add more tests for non-empty positive lookaheads

Author: erik-krogh

javascript/ql/test/query-tests/Performance/ReDoS/PolynomialBackTracking.expected

@@ -497,3 +497,7 @@
 | tst.js:372:24:372:30 | [^"\\s]+ | Strings with many repetitions of '!' can start matching anywhere after the start of the preceeding ("[^"]*?"\|[^"\\s]+)+ |
 | tst.js:373:16:373:21 | [^"]*? | Strings starting with '"' and with many repetitions of '""' can start matching anywhere after the start of the preceeding ("[^"]*?"\|[^"\\s]+)+(?=X) |
 | tst.js:373:24:373:30 | [^"\\s]+ | Strings with many repetitions of '!' can start matching anywhere after the start of the preceeding ("[^"]*?"\|[^"\\s]+)+ |
+| tst.js:374:15:374:16 | x* | Strings with many repetitions of 'x' can start matching anywhere after the start of the preceeding (x*)+(?=$) |
+| tst.js:375:15:375:16 | x* | Strings with many repetitions of 'x' can start matching anywhere after the start of the preceeding (x*)+(?=$\|y) |
+| tst.js:376:15:376:21 | [\\s\\S]* | Strings with many repetitions of 'a' can start matching anywhere after the start of the preceeding ([\\s\\S]*)+(?=$) |
+| tst.js:377:15:377:21 | [\\s\\S]* | Strings with many repetitions of 'a' can start matching anywhere after the start of the preceeding ([\\s\\S]*)+(?=$\|y) |

javascript/ql/test/query-tests/Performance/ReDoS/ReDoS.expected

@@ -174,3 +174,7 @@
 | tst.js:363:15:363:38 | ((?:a{0,2\|-)\|\\w\\{\\d,\\d)+ | This part of the regular expression may cause exponential backtracking on strings containing many repetitions of 'a{0,2'. |
 | tst.js:372:24:372:30 | [^"\\s]+ | This part of the regular expression may cause exponential backtracking on strings containing many repetitions of '!'. |
 | tst.js:373:24:373:30 | [^"\\s]+ | This part of the regular expression may cause exponential backtracking on strings containing many repetitions of '!'. |
+| tst.js:374:15:374:16 | x* | This part of the regular expression may cause exponential backtracking on strings containing many repetitions of 'x'. |
+| tst.js:375:15:375:16 | x* | This part of the regular expression may cause exponential backtracking on strings containing many repetitions of 'x'. |
+| tst.js:376:15:376:21 | [\\s\\S]* | This part of the regular expression may cause exponential backtracking on strings containing many repetitions of 'a'. |
+| tst.js:377:15:377:21 | [\\s\\S]* | This part of the regular expression may cause exponential backtracking on strings containing many repetitions of 'a'. |

javascript/ql/test/query-tests/Performance/ReDoS/tst.js

@@ -370,4 +370,8 @@ var good43 = /("[^"]*?"|[^"\s]+)+(?=\s*|\s*$)/g;
 
 // BAD
 var bad87 = /("[^"]*?"|[^"\s]+)+(?=\s*|\s*$)X/g;
-var bad88 = /("[^"]*?"|[^"\s]+)+(?=X)/g;
+var bad88 = /("[^"]*?"|[^"\s]+)+(?=X)/g;
+var bad89 = /(x*)+(?=$)/
+var bad90 = /(x*)+(?=$|y)/
+var bad91 = /([\s\S]*)+(?=$)/
+var bad92 = /([\s\S]*)+(?=$|y)/