feat: detect grandchild dependency

src/lib/features/dependent-features/dependent-features-service.ts

@@ -96,18 +96,26 @@ export class DependentFeaturesService {
             );
         }
 
-        const [children, parentExists, sameProject] = await Promise.all([
-            this.dependentFeaturesReadModel.getChildren([child]),
-            this.featuresReadModel.featureExists(parent),
-            this.featuresReadModel.featuresInTheSameProject(child, parent),
-        ]);
-
-        if (children.length > 0) {
+        const [grandchildren, grandparents, parentExists, sameProject] =
+            await Promise.all([
+                this.dependentFeaturesReadModel.getChildren([child]),
+                this.dependentFeaturesReadModel.getParents(parent),
+                this.featuresReadModel.featureExists(parent),
+                this.featuresReadModel.featuresInTheSameProject(child, parent),
+            ]);
+
+        if (grandchildren.length > 0) {
             throw new InvalidOperationError(
                 'Transitive dependency detected. Cannot add a dependency to the feature that other features depend on.',
             );
         }
 
+        if (grandparents.length > 0) {
+            throw new InvalidOperationError(
+                'Transitive dependency detected. Cannot add a dependency to the feature that has parent dependency.',
+            );
+        }
+
         if (!parentExists) {
             throw new InvalidOperationError(
                 `No active feature ${parent} exists`,

src/lib/features/dependent-features/dependent.features.e2e.test.ts

@@ -138,7 +138,7 @@ test('should add and delete feature dependencies', async () => {
     ]);
 });
 
-test('should not allow to add a parent dependency to a feature that already has children', async () => {
+test('should not allow to add grandparent', async () => {
     const grandparent = uuidv4();
     const parent = uuidv4();
     const child = uuidv4();
@@ -158,8 +158,28 @@ test('should not allow to add a parent dependency to a feature that already has
     );
 });
 
-test('should not allow to add non-existent parent dependency', async () => {
+test('should not allow to add grandchild', async () => {
     const grandparent = uuidv4();
+    const parent = uuidv4();
+    const child = uuidv4();
+    await app.createFeature(grandparent);
+    await app.createFeature(parent);
+    await app.createFeature(child);
+
+    await addFeatureDependency(parent, {
+        feature: grandparent,
+    });
+
+    await addFeatureDependency(
+        child,
+        {
+            feature: parent,
+        },
+        403,
+    );
+});
+
+test('should not allow to add non-existent parent dependency', async () => {
     const parent = uuidv4();
     const child = uuidv4();
     await app.createFeature(child);