Determine deployment type like Now Desktop (#589)

* Automatically decide deployment type

* Should be a devDep

* Not throwing anymore if both Dockerfile and package.json exist

* Ask to choose type again

* Revert "Not throwing anymore if both Dockerfile and package.json exist"

This reverts commit 2d7136f2dc870406e60289e33de3b2beaea3a917.

* Prettified

lib/read-metadata.js

@@ -5,6 +5,7 @@ const { basename, resolve: resolvePath } = require('path')
 const chalk = require('chalk')
 const { readFile } = require('fs-extra')
 const { parse: parseDockerfile } = require('docker-file-parser')
+const determineType = require('deployment-type')
 
 module.exports = readMetaData
 
@@ -40,32 +41,20 @@ async function readMetaData(
   }
 
   if (!type) {
-    // `now.json` / `pkg.now` get default type preference
-    if (nowConfig) {
-      type = nowConfig.type
-    }
+    type = await determineType(path)
 
     // Both `package.json` and `Dockerfile` exist! Prompt the user to pick one.
-    if (!type && pkg && dockerfile) {
+    // We can remove this soon (details are internal)
+    if (type === 'docker' && (pkg && dockerfile)) {
       const err = new Error(
         'Ambiguous deployment (`package.json` and `Dockerfile` found). ' +
           'Please supply `--npm` or `--docker` to disambiguate.'
       )
+
       err.userError = true
       err.code = 'MULTIPLE_MANIFESTS'
-      throw err
-    }
-
-    if (!type && pkg) {
-      type = 'npm'
-    }
 
-    if (!type && dockerfile) {
-      type = 'docker'
-    }
-
-    if (!type) {
-      type = 'static'
+      throw err
     }
   }
 
@@ -78,16 +67,19 @@ async function readMetaData(
       if (!name && pkg.name) {
         name = String(pkg.name)
       }
+
       description = pkg.description
     }
   } else if (type === 'docker') {
     if (strict && dockerfile.length <= 0) {
       const err = new Error('No commands found in `Dockerfile`')
       err.userError = true
+
       throw err
     }
 
     const labels = {}
+
     dockerfile.filter(cmd => cmd.name === 'LABEL').forEach(({ args }) => {
       for (const key in args) {
         if (!{}.hasOwnProperty.call(args, key)) {
@@ -101,6 +93,7 @@ async function readMetaData(
           const e = new Error(
             `Error parsing value for LABEL ${key} in \`Dockerfile\``
           )
+
           e.userError = true
           throw e
         }

package.json

@@ -73,6 +73,7 @@
     "cross-spawn": "5.1.0",
     "dateformat": "2.0.0",
     "death": "1.1.0",
+    "deployment-type": "1.0.1",
     "docker-file-parser": "1.0.2",
     "dotenv": "4.0.0",
     "download": "6.2.0",