n8n Test Mode Issue: Workflow Stops at IF Branch Convergence

Below is some guidance tailored to the issue you’re encountering:

Understanding the Problem

When using an IF node, the branch that isn’t taken won’t be executed. Later in the workflow, if a node references outputs from both branches or is wired downstream from both branches, the lack of execution on one side can lead to the workflow stalling—even though no explicit error message is shown. This happens because a referenced branch never produces its expected output.

Recommended Troubleshooting Steps

1. Inspect Node References:
   Check any expressions or configurations in the converging node that might reference outputs from the branch that hasn’t run. For example, if you have an expression like:

   JSCopied
   $("SomeBranch").item.json.someValue

   it might be waiting on the branch “SomeBranch” to be executed. Try adding a conditional check or a fallback to handle the case when that branch produces no output.

2. Verify Execution Order Manually:
   In test mode, use the JavaScript snippet to check whether a branch has been executed:

   JSCopied
   $("SomeBranch").isExecuted

   This helps you understand if the branch is skipped as expected.

3. Re-wire or Adjust the Workflow:
   If the converging node depends on outputs from both branches, consider these options:

   • Merge Node Configuration: Use a Merge node configured to pass through data even if one of the branches produces no output. This can prevent the workflow from waiting indefinitely.
   • Dummy Nodes: Insert a dummy node for the branch that might not be executed. The dummy node could output an empty (or default) message so that downstream expressions or nodes always have something to work with.
   • Separate Paths: Re-structure the workflow so that each branch is processed independently, and only merge when all required outputs are confirmed to be available.

4. Test with Minimal Workflow:
   Create a simplified version of the workflow where the IF node’s branches converge. This helps in isolating whether the problem is with the branch convergence or something else in your configuration.

5. Consult the Documentation:
   There is documentation addressing similar issues with branches not executing as expected (e.g., guidance on handling referenced nodes that haven’t executed). This can offer insights into how to structure your workflow to avoid the pitfall.

Summary

The issue is due to the fact that in test mode, when an IF node leads to one branch not being executed, any node relying on that branch’s output will not proceed. Adjusting how branches are merged—by ensuring all expected inputs are present or by adding conditional logic that accounts for missing outputs—can help resolve this behavior.

Hopefully, these steps help you pinpoint and resolve the problem with the IF node branch convergence in your n8n workflow.