⚡️ Run test

This is a debugging node, and a clever little one. ComfyUI only runs the parts of your graph that feed into an output - a Save Image, a preview, something terminal. So if you're building a subgraph and want to test that one branch runs without bothering to wire up a Save Image or produce a final result, you'd normally have to fake an endpoint. Run test is that fake endpoint. The pack describes it exactly: "a simple node used for testing workflows without returning any output."

You connect anything to it, hit run, and the branch feeding it executes. It produces nothing. That's the entire point.

How it works

The trick is that Run test registers itself as an output node. In ComfyUI, output nodes are the roots the execution engine works backward from - it traces every node feeding an output and runs them, and skips everything that doesn't lead to one. Because Run test counts as an output, connecting a branch to it pulls that whole branch into the execution, even though the node itself yields no image, no latent, nothing you can wire onward.

So it's a way to say "run this, I just want to see that it works" without producing a result you don't care about.

The inputs and outputs that matter

There's basically one thing to know:

• any (optional, accepts any type) - plug in whatever you want to force-execute: the tail of a branch, a download node, a custom node you're not sure loads correctly.

There are no outputs. By design. If you're looking for something to come out the other side, you've got the wrong node - this is a terminator.

How to install it

Ships with the SDVN pack. ComfyUI Manager, search SDVN_Comfy_node; or:

cd ComfyUI/custom_nodes
git clone https://github.com/StableDiffusionVN/SDVN_Comfy_node
pip install -r custom_nodes/SDVN_Comfy_node/requirements.txt

from the ComfyUI root, then restart. Nothing to download, no dependencies - it's a one-input utility.

What it's actually good for

A few real uses beyond "does this run":

• Warming a download node. Point a download-a-model node into Run test and hit run to fetch the file up front, before you build the rest of the graph around it.
• Isolating a subgraph. Testing one section without disturbing your main output wiring.
• Sanity-checking a new custom node loads and executes without errors.

Common issues & troubleshooting

It produces nothing - that's correct. If you expected an image, this isn't broken; it's a sink. Wire a Save Image or the pack's Any show if you want to actually see the result.

The branch didn't run. Check the input is actually connected, and that no node in that branch is muted or bypassed. A muted node breaks the chain and the engine won't reach Run test.

It won't re-run. ComfyUI caches results - if nothing upstream changed, it skips re-executing. Change an input (bump a seed on something upstream) if you need it to genuinely run again rather than serve a cached pass.