Skip to content

Prevent log spam when WS subscribe_condition is active#172832

Draft
emontnemery wants to merge 2 commits into
devfrom
ws_subscribe_condition_prevent_log_spam
Draft

Prevent log spam when WS subscribe_condition is active#172832
emontnemery wants to merge 2 commits into
devfrom
ws_subscribe_condition_prevent_log_spam

Conversation

@emontnemery
Copy link
Copy Markdown
Contributor

Proposed change

Prevent log spam related to template issues when WS subscribe_condition is active by adding trace functionality which captures template error messages.

Type of change

  • Dependency upgrade
  • Bugfix (non-breaking change which fixes an issue)
  • New integration (thank you!)
  • New feature (which adds functionality to an existing integration)
  • Deprecation (breaking change to happen in the future)
  • Breaking change (fix/feature causing existing functionality to break)
  • Code quality improvements to existing code or addition of tests

Additional information

Checklist

  • I understand the code I am submitting and can explain how it works.
  • The code change is tested and works locally.
  • Local tests pass. Your PR cannot be merged unless tests pass
  • There is no commented out code in this PR.
  • I have followed the development checklist
  • I have followed the perfect PR recommendations
  • The code has been formatted using Ruff (ruff format homeassistant tests)
  • Tests have been added to verify that the new code works.
  • Any generated code has been carefully reviewed for correctness and compliance with project standards.

If user exposed functionality or configuration variables are added/changed:

If the code communicates with devices, web services, or third-party tools:

  • The manifest file has all fields filled out correctly.
    Updated and included derived files by running: python3 -m script.hassfest.
  • New or updated dependencies have been added to requirements_all.txt.
    Updated by running python3 -m script.gen_requirements_all.
  • For the updated dependencies a diff between library versions and ideally a link to the changelog/release notes is added to the PR description.

To help with the load of incoming pull requests:

@home-assistant
Copy link
Copy Markdown
Contributor

home-assistant Bot commented Jun 2, 2026

Hey there @home-assistant/core, mind taking a look at this pull request as it has been labeled with an integration (websocket_api) you are listed as a code owner for? Thanks!

Code owner commands

Code owners of websocket_api can trigger bot actions by commenting:

  • @home-assistant close Closes the pull request.
  • @home-assistant mark-draft Mark the pull request as draft.
  • @home-assistant ready-for-review Remove the draft status from the pull request.
  • @home-assistant rename Awesome new title Renames the pull request.
  • @home-assistant reopen Reopen the pull request.
  • @home-assistant unassign websocket_api Removes the current integration label and assignees on the pull request, add the integration domain after the command.
  • @home-assistant update-branch Update the pull request branch with the base branch.
  • @home-assistant add-label needs-more-information Add a label (needs-more-information, problem in dependency, problem in custom component, problem in config, problem in device, feature-request) to the pull request.
  • @home-assistant remove-label needs-more-information Remove a label (needs-more-information, problem in dependency, problem in custom component, problem in config, problem in device, feature-request) on the pull request.

Copy link
Copy Markdown
Contributor

Copilot AI left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Pull request overview

This PR reduces log spam from repeated template condition evaluations (notably the WebSocket subscribe_condition command) by allowing template undefined-variable messages to be captured in tracing instead of being logged, and by forwarding those captured messages back to the WebSocket client.

Changes:

  • Add opt-in trace support to record template variable errors/warnings on the active TraceElement rather than logging them.
  • Update subscribe_condition to enable this opt-in behavior, clear traces per evaluation, and forward collected template errors to the client as an errors list.
  • Add/extend tests to verify template errors are traced/forwarded and not repeatedly logged.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file
File Description
homeassistant/helpers/trace.py Extends TraceElement with template_error support and adds the record_template_errors() context manager + ContextVar.
homeassistant/helpers/template/__init__.py Suppresses undefined-variable logging when opted-in and records the message on the active trace element instead.
homeassistant/components/websocket_api/commands.py Clears trace per evaluation, opts into template-error recording for subscribe_condition, and forwards trace-recorded template errors to the client.
tests/helpers/test_condition.py Adds coverage ensuring template variable issues are traced (when opted-in) and logged (when not opted-in).
tests/components/websocket_api/test_commands.py Adds coverage ensuring subscribe_condition forwards template errors without generating template log spam.

Comment on lines +2253 to +2256
trace_element = condition_trace[""][0]
assert trace_element._template_error == expected_template_error
assert trace_element.as_dict()["template_error"] == expected_template_error
assert (trace_element._result or {}) == expected_result
Comment thread tests/helpers/test_condition.py Outdated
Comment on lines +2281 to +2283
condition_trace = trace.trace_get(clear=False)
trace.trace_clear()
assert condition_trace[""][0]._template_error is None
@wendevlin
Copy link
Copy Markdown
Member

I tested it with a connected frontend, before the PR you see core is checking the template with a poll and spams the logs. Afterwards no log at all 👍

for element in elements
if (template_error := element.template_error) is not None
]:
new_event_data["errors"] = errors
Copy link
Copy Markdown
Member

@MartinHjelmare MartinHjelmare Jun 2, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

"errors" looks like a new key in new_event_data. Will the frontend be adapted to consume this item?

Is it confusing to have one item with key "error" and another item with key "errors"?

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Frontend won't use the errors.

@MartinHjelmare MartinHjelmare marked this pull request as draft June 2, 2026 13:38
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Projects

None yet

Development

Successfully merging this pull request may close these issues.

4 participants