feat(call): -c now loads same env as run-script

Fixes: #3

BREAKING CHANGE: scripts invoked with -c will now have a bunch of
variables added to them that were not there before.

README.md

@@ -28,9 +28,9 @@ If a full specifier is included, or if `--package` is used, npx will always use
 
 * `--userconfig <path>` - path to the user configuration file to pass to npm. Defaults to whatever npm's current default is.
 
-* `-c <string>` - Execute `<string>` inside a shell. For unix, this will be `/bin/sh -c <string>`. For Windows, it will be `cmd.exe /d /s /c <string>`. Only the first item in `<string>` will be automatically used as `<command>`. Any others _must_ use `-p`.
+* `-c <string>` - Execute `<string>` inside an `npm run-script`-like shell environment, with all the usual environment variables available. Only the first item in `<string>` will be automatically used as `<command>`. Any others _must_ use `-p`.
 
-* `--shell <string>` - The shell to invoke the command with, if any. Defaults to `false`.
+* `--shell <string>` - The shell to invoke the command with, if any.
 
 * `--shell-auto-fallback [<shell>]` - Generates shell code to override your shell's "command not found" handler with one that calls `npx`. Tries to figure out your shell, or you can pass its name (either `bash`, `fish`, or `zsh`) as an option. See below for how to install.
 
@@ -68,10 +68,11 @@ $ npx git+ssh://my.hosted.git:cowsay.git#semver:^1
 ### Execute a full shell command using one npx call w/ multiple packages
 
 ```
-$ npx -p lolcatjs -p cowsay -c 'echo "foo" | cowsay | lolcatjs'
+$ npx -p lolcatjs -p cowsay -c \
+  'echo "$npm_package_name@$npm_package_version" | cowsay | lolcatjs'
 ...
  _____
-< foo >
+< your-cool-package@1.2.3 >
  -----
         \   ^__^
          \  (oo)\_______

index.js

@@ -4,6 +4,7 @@
 const BB = require('bluebird')
 
 const child = require('./child')
+const dotenv = require('dotenv')
 const getPrefix = require('./get-prefix.js')
 const parseArgs = require('./parse-args.js')
 const path = require('path')
@@ -40,11 +41,14 @@ function main (argv) {
 
   return localBinPath(process.cwd()).then(local => {
     process.env.PATH = `${local}${PATH_SEP}${process.env.PATH}`
-    return getCmdPath(
-      argv.command, argv.package, argv
-    ).then(cmdPath => {
-      return child.runCommand(cmdPath, argv.cmdOpts, argv)
-    }).catch(err => {
+    return BB.join(
+      getCmdPath(argv.command, argv.package, argv),
+      getEnv(argv),
+      (cmdPath, env) => {
+        process.env = env
+        return child.runCommand(cmdPath, argv.cmdOpts, argv)
+      }
+    ).catch(err => {
       console.error(err.message)
       process.exit(err.exitCode || 1)
     })
@@ -58,6 +62,17 @@ function localBinPath (cwd) {
   })
 }
 
+module.exports._getEnv = getEnv
+function getEnv (opts) {
+  if (opts.call) {
+    return child.exec(opts.npm, ['run', 'env']).then(env => {
+      return dotenv.parse(env)
+    })
+  } else {
+    return process.env
+  }
+}
+
 module.exports._getCmdPath = getCmdPath
 function getCmdPath (command, specs, npmOpts) {
   return getExistingPath(command, npmOpts).then(cmdPath => {

package.json

@@ -36,6 +36,7 @@
   "license": "CC0-1.0",
   "dependencies": {
     "bluebird": "^3.5.0",
+    "dotenv": "^4.0.0",
     "npm": "^5.0.2",
     "npm-package-arg": "^5.0.1",
     "rimraf": "^2.6.1",
@@ -50,7 +51,8 @@
     "rimraf",
     "update-notifier",
     "which",
-    "yargs"
+    "yargs",
+    "dotenv"
   ],
   "devDependencies": {
     "marked-man": "^0.2.1",