feat(local): improve the behavior when calling ./local paths (#48)

Fixes: #49

BREAKING CHANGE: `npx ./something` will now execute `./something` as a
binary or script instead of trying to install it as npm would. Other behavior
related to local path deps has likewise been changed. See
[#49](zkat/npx#49) for a detailed explanation
of all the various cases and how each of them is handled.

child.js

@@ -18,6 +18,8 @@ function runCommand (command, opts) {
         }`
       )
       err.exitCode = 127
+    } else {
+      err.message = require('./y.js')`Command failed: ${cmd} ${err.message}`
     }
     throw err
   })

index.js

@@ -123,7 +123,11 @@ function ensurePackages (specs, opts) {
 
 module.exports._getExistingPath = getExistingPath
 function getExistingPath (command, opts) {
-  if (opts.cmdHadVersion || opts.packageRequested || opts.ignoreExisting) {
+  if (opts.isLocal) {
+    return Promise.resolve(command)
+  } else if (
+    opts.cmdHadVersion || opts.packageRequested || opts.ignoreExisting
+  ) {
     return Promise.resolve(false)
   } else {
     return which(command).catch(err => {
@@ -182,9 +186,9 @@ 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 +215,42 @@ 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 && opts.isLocal && path.extname(existing) === '.js') {
+        return existing
+      } else if (opts && opts.isLocal && stat.isDirectory()) {
+        // npx will execute the directory itself
+        try {
+          const pkg = require(path.resolve(existing, 'package.json'))
+          const target = path.resolve(existing, pkg.bin || pkg.main || 'index.js')
+          return findNodeScript(target, opts).then(script => {
+            if (script) {
+              return script
+            } else {
+              throw new Error(Y()`command not found: ${target}`)
+            }
+          })
+        } catch (e) {
+          throw new Error(Y()`command not found: ${existing}`)
+        }
+      } 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
+        })
+      }
     })
   }
 }

parse-args.js

@@ -39,15 +39,16 @@ function parseArgs (argv) {
   if (cmdIndex) {
     const parsed = parser.parse(argv.slice(0, cmdIndex))
     const parsedCmd = npa(argv[cmdIndex])
-    parsed.command = parsed.package
+    parsed.command = parsed.package && parsedCmd.type !== 'directory'
     ? 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') {

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()
 })
 

test/index.js

@@ -164,7 +164,8 @@ test('getNpmCache', t => {
 })
 
 test('findNodeScript', t => {
-  const scriptPath = path.resolve(__dirname, '..', 'index.js')
+  const scriptDir = path.resolve(__dirname, '..')
+  const scriptPath = path.join(scriptDir, 'index.js')
   return main._findNodeScript(scriptPath).then(script => {
     if (process.platform === 'win32') {
       t.notOk(script, 'win32 never detects Node scripts like this')
@@ -178,9 +179,18 @@ test('findNodeScript', t => {
     return main._findNodeScript(null).then(bool => {
       t.notOk(bool, 'no node script found if existing is null')
     })
+  }).then(() => {
+    return main._findNodeScript(scriptDir, {isLocal: true}).then(script => {
+      t.equal(script, scriptPath, 'resolved dir dep to index.js')
+    })
   }).then(() => {
     const findScript = requireInject('../index.js', {
       fs: {
+        stat (file, cb) {
+          cb(null, {
+            isDirectory () { return !file.indexOf('./') }
+          })
+        },
         open (file, perm, cb) {
           cb(null, file)
         },

test/parse-args.js

@@ -140,3 +140,19 @@ test('allows configuration of npm binary', t => {
   t.equal(parsed.npm, './mynpm')
   t.done()
 })
+
+test('treats directory-type commands specially', t => {
+  let parsed = parseArgs(['/node', '/npx', './foo'])
+  t.equal(parsed.command, './foo')
+  t.deepEqual(parsed.package, [])
+  t.equal(parsed.packageRequested, false)
+  t.equal(parsed.cmdHadVersion, false)
+  t.ok(parsed.isLocal)
+  parsed = parseArgs(['/node', '/npx', '-p', 'x', '../foo/bar.sh'])
+  t.equal(parsed.command, '../foo/bar.sh')
+  t.ok(parsed.isLocal)
+  t.deepEqual(parsed.package, ['x@latest'])
+  t.equal(parsed.packageRequested, true)
+  t.equal(parsed.cmdHadVersion, false)
+  t.done()
+})