fix: npm version usage

- Fix `npm version` unexpected arg count usage
- Add tests for lib/version.js

Fixes: npm/statusboard#182

PR-URL: #2205
Credit: @ruyadorno
Close: #2205
Reviewed-by: @nlf

lib/version.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const libversion = require('libnpmversion')
 const npm = require('./npm.js')
 const output = require('./utils/output.js')
@@ -42,7 +44,7 @@ const version = async args => {
         path: npm.prefix,
       }))
     default:
-      throw version.usage
+      throw usage
   }
 }
 

test/lib/version.js

@@ -0,0 +1,160 @@
+const t = require('tap')
+const requireInject = require('require-inject')
+
+let result = []
+
+const noop = () => null
+const npm = {
+  flatOptions: {
+    json: false,
+  },
+  prefix: '',
+  version: '1.0.0',
+}
+const mocks = {
+  libnpmversion: noop,
+  '../../lib/npm.js': npm,
+  '../../lib/utils/output.js': (...msg) => {
+    for (const m of msg)
+      result.push(m)
+  },
+  '../../lib/utils/usage.js': () => 'usage instructions',
+}
+
+const version = requireInject('../../lib/version.js', mocks)
+
+const _processVersions = process.versions
+t.afterEach(cb => {
+  npm.flatOptions.json = false
+  npm.prefix = ''
+  process.versions = _processVersions
+  result = []
+  cb()
+})
+
+t.test('no args', t => {
+  const prefix = t.testdir({
+    'package.json': JSON.stringify({
+      name: 'test-version-no-args',
+      version: '3.2.1',
+    }),
+  })
+  npm.prefix = prefix
+  Object.defineProperty(process, 'versions', { value: { node: '1.0.0' } })
+
+  version([], err => {
+    if (err)
+      throw err
+
+    t.deepEqual(
+      result,
+      [{
+        'test-version-no-args': '3.2.1',
+        node: '1.0.0',
+        npm: '1.0.0',
+      }],
+      'should output expected values for various versions in npm'
+    )
+
+    t.end()
+  })
+})
+
+t.test('too many args', t => {
+  version(['foo', 'bar'], err => {
+    t.match(
+      err,
+      'usage instructions',
+      'should throw usage instructions error'
+    )
+
+    t.end()
+  })
+})
+
+t.test('completion', t => {
+  const { completion } = version
+
+  const testComp = (argv, expect) => {
+    completion({ conf: { argv: { remain: argv } } }, (err, res) => {
+      t.ifError(err)
+      t.strictSame(res, expect, argv.join(' '))
+    })
+  }
+
+  testComp(['npm', 'version'], [
+    'major',
+    'minor',
+    'patch',
+    'premajor',
+    'preminor',
+    'prepatch',
+    'prerelease',
+    'from-git',
+  ])
+  testComp(['npm', 'version', 'major'], [])
+
+  t.end()
+})
+
+t.test('failure reading package.json', t => {
+  const prefix = t.testdir({})
+  npm.prefix = prefix
+
+  version([], err => {
+    if (err)
+      throw err
+
+    t.deepEqual(
+      result,
+      [{
+        npm: '1.0.0',
+        node: '1.0.0',
+      }],
+      'should not have package name on returning object'
+    )
+
+    t.end()
+  })
+})
+
+t.test('--json option', t => {
+  const prefix = t.testdir({})
+  npm.flatOptions.json = true
+  npm.prefix = prefix
+  Object.defineProperty(process, 'versions', { value: {} })
+
+  version([], err => {
+    if (err)
+      throw err
+    t.deepEqual(
+      result,
+      ['{\n  "npm": "1.0.0"\n}'],
+      'should return json stringified result'
+    )
+    t.end()
+  })
+})
+
+t.test('with one arg', t => {
+  const version = requireInject('../../lib/version.js', {
+    ...mocks,
+    libnpmversion: (arg, opts) => {
+      t.equal(arg, 'major', 'should forward expected value')
+      t.deepEqual(
+        opts,
+        {
+          json: false,
+          path: '',
+        },
+        'should forward expected options'
+      )
+      t.end()
+    },
+  })
+
+  version(['major'], err => {
+    if (err)
+      throw err
+  })
+})