fix: minor tweaks to lib/unpublish.js

- Fix handling missing files error on reading package.json
- Fixes autocompletion
- Fixes printing name and version when using no args
- Adds `test/lib/unpublish.js` tests

Fixes: npm/statusboard#180

PR-URL: #2304
Credit: @ruyadorno
Close: #2304
Reviewed-by: @isaacs

lib/unpublish.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const path = require('path')
 const util = require('util')
 const log = require('npmlog')
@@ -11,7 +13,7 @@ const npm = require('./npm.js')
 const usageUtil = require('./utils/usage.js')
 const output = require('./utils/output.js')
 const otplease = require('./utils/otplease.js')
-const whoami = util.promisify(require('./whoami.js'))
+const getIdentity = require('./utils/get-identity.js')
 
 const usage = usageUtil('unpublish', 'npm unpublish [<@scope>/]<pkg>[@<version>]')
 
@@ -25,18 +27,18 @@ const completionFn = async (args) => {
   const { partialWord, conf } = args
 
   if (conf.argv.remain.length >= 3)
-    return
+    return []
 
-  const username = await whoami([], true)
+  const opts = npm.flatOptions
+  const username = await getIdentity({ ...opts }).catch(() => null)
   if (!username)
     return []
-  const opts = npm.flatOptions
 
   const access = await libaccess.lsPackages(username, opts)
   // do a bit of filtering at this point, so that we don't need
   // to fetch versions for more than one thing, but also don't
   // accidentally a whole project
-  let pkgs = Object.keys(access)
+  let pkgs = Object.keys(access || {})
   if (!partialWord || !pkgs.length)
     return pkgs
 
@@ -55,18 +57,20 @@ const completionFn = async (args) => {
 
 async function unpublish (args) {
   if (args.length > 1)
-    throw usage
+    throw new Error(usage)
 
   const spec = args.length && npa(args[0])
   const opts = npm.flatOptions
   const { force, silent, loglevel } = opts
-  let ret
+  let res
+  let pkgName
+  let pkgVersion
 
   log.silly('unpublish', 'args[0]', args[0])
   log.silly('unpublish', 'spec', spec)
 
   if (!spec.rawSpec && !force) {
-    throw (
+    throw new Error(
       'Refusing to delete entire project.\n' +
       'Run with --force to do this.\n' +
       usage
@@ -77,31 +81,34 @@ async function unpublish (args) {
     // if there's a package.json in the current folder, then
     // read the package name and version out of that.
     const pkgJson = path.join(npm.localPrefix, 'package.json')
-    const manifest = await readJson(pkgJson)
-
-    log.verbose('unpublish', manifest)
-
-    const { name, version, publishConfig } = manifest
-    const pkgJsonSpec = npa.resolve(name, version)
-
+    let manifest
     try {
-      ret = await otplease(opts, opts => libunpub(pkgJsonSpec, { ...opts, publishConfig }))
+      manifest = await readJson(pkgJson)
     } catch (err) {
       if (err && err.code !== 'ENOENT' && err.code !== 'ENOTDIR')
         throw err
       else
-        throw `Usage: ${usage}`
+        throw new Error(`Usage: ${usage}`)
     }
-  } else
-    ret = await otplease(opts, opts => libunpub(spec, opts))
 
-  if (!silent && loglevel !== 'silent') {
-    output(`- ${spec.name}${
-      spec.type === 'version' ? `@${spec.rawSpec}` : ''
-    }`)
+    log.verbose('unpublish', manifest)
+
+    const { name, version, publishConfig } = manifest
+    const pkgJsonSpec = npa.resolve(name, version)
+
+    res = await otplease(opts, opts => libunpub(pkgJsonSpec, { ...opts, publishConfig }))
+    pkgName = name
+    pkgVersion = version ? `@${version}` : ''
+  } else {
+    res = await otplease(opts, opts => libunpub(spec, opts))
+    pkgName = spec.name
+    pkgVersion = spec.type === 'version' ? `@${spec.rawSpec}` : ''
   }
 
-  return ret
+  if (!silent && loglevel !== 'silent')
+    output(`- ${pkgName}${pkgVersion}`)
+
+  return res
 }
 
 module.exports = Object.assign(cmd, { completion, usage })