refactor(flow): distribute createActionStep logic to different methods in model

packages/backend/src/controllers/api/v1/flows/create-step.js

@@ -6,7 +6,7 @@ export default async (request, response) => {
     .findById(request.params.flowId)
     .throwIfNotFound();
 
-  const createdActionStep = await flow.createActionStep(
+  const createdActionStep = await flow.createActionStepAfterStepId(
     request.body.previousStepId
   );
 

packages/backend/src/models/flow.js

@@ -151,27 +151,44 @@ class Flow extends Base {
     });
   }
 
-  async createActionStep(previousStepId) {
-    const previousStep = await this.$relatedQuery('steps')
-      .findById(previousStepId)
-      .throwIfNotFound();
+  async getStepById(stepId) {
+    return await this.$relatedQuery('steps').findById(stepId).throwIfNotFound();
+  }
 
-    const createdStep = await this.$relatedQuery('steps').insertAndFetch({
+  async insertActionStepAtPosition(position) {
+    return await this.$relatedQuery('steps').insertAndFetch({
       type: 'action',
-      position: previousStep.position + 1,
+      position,
     });
+  }
 
-    const nextSteps = await this.$relatedQuery('steps')
-      .where('position', '>=', createdStep.position)
-      .whereNot('id', createdStep.id);
+  async getStepsAfterPosition(position) {
+    return await this.$relatedQuery('steps').where('position', '>', position);
+  }
 
-    const nextStepQueries = nextSteps.map(async (nextStep, index) => {
-      return await nextStep.$query().patchAndFetch({
-        position: createdStep.position + index + 1,
+  async alignStepsPositionsAsOfPosition(steps, startPosition) {
+    const nextStepQueries = steps.map(async (nextStep, index) => {
+      return await nextStep.$query().patch({
+        position: startPosition + index,
       });
     });
 
-    await Promise.all(nextStepQueries);
+    return await Promise.all(nextStepQueries);
+  }
+
+  async createActionStepAfterStepId(previousStepId) {
+    const previousStep = await this.getStepById(previousStepId);
+
+    const nextSteps = await this.getStepsAfterPosition(previousStep.position);
+
+    const createdStep = await this.insertActionStepAtPosition(
+      previousStep.position + 1
+    );
+
+    await this.alignStepsPositionsAsOfPosition(
+      nextSteps,
+      createdStep.position + 1
+    );
 
     return createdStep;
   }

packages/backend/src/models/flow.test.js

@@ -198,7 +198,72 @@ describe('Flow model', () => {
     });
   });
 
-  it.todo('createActionStep');
+  it('getStepById should return the step with the given ID from the flow', async () => {
+    const flow = await createFlow();
+
+    const step = await createStep({ flowId: flow.id });
+
+    expect(await flow.getStepById(step.id)).toStrictEqual(step);
+  });
+
+  it('insertActionStepAtPosition should insert action step at given position', async () => {
+    const flow = await createFlow();
+
+    await flow.createInitialSteps();
+
+    const createdStep = await flow.insertActionStepAtPosition(2);
+
+    expect(createdStep).toMatchObject({
+      type: 'action',
+      position: 2,
+    });
+  });
+
+  it('getStepsAfterPosition should return steps after the given position', async () => {
+    const flow = await createFlow();
+
+    await flow.createInitialSteps();
+
+    await createStep({ flowId: flow.id });
+
+    expect(await flow.getStepsAfterPosition(1)).toMatchObject([
+      { position: 2 },
+      { position: 3 },
+    ]);
+  });
+
+  it('alignStepsPositionsAsOfPosition', async () => {
+    const flow = await createFlow();
+
+    await createStep({ type: 'trigger', flowId: flow.id, position: 6 });
+    await createStep({ type: 'action', flowId: flow.id, position: 8 });
+    await createStep({ type: 'action', flowId: flow.id, position: 10 });
+
+    await flow.alignStepsPositionsAsOfPosition(
+      await flow.$relatedQuery('steps'),
+      1
+    );
+
+    expect(await flow.$relatedQuery('steps')).toMatchObject([
+      { position: 1, type: 'trigger' },
+      { position: 2, type: 'action' },
+      { position: 3, type: 'action' },
+    ]);
+  });
+
+  it('createActionStepAfterStep should create an action step after given step ID', async () => {
+    const flow = await createFlow();
+
+    const triggerStep = await createStep({ type: 'trigger', flowId: flow.id });
+    const actionStep = await createStep({ type: 'action', flowId: flow.id });
+
+    const createdStep = await flow.createActionStepAfterStepId(triggerStep.id);
+
+    const refetchedActionStep = await actionStep.$query();
+
+    expect(createdStep).toMatchObject({ type: 'action', position: 2 });
+    expect(refetchedActionStep.position).toBe(3);
+  });
 
   it.todo('delete');