Hanging after assert.deepEqual

[flippmoke]

I have run into a problem where mocha hangs forever in garbage collection using 100% cpu rather then ending.

I have narrowed all this down to a simple test case I have created in this repo.

I am using node version v0.10.35.

You can replicate the error by doing:

git clone [email protected]:flippmoke/mochaAssertHang.git
cd mochaAssertHang
npm install
npm test

You will note however, that simply running node ./index.js will not hang and will just output the exception thrown from assert.deepEqual.

I traced back the last working version of this with mocha and it works properly with 2.2.1 but fails with later versions of mocha.

Here is a screen cap of a sample of the process while hung, as you can see it seems to be stuck doing garbage collection.

[flippmoke]

After digging found that it hangs at this line:

mocha/lib/reporters/base.js

Line 413 in 0c70277

var msg = diff.createPatch('string', err.actual, err.expected);

Therefore this seems to be a problem with diff package.

This would also make sense as this commit 789ac58 would have changed the diff version about the right time.

[flippmoke]

Created an issue on jsdiff and will see if there can be any resolution because the latest version of jsdiff (diff) still does not seem to solve the issue.

[stale]

I am a bot that watches issues for inactivity.
This issue hasn't had any recent activity, and I'm labeling it stale. In 14 days, if there are no further comments or activity, I will close this issue.
Thanks for contributing to Mocha!

[mojavelinux]

This could be the same problem as described in this issue: chaijs/chai#1109. I've provided a workaround (at least for chai).