Issue 6868 - Enable capturing of surrounding wildcards for rewrite filters

lib/common.js

Index: lib/common.js
===================================================================
--- a/lib/common.js
+++ b/lib/common.js
@@ -27,42 +27,51 @@
   return text.replace(/[-/\\^$*+?.()|[\]{}]/g, "\\$&");
 }
 
 exports.textToRegExp = textToRegExp;
 
 /**
  * Converts filter text into regular expression string
  * @param {string} text as in Filter()
+ * @param {boolean} [optimize=true] whether to optimize the regular expression
  * @return {string} regular expression representation of filter text
  */
-function filterToRegExp(text)
+function filterToRegExp(text, optimize = true)

[hub, 2018/08/29 16:23:50]

also, on second thought, I'm not certain that `optimize` is the best naming for
this option. Maybe "capture"? Since the use case is to capture what the regexp
match.

[Manish Jethani, 2018/09/01 14:57:52]

OK, it already captures everything else, just not the stuff that's leading and
trailing. How about `captureAll` in that case?

 {
+  if (optimize)
+  {
+    // remove multiple wildcards
+    text = text.replace(/\*+/g, "*");

[hub, 2018/08/28 22:02:55]

I think we should keep this one unconditionally like it was before, but run it
before this block.

[Manish Jethani, 2018/08/29 13:25:24]

Since the `optimize` argument is supposed to skip all optimizations, shouldn't
we skip this one too? It doesn't make any difference to the matching behavior of
the regular expression, it only makes it match faster, and one can argue that
it's not important for rewrite filters (why would anyone even use two or more
consecutive "*").

[hub, 2018/08/29 16:23:50]

this is more about correctness IMHO. There is an expectation to remove duplicate
'*'

[Manish Jethani, 2018/09/01 14:57:52]

Alright, if we go with the renaming then it makes sense.

Done.

+
+    // remove leading wildcard
+    if (text[0] == "*")
+      text = text.substring(1);
+
+    // remove trailing wildcard
+    if (text[text.length - 1] == "*")
+      text = text.substring(0, text.length - 1);
+  }
+
   return text
-    // remove multiple wildcards
-    .replace(/\*+/g, "*")
     // remove anchors following separator placeholder
     .replace(/\^\|$/, "^")
     // escape special symbols
     .replace(/\W/g, "\\$&")
     // replace wildcards by .*
     .replace(/\\\*/g, ".*")
     // process separator placeholders (all ANSI characters but alphanumeric
     // characters and _%.-)
     .replace(/\\\^/g, "(?:[\\x00-\\x24\\x26-\\x2C\\x2F\\x3A-\\x40\\x5B-\\x5E\\x60\\x7B-\\x7F]|$)")
     // process extended anchor at expression start
     .replace(/^\\\|\\\|/, "^[\\w\\-]+:\\/+(?!\\/)(?:[^\\/]+\\.)?")
     // process anchor at expression start
     .replace(/^\\\|/, "^")
     // process anchor at expression end
-    .replace(/\\\|$/, "$")
-    // remove leading wildcards
-    .replace(/^(\.\*)/, "")
-    // remove trailing wildcards
-    .replace(/(\.\*)$/, "");
+    .replace(/\\\|$/, "$");
 }
 
 exports.filterToRegExp = filterToRegExp;
 
 function splitSelector(selector)
 {
   if (!selector.includes(","))
     return [selector];