daily-tracker

AGENTS.md (26186B)

---

 This is a web application written using the Phoenix web framework.
 
 ## Project guidelines
 
 - Use `mix precommit` alias when you are done with all changes and fix any pending issues
 - Use the already included and available `:req` (`Req`) library for HTTP requests, **avoid** `:httpoison`, `:tesla`, and `:httpc`. Req is included by default and is the preferred HTTP client for Phoenix apps
 
 ### Phoenix v1.8 guidelines
 
 - **Always** begin your LiveView templates with `<Layouts.app flash={@flash} ...>` which wraps all inner content
 - The `MyAppWeb.Layouts` module is aliased in the `my_app_web.ex` file, so you can use it without needing to alias it again
 - Anytime you run into errors with no `current_scope` assign:
   - You failed to follow the Authenticated Routes guidelines, or you failed to pass `current_scope` to `<Layouts.app>`
   - **Always** fix the `current_scope` error by moving your routes to the proper `live_session` and ensure you pass `current_scope` as needed
 - Phoenix v1.8 moved the `<.flash_group>` component to the `Layouts` module. You are **forbidden** from calling `<.flash_group>` outside of the `layouts.ex` module
 - Out of the box, `core_components.ex` imports an `<.icon name="hero-x-mark" class="w-5 h-5"/>` component for hero icons. **Always** use the `<.icon>` component for icons, **never** use `Heroicons` modules or similar
 - **Always** use the imported `<.input>` component for form inputs from `core_components.ex` when available. `<.input>` is imported and using it will save steps and prevent errors
 - If you override the default input classes (`<.input class="myclass px-2 py-1 rounded-lg">)`) class with your own values, no default classes are inherited, so your
 custom classes must fully style the input
 
 ### JS and CSS guidelines
 
 - **Use Tailwind CSS classes and custom CSS rules** to create polished, responsive, and visually stunning interfaces.
 - Tailwindcss v4 **no longer needs a tailwind.config.js** and uses a new import syntax in `app.css`:
 
       @import "tailwindcss" source(none);
       @source "../css";
       @source "../js";
       @source "../../lib/my_app_web";
 
 - **Always use and maintain this import syntax** in the app.css file for projects generated with `phx.new`
 - **Never** use `@apply` when writing raw css
 - **Always** manually write your own tailwind-based components instead of using daisyUI for a unique, world-class design
 - Out of the box **only the app.js and app.css bundles are supported**
   - You cannot reference an external vendor'd script `src` or link `href` in the layouts
   - You must import the vendor deps into app.js and app.css to use them
   - **Never write inline <script>custom js</script> tags within templates**
 
 ### UI/UX & design guidelines
 
 - **Produce world-class UI designs** with a focus on usability, aesthetics, and modern design principles
 - Implement **subtle micro-interactions** (e.g., button hover effects, and smooth transitions)
 - Ensure **clean typography, spacing, and layout balance** for a refined, premium look
 - Focus on **delightful details** like hover effects, loading states, and smooth page transitions
 
 
 <!-- phoenix-gen-auth-start -->
 ## Authentication
 
 - **Always** handle authentication flow at the router level with proper redirects
 - **Always** be mindful of where to place routes. `phx.gen.auth` creates multiple router plugs and `live_session` scopes:
   - A plug `:fetch_current_scope_for_user` that is included in the default browser pipeline
   - A plug `:require_authenticated_user` that redirects to the log in page when the user is not authenticated
   - A `live_session :current_user` scope - for routes that need the current user but don't require authentication, similar to `:fetch_current_scope_for_user`
   - A `live_session :require_authenticated_user` scope - for routes that require authentication, similar to the plug with the same name
   - In both cases, a `@current_scope` is assigned to the Plug connection and LiveView socket
   - A plug `redirect_if_user_is_authenticated` that redirects to a default path in case the user is authenticated - useful for a registration page that should only be shown to unauthenticated users
 - **Always let the user know in which router scopes, `live_session`, and pipeline you are placing the route, AND SAY WHY**
 - `phx.gen.auth` assigns the `current_scope` assign - it **does not assign a `current_user` assign**
 - Always pass the assign `current_scope` to context modules as first argument. When performing queries, use `current_scope.user` to filter the query results
 - To derive/access `current_user` in templates, **always use the `@current_scope.user`**, never use **`@current_user`** in templates or LiveViews
 - **Never** duplicate `live_session` names. A `live_session :current_user` can only be defined __once__ in the router, so all routes for the `live_session :current_user`  must be grouped in a single block
 - Anytime you hit `current_scope` errors or the logged in session isn't displaying the right content, **always double check the router and ensure you are using the correct plug and `live_session` as described below**
 
 ### Routes that require authentication
 
 LiveViews that require login should **always be placed inside the __existing__ `live_session :require_authenticated_user` block**:
 
     scope "/", AppWeb do
       pipe_through [:browser, :require_authenticated_user]
 
       live_session :require_authenticated_user,
         on_mount: [{DailyTrackerWeb.UserAuth, :require_authenticated}] do
         # phx.gen.auth generated routes
         live "/users/settings", UserLive.Settings, :edit
         live "/users/settings/confirm-email/:token", UserLive.Settings, :confirm_email
         # our own routes that require logged in user
         live "/", MyLiveThatRequiresAuth, :index
       end
     end
 
 Controller routes must be placed in a scope that sets the `:require_authenticated_user` plug:
 
     scope "/", AppWeb do
       pipe_through [:browser, :require_authenticated_user]
 
       get "/", MyControllerThatRequiresAuth, :index
     end
 
 ### Routes that work with or without authentication
 
 LiveViews that can work with or without authentication, **always use the __existing__ `:current_user` scope**, ie:
 
     scope "/", MyAppWeb do
       pipe_through [:browser]
 
       live_session :current_user,
         on_mount: [{DailyTrackerWeb.UserAuth, :mount_current_scope}] do
         # our own routes that work with or without authentication
         live "/", PublicLive
       end
     end
 
 Controllers automatically have the `current_scope` available if they use the `:browser` pipeline.
 
 <!-- phoenix-gen-auth-end -->
 
 <!-- usage-rules-start -->
 
 <!-- phoenix:elixir-start -->
 ## Elixir guidelines
 
 - Elixir lists **do not support index based access via the access syntax**
 
   **Never do this (invalid)**:
 
       i = 0
       mylist = ["blue", "green"]
       mylist[i]
 
   Instead, **always** use `Enum.at`, pattern matching, or `List` for index based list access, ie:
 
       i = 0
       mylist = ["blue", "green"]
       Enum.at(mylist, i)
 
 - Elixir variables are immutable, but can be rebound, so for block expressions like `if`, `case`, `cond`, etc
   you *must* bind the result of the expression to a variable if you want to use it and you CANNOT rebind the result inside the expression, ie:
 
       # INVALID: we are rebinding inside the `if` and the result never gets assigned
       if connected?(socket) do
         socket = assign(socket, :val, val)
       end
 
       # VALID: we rebind the result of the `if` to a new variable
       socket =
         if connected?(socket) do
           assign(socket, :val, val)
         end
 
 - **Never** nest multiple modules in the same file as it can cause cyclic dependencies and compilation errors
 - **Never** use map access syntax (`changeset[:field]`) on structs as they do not implement the Access behaviour by default. For regular structs, you **must** access the fields directly, such as `my_struct.field` or use higher level APIs that are available on the struct if they exist, `Ecto.Changeset.get_field/2` for changesets
 - Elixir's standard library has everything necessary for date and time manipulation. Familiarize yourself with the common `Time`, `Date`, `DateTime`, and `Calendar` interfaces by accessing their documentation as necessary. **Never** install additional dependencies unless asked or for date/time parsing (which you can use the `date_time_parser` package)
 - Don't use `String.to_atom/1` on user input (memory leak risk)
 - Predicate function names should not start with `is_` and should end in a question mark. Names like `is_thing` should be reserved for guards
 - Elixir's builtin OTP primitives like `DynamicSupervisor` and `Registry`, require names in the child spec, such as `{DynamicSupervisor, name: MyApp.MyDynamicSup}`, then you can use `DynamicSupervisor.start_child(MyApp.MyDynamicSup, child_spec)`
 - Use `Task.async_stream(collection, callback, options)` for concurrent enumeration with back-pressure. The majority of times you will want to pass `timeout: :infinity` as option
 
 ## Mix guidelines
 
 - Read the docs and options before using tasks (by using `mix help task_name`)
 - To debug test failures, run tests in a specific file with `mix test test/my_test.exs` or run all previously failed tests with `mix test --failed`
 - `mix deps.clean --all` is **almost never needed**. **Avoid** using it unless you have good reason
 
 ## Test guidelines
 
 - **Always use `start_supervised!/1`** to start processes in tests as it guarantees cleanup between tests
 - **Avoid** `Process.sleep/1` and `Process.alive?/1` in tests
   - Instead of sleeping to wait for a process to finish, **always** use `Process.monitor/1` and assert on the DOWN message:
 
       ref = Process.monitor(pid)
       assert_receive {:DOWN, ^ref, :process, ^pid, :normal}
 
    - Instead of sleeping to synchronize before the next call, **always** use `_ = :sys.get_state/1` to ensure the process has handled prior messages
 <!-- phoenix:elixir-end -->
 
 <!-- phoenix:phoenix-start -->
 ## Phoenix guidelines
 
 - Remember Phoenix router `scope` blocks include an optional alias which is prefixed for all routes within the scope. **Always** be mindful of this when creating routes within a scope to avoid duplicate module prefixes.
 
 - You **never** need to create your own `alias` for route definitions! The `scope` provides the alias, ie:
 
       scope "/admin", AppWeb.Admin do
         pipe_through :browser
 
         live "/users", UserLive, :index
       end
 
   the UserLive route would point to the `AppWeb.Admin.UserLive` module
 
 - `Phoenix.View` no longer is needed or included with Phoenix, don't use it
 <!-- phoenix:phoenix-end -->
 
 <!-- phoenix:ecto-start -->
 ## Ecto Guidelines
 
 - **Always** preload Ecto associations in queries when they'll be accessed in templates, ie a message that needs to reference the `message.user.email`
 - Remember `import Ecto.Query` and other supporting modules when you write `seeds.exs`
 - `Ecto.Schema` fields always use the `:string` type, even for `:text`, columns, ie: `field :name, :string`
 - `Ecto.Changeset.validate_number/2` **DOES NOT SUPPORT the `:allow_nil` option**. By default, Ecto validations only run if a change for the given field exists and the change value is not nil, so such as option is never needed
 - You **must** use `Ecto.Changeset.get_field(changeset, :field)` to access changeset fields
 - Fields which are set programmatically, such as `user_id`, must not be listed in `cast` calls or similar for security purposes. Instead they must be explicitly set when creating the struct
 - **Always** invoke `mix ecto.gen.migration migration_name_using_underscores` when generating migration files, so the correct timestamp and conventions are applied
 <!-- phoenix:ecto-end -->
 
 <!-- phoenix:html-start -->
 ## Phoenix HTML guidelines
 
 - Phoenix templates **always** use `~H` or .html.heex files (known as HEEx), **never** use `~E`
 - **Always** use the imported `Phoenix.Component.form/1` and `Phoenix.Component.inputs_for/1` function to build forms. **Never** use `Phoenix.HTML.form_for` or `Phoenix.HTML.inputs_for` as they are outdated
 - When building forms **always** use the already imported `Phoenix.Component.to_form/2` (`assign(socket, form: to_form(...))` and `<.form for={@form} id="msg-form">`), then access those forms in the template via `@form[:field]`
 - **Always** add unique DOM IDs to key elements (like forms, buttons, etc) when writing templates, these IDs can later be used in tests (`<.form for={@form} id="product-form">`)
 - For "app wide" template imports, you can import/alias into the `my_app_web.ex`'s `html_helpers` block, so they will be available to all LiveViews, LiveComponent's, and all modules that do `use MyAppWeb, :html` (replace "my_app" by the actual app name)
 
 - Elixir supports `if/else` but **does NOT support `if/else if` or `if/elsif`**. **Never use `else if` or `elseif` in Elixir**, **always** use `cond` or `case` for multiple conditionals.
 
   **Never do this (invalid)**:
 
       <%= if condition do %>
         ...
       <% else if other_condition %>
         ...
       <% end %>
 
   Instead **always** do this:
 
       <%= cond do %>
         <% condition -> %>
           ...
         <% condition2 -> %>
           ...
         <% true -> %>
           ...
       <% end %>
 
 - HEEx require special tag annotation if you want to insert literal curly's like `{` or `}`. If you want to show a textual code snippet on the page in a `<pre>` or `<code>` block you *must* annotate the parent tag with `phx-no-curly-interpolation`:
 
       <code phx-no-curly-interpolation>
         let obj = {key: "val"}
       </code>
 
   Within `phx-no-curly-interpolation` annotated tags, you can use `{` and `}` without escaping them, and dynamic Elixir expressions can still be used with `<%= ... %>` syntax
 
 - HEEx class attrs support lists, but you must **always** use list `[...]` syntax. You can use the class list syntax to conditionally add classes, **always do this for multiple class values**:
 
       <a class={[
         "px-2 text-white",
         @some_flag && "py-5",
         if(@other_condition, do: "border-red-500", else: "border-blue-100"),
         ...
       ]}>Text</a>
 
   and **always** wrap `if`'s inside `{...}` expressions with parens, like done above (`if(@other_condition, do: "...", else: "...")`)
 
   and **never** do this, since it's invalid (note the missing `[` and `]`):
 
       <a class={
         "px-2 text-white",
         @some_flag && "py-5"
       }> ...
       => Raises compile syntax error on invalid HEEx attr syntax
 
 - **Never** use `<% Enum.each %>` or non-for comprehensions for generating template content, instead **always** use `<%= for item <- @collection do %>`
 - HEEx HTML comments use `<%!-- comment --%>`. **Always** use the HEEx HTML comment syntax for template comments (`<%!-- comment --%>`)
 - HEEx allows interpolation via `{...}` and `<%= ... %>`, but the `<%= %>` **only** works within tag bodies. **Always** use the `{...}` syntax for interpolation within tag attributes, and for interpolation of values within tag bodies. **Always** interpolate block constructs (if, cond, case, for) within tag bodies using `<%= ... %>`.
 
   **Always** do this:
 
       <div id={@id}>
         {@my_assign}
         <%= if @some_block_condition do %>
           {@another_assign}
         <% end %>
       </div>
 
   and **Never** do this – the program will terminate with a syntax error:
 
       <%!-- THIS IS INVALID NEVER EVER DO THIS --%>
       <div id="<%= @invalid_interpolation %>">
         {if @invalid_block_construct do}
         {end}
       </div>
 <!-- phoenix:html-end -->
 
 <!-- phoenix:liveview-start -->
 ## Phoenix LiveView guidelines
 
 - **Never** use the deprecated `live_redirect` and `live_patch` functions, instead **always** use the `<.link navigate={href}>` and  `<.link patch={href}>` in templates, and `push_navigate` and `push_patch` functions LiveViews
 - **Avoid LiveComponent's** unless you have a strong, specific need for them
 - LiveViews should be named like `AppWeb.WeatherLive`, with a `Live` suffix. When you go to add LiveView routes to the router, the default `:browser` scope is **already aliased** with the `AppWeb` module, so you can just do `live "/weather", WeatherLive`
 
 ### LiveView streams
 
 - **Always** use LiveView streams for collections for assigning regular lists to avoid memory ballooning and runtime termination with the following operations:
   - basic append of N items - `stream(socket, :messages, [new_msg])`
   - resetting stream with new items - `stream(socket, :messages, [new_msg], reset: true)` (e.g. for filtering items)
   - prepend to stream - `stream(socket, :messages, [new_msg], at: -1)`
   - deleting items - `stream_delete(socket, :messages, msg)`
 
 - When using the `stream/3` interfaces in the LiveView, the LiveView template must 1) always set `phx-update="stream"` on the parent element, with a DOM id on the parent element like `id="messages"` and 2) consume the `@streams.stream_name` collection and use the id as the DOM id for each child. For a call like `stream(socket, :messages, [new_msg])` in the LiveView, the template would be:
 
       <div id="messages" phx-update="stream">
         <div :for={{id, msg} <- @streams.messages} id={id}>
           {msg.text}
         </div>
       </div>
 
 - LiveView streams are *not* enumerable, so you cannot use `Enum.filter/2` or `Enum.reject/2` on them. Instead, if you want to filter, prune, or refresh a list of items on the UI, you **must refetch the data and re-stream the entire stream collection, passing reset: true**:
 
       def handle_event("filter", %{"filter" => filter}, socket) do
         # re-fetch the messages based on the filter
         messages = list_messages(filter)
 
         {:noreply,
          socket
          |> assign(:messages_empty?, messages == [])
          # reset the stream with the new messages
          |> stream(:messages, messages, reset: true)}
       end
 
 - LiveView streams *do not support counting or empty states*. If you need to display a count, you must track it using a separate assign. For empty states, you can use Tailwind classes:
 
       <div id="tasks" phx-update="stream">
         <div class="hidden only:block">No tasks yet</div>
         <div :for={{id, task} <- @streams.tasks} id={id}>
           {task.name}
         </div>
       </div>
 
   The above only works if the empty state is the only HTML block alongside the stream for-comprehension.
 
 - When updating an assign that should change content inside any streamed item(s), you MUST re-stream the items
   along with the updated assign:
 
       def handle_event("edit_message", %{"message_id" => message_id}, socket) do
         message = Chat.get_message!(message_id)
         edit_form = to_form(Chat.change_message(message, %{content: message.content}))
 
         # re-insert message so @editing_message_id toggle logic takes effect for that stream item
         {:noreply,
          socket
          |> stream_insert(:messages, message)
          |> assign(:editing_message_id, String.to_integer(message_id))
          |> assign(:edit_form, edit_form)}
       end
 
   And in the template:
 
       <div id="messages" phx-update="stream">
         <div :for={{id, message} <- @streams.messages} id={id} class="flex group">
           {message.username}
           <%= if @editing_message_id == message.id do %>
             <%!-- Edit mode --%>
             <.form for={@edit_form} id="edit-form-#{message.id}" phx-submit="save_edit">
               ...
             </.form>
           <% end %>
         </div>
       </div>
 
 - **Never** use the deprecated `phx-update="append"` or `phx-update="prepend"` for collections
 
 ### LiveView JavaScript interop
 
 - Remember anytime you use `phx-hook="MyHook"` and that JS hook manages its own DOM, you **must** also set the `phx-update="ignore"` attribute
 - **Always** provide an unique DOM id alongside `phx-hook` otherwise a compiler error will be raised
 
 LiveView hooks come in two flavors, 1) colocated js hooks for "inline" scripts defined inside HEEx,
 and 2) external `phx-hook` annotations where JavaScript object literals are defined and passed to the `LiveSocket` constructor.
 
 #### Inline colocated js hooks
 
 **Never** write raw embedded `<script>` tags in heex as they are incompatible with LiveView.
 Instead, **always use a colocated js hook script tag (`:type={Phoenix.LiveView.ColocatedHook}`)
 when writing scripts inside the template**:
 
     <input type="text" name="user[phone_number]" id="user-phone-number" phx-hook=".PhoneNumber" />
     <script :type={Phoenix.LiveView.ColocatedHook} name=".PhoneNumber">
       export default {
         mounted() {
           this.el.addEventListener("input", e => {
             let match = this.el.value.replace(/\D/g, "").match(/^(\d{3})(\d{3})(\d{4})$/)
             if(match) {
               this.el.value = `${match[1]}-${match[2]}-${match[3]}`
             }
           })
         }
       }
     </script>
 
 - colocated hooks are automatically integrated into the app.js bundle
 - colocated hooks names **MUST ALWAYS** start with a `.` prefix, i.e. `.PhoneNumber`
 
 #### External phx-hook
 
 External JS hooks (`<div id="myhook" phx-hook="MyHook">`) must be placed in `assets/js/` and passed to the
 LiveSocket constructor:
 
     const MyHook = {
       mounted() { ... }
     }
     let liveSocket = new LiveSocket("/live", Socket, {
       hooks: { MyHook }
     });
 
 #### Pushing events between client and server
 
 Use LiveView's `push_event/3` when you need to push events/data to the client for a phx-hook to handle.
 **Always** return or rebind the socket on `push_event/3` when pushing events:
 
     # re-bind socket so we maintain event state to be pushed
     socket = push_event(socket, "my_event", %{...})
 
     # or return the modified socket directly:
     def handle_event("some_event", _, socket) do
       {:noreply, push_event(socket, "my_event", %{...})}
     end
 
 Pushed events can then be picked up in a JS hook with `this.handleEvent`:
 
     mounted() {
       this.handleEvent("my_event", data => console.log("from server:", data));
     }
 
 Clients can also push an event to the server and receive a reply with `this.pushEvent`:
 
     mounted() {
       this.el.addEventListener("click", e => {
         this.pushEvent("my_event", { one: 1 }, reply => console.log("got reply from server:", reply));
       })
     }
 
 Where the server handled it via:
 
     def handle_event("my_event", %{"one" => 1}, socket) do
       {:reply, %{two: 2}, socket}
     end
 
 ### LiveView tests
 
 - `Phoenix.LiveViewTest` module and `LazyHTML` (included) for making your assertions
 - Form tests are driven by `Phoenix.LiveViewTest`'s `render_submit/2` and `render_change/2` functions
 - Come up with a step-by-step test plan that splits major test cases into small, isolated files. You may start with simpler tests that verify content exists, gradually add interaction tests
 - **Always reference the key element IDs you added in the LiveView templates in your tests** for `Phoenix.LiveViewTest` functions like `element/2`, `has_element/2`, selectors, etc
 - **Never** tests again raw HTML, **always** use `element/2`, `has_element/2`, and similar: `assert has_element?(view, "#my-form")`
 - Instead of relying on testing text content, which can change, favor testing for the presence of key elements
 - Focus on testing outcomes rather than implementation details
 - Be aware that `Phoenix.Component` functions like `<.form>` might produce different HTML than expected. Test against the output HTML structure, not your mental model of what you expect it to be
 - When facing test failures with element selectors, add debug statements to print the actual HTML, but use `LazyHTML` selectors to limit the output, ie:
 
       html = render(view)
       document = LazyHTML.from_fragment(html)
       matches = LazyHTML.filter(document, "your-complex-selector")
       IO.inspect(matches, label: "Matches")
 
 ### Form handling
 
 #### Creating a form from params
 
 If you want to create a form based on `handle_event` params:
 
     def handle_event("submitted", params, socket) do
       {:noreply, assign(socket, form: to_form(params))}
     end
 
 When you pass a map to `to_form/1`, it assumes said map contains the form params, which are expected to have string keys.
 
 You can also specify a name to nest the params:
 
     def handle_event("submitted", %{"user" => user_params}, socket) do
       {:noreply, assign(socket, form: to_form(user_params, as: :user))}
     end
 
 #### Creating a form from changesets
 
 When using changesets, the underlying data, form params, and errors are retrieved from it. The `:as` option is automatically computed too. E.g. if you have a user schema:
 
     defmodule MyApp.Users.User do
       use Ecto.Schema
       ...
     end
 
 And then you create a changeset that you pass to `to_form`:
 
     %MyApp.Users.User{}
     |> Ecto.Changeset.change()
     |> to_form()
 
 Once the form is submitted, the params will be available under `%{"user" => user_params}`.
 
 In the template, the form form assign can be passed to the `<.form>` function component:
 
     <.form for={@form} id="todo-form" phx-change="validate" phx-submit="save">
       <.input field={@form[:field]} type="text" />
     </.form>
 
 Always give the form an explicit, unique DOM ID, like `id="todo-form"`.
 
 #### Avoiding form errors
 
 **Always** use a form assigned via `to_form/2` in the LiveView, and the `<.input>` component in the template. In the template **always access forms this**:
 
     <%!-- ALWAYS do this (valid) --%>
     <.form for={@form} id="my-form">
       <.input field={@form[:field]} type="text" />
     </.form>
 
 And **never** do this:
 
     <%!-- NEVER do this (invalid) --%>
     <.form for={@changeset} id="my-form">
       <.input field={@changeset[:field]} type="text" />
     </.form>
 
 - You are FORBIDDEN from accessing the changeset in the template as it will cause errors
 - **Never** use `<.form let={f} ...>` in the template, instead **always use `<.form for={@form} ...>`**, then drive all form references from the form assign as in `@form[:field]`. The UI should **always** be driven by a `to_form/2` assigned in the LiveView module that is derived from a changeset
 <!-- phoenix:liveview-end -->
 
 <!-- usage-rules-end -->