Mongoose immutable fields plugin
Immutable property guards modifications on a field after document creation.
Mongoose immutable fields plugin was born when I had hard time trying to guard a field from modifications after document creation. I could not find something, which does that for me (maybe the mongoose concept in my head is wrong), but I had need of some way to protect my fields (from developers - myself included).
Operations-Guard
The plugin guards fields modification for following operations :
- re-save
- update
- updateOne
- updateMany
- findAndUpdate
Usage
Note! Immutable-plugin is tested only for below types of fields. The behavior of other types is unknown
object | array | number | string |
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- Simple Field Schema
let SimpleFieldSchema = id: SchemaTypesObjectId simpleFieldA: type: String immutable: true simpleFieldB: Number; SimpleFieldSchema;
- Nested Field Schema
let NestedFieldSchema = id: SchemaTypesObjectId levelA: levelB: levelC1: type: String immutable: true levelC2: String ; NestedFieldSchema;
- Array Field Schema
Note! Array-type field can be immutable, but the plugin will be triggered on array-level, not for array's items properties. That means if you have for example an array of objects and mark an object(array item) property as immutable, plugin wont handle that.
If you mark an array as immutable one, before db update, the whole array will be removed with all modifications on it
let ArrayFieldSchema = id: SchemaTypesObjectId arr: immutable: true type: item: String ; ArrayFieldSchema;
- Mixed Schema
let MixedImmutabilitySchema = id: SchemaTypesObjectId parentA: arr: immutable: true type: item: String childA: String childB: arr1: immutable: true type: item: String arr2: type: item: String childC: type: String immutable: true parentB: String parentC: type: Number immutable: true ; MixedImmutabilitySchema;
Tests
You need to have installed and run mongodb
Run tests -> run the test file with npm run test
Limitations
-
If you use re-save as a way to update a document, you will get back the document in the state before update (field will be updated although it is immutable) but if you retrieve it, it won't be
##### Example :
// You have defined someProp as immutable onelet doc = someProp: 5 ;let createdDOC = await doc;// createdDOC.someProp => 5docsomeProp = 6;let updatedDOC = await doc;// updatedDOC.someProp => 6let retrievedDOCAfterUpdate = await DOCModel;// retrievedDOCAfterUpdate.someProp => 5