fix: conditionally require lint, format (#49)

PR-URL: #49

Author: kjin

src/cli.ts

@@ -17,8 +17,6 @@
 import * as meow from 'meow';
 import * as updateNotifier from 'update-notifier';
 import {init} from './init';
-import {lint} from './lint';
-import {format} from './format';
 import {clean} from './clean';
 
 export interface Logger {
@@ -35,6 +33,9 @@ export interface Options {
   logger: Logger;
 }
 
+export type VerbFunction = (options: Options, fix?: boolean) =>
+    Promise<boolean>;
+
 const logger: Logger = console;
 
 const cli = meow(`
@@ -74,9 +75,15 @@ async function run(verb: string): Promise<boolean> {
     yes: cli.flags.yes || cli.flags.y || false,
     logger: logger
   };
+  // Linting/formatting depend on typescript. We don't want to load the
+  // typescript module during init, since it might not exist.
+  // See: https://github.com/google/ts-style/issues/48
+  if (verb === 'init') {
+    return await init(options);
+  }
+  const lint: VerbFunction = require('./lint');
+  const format: VerbFunction = require('./format');
   switch (verb) {
-    case 'init':
-      return await init(options);
     case 'check':
       return (await lint(options) && await format(options));
     case 'fix':