Co-locate feature flag utilities

Author: adamwathan

src/featureFlags.js

@@ -0,0 +1,71 @@
+import _ from 'lodash'
+import chalk from 'chalk'
+
+const featureFlags = {
+  future: [],
+  experimental: ['uniformColorPalette'],
+}
+
+export function flagEnabled(config, flag) {
+  if (featureFlags.future.includes(flag)) {
+    return _.get(config, ['future', flag], false)
+  }
+
+  if (featureFlags.experimental.includes(flag)) {
+    return _.get(config, ['experimental', flag], false)
+  }
+
+  return false
+}
+
+export function issueFlagNotices(config) {
+  const log = {
+    info(message) {
+      console.log(chalk.bold.cyan('    info'), '-', message)
+    },
+    warn(message) {
+      console.log(chalk.bold.yellow('    warn'), '-', message)
+    },
+    risk(message) {
+      console.log(chalk.bold.magenta('    risk'), '-', message)
+    },
+  }
+
+  if (_.some(featureFlags.future, flag => _.get(config, ['future', flag], false))) {
+    const changes = Object.keys(config.future)
+      .filter(flag => featureFlags.future.includes(flag) && config.future[flag])
+      .map(s => chalk.cyan(s))
+      .join(', ')
+    console.log()
+    log.info(`You have opted-in to future-facing breaking changes: ${changes}`)
+    log.info(
+      'These changes are stable and will be the default behavior in the next major version of Tailwind.'
+    )
+  }
+
+  if (_.some(featureFlags.experimental, flag => _.get(config, ['experimental', flag], false))) {
+    const changes = Object.keys(config.experimental)
+      .filter(flag => featureFlags.experimental.includes(flag) && config.experimental[flag])
+      .map(s => chalk.yellow(s))
+      .join(', ')
+    console.log()
+    log.warn(`You have enabled experimental features: ${changes}`)
+    log.warn(
+      'Experimental features are not covered by semver, may introduce breaking changes, and can change at any time.'
+    )
+  }
+
+  if (Object.keys(_.get(config, 'future', {})).length < featureFlags.future.length) {
+    const changes = featureFlags.future
+      .filter(flag => !_.has(config, ['future', flag]))
+      .map(s => chalk.magenta(s))
+      .join(', ')
+    console.log()
+    log.risk(`There are upcoming breaking changes: ${changes}`)
+    log.risk(
+      'We highly recommend opting-in to these changes now to simplify upgrading Tailwind in the future.'
+    )
+  }
+}
+
+export default featureFlags

src/index.js

@@ -11,13 +11,14 @@ import formatCSS from './lib/formatCSS'
 import resolveConfig from './util/resolveConfig'
 import { defaultConfigFile } from './constants'
 import defaultConfig from '../stubs/defaultConfig.stub.js'
+import { flagEnabled } from './featureFlags'
 
 import uniformColorPalette from './flagged/uniformColorPalette.js'
 
 function getDefaultConfigs(config) {
   const configs = [defaultConfig]
 
-  if (_.get(config, ['experimental', 'uniformColorPalette'], false)) {
+  if (flagEnabled(config, 'uniformColorPalette')) {
     configs.unshift(uniformColorPalette)
   }
 

src/processTailwindFeatures.js

@@ -13,62 +13,7 @@ import purgeUnusedStyles from './lib/purgeUnusedStyles'
 import corePlugins from './corePlugins'
 import processPlugins from './util/processPlugins'
 import cloneNodes from './util/cloneNodes'
-import chalk from 'chalk'
-
-const log = {
-  info(message) {
-    console.log(chalk.bold.cyan('    info'), '-', message)
-  },
-  warn(message) {
-    console.log(chalk.bold.yellow('    warn'), '-', message)
-  },
-  risk(message) {
-    console.log(chalk.bold.magenta('    risk'), '-', message)
-  },
-}
-
-function issueFlagNotices(config) {
-  const featureFlags = {
-    future: [],
-    experimental: ['uniformColorPalette'],
-  }
-
-  if (_.some(featureFlags.future, flag => _.get(config, ['future', flag], false))) {
-    const changes = Object.keys(config.future)
-      .filter(flag => featureFlags.future.includes(flag) && config.future[flag])
-      .map(s => chalk.cyan(s))
-      .join(', ')
-    console.log()
-    log.info(`You have opted-in to future-facing breaking changes: ${changes}`)
-    log.info(
-      'These changes are stable and will be the default behavior in the next major version of Tailwind.'
-    )
-  }
-
-  if (_.some(featureFlags.experimental, flag => _.get(config, ['experimental', flag], false))) {
-    const changes = Object.keys(config.experimental)
-      .filter(flag => featureFlags.experimental.includes(flag) && config.experimental[flag])
-      .map(s => chalk.yellow(s))
-      .join(', ')
-    console.log()
-    log.warn(`You have enabled experimental features: ${changes}`)
-    log.warn(
-      'Experimental features are not covered by semver, may introduce breaking changes, and can change at any time.'
-    )
-  }
-
-  if (Object.keys(_.get(config, 'future', {})).length < featureFlags.future.length) {
-    const changes = featureFlags.future
-      .filter(flag => !_.has(config, ['future', flag]))
-      .map(s => chalk.magenta(s))
-      .join(', ')
-    console.log()
-    log.risk(`There are upcoming breaking changes: ${changes}`)
-    log.risk(
-      'We highly recommend opting-in to these changes now to simplify upgrading Tailwind in the future.'
-    )
-  }
-}
+import { issueFlagNotices } from './featureFlags.js'
 
 export default function(getConfig) {
   return function(css) {