fix: Always return JSON for outdated --json

Close: https://github.com/npm/cli/pull/176

EDIT: Added test, do not set exitStatus to 1 if we're just printing an
empty list as JSON. -- @isaacs

1 files changed, 5 insertions, 2 deletions

diff --git a/lib/outdated.js b/lib/outdated.js
index 17b941461..bb4c346f9 100644
--- a/lib/outdated.js
+++ b/lib/outdated.js
@@ -101,7 +101,10 @@ function outdated (args, silent, cb) {
         return aa[0].path.localeCompare(bb[0].path) ||
           aa[1].localeCompare(bb[1])
       })
-      if (er || silent || list.length === 0) return cb(er, list)
+      if (er || silent ||
+          (list.length === 0 && !opts.json)) {
+        return cb(er, list)
+      }
       if (opts.json) {
         output(makeJSON(list, opts))
       } else if (opts.parseable) {
@@ -129,7 +132,7 @@ function outdated (args, silent, cb) {
         }
         output(table(outTable, tableOpts))
       }
-      process.exitCode = 1
+      process.exitCode = list.length ? 1 : 0
       cb(null, list.map(function (item) { return [item[0].parent.path].concat(item.slice(1, 7)) }))
     })
   }))