Expose info about existence of prev/next page

lib/trento_web/openapi/v1/schema/activity_log.ex

@@ -6,37 +6,95 @@ defmodule TrentoWeb.OpenApi.V1.Schema.ActivityLog do
 
   defmodule ActivityLogEntries do
     @moduledoc false
-    OpenApiSpex.schema(%{
-      type: :array,
-      items: %Schema{
-        title: "ActivityLogEntries",
-        type: :object,
+    OpenApiSpex.schema(
+      %{
+        type: :array,
+        items: %Schema{
+          title: "ActivityLogEntries",
+          type: :object,
+          additionalProperties: false,
+          properties: %{
+            id: %Schema{
+              type: :string,
+              format: :uuid,
+              description: "UUID (v4) of Activity Log entry."
+            },
+            type: %Schema{
+              type: :string,
+              description: "Type of Activity Log entry."
+            },
+            actor: %Schema{
+              type: :string,
+              description: "Actor causing an Activity Log entry. E.g. System or a specific user."
+            },
+            metadata: %Schema{
+              type: :object
+            },
+            occurred_on: %Schema{
+              type: :string,
+              description: "Timestamp upon Activity Log entry insertion."
+            }
+          },
+          required: [:id, :type, :actor, :metadata, :occurred_on]
+        }
+      },
+      struct?: false
+    )
+  end
+
+  defmodule Pagination do
+    @moduledoc false
+    OpenApiSpex.schema(
+      %{
+        title: "Pagination",
+        description: "Pagination metadata for the current list.",
         additionalProperties: false,
+        type: :object,
         properties: %{
-          id: %Schema{
+          start_cursor: %Schema{
             type: :string,
-            format: :uuid,
-            description: "UUID (v4) of Activity Log entry."
+            description: "Cursor pointing to the start of the list.",
+            nullable: true
           },
-          type: %Schema{
+          end_cursor: %Schema{
             type: :string,
-            description: "Type of Activity Log entry."
+            description: "Cursor pointing to the end of the list.",
+            nullable: true
           },
-          actor: %Schema{
-            type: :string,
-            description: "Actor causing an Activity Log entry. E.g. System or a specific user."
+          has_next_page: %Schema{
+            type: :boolean,
+            description: "Flag indicating if there are more pages after the current one.",
+            nullable: false
           },
-          metadata: %Schema{
-            type: :object
+          has_previous_page: %Schema{
+            type: :boolean,
+            description: "Flag indicating if there are more pages before the current one.",
+            nullable: false
           },
-          occurred_on: %Schema{
-            type: :string,
-            description: "Timestamp upon Activity Log entry insertion."
+          first: %Schema{
+            type: :integer,
+            description:
+              "Number of elements requested from the beginning of the list (forward navigation).",
+            nullable: true
+          },
+          last: %Schema{
+            type: :integer,
+            description:
+              "Number of elements requested from the end of the list (backward navigation).",
+            nullable: true
           }
         },
-        required: [:id, :type, :actor, :metadata, :occurred_on]
-      }
-    })
+        required: [
+          :start_cursor,
+          :end_cursor,
+          :has_next_page,
+          :has_previous_page,
+          :first,
+          :last
+        ]
+      },
+      struct?: false
+    )
   end
 
   defmodule ActivityLog do
@@ -49,9 +107,7 @@ defmodule TrentoWeb.OpenApi.V1.Schema.ActivityLog do
         type: :object,
         properties: %{
           data: ActivityLogEntries,
-          pagination: %Schema{
-            type: :object
-          }
+          pagination: Pagination
         },
         required: [:data, :pagination]
       },

lib/trento_web/views/v1/activity_log_view.ex

@@ -23,6 +23,8 @@ defmodule TrentoWeb.V1.ActivityLogView do
     %{
       end_cursor: end_cursor,
       start_cursor: start_cursor,
+      has_next_page?: has_next_page,
+      has_previous_page?: has_previous_page,
       flop: %{
         first: first,
         last: last
@@ -34,7 +36,9 @@ defmodule TrentoWeb.V1.ActivityLogView do
       start_cursor: start_cursor,
       end_cursor: end_cursor,
       first: first,
-      last: last
+      last: last,
+      has_next_page: has_next_page,
+      has_previous_page: has_previous_page
     }
   end
 end

test/trento/activity_log_test.exs

@@ -295,5 +295,36 @@ defmodule Trento.ActivityLogTest do
       assert length(next_logs_alt) == length(next_logs)
       assert next_logs_alt == next_logs
     end
+
+    test "should expose information about the existence of previous or next page to navigate to" do
+      insert_list(100, :activity_log_entry)
+
+      assert {:ok, _,
+              %{has_previous_page?: false, has_next_page?: true, start_cursor: start_cursor}} =
+               ActivityLog.list_activity_log(%{first: 5})
+
+      assert {:ok, [],
+              %{
+                end_cursor: nil,
+                start_cursor: nil
+              }} =
+               ActivityLog.list_activity_log(%{last: 5, before: start_cursor})
+
+      assert {:ok, _, %{has_previous_page?: true, has_next_page?: true}} =
+               ActivityLog.list_activity_log(%{first: 5, after: start_cursor})
+
+      assert {:ok, _, %{has_previous_page?: true, has_next_page?: false, end_cursor: end_cursor}} =
+               ActivityLog.list_activity_log(%{last: 5})
+
+      assert {:ok, [],
+              %{
+                end_cursor: nil,
+                start_cursor: nil
+              }} =
+               ActivityLog.list_activity_log(%{first: 5, after: end_cursor})
+
+      assert {:ok, _, %{has_previous_page?: true, has_next_page?: true}} =
+               ActivityLog.list_activity_log(%{last: 5, before: end_cursor})
+    end
   end
 end