Regular expression error javascript

Question

I am trying to inject a js file(as a string) into tab in chrome using this code in background.html(chrome extension)

error:

Uncaught SyntaxError: Invalid regular expression: /((?)?:w+/: Invalid group

code:

setTimeout(chrome.tabs.executeScript(tab.id ,
{code:'console.log("activetab");(function(a){"use strict";var 
b=this,c=b.SpeechRecognition||b.webkitSpeechRecognition||b.mozSpeechRecognition|
|b.msSpeechRecognition||b.oSpeechRecognition;if(!c)return 
b.annyang=null,a;var d,e,f=[],g={start:[],error:[],end:[],result:  
[],resultMatch:[],resultNoMatch:[],errorNetwork:[],errorPermissionBlocked:
[],errorPermissionDenied:[]},h=0,i=!1,j="font-weight: bold; color: 
#00f;",k=!1,l=/\s*\((.*?)\)\s*/g,m=/(\(\?:[^)]+\))\?/g,n=/(\
(\?)?:\w+/g,o=/\\*\w+/g,p=/[\-{}\[\]+?.,\\\^$|#]/g,q=function(a){return 
a=a.replace(p,"\\$&").replace(l,"(?:$1)?").replace(n,function(a,b){return b?
a:"([^\\s]+)"}).replace(o,"(.*?)").replace(m,"\\s*$1?\\s*"),new     
gExp("^"+a+"$","i")},r=function(a){var 
b=Array.prototype.slice.call(arguments,1);a.forEach(function(a)
{a.callback.apply(a.context,b)})},s=function()
{t()||b.annyang.init({},!1)},t=function(){return d!==a},u=function(a,c,d)
{f.push({command:a,callback:c,originalPhrase:d}),i&&b.console.log("Command 
successfully loaded: %c"+d,j)};b.annyang={init:function(l,m)
{m=m===a?!0:!!m,d&&d.abort&&d.abort(),d=new 
c,d.maxAlternatives=5,d.continuous="http:"===b.location.protocol,d.lang="en-
US",d.onstart=function(){r(g.start)},d.onerror=function(a)
{switch(r(g.error),a.error){case"network":r(g.errorNetwork);break;case"not-
allowed":case"service-not-allowed":e=!1,r((new Date).getTime()-h<200?
g.errorPermissionBlocked:g.errorPermissionDenied)}},d.onend=function()
{if(r(g.end),e){var a=(new Date).getTime()-h;1e3>a?
setTimeout(b.annyang.start,1e3-a):b.annyang.start()}},d.onresult=function(a)
{if(k)return i&&b.console.log("Speech heard, but annyang is 
paused"),!1;for(var c=a.results[a.resultIndex],d=
[],e=0;e<c.length;e++)d[e]=c[e].transcript;r(g.result,d);for(var 
h,l=0;l<d.length;l++){h=d[l].trim(),i&&b.console.log("Speech recognized: 
%c"+h,j);for(var m=0,n=f.length;n>m;m++){var o=f[m].command.exec(h);if(o)
{var p=o.slice(1);return i&&(b.console.log("command matched: 
%c"+f[m].originalPhrase,j),p.length&&b.console.log("with         
parameters",p)),f[m].callback.apply(this,p),r(g.resultMatch,h,f[m].originalPhras
e,d),!0}}}return r(g.resultNoMatch,d),!1},m&&(f=
[]),l.length&&this.addCommands(l)},start:function(c){k=!1,s(),c=c||
{},e=c.autoRestart!==a?!!c.autoRestart:!0,c.continuous!==a&&
(d.continuous=!!c.continuous),h=(new Date).getTime();try{d.start()}catch(f)
{i&&b.console.log(f.message)}},abort:function()
{e=!1,t&&d.abort()},pause:function(){k=!0},resume:function()
{b.annyang.start()},debug:function(a)
{i=arguments.length>0?!!a:!0},setLanguage:function(a)
{s(),d.lang=a},addCommands:function(a){var c;s();for(var d in 
a)if(a.hasOwnProperty(d))if(c=b[a[d]]||a[d],"function"==typeof 
c)u(q(d),c,d);else{if(!("object"==typeof c&&c.regexp instanceof RegExp))
{i&&b.console.log("Can not register command: %c"+d,j);continue}u(new 
RegExp(c.regexp.source,"i"),c.callback,d)}},removeCommands:function(b)
{return b===a?void(f=[]):(b=Array.isArray(b)?b:
[b],void(f=f.filter(function(a){for(var 
c=0;c<b.length;c++)if(b[c]===a.originalPhrase)return!1;return!0})))},addCallback
:function(c,d,e){if(g[c]!==a){var f=b[d]||d;"function"==typeof 
f&&g[c].push({callback:f,context:e||this})}}}}).call(this);if(annyang)
{console.log("hi");annyang.start()}'}, null),400);

http://stackoverflow.com/a/400316/2647442 goes into detail about which characters you need to escape in regex. The gist is that some characters have a special meaning for regex and if you do not escape them they can cause unwanted (e.g. a dot (.) will match ANY character, not just a dot, if not escaped) behavior or cause a syntax error. — Marie, Dec 18 '15 at 17:25

score 1 · Answer 1 · 2015-12-18T18:20:06.820

If you run the sample code as is, that regex is escaping a newline, not a open paren's.
(this is the price of obfuscation)

This

(\
(\?)?:\w+

Parses into this

=    (  <-- Unbalanced  '('
          \n
          ( \? )?                            # (1)
          : \w+

If you take out the newline, it becomes this

(\(\?)?:\w+

which parses into this

 ( \(\? )?                     # (1)
 : \w+

But, you'll notice the error text has the escapes stripped out.

Which is this ((?)?:w+

that parses into this

=    (  <-- Unbalanced  '('
          (                                  # (1 start)
=              ?  <-- Quantifies nothing
          )?                                 # (1 end)
          :w+

I would check the quoting and the newline. One of these are the problem.

A good place to start is to use these two lines

#00f;",k=!1,l=/\s*\((.*?)\)\s*/g,m=/(\(\?:[^)]+\))\?/g,n=/(\(\?)?:\w+/g,
o=/\\*\w+/g,p=/[\-{}\[\]+?.,\\\^$|#]/g,q=function(a){return

in place of those existing lines.

Regular expression error javascript

1 Answers1