From b712f2ce9541571a82f3f6085d6ffa0fc45024c2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kat=20March=C3=A1n?= <kzm@sykosomatic.org>
Date: Sat, 24 Jun 2017 00:30:02 +0100
Subject: [PATCH] feat(local): improve the interaction with local pkgs

BREAKING CHANGE: `npx ./something` will now execute `./something` as a
binary instead of trying to install it as npm would.
---
 index.js                   | 41 ++++++++++++++++++++++++--------------
 parse-args.js              | 17 ++++++++++++----
 test/guess-command-name.js | 13 +++++++-----
 3 files changed, 47 insertions(+), 24 deletions(-)

diff --git a/index.js b/index.js
index 5612a96..3321a3d 100755
--- a/index.js
+++ b/index.js
@@ -125,6 +125,8 @@ module.exports._getExistingPath = getExistingPath
 function getExistingPath (command, opts) {
   if (opts.cmdHadVersion || opts.packageRequested || opts.ignoreExisting) {
     return Promise.resolve(false)
+  } else if (opts.isLocal) {
+    return Promise.resolve(command)
   } else {
     return which(command).catch(err => {
       if (err.code === 'ENOENT') {
@@ -182,9 +184,9 @@ function installPackages (specs, prefix, opts) {
 
 module.exports._execCommand = execCommand
 function execCommand (_existing, argv) {
-  return findNodeScript(_existing).then(existing => {
+  return findNodeScript(_existing, argv).then(existing => {
     const Module = require('module')
-    if (existing && Module.runMain && !argv.shell) {
+    if (existing && Module.runMain && !argv.shell && existing !== __filename) {
       // let it take over the process. This means we can skip node startup!
       if (!argv.noYargs) {
         // blow away built-up yargs crud
@@ -211,22 +213,31 @@ function execCommand (_existing, argv) {
 }
 
 module.exports._findNodeScript = findNodeScript
-function findNodeScript (existing) {
+function findNodeScript (existing, opts) {
   if (!existing || process.platform === 'win32') {
     return Promise.resolve(false)
   } else {
-    // NOTE: only *nix is supported for process-replacement juggling
-    const line = '#!/usr/bin/env node\n'
-    const bytecount = line.length
-    const buf = Buffer.alloc(bytecount)
-    return promisify(fs.open)(existing, 'r').then(fd => {
-      return promisify(fs.read)(fd, buf, 0, bytecount, 0).then(() => {
-        return promisify(fs.close)(fd)
-      }, err => {
-        return promisify(fs.close)(fd).then(() => { throw err })
-      })
-    }).then(() => {
-      return buf.toString('utf8') === line && existing
+    return promisify(fs.stat)(existing).then(stat => {
+      if (opts.isLocal && stat.isDirectory()) {
+        // npx will execute the directory itself
+        try {
+          const pkg = require(path.resolve(existing, 'package.json'))
+          return path.resolve(existing, pkg.main || 'index.js')
+        } catch (e) {}
+      } else {
+        const line = '#!/usr/bin/env node\n'
+        const bytecount = line.length
+        const buf = Buffer.alloc(bytecount)
+        return promisify(fs.open)(existing, 'r').then(fd => {
+          return promisify(fs.read)(fd, buf, 0, bytecount, 0).then(() => {
+            return promisify(fs.close)(fd)
+          }, err => {
+            return promisify(fs.close)(fd).then(() => { throw err })
+          })
+        }).then(() => {
+          return buf.toString('utf8') === line && existing
+        })
+      }
     })
   }
 }
diff --git a/parse-args.js b/parse-args.js
index 165ec80..09ab521 100644
--- a/parse-args.js
+++ b/parse-args.js
@@ -42,12 +42,13 @@ function parseArgs (argv) {
     parsed.command = parsed.package
     ? argv[cmdIndex]
     : guessCmdName(parsedCmd)
+    parsed.isLocal = parsedCmd.type === 'directory'
     parsed.cmdOpts = argv.slice(cmdIndex + 1)
     if (typeof parsed.package === 'string') {
       parsed.package = [parsed.package]
     }
     parsed.packageRequested = !!parsed.package
-    parsed.cmdHadVersion = parsed.package
+    parsed.cmdHadVersion = parsed.package || parsedCmd.type === 'directory'
     ? false
     : parsedCmd.name !== parsedCmd.raw
     const pkg = parsed.package || [argv[cmdIndex]]
@@ -95,13 +96,21 @@ function fastPathArgs (argv) {
   } else {
     npa = require('npm-package-arg')
     parsedCmd = npa(argv[2])
-    pkg = [parsedCmd.toString()]
+    if (parsedCmd.type === 'directory') {
+      pkg = []
+    } else {
+      pkg = [parsedCmd.toString()]
+    }
   }
   return {
     command: guessCmdName(parsedCmd),
     cmdOpts: argv.slice(3),
     packageRequested: false,
-    cmdHadVersion: parsedCmd.name !== parsedCmd.raw,
+    isLocal: parsedCmd.type === 'directory',
+    cmdHadVersion: (
+      parsedCmd.name !== parsedCmd.raw &&
+      parsedCmd.type !== 'directory'
+    ),
     package: pkg,
     p: pkg,
     shell: false,
@@ -129,7 +138,7 @@ function guessCmdName (spec) {
     const match = spec.fetchSpec.match(/([a-z0-9-]+)(?:\.git)?$/i)
     return match[1]
   } else if (spec.type === 'directory') {
-    return path.basename(spec.fetchSpec)
+    return spec.raw
   } else if (spec.type === 'file' || spec.type === 'remote') {
     let ext = path.extname(spec.fetchSpec)
     if (ext === '.gz') {
diff --git a/test/guess-command-name.js b/test/guess-command-name.js
index 454df8c..80598b5 100644
--- a/test/guess-command-name.js
+++ b/test/guess-command-name.js
@@ -26,11 +26,14 @@ test('guesses git binaries', t => {
   t.done()
 })
 
-test('guesses local directory binaries', t => {
-  t.equal(guessCmdName('./foo'), 'foo')
-  t.equal(guessCmdName('./dir/foo'), 'foo')
-  t.equal(guessCmdName('../../../dir/foo'), 'foo')
-  t.equal(guessCmdName('C:\\Program Files\\node\\foo'), 'foo')
+test('leaves local directory/file commands intact', t => {
+  t.equal(guessCmdName('./foo'), './foo')
+  t.equal(guessCmdName('./dir/foo'), './dir/foo')
+  t.equal(guessCmdName('../../../dir/foo'), '../../../dir/foo')
+  t.equal(
+    guessCmdName('C:\\Program Files\\node\\foo'),
+    'C:\\Program Files\\node\\foo'
+  )
   t.done()
 })