config: provide --json cli switch to npm config list

This will support other CLI tools, notably cipm, that
need to query npm for its configuration without having
to parse ini format.

PR-URL: https://github.com/npm/npm/pull/18025
Credit: @mikesherov
Reviewed-By: @zkat

1 files changed, 19 insertions, 2 deletions

diff --git a/lib/config.js b/lib/config.js
index b4ac74c74..d260c04a5 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -19,7 +19,7 @@ config.usage = usage(
   'npm config set <key> <value>' +
   '\nnpm config get [<key>]' +
   '\nnpm config delete <key>' +
-  '\nnpm config list' +
+  '\nnpm config list [--json]' +
   '\nnpm config edit' +
   '\nnpm set <key> <value>' +
   '\nnpm get [<key>]'
@@ -69,7 +69,7 @@ function config (args, cb) {
       return del(args[0], cb)
     case 'list':
     case 'ls':
-      return list(cb)
+      return npm.config.get('json') ? listJson(cb) : list(cb)
     case 'edit':
       return edit(cb)
     default:
@@ -177,6 +177,23 @@ function getKeys (data) {
   return Object.keys(data).filter(publicVar).sort(sort)
 }
 
+function listJson (cb) {
+  const publicConf = npm.config.keys.reduce((publicConf, k) => {
+    var value = npm.config.get(k)
+
+    if (publicVar(k) &&
+        // argv is not really config, it's command config
+        k !== 'argv' &&
+        // logstream is a Stream, and would otherwise produce circular refs
+        k !== 'logstream') publicConf[k] = value
+
+    return publicConf
+  }, {})
+
+  output(JSON.stringify(publicConf, null, 2))
+  return cb()
+}
+
 function listFromSource (title, conf, long) {
   var confKeys = getKeys(conf)
   var msg = ''