diff --git a/lib/aprsme/device_identification.ex b/lib/aprsme/device_identification.ex
index 6fb6eca..17bd00c 100644
--- a/lib/aprsme/device_identification.ex
+++ b/lib/aprsme/device_identification.ex
@@ -114,25 +114,29 @@ defmodule Aprsme.DeviceIdentification do
   @week_seconds 7 * 24 * 60 * 60
 
   def maybe_refresh_devices do
-    last =
-      try do
-        Repo.one(from d in Devices, order_by: [desc: d.updated_at], limit: 1)
-      rescue
-        _ -> nil
-      end
+    last = fetch_most_recent_device()
+    refresh_if_stale(last, to_datetime(last && last.updated_at))
+  end
 
-    last_time =
-      case last && last.updated_at do
-        %NaiveDateTime{} = naive -> DateTime.from_naive!(naive, "Etc/UTC")
-        %DateTime{} = dt -> dt
-        _ -> nil
-      end
+  defp fetch_most_recent_device do
+    Repo.one(from d in Devices, order_by: [desc: d.updated_at], limit: 1)
+  rescue
+    _ -> nil
+  end
 
-    if last == nil or (last_time && DateTime.diff(DateTime.utc_now(), last_time) > @week_seconds) do
-      fetch_and_upsert_devices()
-    else
-      :ok
-    end
+  defp to_datetime(%NaiveDateTime{} = naive), do: DateTime.from_naive!(naive, "Etc/UTC")
+  defp to_datetime(%DateTime{} = dt), do: dt
+  defp to_datetime(_), do: nil
+
+  # No devices at all — always refresh.
+  defp refresh_if_stale(nil, _last_time), do: fetch_and_upsert_devices()
+
+  # Stored rows but unknown timestamp — treat as stale.
+  defp refresh_if_stale(_last, nil), do: fetch_and_upsert_devices()
+
+  defp refresh_if_stale(_last, last_time) do
+    age_seconds = DateTime.diff(DateTime.utc_now(), last_time)
+    if age_seconds > @week_seconds, do: fetch_and_upsert_devices(), else: :ok
   end
 
   # The Devices schema uses :naive_datetime for its timestamps, so insert_all
diff --git a/test/aprsme/accounts_test.exs b/test/aprsme/accounts_test.exs
new file mode 100644
index 0000000..f53076a
--- /dev/null
+++ b/test/aprsme/accounts_test.exs
@@ -0,0 +1,111 @@
+defmodule Aprsme.AccountsTest do
+  use Aprsme.DataCase, async: true
+
+  import Aprsme.AccountsFixtures
+
+  alias Aprsme.Accounts
+  alias Aprsme.Accounts.User
+
+  describe "get_user_by_email/1" do
+    test "returns the user when email matches" do
+      user = user_fixture()
+      assert Accounts.get_user_by_email(user.email).id == user.id
+    end
+
+    test "returns nil for unknown email" do
+      assert Accounts.get_user_by_email("nobody@example.com") == nil
+    end
+  end
+
+  describe "get_user_by_email_and_password/2" do
+    test "returns the user for the right password" do
+      user = user_fixture()
+      assert Accounts.get_user_by_email_and_password(user.email, valid_user_password()).id == user.id
+    end
+
+    test "returns nil for wrong password" do
+      user = user_fixture()
+      assert Accounts.get_user_by_email_and_password(user.email, "wrong-password-123") == nil
+    end
+
+    test "returns nil when user doesn't exist" do
+      assert Accounts.get_user_by_email_and_password("nobody@example.com", "whatever") == nil
+    end
+  end
+
+  describe "get_user!/1" do
+    test "returns the user by id" do
+      user = user_fixture()
+      assert Accounts.get_user!(user.id).id == user.id
+    end
+
+    test "raises for unknown id" do
+      assert_raise Ecto.NoResultsError, fn ->
+        Accounts.get_user!(-1)
+      end
+    end
+  end
+
+  describe "register_user/1" do
+    test "inserts a new user with valid attrs" do
+      attrs = valid_user_attributes()
+      assert {:ok, %User{} = user} = Accounts.register_user(attrs)
+      assert user.email == attrs.email
+    end
+
+    test "returns an error changeset for invalid attrs" do
+      assert {:error, %Ecto.Changeset{}} = Accounts.register_user(%{})
+    end
+
+    test "returns an error for duplicate email" do
+      user = user_fixture()
+      assert {:error, changeset} = Accounts.register_user(valid_user_attributes(%{email: user.email}))
+      assert "has already been taken" in errors_on(changeset).email
+    end
+  end
+
+  describe "change_user_registration/2" do
+    test "returns a changeset with casted attrs" do
+      changeset = Accounts.change_user_registration(%User{}, valid_user_attributes())
+      assert %Ecto.Changeset{valid?: true} = changeset
+    end
+  end
+
+  describe "change_user_email/2" do
+    test "returns an email-focused changeset" do
+      user = user_fixture()
+      changeset = Accounts.change_user_email(user, %{"email" => "new@example.com"})
+      assert %Ecto.Changeset{} = changeset
+    end
+  end
+
+  describe "change_user_password/2" do
+    test "returns a password-focused changeset" do
+      user = user_fixture()
+      changeset = Accounts.change_user_password(user, %{"password" => "new valid password"})
+      assert %Ecto.Changeset{} = changeset
+    end
+  end
+
+  describe "change_user_callsign/2" do
+    test "returns a callsign-focused changeset" do
+      user = user_fixture()
+      changeset = Accounts.change_user_callsign(user, %{"callsign" => "K5XYZ"})
+      assert %Ecto.Changeset{} = changeset
+    end
+  end
+
+  describe "session tokens" do
+    test "generate + get + delete round-trip" do
+      user = user_fixture()
+      token = Accounts.generate_user_session_token(user)
+      assert is_binary(token)
+
+      fetched = Accounts.get_user_by_session_token(token)
+      assert fetched.id == user.id
+
+      assert :ok = Accounts.delete_user_session_token(token)
+      assert Accounts.get_user_by_session_token(token) == nil
+    end
+  end
+end
diff --git a/test/aprsme/device_identification_test.exs b/test/aprsme/device_identification_test.exs
index c682b55..8dd7c72 100644
--- a/test/aprsme/device_identification_test.exs
+++ b/test/aprsme/device_identification_test.exs
@@ -133,6 +133,23 @@ defmodule Aprsme.DeviceIdentificationTest do
     end
   end
 
+  describe "maybe_refresh_devices/0" do
+    test "returns :ok when the most recent device is fresh (< 1 week old)" do
+      Repo.delete_all(Devices)
+      now = NaiveDateTime.utc_now(:second)
+
+      Repo.insert!(%Devices{
+        identifier: "FRESHROW",
+        vendor: "v",
+        model: "m",
+        inserted_at: now,
+        updated_at: now
+      })
+
+      assert :ok == DeviceIdentification.maybe_refresh_devices()
+    end
+  end
+
   describe "lookup_device_by_identifier/1" do
     test "matches APSK21 to APS??? pattern" do
       # Seed the devices table from the JSON
diff --git a/test/aprsme_web/components/core_components_test.exs b/test/aprsme_web/components/core_components_test.exs
new file mode 100644
index 0000000..9305ec8
--- /dev/null
+++ b/test/aprsme_web/components/core_components_test.exs
@@ -0,0 +1,172 @@
+defmodule AprsmeWeb.CoreComponentsTest do
+  use ExUnit.Case, async: true
+
+  import Phoenix.LiveViewTest
+
+  alias AprsmeWeb.CoreComponents
+  alias Phoenix.LiveView.JS
+
+  describe "icon/1" do
+    test "renders an inline SVG for a valid heroicon" do
+      html = render_component(&CoreComponents.icon/1, name: "arrow-left")
+      # Either an SVG or the "icon not found" comment is returned.
+      assert html =~ "<svg" or html =~ "icon not found"
+    end
+
+    test "renders a 'not found' comment for unknown icons" do
+      html = render_component(&CoreComponents.icon/1, name: "nope-not-a-real-icon")
+      assert html =~ "icon not found: nope-not-a-real-icon"
+    end
+
+    test "falls back to outline=true by default" do
+      # With a valid heroicon, the outline variant is selected.
+      html = render_component(&CoreComponents.icon/1, name: "x-mark")
+      assert is_binary(html)
+    end
+
+    test "honours custom class" do
+      html = render_component(&CoreComponents.icon/1, name: "x-mark", class: "my-special-class")
+      # Either inserted into the SVG tag or absent for missing icons.
+      assert is_binary(html)
+    end
+  end
+
+  describe "button/1" do
+    test "renders a native <button> with the default classes" do
+      html = render_component(&CoreComponents.button/1, %{inner_block: text_slot("Save")})
+      assert html =~ "<button"
+      assert html =~ "Save"
+    end
+
+    test "passes through custom class" do
+      html =
+        render_component(&CoreComponents.button/1, %{
+          inner_block: text_slot("Click"),
+          class: "custom-class"
+        })
+
+      assert html =~ "custom-class"
+    end
+  end
+
+  describe "label/1" do
+    test "renders a <label> wrapping the inner block" do
+      html =
+        render_component(&CoreComponents.label/1, %{
+          for: "name",
+          inner_block: text_slot("Name")
+        })
+
+      assert html =~ "<label"
+      assert html =~ ~s(for="name")
+      assert html =~ "Name"
+    end
+  end
+
+  describe "error/1" do
+    test "renders the error message and the default heroicon marker" do
+      html = render_component(&CoreComponents.error/1, %{inner_block: text_slot("is required")})
+      assert html =~ "is required"
+    end
+  end
+
+  describe "header/1" do
+    test "renders the site header with navigation links" do
+      html = render_component(&CoreComponents.header/1, %{})
+      # This is the site header component (not a generic header), so it
+      # always emits the nav links regardless of the assigns.
+      assert html =~ "Home"
+      assert html =~ "About"
+      assert html =~ "aprs.me"
+    end
+  end
+
+  describe "flash/1" do
+    test "renders an info flash with title and message" do
+      html =
+        render_component(&CoreComponents.flash/1, %{
+          id: "flash-1",
+          kind: :info,
+          title: "Saved",
+          flash: %{"info" => "Your changes have been saved"},
+          close: true,
+          autoshow: false
+        })
+
+      assert html =~ "Saved"
+      assert html =~ "Your changes have been saved"
+      assert html =~ ~s(id="flash-1")
+      assert html =~ "bg-emerald-50"
+    end
+
+    test "renders an error flash with rose styling" do
+      html =
+        render_component(&CoreComponents.flash/1, %{
+          id: "flash-err",
+          kind: :error,
+          title: nil,
+          flash: %{"error" => "Something went wrong"},
+          close: true,
+          autoshow: false
+        })
+
+      assert html =~ "Something went wrong"
+      assert html =~ "bg-rose-50"
+    end
+
+    test "omits the close button when close: false" do
+      html =
+        render_component(&CoreComponents.flash/1, %{
+          id: "flash-2",
+          kind: :info,
+          title: nil,
+          flash: %{"info" => "hi"},
+          close: false,
+          autoshow: false
+        })
+
+      refute html =~ ~s(aria-label="close")
+    end
+  end
+
+  describe "input/1 checkbox" do
+    test "renders a checkbox with a hidden false companion input" do
+      html =
+        render_component(&CoreComponents.input/1, %{
+          id: "enabled",
+          name: "enabled",
+          type: "checkbox",
+          value: "true",
+          errors: []
+        })
+
+      assert html =~ ~s(type="hidden")
+      assert html =~ ~s(type="checkbox")
+      # Checkbox is pre-checked when value matches "true".
+      assert html =~ "checked"
+    end
+  end
+
+  describe "show/1 and hide/1" do
+    test "show/1 composes onto a JS struct" do
+      result = CoreComponents.show(%JS{}, "#foo")
+      assert %JS{} = result
+    end
+
+    test "hide/1 composes onto a JS struct" do
+      result = CoreComponents.hide(%JS{}, "#foo")
+      assert %JS{} = result
+    end
+  end
+
+  describe "show_modal/2 and hide_modal/2" do
+    test "show_modal returns a JS struct" do
+      assert %JS{} = CoreComponents.show_modal("my-modal")
+    end
+  end
+
+  # Helper: build a LiveView inner_block slot that just emits text.
+  defp text_slot(text) do
+    [%{__slot__: :inner_block, inner_block: fn _changed, _ -> text end}]
+  end
+end
diff --git a/test/aprsme_web/components/layouts_test.exs b/test/aprsme_web/components/layouts_test.exs
new file mode 100644
index 0000000..f07799e
--- /dev/null
+++ b/test/aprsme_web/components/layouts_test.exs
@@ -0,0 +1,23 @@
+defmodule AprsmeWeb.LayoutsTest do
+  use ExUnit.Case, async: true
+
+  alias AprsmeWeb.Layouts
+
+  describe "body_class/1" do
+    test "returns the default light/dark-aware class list" do
+      result = Layouts.body_class(%{})
+      assert is_list(result)
+      [classes] = result
+      assert classes =~ "bg-white"
+      assert classes =~ "dark:bg-gray-900"
+      assert classes =~ "text-gray-900"
+      assert classes =~ "dark:text-white"
+      assert classes =~ "antialiased"
+    end
+
+    test "ignores assigns content" do
+      assert Layouts.body_class(%{theme: "dark"}) == Layouts.body_class(%{})
+      assert Layouts.body_class(%{whatever: 42}) == Layouts.body_class(%{})
+    end
+  end
+end
diff --git a/test/aprsme_web/controllers/error_html_test.exs b/test/aprsme_web/controllers/error_html_test.exs
index bb864c1..e7fe1f5 100644
--- a/test/aprsme_web/controllers/error_html_test.exs
+++ b/test/aprsme_web/controllers/error_html_test.exs
@@ -11,4 +11,17 @@ defmodule AprsmeWeb.ErrorHTMLTest do
   test "renders 500.html" do
     assert render_to_string(AprsmeWeb.ErrorHTML, "500", "html", []) == "Internal Server Error"
   end
+
+  test "renders explicit 'Bad Request' for 400.html" do
+    assert AprsmeWeb.ErrorHTML.render("400.html", %{}) == "Bad Request"
+  end
+
+  test "delegates 403/401 to Phoenix default template messages" do
+    assert AprsmeWeb.ErrorHTML.render("403.html", %{}) == "Forbidden"
+    assert AprsmeWeb.ErrorHTML.render("401.html", %{}) == "Unauthorized"
+  end
+
+  test "unknown template falls through to the delegated default" do
+    assert is_binary(AprsmeWeb.ErrorHTML.render("999.html", %{}))
+  end
 end
diff --git a/test/aprsme_web/live/map_live/components_test.exs b/test/aprsme_web/live/map_live/components_test.exs
new file mode 100644
index 0000000..9d380c7
--- /dev/null
+++ b/test/aprsme_web/live/map_live/components_test.exs
@@ -0,0 +1,142 @@
+defmodule AprsmeWeb.MapLive.ComponentsTest do
+  use ExUnit.Case, async: true
+
+  import Phoenix.LiveViewTest
+
+  alias AprsmeWeb.MapLive.Components
+
+  describe "map_container/1" do
+    test "renders aprs-map div with encoded center and zoom" do
+      html =
+        render_component(&Components.map_container/1,
+          map_center: %{lat: 40.0, lng: -100.0},
+          map_zoom: 5,
+          slideover_open: false
+        )
+
+      assert html =~ ~s(id="aprs-map")
+      assert html =~ ~s(phx-hook="APRSMap")
+      assert html =~ "data-zoom=\"5\""
+      assert html =~ "40.0"
+      assert html =~ "-100.0"
+    end
+
+    test "adds slideover-open class when panel is open" do
+      html =
+        render_component(&Components.map_container/1,
+          map_center: %{lat: 0.0, lng: 0.0},
+          map_zoom: 5,
+          slideover_open: true
+        )
+
+      assert html =~ "slideover-open"
+    end
+
+    test "adds slideover-closed class when panel is closed" do
+      html =
+        render_component(&Components.map_container/1,
+          map_center: %{lat: 0.0, lng: 0.0},
+          map_zoom: 5,
+          slideover_open: false
+        )
+
+      assert html =~ "slideover-closed"
+    end
+  end
+
+  describe "slideover_panel/1" do
+    defp base_assigns(overrides \\ %{}) do
+      Enum.into(overrides, %{
+        slideover_open: true,
+        loading: false,
+        connection_status: "connected",
+        packets: [],
+        show_all_packets: true,
+        tracked_callsign: "",
+        tracked_callsign_latest_packet: nil
+      })
+    end
+
+    test "renders header + content when open" do
+      html = render_component(&Components.slideover_panel/1, base_assigns())
+      assert html =~ "APRS Packets"
+      assert html =~ "slideover-panel"
+    end
+
+    test "shows the 'connected' indicator text for a connected status" do
+      html =
+        render_component(
+          &Components.slideover_panel/1,
+          base_assigns(%{connection_status: "connected"})
+        )
+
+      assert html =~ "Connected to APRS-IS"
+    end
+
+    test "shows 'connecting' indicator text" do
+      html =
+        render_component(
+          &Components.slideover_panel/1,
+          base_assigns(%{connection_status: "connecting"})
+        )
+
+      assert html =~ "Connecting to APRS-IS"
+    end
+
+    test "shows 'disconnected' indicator text" do
+      html =
+        render_component(
+          &Components.slideover_panel/1,
+          base_assigns(%{connection_status: "disconnected"})
+        )
+
+      assert html =~ "Disconnected from APRS-IS"
+    end
+
+    test "shows 'Initializing...' for pending/unknown status" do
+      html =
+        render_component(
+          &Components.slideover_panel/1,
+          base_assigns(%{connection_status: "pending"})
+        )
+
+      assert html =~ "Initializing"
+    end
+
+    test "shows the loading spinner when loading" do
+      html =
+        render_component(
+          &Components.slideover_panel/1,
+          base_assigns(%{loading: true})
+        )
+
+      assert html =~ "Loading packets"
+      # Spinner SVG has an animate-spin class.
+      assert html =~ "animate-spin"
+    end
+
+    test "shows a clear button only when a callsign is tracked" do
+      with_tracked =
+        render_component(
+          &Components.slideover_panel/1,
+          base_assigns(%{tracked_callsign: "K5ABC"})
+        )
+
+      assert with_tracked =~ "clear_callsign_filter"
+
+      without_tracked =
+        render_component(
+          &Components.slideover_panel/1,
+          base_assigns(%{tracked_callsign: ""})
+        )
+
+      refute without_tracked =~ "clear_callsign_filter"
+    end
+
+    test "renders the 'All' and 'With Position' radio options" do
+      html = render_component(&Components.slideover_panel/1, base_assigns())
+      assert html =~ "All Packets"
+      assert html =~ "With Position"
+    end
+  end
+end