feat: make the cli work with/without prettier-eslint peer

package.json

@@ -26,7 +26,16 @@
     "JounQin (https://www.1stG.me) <admin@1stg.me>"
   ],
   "license": "MIT",
+  "peerDependencies": {
+    "prettier-eslint": "*"
+  },
+  "peerDependenciesMeta": {
+    "prettier-eslint": {
+      "optional": true
+    }
+  },
   "dependencies": {
+    "@prettier/eslint": "npm:prettier-eslint@^15.0.1",
     "arrify": "^2.0.1",
     "boolify": "^1.0.1",
     "camelcase-keys": "^7.0.2",
@@ -42,7 +51,6 @@
     "lodash.memoize": "^4.1.2",
     "loglevel-colored-level-prefix": "^1.0.0",
     "messageformat": "^2.3.0",
-    "prettier-eslint": "^15.0.1",
     "rxjs": "^7.5.6",
     "yargs": "^13.1.1"
   },

src/format-files.js

@@ -5,14 +5,14 @@ import fs from 'fs';
 import glob from 'glob';
 import { bindNodeCallback, from, of } from 'rxjs';
 import { catchError, concatAll, distinct, map, mergeMap } from 'rxjs/operators';
-import format from 'prettier-eslint';
 import chalk from 'chalk';
 import getStdin from 'get-stdin';
 import nodeIgnore from 'ignore';
 import findUp from 'find-up';
 import memoize from 'lodash.memoize';
 import indentString from 'indent-string';
 import getLogger from 'loglevel-colored-level-prefix';
+import format from './prettier-eslint';
 import * as messages from './messages';
 
 const LINE_SEPERATOR_REGEX = /(\r|\n|\r\n)/;

src/format-files.test.js

@@ -1,10 +1,10 @@
 /* eslint no-console:0 */
 import fsMock from 'fs';
 import findUpMock from 'find-up';
-import formatMock from 'prettier-eslint';
 import globMock from 'glob';
 import mockGetStdin from 'get-stdin';
 import getLogger from 'loglevel-colored-level-prefix';
+import formatMock from './prettier-eslint';
 import formatFiles from './format-files';
 
 jest.mock('fs');

src/prettier-eslint.js

@@ -0,0 +1,17 @@
+const getLogger = require('loglevel-colored-level-prefix');
+
+const logger = getLogger({ prefix: 'prettier-eslint-cli' });
+
+try {
+  // if `prettier-eslint` is installed by the user manually
+  module.exports = require('prettier-eslint');
+} catch (err) /* istanbul ignore next */ {
+  logger.info('We detected that no `prettier-eslint` is installed.');
+  logger.info('We will use our internal fallback one instead.');
+  logger.info(
+    'You can install `prettier-eslint` as dependency to skip this message.'
+  );
+
+  // it is an internal dependency using `prettier-eslint` as fallback
+  module.exports = require('@prettier/eslint');
+}

test/tests/cli.spec.js

@@ -24,7 +24,7 @@ test('help outputs usage information and flags', async () => {
   // terminal I think)...
   const stdout = await runPrettierESLintCLI('--help');
   expect(stdout).toMatch(/Usage:.*?<globs>.../);
-  expect(stdout).toContain('Options:\n');
+  expect(stdout).toContain('Valid options:\n');
   // just a sanity check.
   // If it's ever longer than 2000 then we've probably got a problem...
   // eslint-disable-next-line jest/no-conditional-in-test