namespaces returned by debug.disable are not always accepted by debug.enable

Open
#918 1 comment 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
45/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
javascript
Domain
tooling

Research direction

Start in common.js at the enable implementation around line 184 and reproduce the issue with DEBUG=":error:". Trace how debug.disable() transforms the namespace before it is passed back to debug.enable(). Done means the namespace returned by disable() can be passed to enable() without an invalid regular expression error.

Written by the indexing model from the issue text.

Description

bug

I have seen some strange behavior when temporary disabling the current namespaces, and trying to re-enable the namespaces returned by the debug.disable() call later in the debug.enable() call.
This happened while debugging a node-red custom node that I'm working on:

First I start node-red with some logging enabled:
DEBUG="*:error:*" node-red
Then using a REST call i fetch the current namespaces as follows:

    RED.httpAdmin.get('/debug', function (req, res) {
        console.log("/debug",req.method);
        var namespaces = debug.disable();
        console.log("/debug",req.method,namespaces);
        debug.enable(namespaces);
        res.end(JSON.stringify(Object({ "namespaces": namespaces })));
    });

When this function is called, it prints the following on the console:

/debug GET
/debug GET .*?:error:*
SyntaxError: Invalid regular expression: /^..*??:error:.*?$/: Nothing to repeat
    at new RegExp (<anonymous>)
    at Function.enable (/home/hurenkam/Workspace/node-red-contrib-mh-hue/node_modules/debug/src/common.js:184:28)
    at /home/hurenkam/Workspace/node-red-contrib-mh-hue/src/debug.js:21:15
    at Layer.handle [as handle_request] (/usr/local/lib/node_modules/node-red/node_modules/express/lib/router/layer.js:95:5)
    at next (/usr/local/lib/node_modules/node-red/node_modules/express/lib/router/route.js:144:13)
    at Route.dispatch (/usr/local/lib/node_modules/node-red/node_modules/express/lib/router/route.js:114:3)
    at Layer.handle [as handle_request] (/usr/local/lib/node_modules/node-red/node_modules/express/lib/router/layer.js:95:5)
    at /usr/local/lib/node_modules/node-red/node_modules/express/lib/router/index.js:284:15
    at Function.process_params (/usr/local/lib/node_modules/node-red/node_modules/express/lib/router/index.js:346:12)
    at next (/usr/local/lib/node_modules/node-red/node_modules/express/lib/router/index.js:280:10)

It would seem that the wildcard namespace "*:error:*" is being translated to ".*?:error:*" which when fed back into debug.enable() triggers an error in common.js @ line 184 when trying to push the expression into a RegExp:

common.js:
184: createDebug.names.push(new RegExp('^' + namespaces + '$'));

Dominant language
JavaScript
Stars
11.5k
Forks
992
PR merge metrics
No merged PRs in 30d

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from debug-js/debug

All issues in debug-js/debug

Similar issues

More JavaScript issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.