test: add full streaming error UI tests with Finch mocking

Add comprehensive tests for streaming error handling:
- Test retry_streaming event handler (passing)
- Test cancel_streaming event handler (passing)
- Test streaming error UI rendering (passing)

Implemented Finch mocking to prevent real SSE connection attempts
during tests. The mock blocks indefinitely allowing simulated errors
to be broadcast without interference from connection failures.

Key changes:
- Added Finch to Mimic.copy in test_helper.exs
- Updated stub_online to mock Finch.stream with global mode
- Used eventually blocks to click buttons while UI is visible
- Tests now fully cover streaming error branches in component.ex

Author: elias-ba

test/lightning_web/live/ai_assistant_live_test.exs

@@ -4,6 +4,7 @@ defmodule LightningWeb.AiAssistantLiveTest do
   import Lightning.Factories
   import Lightning.WorkflowLive.Helpers
   import Mox
+  import Eventually
   use Oban.Testing, repo: Lightning.Repo
   import Phoenix.Component
   import Phoenix.LiveViewTest
@@ -3120,6 +3121,200 @@ defmodule LightningWeb.AiAssistantLiveTest do
       # User should be able to retry
       assert has_element?(view, "[phx-click='retry_message']")
     end
+
+    @tag email: "user@openfn.org"
+    test "users can retry streaming errors", %{
+      conn: conn,
+      project: project,
+      workflow: %{jobs: [job_1 | _]} = workflow,
+      user: user
+    } do
+      Lightning.AiAssistantHelpers.stub_online()
+      skip_disclaimer(user)
+
+      {:ok, view, _html} =
+        live(
+          conn,
+          ~p"/projects/#{project.id}/w/#{workflow.id}?s=#{job_1.id}&m=expand"
+        )
+
+      render_async(view)
+
+      # Create session manually without processing the message
+      {:ok, session} =
+        Lightning.AiAssistant.create_session(job_1, user, "Test query")
+
+      # Subscribe to the session PubSub topic
+      Phoenix.PubSub.subscribe(Lightning.PubSub, "ai_session:#{session.id}")
+
+      # Simulate error WITHOUT waiting for message save
+      Lightning.AiAssistantHelpers.simulate_streaming_error(
+        session.id,
+        "Connection timeout"
+      )
+
+      # Wait for LiveView to receive the error
+      assert_receive {:ai_assistant, :streaming_error, _}, 1000
+
+      render_async(view)
+
+      # Wait for UI and click retry button while it's visible
+      eventually(
+        fn ->
+          if has_element?(view, "[phx-click='retry_streaming']") and
+               has_element?(view, "[phx-click='cancel_streaming']") do
+            # UI is visible, click retry button
+            view
+            |> element("[phx-click='retry_streaming']")
+            |> render_click()
+
+            true
+          else
+            false
+          end
+        end,
+        true,
+        5000,
+        50
+      )
+
+      Lightning.AiAssistantHelpers.simulate_streaming_response(
+        session.id,
+        "Successfully retried"
+      )
+
+      # Wait for streaming to complete
+      assert_receive {:ai_assistant, :streaming_payload_complete, _}, 1000
+
+      # Poll until the response appears in the UI
+      eventually(
+        fn ->
+          render_async(view)
+          html = render(view)
+          html =~ "Successfully retried"
+        end,
+        true,
+        5000,
+        50
+      )
+    end
+
+    @tag email: "user@openfn.org"
+    test "users can cancel streaming errors", %{
+      conn: conn,
+      project: project,
+      workflow: %{jobs: [job_1 | _]} = workflow,
+      user: user
+    } do
+      Lightning.AiAssistantHelpers.stub_online()
+      skip_disclaimer(user)
+
+      {:ok, view, _html} =
+        live(
+          conn,
+          ~p"/projects/#{project.id}/w/#{workflow.id}?s=#{job_1.id}&m=expand"
+        )
+
+      render_async(view)
+
+      # Create session manually without processing the message
+      {:ok, session} =
+        Lightning.AiAssistant.create_session(job_1, user, "Test query")
+
+      # Subscribe to the session PubSub topic
+      Phoenix.PubSub.subscribe(Lightning.PubSub, "ai_session:#{session.id}")
+
+      # Simulate error WITHOUT waiting for message save
+      Lightning.AiAssistantHelpers.simulate_streaming_error(
+        session.id,
+        "Server unavailable"
+      )
+
+      # Wait for LiveView to receive the error
+      assert_receive {:ai_assistant, :streaming_error, _}, 1000
+
+      render_async(view)
+
+      # Wait for UI and click cancel button while it's visible
+      eventually(
+        fn ->
+          if has_element?(view, "[phx-click='cancel_streaming']") do
+            # UI is visible, click cancel button
+            view
+            |> element("[phx-click='cancel_streaming']")
+            |> render_click()
+
+            true
+          else
+            false
+          end
+        end,
+        true,
+        5000,
+        50
+      )
+
+      render_async(view)
+
+      assert has_element?(
+               view,
+               "#ai-assistant-form-job-#{job_1.id}-ai-assistant"
+             )
+    end
+
+    @tag email: "user@openfn.org"
+    test "streaming error UI is rendered correctly", %{
+      conn: conn,
+      project: project,
+      workflow: %{jobs: [job_1 | _]} = workflow,
+      user: user
+    } do
+      Lightning.AiAssistantHelpers.stub_online()
+      skip_disclaimer(user)
+
+      {:ok, view, _html} =
+        live(
+          conn,
+          ~p"/projects/#{project.id}/w/#{workflow.id}?s=#{job_1.id}&m=expand"
+        )
+
+      render_async(view)
+
+      # Create session manually without processing the message
+      {:ok, session} =
+        Lightning.AiAssistant.create_session(job_1, user, "Test query")
+
+      # Subscribe to the session PubSub topic
+      Phoenix.PubSub.subscribe(Lightning.PubSub, "ai_session:#{session.id}")
+
+      # Simulate error WITHOUT waiting for message save
+      Lightning.AiAssistantHelpers.simulate_streaming_error(
+        session.id,
+        "Custom error message"
+      )
+
+      # Wait for LiveView to receive the error
+      assert_receive {:ai_assistant, :streaming_error, _}, 1000
+
+      render_async(view)
+
+      # Check error UI elements are present
+      eventually(
+        fn ->
+          html = render(view)
+
+          html =~ "hero-exclamation-triangle" and
+            html =~ "Custom error message" and
+            html =~ "Retry" and
+            html =~ "Cancel" and
+            html =~ "bg-red-50" and
+            html =~ "text-red-800"
+        end,
+        true,
+        5000,
+        50
+      )
+    end
   end
 
   defp create_project_for_user(%{user: user}) do

test/support/ai_assistant_helpers.ex

@@ -27,7 +27,17 @@ defmodule Lightning.AiAssistantHelpers do
     end)
 
     # Stub Finch to prevent actual SSE connections
-    # SSEStream will spawn, fail immediately, and streaming simulation will take over
+    # This prevents Oban jobs from attempting real HTTP requests during tests
+    # Use :global mode so stub works in spawned Oban worker processes
+    Mimic.set_mimic_global()
+
+    Mimic.stub(Finch, :stream, fn _request, _finch_name, _acc, _fun ->
+      # Block indefinitely - the stream is "in progress" but never completes
+      # This allows simulated errors to be broadcast without interference
+      Process.sleep(:infinity)
+      {:ok, %{status: 200}}
+    end)
+
     :ok
   end
 

test/test_helper.exs

@@ -9,6 +9,7 @@ Mox.defmock(Lightning.Tesla.Mock, for: Tesla.Adapter)
 
 Mimic.copy(:hackney)
 Mimic.copy(File)
+Mimic.copy(Finch)
 Mimic.copy(IO)
 Mimic.copy(Lightning.FailureEmail)
 Mimic.copy(Mix.Tasks.Lightning.InstallSchemas)