1 files changed, 31 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/regexp_parse/Lookahead.js b/js/src/jit-test/tests/regexp_parse/Lookahead.js
new file mode 100644
index 000000000..96fc20fe9
--- /dev/null
+++ b/js/src/jit-test/tests/regexp_parse/Lookahead.js
@@ -0,0 +1,31 @@
+if (typeof parseRegExp === 'undefined')
+    quit();
+
+load(libdir + "regexp_parse.js");
+
+test_mix("(?=abc)", all_flags,
+         Lookahead(Atom("abc")));
+
+test_mix("(?!abc)", all_flags,
+         NegativeLookahead(Atom("abc")));
+
+test_mix("(?=abc)+", no_unicode_flags,
+         Lookahead(Atom("abc")));
+
+// Lookahead becomes Empty because max_match of Lookahead is 0 and the min vaue
+// of Quantifier is also 0.
+test("(?=abc)*", no_unicode_flags,
+     Empty());
+test("X(?=abc)*Y", no_unicode_flags,
+     Alternative([
+         Atom("X"),
+         Atom("Y"),
+     ]));
+
+test("(?=abc)?", no_unicode_flags,
+     Empty());
+test("X(?=abc)?Y", no_unicode_flags,
+     Alternative([
+         Atom("X"),
+         Atom("Y"),
+     ]));