The latest updates on your projects. Learn more about Vercel for GitHub.

1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
docs	Skipped		Apr 8, 2026 7:46am

PR Summary

Medium Risk
Changes parallel execution completion/aggregation behavior in the executor, which can affect when/if parallel results are produced for real workflows; scope is contained to parallel orchestration and covered by existing tests.

Overview
Fixes parallel block completion by removing the node-counting based “all branches complete” detection that broke when branches follow conditional/error paths.

ParallelScope/ExecutionContext.parallelExecutions drop completedCount/totalExpectedNodes, initializeParallelScope no longer accepts a terminal-node count, and handleParallelBranchCompletion now only records per-branch outputs while aggregation is performed solely by the parallel sentinel-end path. Tests were updated to match the new initializer signature and scope shape.

^{Reviewed by Cursor Bugbot for commit 8c7b975. Configure here.}

Greptile Summary

This PR removes a broken node-counting completion mechanism from parallel block execution. Previously, parallel completion was detected by counting node executions against totalExpectedNodes = branchCount * allNodesInParallel, which failed whenever branches took conditional paths (error edges, condition gates) — since each branch could execute a different number of nodes, the counter never matched and aggregation could misfire or never fire. The fix removes completedCount and totalExpectedNodes entirely from ParallelScope and delegates completion detection solely to the sentinel-end node, which is only reached once all branches have exited via the DAG edge mechanism.

Key changes:

• Removed completedCount / totalExpectedNodes from ParallelScope (state.ts), ExecutionContext.parallelExecutions inline type (types.ts), all test fixtures, and the orchestrator logic (parallel.ts)
• handleParallelBranchCompletion now returns void instead of boolean — its sole job is to record the branch output
• All call sites in node.ts that previously checked the boolean return value and called aggregateParallelResults on true are updated; aggregation is now exclusively triggered inside handleParallelSentinel when sentinelType === 'end'
• initializeParallelScope signature simplified (removed terminalNodesCount parameter)
• Test fixtures updated to drop the two removed fields

Confidence Score: 5/5

Safe to merge — the fix is correct, the cleanup is thorough, and all 662 existing tests pass.

The broken counting mechanism is fully excised and the sentinel-end trigger is the right and only completion signal. All callers in node.ts are updated, the interface types are consistent, and the test fixtures are cleaned up. The only remaining item is a P2 suggestion for an explicit regression test for the conditional-path scenario, which does not block merge.

apps/sim/executor/orchestrators/parallel.test.ts — could benefit from a regression test for the conditional-path bug scenario described in the PR.

Important Files Changed

Sequence Diagram

sequenceDiagram
    participant E as EdgeProcessor
    participant N as NodeExecutionOrchestrator
    participant P as ParallelOrchestrator
    participant S as ExecutionState

    Note over E,S: Branch node execution (per branch, per node)
    E->>N: executeNode(branchNode)
    N->>S: execute block
    S-->>N: output
    N->>N: handleNodeCompletion(branchNode)
    N->>P: handleParallelBranchCompletion(parallelId, nodeId, output)
    P->>P: branchOutputs.set(branchIndex, output)
    Note right of P: void — no count check

    Note over E,S: Sentinel-end reached (all branches finished via DAG edges)
    E->>N: executeNode(sentinel-end)
    N->>N: handleParallelSentinel(sentinelType=end)
    N->>P: aggregateParallelResults(parallelId)
    P->>P: collect branchOutputs[0..N]
    P->>S: setBlockOutput(parallelId, results)
    P-->>N: ParallelAggregationResult
    N-->>E: { results, sentinelEnd, selectedRoute: PARALLEL_EXIT }

_{Reviews (1): Last reviewed commit: "fix(parallel): remove broken node-counti..." | Re-trigger Greptile}