add collection scaling logic to backupCollection, add .gitkeep files to preserve directories

Author: bennyschmidt

.dss/data/backups/.gitkeep

@@ -15,10 +15,28 @@ const Database = dataURI => {
   let getCollection, updateCollection, backupCollection, storeMedia;
 
   backupCollection = async collectionName => {
-    const data = await fs.readFile(`${dataURI}/${collectionName}.json`, 'utf8');
+    const files = await fs.readdir(dataURI);
+
+    const documents = files
+      .filter(file => (
+        file
+          .split('.')[0]
+          .split('-')[0] === collectionName
+      ))
+      .map(file => (
+        file.replace('.json', '')
+      ));
+
+    const fileName = documents.length > 1
+      ? documents.sort().pop()
+      : collectionName;
+
+    const fileSrc = `${dataURI}/${fileName}.json`;
+
+    const data = await fs.readFile(fileSrc, 'utf8');
 
     await fs.writeFile(
-      `${dataURI}/${collectionName}-${Date.now()}.json`,
+      `${dataURI}/backups/${collectionName}-${Date.now()}.json`,
       data,
       'utf8'
     );

.dss/data/json/.gitkeep

@@ -1,6 +1,6 @@
 {
   "name": "diamond-search-and-store",
-  "version": "0.2.7",
+  "version": "0.2.9",
   "engines": {
     "node": "16.14.2"
   },