Decyjphr/pr 682 (#685)

* update comments from #249

I found the logic behind some of what happened here hard to follow and updated the comments to try to make it easier to follow.

* fix environments updating global array

The environments plugin was changing `MergeDeep.NAME_FIELDS`, which is a global object. The reason was to avoid environments being filtered out from the change list if they only have a name field.
However, the environments plugin has it's own overriden sync method, and thus we can simply drop the whole filtering from that method.

Fixes #108

* remove repeating line

This has to be a "typo" from 9a74e05 calling the same assignment twice. Removing to clean up.

---------

Co-authored-by: Torgeir S. hos Sykehuspartner <93591857+torgst@users.noreply.github.com>

Author: decyjphr

lib/mergeDeep.js

@@ -378,5 +378,4 @@ class MergeDeep {
   }
 }
 MergeDeep.NAME_FIELDS = NAME_FIELDS
-MergeDeep.NAME_FIELDS = NAME_FIELDS
 module.exports = MergeDeep

lib/plugins/diffable.js

@@ -93,14 +93,15 @@ module.exports = class Diffable extends ErrorStash {
           }
         }
 
-        // Filter out all empty entries (usually from repo override)
+        // Remove any null or undefined values from the diffables (usually comes from repo override)
         for (const entry of filteredEntries) {
           for (const key of Object.keys(entry)) {
             if (entry[key] === null || entry[key] === undefined) {
               delete entry[key]
             }
           }
         }
+        // Delete any diffable that now only has name and no other attributes
         filteredEntries = filteredEntries.filter(entry => Object.keys(entry).filter(key => !MergeDeep.NAME_FIELDS.includes(key)).length !== 0)
 
         const changes = []

lib/plugins/environments.js

@@ -17,10 +17,6 @@ module.exports = class Environments extends Diffable {
               }
             })
         }
-
-        // Remove 'name' from filtering list so Environments with only a name defined are processed.
-        MergeDeep.NAME_FIELDS.splice(MergeDeep.NAME_FIELDS.indexOf('name'), 1)
-
     }
 
     async find() {
@@ -296,15 +292,15 @@ module.exports = class Environments extends Diffable {
         let filteredEntries = this.filterEntries()
         return this.find().then(existingRecords => {
 
-          // Filter out all empty entries (usually from repo override)
+          // Remove any null or undefined values from the diffables (usually comes from repo override)
           for (const entry of filteredEntries) {
             for (const key of Object.keys(entry)) {
               if (entry[key] === null || entry[key] === undefined) {
                 delete entry[key]
               }
             }
           }
-          filteredEntries = filteredEntries.filter(entry => Object.keys(entry).filter(key => !MergeDeep.NAME_FIELDS.includes(key)).length !== 0)
+          // For environments, we want to keep the entries with only name defined.
 
           const changes = []