Editing a cell does not mark its dependents as stale

[zmbc]

Describe the bug

I may be misinterpreting how this is supposed to work, but it is quite surprising to me that when you edit the contents of a Python cell, and even when you then de-focus that cell, the only cell that is marked stale is the one you edited. You then have to press "run all stale cells" twice to get everything to update.

Will you submit a PR?

• Yes

Environment

Details

{
  "marimo": "0.19.7",
  "editable": false,
  "location": "/mnt/share/homes/zmbc/mambaforge/envs/vivarium_gates_mncnh_artifact/lib/python3.11/site-packages/marimo",
  "OS": "Linux",
  "OS Version": "5.4.0-216-generic",
  "Processor": "x86_64",
  "Python Version": "3.11.14",
  "Locale": "en_US",
  "Binaries": {
    "Browser": "--",
    "Node": "--"
  },
  "Dependencies": {
    "click": "8.3.1",
    "docutils": "0.22.4",
    "itsdangerous": "2.2.0",
    "jedi": "0.19.2",
    "markdown": "3.10.1",
    "narwhals": "2.15.0",
    "packaging": "25.0",
    "psutil": "7.2.1",
    "pygments": "2.19.2",
    "pymdown-extensions": "10.20.1",
    "pyyaml": "6.0.3",
    "starlette": "0.52.1",
    "tomlkit": "0.14.0",
    "typing-extensions": "4.15.0",
    "uvicorn": "0.40.0",
    "websockets": "16.0"
  },
  "Optional Dependencies": {
    "altair": "6.0.0",
    "duckdb": "1.4.3",
    "ibis-framework": "11.0.0",
    "loro": "1.10.3",
    "nbformat": "5.10.4",
    "openai": "2.16.0",
    "pandas": "1.5.3",
    "polars": "1.37.1",
    "pyarrow": "23.0.0",
    "pytest": "9.0.2",
    "ruff": "0.14.14",
    "sqlglot": "27.29.0"
  },
  "Experimental Flags": {}
}

Code to reproduce

No response

[mscolnick]

@zmbc i assume you have on-cell-change off like below?

I can see your argument for sure. I'm not sure what feels more correct.

[zmbc]

Yes -- this is with everything set to "lazy." I tried to add a video but was having some trouble recording my screen.

My thinking is that the "run all stale cells" action should always result in there being no remaining stale cells.

[mscolnick]

We likely won't color yellow the cells downstream of an edited cell, but I think you are right that you should not need to click twice to run all stale cells.

Chatted with the team. We are planning to stick with the current way. In lazy mode, we want to be careful re-running un-intended cells. And this change would catch a wider net and can be more distruptive.

[akshayka]

I'm inclined to keep this the way that it is, since the point of the lazy executor is to be extra careful not to run expensive cells