[MRF-11] PLU-520: (backend) create step approval config

packages/backend/src/apps/formsg/common/types.ts

@@ -50,3 +50,8 @@ export interface ParsedMrfWorkflow {
   trigger: Omit<ParsedMrfWorkflowStep, 'approvalField'>
   actions: ParsedMrfWorkflowStep[]
 }
+
+export const stepApprovalConfigSchema = z.object({
+  branch: z.literal('reject'),
+  stepId: z.string().uuid(),
+})

packages/backend/src/graphql/mutations/create-step.ts

@@ -1,7 +1,10 @@
+import { IStepConfig } from '@plumber/types'
+
 import { raw } from 'objection'
 
 import { BadUserInputError } from '@/errors/graphql-errors'
 import logger from '@/helpers/logger'
+import { validateApprovalConfig } from '@/helpers/validate-approval-config'
 import App from '@/models/app'
 import FlowConnections from '@/models/flow-connections'
 import Step from '@/models/step'
@@ -38,6 +41,7 @@ const createStep: MutationResolvers['createStep'] = async (
       throw new BadUserInputError('Action can only be created by system')
     }
   }
+
   return await Step.transaction(async (trx) => {
     await trx.raw('SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;')
 
@@ -77,21 +81,29 @@ const createStep: MutationResolvers['createStep'] = async (
       })
       .throwIfNotFound()
 
+    const validationResult = await validateApprovalConfig(
+      input.config as IStepConfig,
+      previousStep,
+    )
+    if (!validationResult.isApprovalConfigValid) {
+      throw new BadUserInputError('Invalid approval config')
+    }
+
     await flow
       .$relatedQuery('steps', trx)
       .patch({
         position: raw(`position + 1`),
       })
-      .where('position', '>=', previousStep.position + 1)
+      .where('position', '>=', validationResult.newStepPosition)
 
     const step = await flow.$relatedQuery('steps', trx).insertAndFetch({
       key: input.key,
       appKey: input.appKey,
       type: 'action',
-      position: previousStep.position + 1,
+      position: validationResult.newStepPosition,
       parameters: input.parameters,
       connectionId: input.connection?.id,
-      config: input.config,
+      config: input.config as IStepConfig,
     })
 
     // NOTE: add flow connection to the flow_connections table

packages/backend/src/graphql/mutations/duplicate-branch.ts

@@ -1,3 +1,5 @@
+import { IStepConfig } from '@plumber/types'
+
 import { raw } from 'objection'
 
 import { BadUserInputError } from '@/errors/graphql-errors'
@@ -78,7 +80,7 @@ const duplicateBranch: MutationResolvers['duplicateBranch'] = async (
         position: previousStep.position + 1,
         parameters,
         connectionId: connection?.id,
-        config,
+        config: config as IStepConfig,
       })
 
       newSteps.push(step)

packages/backend/src/graphql/schema.graphql

@@ -590,8 +590,16 @@ input CreateStepInput {
   config: StepConfigInput
 }
 
+
+
+input StepApprovalConfigInput {
+  branch: String!
+  stepId: String!
+}
+
 input StepConfigInput {
   stepName: String
+  approval: StepApprovalConfigInput
 }
 
 input UpdateStepInput {
@@ -710,12 +718,18 @@ type Step {
 type StepConfig {
   templateConfig: StepTemplateConfig
   stepName: String
+  approval: StepApprovalConfig
 }
 
 type StepTemplateConfig {
   appEventKey: String
 }
 
+type StepApprovalConfig {
+  branch: String
+  stepId: String
+}
+
 input StepConnectionInput {
   id: String
 }

packages/backend/src/helpers/validate-approval-config.ts

@@ -0,0 +1,149 @@
+import { IStep, IStepConfig } from '@plumber/types'
+
+import get from 'lodash.get'
+
+import { stepApprovalConfigSchema } from '@/apps/formsg/common/types'
+import Step from '@/models/step'
+
+import logger from './logger'
+
+/**
+ * TODO: write unit test for this function
+ */
+export async function validateApprovalConfig(
+  config: IStepConfig,
+  prevStep: IStep,
+): Promise<
+  | {
+      isApprovalConfigValid: true
+      newStepPosition: number
+    }
+  | {
+      isApprovalConfigValid: false
+    }
+> {
+  /**
+   * Case 1: new step is a trigger step, return early
+   */
+  if (!prevStep) {
+    return {
+      isApprovalConfigValid: true,
+      newStepPosition: 1,
+    }
+  }
+
+  const isPreviousStepMrfApprovalStep =
+    prevStep.appKey === 'formsg' &&
+    prevStep.key === 'mrfSubmission' &&
+    // if no approval field, it's just a normal mrf step
+    !!get(prevStep.parameters, 'mrf.approvalField')
+
+  /**
+   * Case 2: Prev step has no approval config and is not an mrf approval step,
+   * current step should have no approval config either
+   */
+  if (!prevStep.config.approval && !isPreviousStepMrfApprovalStep) {
+    if (!config?.approval) {
+      return {
+        isApprovalConfigValid: true,
+        newStepPosition: prevStep.position + 1,
+      }
+    }
+    logger.error(
+      'Invalid approval config: previous step has no approval config and is not an mrf approval step. This step should not have an approval config.',
+    )
+    return {
+      isApprovalConfigValid: false,
+    }
+  }
+
+  /**
+   * Case 3: Prev step is part of an approval branch, check that
+   * the new step has the same approval config
+   */
+  if (prevStep.config.approval) {
+    const isSameApprovalConfig =
+      prevStep.config.approval?.branch === config?.approval?.branch &&
+      prevStep.config.approval?.stepId === config?.approval?.stepId
+    if (isSameApprovalConfig) {
+      return {
+        isApprovalConfigValid: true,
+        newStepPosition: prevStep.position + 1,
+      }
+    }
+    logger.error(
+      'Invalid approval config: new step approval config is not the same as previous step',
+    )
+    return {
+      isApprovalConfigValid: false,
+    }
+  }
+
+  /**
+   * Case 4: Previous step is an approval step
+   */
+  if (isPreviousStepMrfApprovalStep) {
+    // If previous step is an approval step, but this step has no approval config, it is part of the approve flow
+    if (!config?.approval) {
+      return {
+        isApprovalConfigValid: true,
+        newStepPosition: prevStep.position + 1,
+      }
+    }
+    // validate approval config
+    const { success } = stepApprovalConfigSchema.safeParse(config?.approval)
+    // validate approval config step id is the same as prev step id
+    if (!success || config.approval.stepId !== prevStep.id) {
+      logger.error(
+        'Invalid approval config: invalid approval config or new step id is not the same as approval step id',
+        {
+          approvalConfig: config?.approval,
+        },
+      )
+      return {
+        isApprovalConfigValid: false,
+      }
+    }
+    // For reject branch, find the end of the approval branch and add one to that step
+    // first find the next mrf step (if any)
+    const nextMrfStep = await Step.query()
+      .where('flow_id', prevStep.flowId)
+      .andWhere('type', 'action')
+      .andWhere('key', 'mrfSubmission')
+      .andWhere('position', '>', prevStep.position)
+      .orderBy('position', 'asc')
+      .first()
+    // then find the step in the approve branch (if any)
+    const lastStepOfApproveFlowQuery = Step.query()
+      .where('flow_id', prevStep.flowId)
+      .andWhere('position', '>', prevStep.position)
+
+      .orderBy('position', 'desc')
+      .first()
+
+    if (nextMrfStep) {
+      lastStepOfApproveFlowQuery.andWhere('position', '<', nextMrfStep.position)
+    }
+    const lastStepOfapproveFlow = await lastStepOfApproveFlowQuery.first()
+    // If last approval step exists, return the position after that
+    if (lastStepOfapproveFlow) {
+      return {
+        isApprovalConfigValid: true,
+        newStepPosition: lastStepOfapproveFlow.position + 1,
+      }
+    } else {
+      // If no last approval step, return the position after the previous step
+      return {
+        isApprovalConfigValid: true,
+        newStepPosition: prevStep.position + 1,
+      }
+    }
+  }
+
+  /**
+   * Catch all branch, something seems fishy
+   */
+  return {
+    isApprovalConfigValid: false,
+  }
+}

packages/frontend/src/graphql/mutations/create-step.ts

@@ -16,6 +16,13 @@ export const CREATE_STEP = gql`
       }
       config {
         stepName
+        templateConfig {
+          appEventKey
+        }
+        approval {
+          branch
+          stepId
+        }
       }
       flow {
         updatedAt

packages/frontend/src/graphql/mutations/update-step.ts

@@ -20,6 +20,10 @@ export const UPDATE_STEP = graphql(`
         templateConfig {
           appEventKey
         }
+        approval {
+          branch
+          stepId
+        }
       }
       flow {
         updatedAt

packages/frontend/src/graphql/queries/get-flow.ts

@@ -32,6 +32,10 @@ export const FLOW_FIELDS = gql`
         templateConfig {
           appEventKey
         }
+        approval {
+          branch
+          stepId
+        }
       }
     }
     config {

packages/frontend/src/graphql/queries/get-test-execution-steps.ts

@@ -20,6 +20,10 @@ export const GET_TEST_EXECUTION_STEPS = gql`
             appEventKey
           }
           stepName
+          approval {
+            branch
+            stepId
+          }
         }
         key
         appKey

packages/types/index.d.ts

@@ -168,8 +168,14 @@ export interface IExecution {
 
 export type IStepApprovalBranch = 'approve' | 'reject'
 
+export interface IStepApprovalConfig {
+  branch: 'reject'
+  stepId: string
+}
+
 export interface IStepConfig {
   stepName?: string
+  approval?: IStepApprovalConfig
   templateConfig?: IStepTemplateConfig
   adminOverride?: IJSONObject
 }