feat: improved yarn support

Any commands with a --yarn flag will look for a "yarn.lock" file in the working directory. When a lockfile exists, the --yarn flag will be true by default.

Other fixes:
- actually use argv.yarn for the "link" command
- actually use the `getPackageManager` function's argument
- remove unused `showVersion` function

src/index.ts

@@ -1,11 +1,9 @@
 import * as fs from 'fs-extra'
-import * as path from 'path'
+import { join } from 'path'
 import { PackageName } from './installations'
 
 const userHome = require('user-home')
 
-const { join } = path
-
 export const values = {
   myNameIs: 'yalc',
   ignoreFileName: '.yalcignore',
@@ -56,7 +54,7 @@ export function getStorePackagesDir(): string {
 }
 
 export const getPackageStoreDir = (packageName: string, version = '') =>
-  path.join(getStorePackagesDir(), packageName, version)
+  join(getStorePackagesDir(), packageName, version)
 
 export type PackageScripts = Partial<{
   preinstall: string
@@ -83,8 +81,8 @@ export interface PackageManifest {
   __JSONSpaces: number
 }
 
-export const getPackageManager = (workingDir: string) =>
-  fs.existsSync('yarn.lock') ? 'yarn' : 'npm'
+export const getPackageManager = (cwd: string) =>
+  fs.existsSync(join(cwd, 'yarn.lock')) ? 'yarn' : 'npm'
 
 export const execLoudOptions = { stdio: 'inherit' }
 

src/yalc.ts

@@ -7,7 +7,8 @@ import {
   addPackages,
   updatePackages,
   removePackages,
-  getStoreMainDir
+  getStoreMainDir,
+  getPackageManager
 } from '.'
 
 import { showInstallations, cleanInstallations } from './installations'
@@ -23,9 +24,8 @@ const getVersionMessage = () => {
   return pkg.version
 }
 
-const showVersion = () => {
-  console.log(getVersionMessage())
-}
+const isYarn = (cwd: string = process.cwd()) =>
+  getPackageManager(cwd) === 'yarn'
 
 /* tslint:disable-next-line */
 yargs
@@ -53,6 +53,7 @@ yargs
     builder: () => {
       return yargs
         .default('sig', true)
+        .default('yarn', isYarn())
         .boolean(['push', 'push-safe'].concat(publishFlags))
     },
     handler: argv => {
@@ -100,6 +101,7 @@ yargs
       return yargs
         .default('force', undefined)
         .default('sig', true)
+        .default('yarn', isYarn())
         .boolean(['safe'].concat(publishFlags))
     },
     handler: argv => {
@@ -122,7 +124,7 @@ yargs
     describe: 'Add package from yalc repo to the project',
     builder: () => {
       return yargs
-        .default('yarn', false)
+        .default('yarn', isYarn())
         .boolean(['file', 'dev', 'save-dev', 'link', 'yarn', 'pure'])
         .help(true)
     },
@@ -144,11 +146,12 @@ yargs
     command: 'link',
     describe: 'Link package from yalc repo to the project',
     builder: () => {
-      return yargs.default('yarn', true).help(true)
+      return yargs.default('yarn', isYarn()).help(true)
     },
     handler: argv => {
       return addPackages(argv._.slice(1), {
         link: true,
+        yarn: argv.yarn,
         workingDir: process.cwd()
       })
     }