fix(grpc): allow multiple wildcard subscriptions when topic validation disabled

[Rishabh-git10]

Description

Fixes a ValueError startup crash and subscription drop when registering multiple wildcard paths on the same pub/sub component with disable_topic_validation=True.

Previously, enabling this flag collapsed internal tracking keys down to the pub/sub identifier alone, causing map collisions and rendering the sidecar blind to subsequent subscriptions. This change standardizes discrete internal dictionary keys across all registration paths. It introduces a regex-based pattern matching fallback evaluation inside OnTopicEvent and _handle_bulk_topic_event to route events when direct string lookups fail.

Issue reference

Closes #436

Checklist

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• Code compiles correctly
• Created/updated tests
• Extended the documentation

[seherv]

Thanks a lot for contributing to Dapr! Here are my comments

[seherv]

Here you should build an additional route map based on topic to know which handler actually takes it in case you get a wildcard. Something like

if disable_topic_validation and rule is None:
    sub.routes.default = topic
    self._route_map[(pubsub_name, topic)] = cb

[Rishabh-git10]

Thanks for the review and guidance @seherv.
I have consolidated the fallback routing logic into _get_topic_callback to remove duplication. Removed the redundant _match_topic function.

[CasperGN]

@Rishabh-git10 can you fix the conflicts pls?

[Rishabh-git10]

Hey, @CasperGN I have resolved the conflicts. Let's see if the checks are happy with it.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.09%. Comparing base (bffb749) to head (893cbb1).
⚠️ Report is 150 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1083      +/-   ##
==========================================
- Coverage   86.63%   82.09%   -4.54%     
==========================================
  Files          84      116      +32     
  Lines        4473     9585    +5112     
==========================================
+ Hits         3875     7869    +3994     
- Misses        598     1716    +1118     

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[Copilot]

Pull request overview

This PR updates the dapr.ext.grpc callback servicer’s pub/sub routing to avoid key collisions when disable_topic_validation=True, aiming to support multiple wildcard-style subscriptions on the same pubsub component without startup crashes or silently dropped subscriptions.

Changes:

• Standardizes internal subscription keying in register_topic() to always include pubsub_name + topic.
• Introduces _get_topic_callback() to centralize callback selection and adds additional routing maps for fallback lookup.
• Adds a unit test that registers multiple wildcard-like subscriptions under the same pubsub with topic validation disabled.

Reviewed changes

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

File	Description
dapr/ext/grpc/_servicer.py	Refactors topic registration and event dispatch to use a shared callback resolver and new routing maps.
tests/ext/grpc/test_servicier.py	Adds coverage for multiple wildcard-style subscriptions under disable_topic_validation=True.

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