# Business rules — task-ledger-api Evidence date: 2026-10-01. Source: `git@bitbucket.org:overdrive/task-ledger-api.git`, `main` at `8ab244e` (2026-01-03). There is no business-rules document in the source repository. Every rule below is taken from code, the EF model, tests, or `cursor.rules.md`. Rules the code enforces are **Implemented**. Rules that are a reasonable reading of that code, and are not written down as policy, are **Inferred**. Statements that exist only as coding-agent instructions are **Documented** and are not treated as product policy until someone confirms them. `TaskService` comments label two behaviours as business rules: title is required, and `CreatedUtc` is set on the server. Those comments are evidence. They are still marked **Implemented**, because the code does those things. ## Access ### BR-001 — Any caller who can reach the process may create and list tasks **Implemented.** `Program.cs` registers controllers and HTTPS redirection. It does not register authentication or authorization. No action has `[Authorize]`. `launchSettings.json` sets `anonymousAuthentication` to true and `windowsAuthentication` to false. **Inferred:** there is no per-user task list. `GET /api/Tasks` returns every row. **Unknown / Requires Confirmation:** whether a reverse proxy or private network is expected to be the only access control. The repository does not mention one. ### BR-002 — The database login is a Windows trusted connection **Implemented** in both appsettings files: `Trusted_Connection=true` against `(localdb)\mssqllocaldb`. No SQL user or password is stored in git. **Documented** in `cursor.rules.md`: "NEVER connect to or reference production databases" and "SQL Server is local only (localhost)". The committed server is LocalDB, which is local. The rule text says `localhost`; the connection string since `8ab244e` says `(localdb)\mssqllocaldb`. ## Creating a task ### BR-003 — Title is required **Implemented.** `TaskService.CreateTaskAsync` throws `ArgumentException` with message "Title is required." when the title is null, empty, or whitespace. `TasksController.CreateTask` catches `ArgumentException` and returns HTTP 400 with `{ "error": "" }`. Tests: `CreateTaskAsync_WithNullTitle_ShouldThrowArgumentException`, `CreateTaskAsync_WithEmptyTitle_ShouldThrowArgumentException`, `CreateTaskAsync_WithWhitespaceTitle_ShouldThrowArgumentException`. The comment in the service calls this a business rule. `CreateTaskRequest` has no `[Required]` attribute. The check that returns 400 is the service, not model validation. A JSON body that omits `Title` binds the default `string.Empty` and fails the same check. ### BR-004 — Title and description are trimmed **Implemented.** The stored title is `title.Trim()`. A non-null description is `description.Trim()`. Test: `CreateTaskAsync_ShouldTrimTitleAndDescription` (" Test Task " and " Test Description " become "Test Task" and "Test Description"). **Inferred:** a description that is only whitespace is stored as an empty string, because `Trim()` of whitespace is empty and the code does not turn that into null. Null description stays null. Test `CreateTaskAsync_WithNullDescription_ShouldCreateTask` covers null only. ### BR-005 — Title length is at most 200 characters; description at most 1000 **Implemented** as EF configuration and as the migration columns `nvarchar(200)` and `nvarchar(1000)`. `Title` is required at the database. `Description` is nullable. **Not implemented** in the service. `CreateTaskAsync` does not check length. The controller does not catch database update failures. A value past those limits is not the 400 path used for a missing title. **Inferred:** EF Core will fail the save when the value exceeds the configured maximum. The HTTP status for that failure is the host's unhandled-exception response. This was not executed during documentation. ### BR-006 — Duplicate titles are allowed **Inferred.** The model has no unique index on `Title`. Two creates with the same title are two rows. No test covers this. ### BR-007 — A new task is not completed **Implemented.** `CreateTaskAsync` sets `IsCompleted = false`. The column is non-nullable. Test `CreateTaskAsync_WithValidTitle_ShouldCreateTask` asserts false. No method sets the flag to true. The client cannot send `IsCompleted`; `CreateTaskRequest` has only `Title` and `Description`. ### BR-008 — Creation time is assigned by the server in UTC **Implemented.** `CreatedUtc = DateTime.UtcNow`. The client cannot send it. The service comment calls this a business rule. Tests: `CreateTaskAsync_ShouldSetCreatedUtcToUtcNow` asserts the value lies between the times taken before and after the call, and that `Kind` is `Utc`. The valid-create test asserts the timestamp is within the last minute and not after `UtcNow`. **Inferred:** two tasks created in the same tick can share a `CreatedUtc`. The list sort has no tie-break. ## Reading tasks ### BR-009 — The list is every task, oldest creation time first **Implemented.** `GetAllTasksAsync` returns `Tasks.OrderBy(t => t.CreatedUtc)`. There is no skip, take, or where clause. Test: three creates separated by a 10 ms delay come back as first, second, third, and each `CreatedUtc` is less than or equal to the next. ### BR-010 — An empty ledger returns an empty list **Implemented** in `GetAllTasksAsync_WithNoTasks_ShouldReturnEmptyList`. The controller returns `Ok(tasks)`, so the HTTP status is 200. The test does not call the controller. ## Data that is stored and never updated ### BR-011 — Rows are insert-only on this API **Implemented.** The only write is `Tasks.Add` followed by `SaveChangesAsync`. There is no update or delete in `TaskService` or in the controller. **Discrepancy.** Commit `8f0658b` describes update and delete methods. Those methods are not in source. Do not treat the commit message as a rule. ### BR-012 — There is no updated-at value **Implemented** on `main`. The current entity has `CreatedUtc` only. **Changed.** At `e12e94a` the entity required `UpdatedAt` as well as `CreatedAt`. That pair was removed in `310c137`. No current rule sets an update time, because nothing updates a row. ## Database process rules These are instructions in `cursor.rules.md`. The API does not check them at runtime. ### BR-013 — Migrations are generated and not applied by the application **Documented.** `cursor.rules.md` says migrations must be generated and never applied automatically, and it denies `dotnet ef database update`. **Implemented** in `Program.cs`: the host does not call `Database.Migrate` or `EnsureCreated`. **Unknown / Requires Confirmation:** whether a person has applied `Migrations/InitialCreate.sql` or updated the database by hand. ### BR-014 — Schema scripts should be idempotent and non-destructive **Documented.** `cursor.rules.md` says to generate idempotent SQL and forbids `DROP DATABASE` and `TRUNCATE`. **Implemented** in `Migrations/InitialCreate.sql`: each step checks `__EFMigrationsHistory` before creating the table or inserting the history row. The script does not drop a database or truncate a table. The EF `Down` method in `20260101150955_InitialCreate.cs` drops table `Tasks`. That method is not the idempotent script. Nothing in `Program.cs` calls `Down`. ### BR-015 — Transient SQL errors are retried **Implemented.** `EnableRetryOnFailure(maxRetryCount: 5, maxRetryDelay: 30 seconds, errorNumbersToAdd: null)` on the SQL Server options. **Inferred:** only errors EF Core already treats as transient are retried. The call passes no extra error numbers. A failure after the retries still leaves the controller, which only catches `ArgumentException`. ## HTTP behaviour that is not a domain rule ### BR-016 — HTTPS redirection is always on **Implemented.** `app.UseHttpsRedirection()` is outside the Development check. Swagger is inside that check. ### BR-017 — Host filtering allows any host **Implemented.** `appsettings.json` sets `AllowedHosts` to `*`. `appsettings.Development.json` does not override it. ### BR-018 — The 201 Location points at the list action **Implemented.** `CreateTask` returns `CreatedAtAction(nameof(GetAllTasks), new { id = task.Id }, task)`. **Inferred:** because `GetAllTasks` has no `id` parameter, the generated location carries `id` as a query string, and the list action ignores it. There is no get-by-id resource to point at. ## Rules that are not enforced - A maximum title or description length as an HTTP 400 (BR-005 is a column constraint only). - Uniqueness of titles (BR-006). - A caller identity (BR-001). - Changing `IsCompleted` (BR-007). - Automatic migration on startup (BR-013).