", str.substr(positiveHeapNumber, -1));
+
+  assertEquals("abc", str.substr(undefined));
+  assertEquals("abc", str.substr(undefined, undefined));
+}