code: function handleWarnings (warnings) {
    clearOutdatedErrors()
  
    var isHotUpdate = !isFirstCompilation
    isFirstCompilation = false
    hasCompileErrors = false
  
    function printWarnings () {
      // Print warnings to the console.
      var formatted = formatWebpackMessages({
        warnings: warnings,
        errors: [],
      })
  
      if (typeof console !== 'undefined' && typeof console.warn === 'function') {
        for (var i = 0; i < formatted.warnings.length; i++) {
          if (i === 5) {
            console.warn(
              'There were more warnings in other files.\n' +
                'You can find a complete log in the terminal.'
            )
            break
          }
          console.warn(stripAnsi(formatted.warnings[i]))
        }
      }
    }
  
    // Attempt to apply hot updates or reload.
    if (isHotUpdate) {
      tryApplyUpdates(function onSuccessfulHotUpdate () {
        // Only print warnings if we aren't refreshing the page.
        // Otherwise they'll disappear right away anyway.
        printWarnings()
        // Only dismiss it when we're sure it's a hot update.
        // Otherwise it would flicker right before the reload.
        ErrorOverlay.dismissBuildError()
      })
    } else {
      // Print initial warnings immediately.
      printWarnings()
    }
  }
docs: Compilation with warnings (e.g. ESLint).