feat(cli): add symlink type customization

closes #13

README.md

@@ -69,6 +69,7 @@ success Already up-to-date.
 |`--only` | Set package [updating scope](https://docs.npmjs.com/cli/audit): `dev`/`prod`
 |`--force` | Have audit fix install semver-major updates to toplevel dependencies, not just semver-compatible ones | false
 |`--audit-level` | Include a vulnerability with a level as defined or higher | moderate
+|`--symlink` | Specify symlink type for temp assets: `dir` or `junction` (Windows only) | dir
 
 ## License
 [MIT](./LICENSE)

src/main/ts/index.ts

@@ -1,9 +1,9 @@
-import fs from 'fs-extra'
+import fs, {SymlinkType} from 'fs-extra'
 import synp from 'synp'
 import {join} from 'path'
 import findCacheDir from 'find-cache-dir'
 import chalk from 'chalk'
-import {invoke, formatFlags} from './util'
+import {invoke, formatFlags, getSymlinkType} from './util'
 
 type TContext = { cwd: string, temp: string, flags: Record<string, any> }
 
@@ -16,10 +16,10 @@ type TStage = [string, ...TCallback[]]
  * @param {TContext} cxt
  * @return {void}
  */
-const createTempAssets: TCallback = ({temp}) => {
+const createTempAssets: TCallback = ({temp, flags}) => {
   fs.copyFileSync('yarn.lock', join(temp, 'yarn.lock'))
   fs.copyFileSync('package.json', join(temp, 'package.json'))
-  fs.createSymlinkSync('node_modules', join(temp, 'node_modules'), 'dir')
+  fs.createSymlinkSync('node_modules', join(temp, 'node_modules'), getSymlinkType(flags.symlink) as SymlinkType) // TODO fix fs-extra typings issue
 }
 
 /**

src/main/ts/util.ts

@@ -1,5 +1,6 @@
 import cp from 'child_process'
 import chalk from 'chalk'
+import {FsSymlinkType} from 'fs-extra'
 
 export const invoke = (cmd: string, args: string[], cwd: string) => {
   console.log(chalk.bold('invoke'), cmd, ...args)
@@ -26,3 +27,10 @@ export const formatFlags = (flags: Record<string, any>, ...picklist: string[]):
 
   return memo
 }, [])
+
+export const isWindows = () => process.platform === 'win32' || /^(msys|cygwin)$/.test(process.env.OSTYPE as string)
+
+export const getSymlinkType = (type?: string): FsSymlinkType =>
+  type === 'junction' && isWindows()
+    ? type
+    : 'dir'

src/test/ts/util.ts

@@ -1,4 +1,4 @@
-import {formatFlags} from '../../main/ts/util'
+import {formatFlags, getSymlinkType} from '../../main/ts/util'
 import minimist from 'minimist'
 
 describe('util', () => {
@@ -28,4 +28,18 @@ describe('util', () => {
       })
     })
   })
+
+  describe('#getSymlinkType', () => {
+    it('resolves type by system profile and arg', () => {
+      process.env.OSTYPE = 'msys'
+      expect(getSymlinkType('junction')).toBe('junction')
+      expect(getSymlinkType('foo')).toBe('dir')
+      expect(getSymlinkType()).toBe('dir')
+
+      process.env.OSTYPE = 'unknown'
+      expect(getSymlinkType('junction')).toBe('dir')
+      expect(getSymlinkType('foo')).toBe('dir')
+      expect(getSymlinkType()).toBe('dir')
+    })
+  })
 })