Add ngo.bin, tweak readme a bit

README.md

@@ -1,6 +1,6 @@
 # ngo [![NPM version](https://badge.fury.io/js/ngo.svg)](https://npmjs.org/package/ngo)   [![js-standard-style](https://img.shields.io/badge/code%20style-standard-brightgreen.svg?style=flat)](https://github.com/feross/standard)   [![Dependency Status](https://dependencyci.com/github/doesdev/ngo/badge)](https://dependencyci.com/github/doesdev/ngo)   [![Build status](https://ci.appveyor.com/api/projects/status/0wutjytsl4hmha1j?svg=true)](https://ci.appveyor.com/project/doesdev/ngo)   [![Build Status](https://travis-ci.org/doesdev/ngo.svg)](https://travis-ci.org/doesdev/ngo)   
 
-> Run Go commands, whether your Go env is in place or not
+> Run Go commands from Node or CLI, Go env not required
 
 Will download latest binaries locally if Go isn't already in PATH
 
@@ -39,6 +39,7 @@ returns promise that resolves to `execa` style object without the `child_process
 ```js
 const goOpts = {}
 const ngo = require('ngo')(goOpts)
+const golint = ngo.bin('golint')
 
 ngo('version').then(console.log).catch(console.error)
 /* {
@@ -50,26 +51,38 @@ ngo('version').then(console.log).catch(console.error)
  signal: null,
  cmd: 'C:\\Go\\bin\\go version'
 } */
+
+golint('main.go').then(console.log).catch(console.error)
 ```
 
 ## api
 
-### const ngo = require('ngo')(opts)
-accepts `opts` as below, returns `ngo` function which executes Go commands,
-- **options** *[Object - optional]*
-  - **useLocal** *[Boolean `false`] - use locally downloaded Go binaries)*
-  - **update** *[Boolean `false`] - update local install to latest*
-  - **installDeps** *[Boolean `true`] - attempt to install missing packages*
-  - **env** *[Object] - environment vars to set for the Go command*
-  - **goRoot** *[String] - Go root path (ex. `/usr/local/go`)*
-  - **goPath** *[String] - Go workspace path (ex. `~/work`)*
-
-### ngo(arguments, options)
-returns promise which resolves to [`execa`](https://github.com/sindresorhus/execa) styled object
-- **arguments** *[Array | String - required] - argument(s) to call with `go` command*
-- **options** *[Object - optional]*
- - same options as [`child_process.spawn`](https://nodejs.org/api/child_process.html#child_process_child_process_spawn_command_args_options)
- - additonal options available same as [`execa`](https://github.com/sindresorhus/execa#options)
+### const ngo = require('ngo')(`options`)
+- **Purpose:** initialize `ngo`
+- **Arguments:**
+  - **options** *[`Object` - optional]*
+    - **useLocal** *[`Boolean` `false`] - use locally downloaded Go binaries)*
+    - **update** *[`Boolean` `false`] - update local install to latest*
+    - **installDeps** *[`Boolean` `true`] - attempt to install missing packages*
+    - **env** *[`Object`] - environment vars to set for the Go command*
+    - **goRoot** *[`String`] - Go root path (ex. `/usr/local/go`)*
+    - **goPath** *[`String`] - Go workspace path (ex. `~/work`)*
+- **Returns:** `Function` (`ngo`) which executes Go commands
+
+### ngo(`commandArgs`, `options`)
+- **Purpose:** - execute `go` commands
+- **Arguments:**
+  - **commandArgs** *[`Array` | `String` - required] - argument(s) to call with `go` command*
+  - **options** *[`Object` - optional]*
+   - same options as [`child_process.spawn`](https://nodejs.org/api/child_process.html#child_process_child_process_spawn_command_args_options)
+   - additonal options available same as [`execa`](https://github.com/sindresorhus/execa#options)
+- **Returns:** `Promise` which resolves to [`execa`](https://github.com/sindresorhus/execa) styled object
+
+### ngo.bin(`binary`)
+- **Purpose:** - execute commands on binaries in the `GOBIN` directory
+- **Arguments:**
+  - **binary** [`String`] - name of binary file to be executed in returned function
+- **Returns:** `Function` (identical to `ngo`, but runs specified binary instead of `go`)
 
 ### ngo.env
 this is a copy of ngo's `process.env` with the Go environment variables added to it

index.js

@@ -23,21 +23,23 @@ module.exports = (opts = {}) => {
   env.ngoBin = path.join(goRoot, 'bin', 'go')
   try { env.hasBin = exists(path.join(goRoot, 'bin')) } catch (ex) {}
   if (opts.update) delete env.hasBin
-  let ngoRunner = (args, cmdOpts = {}) => {
+  let ngoRunner = (args, cmdOpts = {}, binary) => {
     if (opts.update) args = args || ['version']
-    return runner(args, Object.assign({}, cmdOpts, {env}))
+    return runner(args, Object.assign({}, cmdOpts, {env}), binary)
   }
   ngoRunner.env = env
+  ngoRunner.bin = (binary) => (args, opts) => ngoRunner(args, opts, binary)
   return ngoRunner
 }
 
-function runner (args, opts) {
+function runner (args, opts, binary) {
   if (!args) return Promise.reject(new Error(`No Go command specified`))
   args = Array.isArray(args) ? args : [args]
   let env = opts.env
+  if (binary && env.GOBIN) binary = path.join(env.GOBIN, binary)
   let lastDep
   let run = () => {
-    let go = execa(env.ngoBin, args, opts)
+    let go = execa(binary || env.ngoBin, args, opts)
     if (opts.installDeps === false) return go
     go.catch((err) => {
       let dep = (`${err}`.match(/cannot find package "(.+?)"/) || [])[1]

package.json

@@ -1,7 +1,7 @@
 {
   "name": "ngo",
   "version": "2.4.5",
-  "description": "Run Go commands, whether your Go env is in place or not",
+  "description": "Run Go commands from Node or CLI, Go env not required",
   "engines": {
     "node": ">=6.0.0"
   },

test/fixtures/errors.go

@@ -0,0 +1,38 @@
+// Copyright (c) 2013 The Go Authors. All rights reserved.
+// Source: https://github.com/golang/lint/blob/master/testdata/errors.go
+// Test for naming errors.
+
+// Package foo ...
+package foo
+
+import (
+	"errors"
+	"fmt"
+)
+
+var unexp = errors.New("some unexported error") // MATCH /error var.*unexp.*errFoo/
+
+// Exp ...
+var Exp = errors.New("some exported error") // MATCH /error var.*Exp.*ErrFoo/
+
+var (
+	e1 = fmt.Errorf("blah %d", 4) // MATCH /error var.*e1.*errFoo/
+	// E2 ...
+	E2 = fmt.Errorf("blah %d", 5) // MATCH /error var.*E2.*ErrFoo/
+)
+
+func f() {
+	var whatever = errors.New("ok") // ok
+	_ = whatever
+}
+
+// Check for the error strings themselves.
+
+func g(x int) error {
+	if x < 1 {
+		return fmt.Errorf("This %d is too low", x) // MATCH /error strings.*not be capitalized/
+	} else if x == 0 {
+		return fmt.Errorf("XML time") // ok
+	}
+	return errors.New(`too much stuff.`) // MATCH /error strings.*not end with punctuation/
+}

test/fixtures/good.go

@@ -0,0 +1,7 @@
+// Package foo ...
+package foo
+
+import (
+	"errors"
+	"fmt"
+)

test.js → test/index.js

@@ -4,15 +4,15 @@
 import path from 'path'
 import { remove } from 'fs-extra'
 import test from 'ava'
-import ngo from './index'
+import ngo from './../index'
 const goBinPath = path.resolve(__dirname, '..', 'vendor', 'go')
 
 test.before(() => {
   let finish = () => ngo({useLocal: true})('version')
   return remove(goBinPath).then(finish).catch(finish)
 })
 
-test(`go.env returns environment`, (assert) => {
+test.serial(`go.env returns environment`, (assert) => {
   let go = ngo({useLocal: true})
   assert.truthy(go.env.GOPATH)
   assert.truthy(go.env.GOROOT)
@@ -33,3 +33,18 @@ test.serial(`go(['get', 'somepackage']) works`, async (assert) => {
   let go = ngo({useLocal: true})
   await assert.notThrows(go(['get', '-u', 'golang.org/x/lint/golint']))
 })
+
+test.serial(`go.bin('golint')('errors.go') works`, async (assert) => {
+  let golint = ngo({useLocal: true}).bin('golint')
+  let goFile = path.join(__dirname, 'fixtures', 'errors.go')
+  let anError = /var unexp should have name of the form/
+  let results = (await golint(goFile)).stdout
+  assert.regex(results, anError)
+})
+
+test.serial(`go.bin('golint')('good.go') works`, async (assert) => {
+  let golint = ngo({useLocal: true}).bin('golint')
+  let goFile = path.join(__dirname, 'fixtures', 'good.go')
+  let results = (await golint(goFile)).stdout
+  assert.falsy(results)
+})