Protect referenced feeder structures from deletion

tests/circuit-structure-project-command.repository.test.ts

@@ -14,6 +14,7 @@ import { circuitDeviceRows } from "../src/db/schema/circuit-device-rows.js";
 import { circuitProtectionDevices } from "../src/db/schema/circuit-protection-devices.js";
 import { circuitSections } from "../src/db/schema/circuit-sections.js";
 import { circuits } from "../src/db/schema/circuits.js";
+import { distributionBoards } from "../src/db/schema/distribution-boards.js";
 import { projectDevices } from "../src/db/schema/project-devices.js";
 import { projectRevisions } from "../src/db/schema/project-revisions.js";
 import { projects } from "../src/db/schema/projects.js";
@@ -442,6 +443,48 @@ describe("circuit structure project-command repository", () => {
     }
   });
 
+  it("blocks deleting a circuit that feeds a distribution board", () => {
+    const fixture = createTestDatabase();
+    try {
+      const downstream = new DistributionBoardFixtureRepository(
+        fixture.context.db
+      ).createWithCircuitListAndDefaultSections("project-1", "UV Unterverteiler");
+      fixture.context.db
+        .update(distributionBoards)
+        .set({
+          boardNumber: "UV-02",
+          feedingDistributionBoardId: fixture.circuitListId,
+          feedingCircuitId: "circuit-existing",
+        })
+        .where(eq(distributionBoards.id, downstream.id))
+        .run();
+
+      const store = new CircuitStructureProjectCommandRepository(
+        fixture.context.db
+      );
+      assert.throws(
+        () =>
+          store.execute({
+            projectId: "project-1",
+            expectedRevision: 0,
+            source: "user",
+            command: createCircuitDeleteProjectCommand(
+              "circuit-existing",
+              fixture.circuitListId
+            ),
+          }),
+        /Speist UV-02 – erst Einspeisung ändern\./
+      );
+      assert.ok(getCircuit(fixture.context, "circuit-existing"));
+      assert.equal(
+        fixture.context.db.select().from(projectRevisions).all().length,
+        0
+      );
+    } finally {
+      fixture.context.close();
+    }
+  });
+
   it("rolls back insert and delete for late history failures", () => {
     const fixture = createTestDatabase();
     try {