feat(gatsby-cli): Added support and docs for NO_COLOR env variable (#16372)

* Added support and docs for NO_COLOR env variable

Closes #16324

* Refactored noColor section

* Moved FORCE_COLOR env variable into Reporter

* rewrite code style 💅

Author: evolkmann

docs/docs/gatsby-cli.md

@@ -153,3 +153,7 @@ You can type in a command, such as one of these:
 When combined with the [GraphQL explorer](/docs/introducing-graphiql/), these REPL commands could be very helpful for understanding your Gatsby site's data.
 
 See the Gatsby REPL documentation [here](/docs/gatsby-repl/).
+
+### Disabling colored output
+
+In addition to the explicit `--no-color` option, the CLI respects the presence of the `NO_COLOR` environment variable (see [no-color.org](https://no-color.org/)).

packages/gatsby-cli/src/create-cli.js

@@ -82,14 +82,8 @@ function buildLocalCommands(cli, isLocalSite) {
   function getCommandHandler(command, handler) {
     return argv => {
       report.setVerbose(!!argv.verbose)
-      if (argv.noColor) {
-        // disables colors in popular terminal output coloring packages
-        //  - chalk: see https://www.npmjs.com/package/chalk#chalksupportscolor
-        //  - ansi-colors: see https://github.com/doowb/ansi-colors/blob/8024126c7115a0efb25a9a0e87bc5e29fd66831f/index.js#L5-L7
-        process.env.FORCE_COLOR = `0`
-      }
 
-      report.setNoColor(!!argv.noColor)
+      report.setNoColor(argv.noColor || process.env.NO_COLOR)
 
       process.env.gatsby_log_level = argv.verbose ? `verbose` : `normal`
       report.verbose(`set gatsby_log_level: "${process.env.gatsby_log_level}"`)

packages/gatsby-cli/src/reporter/index.js

@@ -38,6 +38,13 @@ const reporter: Reporter = {
     if (isNoColor) {
       errorFormatter.withoutColors()
     }
+
+    // disables colors in popular terminal output coloring packages
+    //  - chalk: see https://www.npmjs.com/package/chalk#chalksupportscolor
+    //  - ansi-colors: see https://github.com/doowb/ansi-colors/blob/8024126c7115a0efb25a9a0e87bc5e29fd66831f/index.js#L5-L7
+    if (isNoColor) {
+      process.env.FORCE_COLOR = `0`
+    }
   },
   /**
    * Log arguments and exit process with status 1.