feat: add --only-version option to skip JSON and only print version number

Author: ljharb

bin/nv

@@ -18,14 +18,20 @@ require('yargs')
         defaultDescription: 'pretty print json spaces, default 2 (--no-pretty-json for new line delimted json)',
         description: 'Pretty print json'
       })
+      yargs.option('only-version', {
+        type: 'boolean',
+        description: 'show version number only'
+      })
     },
     handler: (argv) => {
       nv(argv.versions, {
         mirror: argv.mirror
       })
         .then(result => {
           result.forEach(r => {
-            if (argv.prettyJson === false) {
+            if (argv['only-version']) {
+              console.log(r.version)
+            } else if (argv.prettyJson === false) {
               console.log(JSON.stringify(r))
             } else if (!isNaN(parseInt(argv.prettyJson, 10))) {
               console.log(JSON.stringify(r, null, parseInt(argv.prettyJson, 10)))

test/cli.js

@@ -3,6 +3,7 @@ const assert = require('assert')
 const { suite, test } = require('mocha')
 const { execFileSync } = require('child_process')
 const path = require('path')
+const semver = require('semver')
 
 const nv = path.join(__dirname, '..', 'bin', 'nv')
 const cwd = path.join(__dirname, '..')
@@ -17,14 +18,26 @@ suite('nv cli', () => {
     const result = JSON.parse(execFileSync(nv, ['ls', '8'], { cwd: cwd }).toString())
     assert.strictEqual(result.codename, 'carbon')
   })
+
   test('should contain output newline json', () => {
     const result = execFileSync(nv, ['ls', '8.x', '--no-pretty-json'], { cwd: cwd })
       .toString().trim().split('\n')
       .map((line) => JSON.parse(line))
 
     assert(Array.isArray(result))
     result.forEach((r) => {
-      assert(r.version.startsWith('8.'))
+      assert(semver.satisfies(r.version, '8.x'))
+    })
+  })
+
+  test('only outputs the version number', () => {
+    const result = execFileSync(nv, ['ls', '8.x', '--only-version'], { cwd: cwd })
+      .toString().trim().split('\n')
+
+    assert(Array.isArray(result))
+    result.forEach((r) => {
+      assert(semver.satisfies(r, '8.x'))
+      assert(semver.valid(r))
     })
   })
 })