fix(parallel): error-sticky block run status to prevent branch success masking failure

Author: waleedlatif1

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/hooks/use-workflow-execution.ts

@@ -20,7 +20,10 @@ import {
   TriggerUtils,
 } from '@/lib/workflows/triggers/triggers'
 import { useCurrentWorkflow } from '@/app/workspace/[workspaceId]/w/[workflowId]/hooks/use-current-workflow'
-import { updateActiveBlockRefCount } from '@/app/workspace/[workspaceId]/w/[workflowId]/utils/workflow-execution-utils'
+import {
+  resolveBlockRunStatus,
+  updateActiveBlockRefCount,
+} from '@/app/workspace/[workspaceId]/w/[workflowId]/utils/workflow-execution-utils'
 import { getBlock } from '@/blocks'
 import type { SerializableExecutionState } from '@/executor/execution/types'
 import type {
@@ -65,6 +68,8 @@ interface BlockEventHandlerConfig {
   workflowEdges: Array<{ id: string; target: string; sourceHandle?: string | null }>
   activeBlocksSet: Set<string>
   activeBlockRefCounts: Map<string, number>
+  /** Tracks blocks that have errored in any parallel branch — prevents later success from masking errors. */
+  blockRunErrors: Set<string>
   accumulatedBlockLogs: BlockLog[]
   accumulatedBlockStates: Map<string, BlockState>
   executedBlockIds: Set<string>
@@ -312,6 +317,7 @@ export function useWorkflowExecution() {
         workflowEdges,
         activeBlocksSet,
         activeBlockRefCounts,
+        blockRunErrors,
         accumulatedBlockLogs,
         accumulatedBlockStates,
         executedBlockIds,
@@ -484,7 +490,12 @@ export function useWorkflowExecution() {
       const onBlockCompleted = (data: BlockCompletedData) => {
         if (isStaleExecution()) return
         updateActiveBlocks(data.blockId, false)
-        if (workflowId) setBlockRunStatus(workflowId, data.blockId, 'success')
+        if (workflowId)
+          setBlockRunStatus(
+            workflowId,
+            data.blockId,
+            resolveBlockRunStatus(blockRunErrors, data.blockId, 'success')
+          )
 
         executedBlockIds.add(data.blockId)
         accumulatedBlockStates.set(data.blockId, {
@@ -515,7 +526,12 @@ export function useWorkflowExecution() {
       const onBlockError = (data: BlockErrorData) => {
         if (isStaleExecution()) return
         updateActiveBlocks(data.blockId, false)
-        if (workflowId) setBlockRunStatus(workflowId, data.blockId, 'error')
+        if (workflowId)
+          setBlockRunStatus(
+            workflowId,
+            data.blockId,
+            resolveBlockRunStatus(blockRunErrors, data.blockId, 'error')
+          )
 
         executedBlockIds.add(data.blockId)
         accumulatedBlockStates.set(data.blockId, {
@@ -1280,6 +1296,7 @@ export function useWorkflowExecution() {
 
       const activeBlocksSet = new Set<string>()
       const activeBlockRefCounts = new Map<string, number>()
+      const blockRunErrors = new Set<string>()
       const streamedContent = new Map<string, string>()
       const accumulatedBlockLogs: BlockLog[] = []
       const accumulatedBlockStates = new Map<string, BlockState>()
@@ -1293,6 +1310,7 @@ export function useWorkflowExecution() {
           workflowEdges,
           activeBlocksSet,
           activeBlockRefCounts,
+          blockRunErrors,
           accumulatedBlockLogs,
           accumulatedBlockStates,
           executedBlockIds,
@@ -1904,6 +1922,7 @@ export function useWorkflowExecution() {
       const executedBlockIds = new Set<string>()
       const activeBlocksSet = new Set<string>()
       const activeBlockRefCounts = new Map<string, number>()
+      const blockRunErrors = new Set<string>()
 
       try {
         const blockHandlers = buildBlockEventHandlers({
@@ -1912,6 +1931,7 @@ export function useWorkflowExecution() {
           workflowEdges,
           activeBlocksSet,
           activeBlockRefCounts,
+          blockRunErrors,
           accumulatedBlockLogs,
           accumulatedBlockStates,
           executedBlockIds,
@@ -2108,6 +2128,7 @@ export function useWorkflowExecution() {
     const workflowEdges = useWorkflowStore.getState().edges
     const activeBlocksSet = new Set<string>()
     const activeBlockRefCounts = new Map<string, number>()
+    const blockRunErrors = new Set<string>()
     const accumulatedBlockLogs: BlockLog[] = []
     const accumulatedBlockStates = new Map<string, BlockState>()
     const executedBlockIds = new Set<string>()
@@ -2120,6 +2141,7 @@ export function useWorkflowExecution() {
       workflowEdges,
       activeBlocksSet,
       activeBlockRefCounts,
+      blockRunErrors,
       accumulatedBlockLogs,
       accumulatedBlockStates,
       executedBlockIds,

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/utils/workflow-execution-utils.ts

@@ -5,6 +5,22 @@ import { useTerminalConsoleStore } from '@/stores/terminal'
 import { useWorkflowRegistry } from '@/stores/workflows/registry/store'
 import { useWorkflowStore } from '@/stores/workflows/workflow/store'
 
+/**
+ * Returns the run status to persist for a block, using an error-sticky policy.
+ * Once any parallel branch for a block has errored, the block status stays 'error'
+ * even if a later branch completes successfully — preventing failures from being masked.
+ */
+export function resolveBlockRunStatus(
+  erroredBlocks: Set<string>,
+  blockId: string,
+  status: 'success' | 'error'
+): 'success' | 'error' {
+  if (status === 'error') {
+    erroredBlocks.add(blockId)
+  }
+  return erroredBlocks.has(blockId) ? 'error' : 'success'
+}
+
 /**
  * Updates the active blocks set and ref counts for a single block.
  * Ref counting ensures a block stays active until all parallel branches for it complete.
@@ -64,6 +80,7 @@ export async function executeWorkflowWithFullLogging(
 
   const activeBlocksSet = new Set<string>()
   const activeBlockRefCounts = new Map<string, number>()
+  const blockRunErrors = new Set<string>()
 
   const payload: any = {
     input: options.workflowInput,
@@ -154,7 +171,11 @@ export async function executeWorkflowWithFullLogging(
               )
               setActiveBlocks(wfId, new Set(activeBlocksSet))
 
-              setBlockRunStatus(wfId, event.data.blockId, 'success')
+              setBlockRunStatus(
+                wfId,
+                event.data.blockId,
+                resolveBlockRunStatus(blockRunErrors, event.data.blockId, 'success')
+              )
 
               addConsole({
                 input: event.data.input || {},
@@ -190,7 +211,11 @@ export async function executeWorkflowWithFullLogging(
               )
               setActiveBlocks(wfId, new Set(activeBlocksSet))
 
-              setBlockRunStatus(wfId, event.data.blockId, 'error')
+              setBlockRunStatus(
+                wfId,
+                event.data.blockId,
+                resolveBlockRunStatus(blockRunErrors, event.data.blockId, 'error')
+              )
 
               addConsole({
                 input: event.data.input || {},