Can't regex process <hX> when X is an integer

[bloo]

It works for any other letter besides "h", but breaks when in angle brackets, pared with an integer - whether the brackets are escaped or not.

good:

a1
<a1>
\<a1\>
h1
<9h>

bad:

<h2>
\<h2\>
\<hh2\>
\<h2h\>

Here's the stack:

/usr/local/lib/node_modules/doctoc/lib/get-html-headers.js:11
      if (new RegExp(x.text[0]).test(line)) {
          ^
SyntaxError: Invalid regular expression: /

* HTML5 container semantics
  * proper use of [**\/: \ at end of pattern
    at new RegExp (<anonymous>)
    at /usr/local/lib/node_modules/doctoc/lib/get-html-headers.js:11:11
    at Array.map (native)
    at addLinenos (/usr/local/lib/node_modules/doctoc/lib/get-html-headers.js:8:18)
    at module.exports (/usr/local/lib/node_modules/doctoc/lib/get-html-headers.js:66:13)
    at transform (/usr/local/lib/node_modules/doctoc/lib/transform.js:127:13)
    at /usr/local/lib/node_modules/doctoc/doctoc.js:26:20
    at Array.map (native)
    at transformAndSave (/usr/local/lib/node_modules/doctoc/doctoc.js:24:6)
    at Object.<anonymous> (/usr/local/lib/node_modules/doctoc/doctoc.js:66:1)

[thlorenz]

I have a hunch what causes this.
It'll take a bit of digging to fix it. Do you mind providing a failing test case to reproduce this bug?

Thanks.

[bloo]

#37

[RyanZim]

Is this fixed by #107?

[thlorenz]

Should be, closing since no action for over a year.

[mkfreeman]

Hi,

I'm having the same issue while writing README documents that describe HMTL elements (namely headers):

DocToccing single file "README.md" for github.com.

==================

/usr/local/lib/node_modules/doctoc/lib/get-html-headers.js:11
      if (new RegExp(x.text[0]).test(line)) {
          ^

SyntaxError: Invalid regular expression: /` element tells the reader that the content inside is a top-level heading.

The end tag is just like the start tag except that it has a forward slash added just after the less-than sign (`/: Unterminated group
    at new RegExp (native)
    at /usr/local/lib/node_modules/doctoc/lib/get-html-headers.js:11:11
    at Array.map (native)
    at addLinenos (/usr/local/lib/node_modules/doctoc/lib/get-html-headers.js:8:18)
    at module.exports (/usr/local/lib/node_modules/doctoc/lib/get-html-headers.js:66:13)
    at transform (/usr/local/lib/node_modules/doctoc/lib/transform.js:123:13)
    at /usr/local/lib/node_modules/doctoc/doctoc.js:25:20
    at Array.map (native)
    at transformAndSave (/usr/local/lib/node_modules/doctoc/doctoc.js:23:6)
    at Object.<anonymous> (/usr/local/lib/node_modules/doctoc/doctoc.js:100:3)

When I use any other tag (besides <h1>) I'm fine. Any thoughts/progress on this?

[RyanZim]

@mkfreeman Please open a new issue for this and provide a snippet of the markdown that causes this error.

[mkfreeman]

@RyanZim done, thanks: #120