remove other link fields when you delete a model

packages/server/src/api/controllers/model.js

@@ -27,6 +27,23 @@ exports.create = async function(ctx) {
   const result = await db.post(newModel)
   newModel._rev = result.rev
 
+  const { schema } = ctx.request.body
+  for (let key in schema) {
+    // model has a linked record
+    if (schema[key].type === "link") {
+      // create the link field in the other model
+      const linkedModel = await db.get(schema[key].modelId);
+      linkedModel.schema[newModel.name] = {
+        type: "link",
+        modelId: newModel._id,
+        constraints: {
+          type: "array"
+        }
+      }
+      await db.put(linkedModel);
+    }
+  }
+
   const designDoc = await db.get("_design/database")
   designDoc.views = {
     ...designDoc.views,
@@ -50,7 +67,9 @@ exports.update = async function() {}
 exports.destroy = async function(ctx) {
   const db = new CouchDB(ctx.params.instanceId)
 
-  await db.remove(ctx.params.modelId, ctx.params.revId)
+  const modelToDelete = await db.get(ctx.params.modelId);
+
+  await db.remove(modelToDelete)
   const modelViewId = `all_${ctx.params.modelId}`
 
   // Delete all records for that model
@@ -59,6 +78,17 @@ exports.destroy = async function(ctx) {
     records.rows.map(record => ({ id: record.id, _deleted: true }))
   )
 
+  // Delete linked record fields in dependent models
+  for (let key in modelToDelete.schema) {
+    const { type, modelId } = modelToDelete.schema[key];
+    if (type === "link") {
+      const linkedModel = await db.get(modelId);
+      delete linkedModel.schema[modelToDelete.name]
+      await db.put(linkedModel)
+    }
+  }
+
+
   // delete the "all" view
   const designDoc = await db.get("_design/database")
   delete designDoc.views[modelViewId]

packages/server/src/api/routes/tests/couchTestUtils.js

@@ -253,3 +253,7 @@ exports.insertDocument = async (databaseId, document) => {
 exports.destroyDocument = async (databaseId, documentId) => {
   return await new CouchDB(databaseId).destroy(documentId)
 }
+
+exports.getDocument = async (databaseId, documentId) => {
+  return await new CouchDB(databaseId).get(documentId)
+}

packages/server/src/api/routes/tests/model.spec.js

@@ -5,7 +5,8 @@ const {
   createClientDatabase, 
   createApplication,
   defaultHeaders,
-  builderEndpointShouldBlockNormalUsers
+  builderEndpointShouldBlockNormalUsers,
+  getDocument
 } = require("./couchTestUtils")
 
 describe("/models", () => {
@@ -119,6 +120,41 @@ describe("/models", () => {
         });
       })
 
+    it("deletes linked references to the model after deletion", async done => {
+      const linkedModel = await createModel(request, instance._id, {
+        name: "LinkedModel",
+        type: "model",
+        key: "name",
+        schema: {
+          name: {
+            type: "text",
+            constraints: {
+              type: "string",
+            },
+          },
+          TestModel: {
+            type: "link",
+            modelId: testModel._id,
+            constraints: {
+              type: "array"
+            }
+          }
+        },
+      })
+
+      request
+        .delete(`/api/${instance._id}/models/${testModel._id}/${testModel._rev}`)
+        .set(defaultHeaders)
+        .expect('Content-Type', /json/)
+        .expect(200)
+        .end(async (_, res) => {
+            expect(res.res.statusMessage).toEqual(`Model ${testModel._id} deleted.`);            
+            const dependentModel = await getDocument(instance._id, linkedModel._id)
+            expect(dependentModel.schema.TestModel).not.toBeDefined();
+            done();
+        });
+      })
+
     it("should apply authorization to endpoint", async () => {
       await builderEndpointShouldBlockNormalUsers({
         request,