Fix race in notify setup

[bdraco]

Please see below. I may be missing something but it doesn't look like slack and discord pass hass_config which may be the actual root cause here (although I think there is still a race).

It would be helpful if someone could validate that or tell me I'm reading it wrong 😄

details: #76954 (comment)

Proposed change

The discovery dispatcher must be connected before we can add
to hass.config.components to ensure signals are
not missed since the legacy setup await can return control
to the event loop before it gets connected.

Fixes #76564
Fixes #76402
Fixes #76343
Fixes #76919

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• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

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• This PR fixes or closes issue: fixes #
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[probot-home-assistant]

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

I think there is still a race here with yaml ones

I think we need to separate async_setup_legacy so we attach the, then add the comp, then setup platforms

    hass.data[NOTIFY_DISCOVERY_DISPATCHER] = discovery.async_listen_platform(
        hass, DOMAIN, async_platform_discovered
    )

[tkdrob]

#76919 also possibly solved

[bdraco]

I'm pretty sure this will fix it, but I'm not comfortable merging it without adding some more tests since we are obviously lacking ones to catch this case in the first place.

That might have to be tomorrow though

[bdraco]

Need to step away for a bit since I've been sitting for too long. I'll write tests when I get back.

[bdraco]

• nfandroidtv looks like its passing hass_config correctly
  

  core/homeassistant/components/nfandroidtv/__init__.py

  Line 43 in d2e5d91

  hass.data[DATA_HASS_CONFIG],

• mobile_app looks like its passing hass_config correctly
  

  core/homeassistant/components/mobile_app/__init__.py

  Line 68 in d2e5d91

  discovery.async_load_platform(hass, Platform.NOTIFY, DOMAIN, {}, config)

• discord doesn't look like it passing the actual hass_config Pass the real config for Discord #76959

core/homeassistant/components/discord/__init__.py

Line 37 in d2e5d91

hass.data[DOMAIN],

    hass.async_create_task(
        discovery.async_load_platform(
            hass,
            Platform.NOTIFY,
            DOMAIN,
            hass.data[DOMAIN][entry.entry_id],
            hass.data[DOMAIN],
        )
    )

• slack doesn't look like it passing the actual hass_config Pass the real config for Slack #76960
  

  core/homeassistant/components/slack/__init__.py

  Line 58 in d2e5d91

  hass.data[DOMAIN],

    hass.async_create_task(
        discovery.async_load_platform(
            hass,
            Platform.NOTIFY,
            DOMAIN,
            hass.data[DOMAIN][entry.entry_id],
            hass.data[DOMAIN],
        )
    )

[tkdrob]

Pulled this PR and ran local tests with changes from #76959 and #76960. Things are looking good.

[balloob]

This is an improvement as it could race. Not sure if it is the issue though. I think the forwarding not real hass_config to discovery is the real cause.

[tkdrob]

This is an improvement as it could race. Not sure if it is the issue though. I think the forwarding not real hass_config to discovery is the real cause.

This may be true except that nfandroidtv was passing correctly yet was reported with the same issue. Like Nick has told me, it's a very narrow window. People who ran into this were very unlucky.