feat(build-from-scratch): create webhook workflow from landing screen

Adds the "Build from scratch" entry point on the new-workflow landing
screen: Workflows.create_webhook_workflow/2 builds a workflow with a
webhook trigger, one job, and an always-on edge; the build_from_scratch
LiveView event authorizes via the role-scoped ProjectUsers
:create_workflow check so viewers can't trigger it.

Author: lmac-1

assets/js/collaborative-editor/CollaborativeEditor.tsx

@@ -18,7 +18,10 @@ import { VersionDropdown } from './components/VersionDropdown';
 import { WorkflowEditor } from './components/WorkflowEditor';
 import { YAMLImportModal } from './components/YAMLImportModal';
 import { CredentialModalProvider } from './contexts/CredentialModalContext';
-import { LiveViewActionsProvider } from './contexts/LiveViewActionsContext';
+import {
+  LiveViewActionsProvider,
+  useLiveViewActions,
+} from './contexts/LiveViewActionsContext';
 import { MonacoRefProvider } from './contexts/MonacoRefContext';
 import { SessionProvider } from './contexts/SessionProvider';
 import { StoreProvider } from './contexts/StoreProvider';
@@ -185,6 +188,7 @@ function LandingScreenWrapper({
   const showLandingScreen = useShowLandingScreen();
   const { openYAMLImportModal, dismissLandingScreen, openAIAssistantPanel } =
     useUICommands();
+  const { pushEvent } = useLiveViewActions();
 
   if (!showLandingScreen) return null;
 
@@ -196,7 +200,7 @@ function LandingScreenWrapper({
           dismissLandingScreen();
           openAIAssistantPanel(prompt);
         }}
-        onBuildFromScratch={() => {}}
+        onBuildFromScratch={() => pushEvent('build_from_scratch', {})}
         onBrowseTemplates={() => {}}
         onImportYAML={openYAMLImportModal}
       />

lib/lightning/workflows.ex

@@ -203,6 +203,48 @@ defmodule Lightning.Workflows do
     |> save_workflow(actor, opts)
   end
 
+  @doc """
+  Creates a new workflow with a webhook trigger, one job, and one always-on edge.
+  Used by the "Build from Scratch" entry point on the new workflow screen.
+  Returns `{:ok, workflow, trigger_id}` or `{:error, changeset}`.
+  """
+  @spec create_webhook_workflow(String.t(), struct()) ::
+          {:ok, Workflow.t(), String.t()} | {:error, Ecto.Changeset.t()}
+  def create_webhook_workflow(project_id, actor) do
+    trigger_id = Ecto.UUID.generate()
+    job_id = Ecto.UUID.generate()
+
+    attrs = %{
+      name: "New Workflow",
+      project_id: project_id,
+      triggers: [%{id: trigger_id, type: :webhook, enabled: true}],
+      jobs: [
+        %{
+          id: job_id,
+          name: "Transform Data",
+          adaptor: "@openfn/language-common@latest",
+          body: """
+          // Check out the Job Writing Guide for help getting started:
+          // https://docs.openfn.org/documentation/jobs/job-writing-guide
+          """
+        }
+      ],
+      edges: [
+        %{
+          source_trigger_id: trigger_id,
+          target_job_id: job_id,
+          condition_type: :always,
+          enabled: true
+        }
+      ]
+    }
+
+    case save_workflow(attrs, actor) do
+      {:ok, workflow} -> {:ok, workflow, trigger_id}
+      {:error, changeset} -> {:error, changeset}
+    end
+  end
+
   # Builds the Ecto.Multi pipeline for save_workflow. Does NOT call
   # Repo.transaction — that stays in the try/rescue block of the caller so
   # rescue wraps only the transaction, not this builder.

lib/lightning_web/live/workflow_live/collaborate.ex

@@ -12,6 +12,7 @@ defmodule LightningWeb.WorkflowLive.Collaborate do
 
   alias Lightning.AiAssistant
   alias Lightning.Policies.Permissions
+  alias Lightning.Policies.ProjectUsers
   alias Lightning.Projects
   alias Lightning.Projects.Project
   alias Lightning.Workflows
@@ -178,6 +179,38 @@ defmodule LightningWeb.WorkflowLive.Collaborate do
      )}
   end
 
+  def handle_event("build_from_scratch", _params, socket) do
+    with :ok <-
+           Permissions.can(
+             ProjectUsers,
+             :create_workflow,
+             socket.assigns.current_user,
+             socket.assigns.project
+           ),
+         {:ok, workflow, trigger_id} <-
+           Workflows.create_webhook_workflow(
+             socket.assigns.project.id,
+             socket.assigns.current_user
+           ) do
+      {:noreply,
+       push_navigate(socket,
+         to:
+           ~p"/projects/#{socket.assigns.project}/w/#{workflow}?#{%{trigger: trigger_id}}"
+       )}
+    else
+      {:error, :unauthorized} ->
+        {:noreply,
+         put_flash(
+           socket,
+           :error,
+           "You don't have permission to create workflows"
+         )}
+
+      {:error, _changeset} ->
+        {:noreply, put_flash(socket, :error, "Failed to create workflow")}
+    end
+  end
+
   @impl true
   def render(assigns) do
     ~H"""

test/lightning/workflows_test.exs

@@ -932,6 +932,57 @@ defmodule Lightning.WorkflowsTest do
     end
   end
 
+  describe "create_webhook_workflow/2" do
+    test "creates a workflow with a webhook trigger, a job, and an always edge" do
+      project = insert(:project)
+      user = insert(:user)
+
+      assert {:ok, workflow, trigger_id} =
+               Workflows.create_webhook_workflow(project.id, user)
+
+      workflow =
+        Repo.preload(workflow, [:triggers, :jobs, :edges])
+
+      assert workflow.name == "New Workflow"
+      assert workflow.project_id == project.id
+
+      assert [%Trigger{id: ^trigger_id, type: :webhook, enabled: true}] =
+               workflow.triggers
+
+      assert [
+               %{
+                 name: "Transform Data",
+                 adaptor: "@openfn/language-common@latest",
+                 body: body
+               }
+             ] = workflow.jobs
+
+      assert body =~ "Job Writing Guide"
+
+      [job] = workflow.jobs
+
+      assert [
+               %{
+                 source_trigger_id: ^trigger_id,
+                 target_job_id: job_id,
+                 condition_type: :always,
+                 enabled: true
+               }
+             ] = workflow.edges
+
+      assert job_id == job.id
+    end
+
+    test "returns {:error, changeset} for an invalid project_id" do
+      user = insert(:user)
+
+      assert {:error, %Ecto.Changeset{} = changeset} =
+               Workflows.create_webhook_workflow(Ecto.UUID.generate(), user)
+
+      assert %{project: ["does not exist"]} = errors_on(changeset)
+    end
+  end
+
   describe "save_workflow/3 rescue" do
     setup do
       Mimic.copy(Lightning.WorkflowVersions)

test/lightning_web/live/workflow_live/collaborate_test.exs

@@ -1,6 +1,7 @@
 defmodule LightningWeb.WorkflowLive.CollaborateTest do
   use LightningWeb.ConnCase, async: false
 
+  import Ecto.Query
   import Lightning.Factories
   import Lightning.WorkflowsFixtures
   import Phoenix.LiveViewTest
@@ -2723,4 +2724,118 @@ defmodule LightningWeb.WorkflowLive.CollaborateTest do
       assert html =~ "collaborative-editor-react"
     end
   end
+
+  describe "build_from_scratch event" do
+    test "creates a webhook workflow and navigates to it with the trigger param",
+         %{conn: conn} do
+      user = insert(:user)
+
+      project =
+        insert(:project,
+          project_users: [%{user_id: user.id, role: :owner}]
+        )
+
+      workflow = workflow_fixture(project_id: project.id)
+
+      conn = log_in_user(conn, user)
+
+      {:ok, view, _html} =
+        live(
+          conn,
+          ~p"/projects/#{project.id}/w/#{workflow.id}"
+        )
+
+      view
+      |> element("#collaborative-editor-react")
+      |> render_hook("build_from_scratch", %{})
+
+      {path, _flash} = assert_redirect(view)
+
+      assert %{"trigger" => trigger_id} =
+               URI.decode_query(URI.parse(path).query)
+
+      assert path =~ ~r{^/projects/#{project.id}/w/[0-9a-f-]+\?}
+
+      new_workflow_id =
+        path
+        |> String.split("/w/")
+        |> List.last()
+        |> String.split("?")
+        |> List.first()
+
+      new_workflow =
+        Lightning.Workflows.get_workflow!(new_workflow_id)
+        |> Lightning.Repo.preload(:triggers)
+
+      assert new_workflow.project_id == project.id
+      assert [%{id: ^trigger_id, type: :webhook}] = new_workflow.triggers
+    end
+
+    test "user without project access gets a flash error", %{conn: conn} do
+      user = insert(:user)
+
+      project =
+        insert(:project,
+          project_users: [%{user_id: user.id, role: :owner}]
+        )
+
+      workflow = workflow_fixture(project_id: project.id)
+
+      conn = log_in_user(conn, user)
+
+      {:ok, view, _html} =
+        live(
+          conn,
+          ~p"/projects/#{project.id}/w/#{workflow.id}"
+        )
+
+      # Revoke the user's membership after mount (e.g. removed from the
+      # project mid-session) so the LiveView's cached `project`/`current_user`
+      # assigns remain, but Bodyguard's live authorization check now fails.
+      Lightning.Repo.delete_all(
+        from(pu in Lightning.Projects.ProjectUser,
+          where: pu.project_id == ^project.id and pu.user_id == ^user.id
+        )
+      )
+
+      view
+      |> element("#collaborative-editor-react")
+      |> render_hook("build_from_scratch", %{})
+
+      assert %{"error" => "You don't have permission to create workflows"} =
+               :sys.get_state(view.pid).socket.assigns.flash
+    end
+
+    test "viewer gets a flash error and no workflow is created", %{conn: conn} do
+      user = insert(:user)
+
+      project =
+        insert(:project,
+          project_users: [%{user_id: user.id, role: :viewer}]
+        )
+
+      workflow = workflow_fixture(project_id: project.id)
+
+      conn = log_in_user(conn, user)
+
+      {:ok, view, _html} =
+        live(
+          conn,
+          ~p"/projects/#{project.id}/w/#{workflow.id}"
+        )
+
+      workflow_count_before =
+        Lightning.Repo.aggregate(Lightning.Workflows.Workflow, :count)
+
+      view
+      |> element("#collaborative-editor-react")
+      |> render_hook("build_from_scratch", %{})
+
+      assert %{"error" => "You don't have permission to create workflows"} =
+               :sys.get_state(view.pid).socket.assigns.flash
+
+      assert Lightning.Repo.aggregate(Lightning.Workflows.Workflow, :count) ==
+               workflow_count_before
+    end
+  end
 end