errors not shown after starting webpack dev server after initial start

[kelly-tock]

node 11.12.0
webpack 4.8.2
webpack dev server 3.1.1
eslint-loader 2.1.2

after doing a fresh install, and starting webpack dev server, the loader will properly display lint warnings/errors. I can go through and edit files to fix the issues, and when dev server refreshes, it shows the remaining issues.

if I stop the dev server, then just start it, no warnings/errors are displayed, even though I know there still are some.

{
        enforce: 'pre',
        test: /\.(ts|tsx)$/,
        include: [path.join(cwd, 'src/js')],
        loader: 'eslint-loader',
        options: {
          configFile: '.eslintrc.js',
          emitWarning: true,
          cache: false,
        },
      },
      {
        include: [path.join(cwd, 'src/js')],
        test: /\.(ts|tsx)$/,
        use: [
          {
            loader: 'cache-loader',
          },
          {
            loader: 'thread-loader',
            options: threadLoaderOptions,
          },
          {
            loader: 'babel-loader',
            options: {
              cacheDirectory: true,
              cacheCompression: false,
              babelrc: false,
             .....other stuff
            },
          },
        ],
      },

if I remove cache loader it displays all the time and this issue does not occur.

is there a way to display the issues all the time while using cache loader?

[kelly-tock]

just to update, I also found that if I add

failOnWarning: true

this issue doesn't occur. however during development, i'm wanting it to still compile, and fix as I go.

we have a pretty large project, so disabling cache loader doesn't seem to be an option for.

[kelly-tock]

any enabling of cacheing in the loader causes this issue as well. tried cache: true, and failOnWarning: true, but the issue persists.

[tmcdos]

Exactly the same situation here. If I clear the .cache folder, then build the project - I see all linting errors, but if I build twice in a row there are no errors or warnings on the second build.
Any chance to fix this?

[kelly-tock]

We ended up removing cache loader and turning on cacheing for eslint loader not as fast but ok for now

[hq5544]

The same.

[kelly-tock]

I found that if you make sure to enable root: true and what not from eslint to make sure it doesn't recursively check for eslint, that gave us a perf boost for sure.

[ricardogobbosouza]

@kelly-tock Please provide a repository with the issue.

[barberdt]

@ricardogobbosouza @kelly-tock

Repro repository provided here: https://github.com/barberdt/loader-issue

Repro steps:

Yarn version: 1.17.3
Node version: 12.9.0

$ git clone git@github.com:barberdt/loader-issue.git
$ cd loader-issue
$ yarn install
$ yarn run test

• Observe the output of the single eslint error:

ERROR in ./index.js
Module Error (from ./node_modules/eslint-loader/dist/cjs.js):

/Users/davis/github/loader-issue/index.js
  1:13  error  'foo' is not defined  no-undef

✖ 1 problem (1 error, 0 warnings)

ℹ ｢wdm｣: Failed to compile.

• Kill the dev server
• Start the dev server again (yarn run test)
• Observe a successful build instead of seeing the expected error.

Restarting the server from this point forward should continue to show a false successful build.

Without having dug into the issue itself, I'm not 100% sure which repo this issue belongs to between eslint-loader, cache-loader, babel-loader, webpack, and webpack-dev-server, but this was the most fleshed out of the related issues, so I thought I'd post here. Happy to move this repro around wherever needed.

[kelly-tock]

Thanks for providing this!

[ricardogobbosouza]

Hi @barberdt, @kelly-tock
Thanks for reporting, sorry for the late reply

I do not recommend using cache-loader and eslint-loader together, use the cache option
But if you want to use both together, enable the failOnError option.

Soon this loader will be deprecated in favor of this plugin eslint-webpack-plugin

[kelly-tock]

I am using typescript so recently switched raking over to be handled by fork ts checker plugin

[onebree]

@ricardogobbosouza Which loader exactly will be deprecated? Caching or ESLint? When will that deprecation happen, and is there a guide present for moving from one to the new plugin?

[ricardogobbosouza]

Hi @onebree

• We are analyzing the depreciation of the eslint-loader
• We will be launching v1.0.0 of eslint-webpack-plugin until this weekend

[ricardogobbosouza]

Please use eslint-webpack-plugin. eslint-loader will be deprecated.