postcss-loader warnings

[egoist]

vuepress/lib/build.js

Lines 99 to 107 in 2d6f02f

	if (stats.hasErrors()) {
	stats.toJson().errors.forEach(err => {
	console.error(err)
	})
	reject(new Error(`Failed to compile with errors.`))
	return
	}
	resolve(stats.toJson({ modules: false }))
	})

VuePress didn't handle webpack warnings, but if you add following lines:

if (stats.hasWarnings()) {
  return reject(new Error(stats.toString()))
}

And if you run yarn build --debug in VuePress repo, there're actually postcss-loader warnings:

Not sure if this is a vue-loader bug since I can only reproduce it in this repo. I've tried console.log this.sourceMap in vue-loader, seems it's always true even if I already set webpackConfig.devtool: false

Test against latest commit: 2d6f02f

[meteorlxy]

And another warning:

DeprecationWarning: Tapable.plugin is deprecated. Use new API on .hooks instead

[ulivz]

Reproduced this problem, It works when set sourceMap to true. but what is strange is that no source map was generated. maybe need more investigation.

rule.use('postcss-loader').loader('postcss-loader').options(Object.assign({
        plugins: [require('autoprefixer')],
        sourceMap: true
      }, siteConfig.postcss))

[meteorlxy]

  if (debug) {
    // config.devtool('source-map')
  } else if (!isProd) {
    config.devtool('cheap-module-eval-source-map')
  }

I tried to comment that line but failed.

Maybe the sourceMap should be set to !isProd || debug?

[ulivz]

It should be:

  if (!isProd) {
    config.devtool('cheap-module-eval-source-map')
  } else if (debug) {
    config.devtool('source-map')
  }

[meteorlxy]

Yes, but it will still cause the warning if we don't set the sourceMap to true in debug mode.

[ulivz]

😅have you tested for that?

[egoist]

@meteorlxy hmm I was just using --debug to disable progress bar. The problem still exists without that flag.

The actual problem is vue-loader will return sourcemaps for style block in .vue file when devtool is set to false. That's what cause postcss-loader to throw warnings I guess.

[ulivz]

Oh my egoist! I cannot repro it against 87e88f3 😂

[meteorlxy]

Oh my ulivz, me neither!!

[ulivz]

So amazing, what happened?

[meteorlxy]

I have nooooooooo idea.

[meteorlxy]

I even re-clone our repo again and cannot repro it....

[meteorlxy]

emmm did you forget to add the hasWarning code.........

[ulivz]

emmm this warning would be another issue 😅 It looks like one of our dependencies is outdated, or our dependencies' dependencies, or .....

[ulivz]

Welcome to find it out, thanks!

[meteorlxy]

@ulivz For me, after many times of git reset, I forgot to add:

if (stats.hasWarnings()) {
  return reject(new Error(stats.toString()))
}

After adding that again, I repro it successfully.....

（老哥咱俩是不是蠢到一块去了）

[ulivz]

（老哥，咱俩是蠢到一块去了 😂）

[egoist]

@yyx990803 might be a bug in vue-loader?

[meteorlxy]

Two things cause these warnings:

1. stylus-loader default sourceMap options is { comment: false } but not false, so we have to disable it mannually in production mode. See related code of stylus-loader

2. css-loader with modules: true may always have sourceMap before postcss-loader.

After I fix the stylus-loader's sourceMap problem, there are still two warnings about file docs/guide/using-vue.md and docs/zh/guide/using-vue.md, in which there is a css-module usage at the end of those two pages. So I realized the second point, but I'm not sure about the cause of that.

I will make a PR to fix this issue later.

[ulivz]

Fixed at 34c7f99
Thanks to Evan at webpack-contrib/postcss-loader#361