feat(commands): -p and @Version now trigger installs

Fixes: #9

BREAKING CHANGE: If a command has an explicit --package option, or if the command has an @Version part, any version of the command in $PATH will be ignored and a regular install will be executed.

README.md

@@ -16,6 +16,8 @@ Executes `<command>` either from a local `node_modules/.bin`, or from a central
 
 By default, `<command>` will be installed prior to execution. An optional `@version` may be appended to specify the package version required.
 
+If a version specifier is included, or if `--package` is used, npx will ignore the version of the package in the current path, if it exists.
+
 * `-p, --package <package>` - define the package to be installed. This defaults to the value of `<command>`. This is only needed for packages with multiple binaries if you want to call one of the other executables, or where the binary name does not match the package name. If this option is provided `<command>` will be executed as-is, without interpreting `@version` if it's there.
 
 * `--cache <path>` - set the location of the npm cache. Defaults to npm's own cache settings.

index.js

@@ -61,7 +61,17 @@ function getCmdPath (command, spec, npmOpts) {
 }
 
 function getExistingPath (command, opts) {
-  if (opts.saveProd || opts.saveDev || opts.saveOptional || opts.global) {
+  if (
+    opts.saveProd ||
+    opts.saveDev ||
+    opts.saveOptional ||
+    opts.saveBundle ||
+    opts.saveExact ||
+    opts.global ||
+    opts.prefix ||
+    opts.cmdHadVersion ||
+    opts.packageRequested
+  ) {
     return BB.resolve(false)
   } else {
     return which(command).catch({code: 'ENOENT'}, () => false)
@@ -91,6 +101,7 @@ function buildArgs (spec, prefix, opts) {
   }
   if (opts.cache) args.push('--cache', opts.cache)
   if (opts.userconfig) args.push('--userconfig', opts.userconfig)
+  args.push('--loglevel', 'error')
 
   return args
 }

parse-args.js

@@ -87,29 +87,38 @@ function parseArgs () {
   }
   if (cmdIndex) {
     const parsed = parser.parse(process.argv.slice(0, cmdIndex))
+    const parsedCmd = npa(process.argv[cmdIndex])
     parsed.command = parsed.package
     ? process.argv[cmdIndex]
-    : npa(process.argv[cmdIndex]).name
+    : parsedCmd.name
     parsed.cmdOpts = process.argv.slice(cmdIndex + 1)
+    parsed.packageRequested = !!parsed.package
+    parsed.cmdHadVersion = parsedCmd.name !== parsedCmd.raw
     const pkg = parsed.package || process.argv[cmdIndex]
     parsed.p = parsed.package = npa(pkg).toString()
     return parsed
   } else {
     const parsed = parser.argv
     if (parsed.call) {
       const splitCmd = parsed.call.trim().split(/\s+/)
+      const parsedCmd = npa(splitCmd[0])
       parsed.command = parsed.package
       ? splitCmd[0]
-      : npa(splitCmd[0]).name
+      : parsedCmd.name
       parsed.cmdOpts = splitCmd.slice(1)
+      parsed.packageRequested = !!parsed.package
+      parsed.cmdHadVersion = parsedCmd.name !== parsedCmd.raw
       const pkg = parsed.package || splitCmd[0]
       parsed.p = parsed.package = npa(pkg).toString()
     } else if (hasDashDash) {
       const splitCmd = parsed._
+      const parsedCmd = npa(splitCmd[0])
       parsed.command = parsed.package
       ? splitCmd[0]
-      : npa(splitCmd[0]).name
+      : parsedCmd.name
       parsed.cmdOpts = splitCmd.slice(1)
+      parsed.packageRequested = !!parsed.package
+      parsed.cmdHadVersion = parsedCmd.name !== parsedCmd.raw
     }
     return parsed
   }