basic testcase for string overflows (now check Array.prototype.join(), internally duk_concat())

ecmascript-testcases/test-misc-strings-overflows.js

@@ -0,0 +1,61 @@
+/*
+ *  String overflow tests.
+ *
+ *  Strings overflow at 4G bytes (at the latest) even on 64-bit platforms,
+ *  at least for the moment.  Most string concat operations now use duk_concat()
+ *  internally, which is exercised fully by Array.prototype.join().
+ */
+
+/*===
+1048576
+===*/
+
+var oneMeg = 'x';
+var i;
+for (i = 0; i < 20; i++) {
+    oneMeg += oneMeg;
+}
+print(oneMeg.length);
+
+/*===
+RangeError
+RangeError
+RangeError
+===*/
+
+function arrayJoinSepOverflow() {
+    /* The internal helper first computes total size of separators, so see
+     * that the overflow check for that works.
+     */
+
+    var test = [];
+    var i;
+    for (i = 0; i < 4097; i++) {
+        test[i] = '';
+    }
+    test.join(oneMeg);  /* 4096 seps * 1M = 2**32 -> overflow */
+    print('still here');
+}
+
+function arrayJoinResultOverflow() {
+    var test = [];
+    var i;
+    for (i = 0; i < 4097; i++) {
+        test[i] = oneMeg;
+    }
+    test.join('');
+    print('still here');
+}
+
+try {
+    arrayJoinSepOverflow();
+} catch (e) {
+    print(e.name);
+}
+
+try {
+    arrayJoinResultOverflow();
+} catch (e) {
+    print(e.name);
+}
+