refactor: add deprecation message lib (#113)

Author: justinhelmer

lib/deprecate.js

@@ -0,0 +1,12 @@
+const chalk = require('chalk')
+const logger = require('./logger')
+
+const replace = (oldThing, newThing) => {
+  logger.warn(chalk.bold.yellow('Deprecation Warning:'), '\n')
+  logger.warn(chalk.yellow(`Option ${chalk.bold(`"${oldThing}"`)} has been removed, and replaced by ${chalk.bold(`"${newThing}"`)}`), '\n')
+  logger.warn(chalk.yellow('This option will be removed in the next major version of `vue-jest`. Please update your configuration.'), '\n')
+  logger.warn(chalk.bold.yellow('Configuration Documentation:'))
+  logger.warn(chalk.yellow('https://github.com/vuejs/vue-jest'))
+}
+
+module.exports = { replace }

test/deprecate.spec.js

@@ -0,0 +1,13 @@
+import chalk from 'chalk'
+import { replace } from '../lib/deprecate'
+import logger from '../lib/logger'
+
+describe('display deprecation messaging', () => {
+  it('should format the warning with the correct information', () => {
+    logger.warn = jest.fn()
+    replace('foo', 'bar')
+    expect(logger.warn).toHaveBeenCalledWith(chalk.bold.yellow('Deprecation Warning:'), '\n')
+    expect(logger.warn).toHaveBeenCalledWith(chalk.yellow(`Option ${chalk.bold('"foo"')} has been removed, and replaced by ${chalk.bold('"bar"')}`), '\n')
+    logger.warn.mockRestore()
+  })
+})