set default values for document timestamps

frontend/package-lock.json

@@ -3210,7 +3210,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -3625,7 +3626,8 @@
         "safe-buffer": {
           "version": "5.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -3681,6 +3683,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -3724,12 +3727,14 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },

src/entity/Document.ts

@@ -27,10 +27,10 @@ export class Document extends BaseEntity {
     @Column({ type: "text" })
     public content: string;
 
-    @Column({ type: "timestamp" })
+    @Column({ type: "timestamp", default: null })
     public createdAt: Date;
 
-    @Column({ type: "timestamp" })
+    @Column({ type: "timestamp", default: null })
     public editedAt: Date;
 
     constructor(user: User, name: string, content: string) {