README.md

(Some minimal) reproduction for facebook/docusaurus#5252

• test-docusaurus-2.0.0-beta.4

  This was installed using:

  $ npx -y @docusaurus/init@2.0.0-beta.4 init test-docusaurus-2.0.0-beta.4 classic

  The .gitignore file was removed so that all the files can be committed to the repository.

  To reproduce:

  • on one terminal, execute yarn start

  • on another terminal, edit title inside docusaurus.config.js using vim and save, twice: on the first save the site will be rebuilt, on the second save the site won't be rebuilt

  This effect is not always reproducible with 2 saves. Sometimes it takes a few saves. Once the site is not rebuilt, it won't be rebuilt anymore until the development server is shut down and yarn start is executed again.

  This effect is only reproducible using vim. nano and VS Code won't work. This is due to vim using an "atomic save" instead of replacing the edited file directly: paulmillr/chokidar#35

  Also, any element inside docusaurus.config.js can be used (edited) for this demonstration. It can be the theme, it can be any other element, as long as it changes the configuration. Just simply touch-ing the file won't work.

• test-docusaurus-2.0.0-beta.4-extraLogging

  This is a copy of test-docusaurus-2.0.0-beta.4:

  $ cp -a test-docusaurus-2.0.0-beta.4 test-docusaurus-2.0.0-beta.4-extraLogging

  Then it was modified to print out more logs onto the terminal.

  To reproduce the problem, use yarn start and vim the same way as reproducing with test-docusaurus-2.0.0-beta.4. However, in this version, you can see what's going on: upon the first save, there is a change event for docusaurus.config.js

  We can see that most of the time, following the change event, there will be an unlink event. After the unlink event, changes to docusaurus.config.js are not watched anymore.

• test-chokidar-3.5.2-extralogging

  This contains the files from the default docusaurus initialization, but with the docusaurus libraries removed. It seems that the presence of the files help with reproducing the problem.

  To reproduce the problem, execute node test1.js in this directory. Then use vim to modify docusaurus.config.js. This script calls chokidar's watch() function with the parameter atomic set to 2000 (ms), and will quit once there is an unlink event.

  Sometimes, there will only be a change event. Just edit the file docusaurus.config.js again a few times, most of the time there will be an unlink event.

• test-minimal

  This is a minimal reproduction. Running node test1.js and then editing docusaurus.config.js will reproduce the problem most of the time.

  One other way to reproduce the problem is by running node test1.js in one terminal, and then cp docusaurus.config.js docusaurus.config.js.bak && rm docusaurus.config.js && cp docusaurus.config.js.bak docusaurus.config.js in another terminal. The whole cp ... && rm ... && cp ... command sequence simulates vim saving a file.

  Yet another way, is to run node test_self.js. This script watches the file docusaurus.config.js and then repeatedly executes the above command sequence. Usually we get this output:

  [ 'blog/*.md', 'docusaurus.config.js' ]
  2021-08-01T12:12:09.892Z change docusaurus.config.js
  2021-08-01T12:12:10.397Z unlink docusaurus.config.js
  

  But sometimes (maybe 10% of the time) we get something like this:

  [ 'blog/*.md', 'docusaurus.config.js' ]
  2021-08-01T12:12:12.982Z unlink docusaurus.config.js
  

  Which means that the change event never appeared at all. Also, sometimes (less than 5% of the time) we get something like this:

  [ 'blog/*.md', 'docusaurus.config.js' ]
  2021-08-01T12:15:39.524Z change docusaurus.config.js
  2021-08-01T12:15:40.521Z change docusaurus.config.js
  2021-08-01T12:15:42.024Z unlink docusaurus.config.js