feat: protect referenced rental resources (#27)

frontend/src/app/services/workspace-resource.ts

@@ -1,5 +1,6 @@
 import { signal } from '@angular/core';
 import { finalize, Observable } from 'rxjs';
+import { httpErrorMessage } from './http-error-message';
 import { withoutRecordKey, withoutSetValue } from './immutable-state';
 
 export interface LoadState {
@@ -69,8 +70,11 @@ export class WorkspaceResource<T extends { id?: string }> {
           this.confirmChange((items) => items.filter((item) => item.id !== id));
           this.load();
         },
-        error: () =>
-          this.deleteErrors.update((errors) => ({ ...errors, [id]: this.messages.delete })),
+        error: (error) =>
+          this.deleteErrors.update((errors) => ({
+            ...errors,
+            [id]: httpErrorMessage(error, this.messages.delete),
+          })),
       });
   }
 

frontend/src/app/services/workspace.service.spec.ts

@@ -97,7 +97,9 @@ describe('WorkspaceService', () => {
     leases.deleteLease.mockReturnValue(of(undefined));
     leases.downloadPdf.mockReturnValue(of(new Blob(['pdf'])));
     rentPayments.getRentPayments.mockReturnValue(of([rentPayment]));
-    rentPayments.markPaid.mockReturnValue(of({ ...rentPayment, status: 'PAID', paidAt: '2026-01-02' }));
+    rentPayments.markPaid.mockReturnValue(
+      of({ ...rentPayment, status: 'PAID', paidAt: '2026-01-02' }),
+    );
     rentPayments.downloadReceipt.mockReturnValue(of(new Blob(['receipt'])));
     dialog.open.mockImplementation(() => ({ afterClosed: () => of(true) }));
     vi.stubGlobal('URL', { createObjectURL: vi.fn(() => 'blob:test'), revokeObjectURL: vi.fn() });
@@ -247,8 +249,10 @@ describe('WorkspaceService', () => {
     expect(service.apartmentLoadState().loading).toBe(true);
   });
 
-  it('preserves a record and exposes a local error when deletion fails', () => {
-    apartments.deleteApartment.mockReturnValueOnce(throwError(() => new Error('offline')));
+  it('preserves a referenced apartment and exposes the conflict message when deletion fails', () => {
+    apartments.deleteApartment.mockReturnValueOnce(
+      throwError(() => ({ error: { message: 'Cet appartement est référencé par un bail.' } })),
+    );
     const service = TestBed.inject(WorkspaceService);
     service.apartments.set([apartment]);
 
@@ -257,7 +261,7 @@ describe('WorkspaceService', () => {
     expect(service.apartments()).toEqual([apartment]);
     expect(service.deletingApartmentIds().has(apartment.id)).toBe(false);
     expect(service.apartmentDeleteErrors()[apartment.id]).toBe(
-      'Impossible de supprimer cet appartement.',
+      'Cet appartement est référencé par un bail.',
     );
   });
 
@@ -357,7 +361,11 @@ describe('WorkspaceService', () => {
     expect(apartments.updateApartment).toHaveBeenCalledWith('apartment-1', apartment);
     expect(tenants.updateTenant).toHaveBeenCalledWith('tenant-1', tenant);
     expect(leases.deleteLease).toHaveBeenCalledWith('lease-1');
-    expect(rentPayments.markPaid).toHaveBeenCalledWith('payment-1', rentPayment.rent, rentPayment.charges);
+    expect(rentPayments.markPaid).toHaveBeenCalledWith(
+      'payment-1',
+      rentPayment.rent,
+      rentPayment.charges,
+    );
   });
 
   it('opens a confirmation pop-in before deleting a resource', () => {
@@ -429,7 +437,9 @@ describe('WorkspaceService', () => {
     service.downloadLeasePdf(lease);
 
     await vi.waitFor(() =>
-      expect(service.leaseDownloadError(lease.id)).toBe('Complétez votre profil dans les réglages.'),
+      expect(service.leaseDownloadError(lease.id)).toBe(
+        'Complétez votre profil dans les réglages.',
+      ),
     );
   });
 });