tests: Migrate watch tests to common pkg

[joshjms]

Please read https://github.com/etcd-io/etcd/blob/main/CONTRIBUTING.md#contribution-flow.

Ref: #13637, #20607

/cc @yagikota @serathius

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[joshjms]

I'll make it not draft to test the CI :)

[joshjms]

/hold

[joshjms]

On closer inspection the watch tests in e2e is quite different in purpose than the one in integration :) Should I keep them separated?

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 69.20%. Comparing base (487e5b6) to head (c74838c).
⚠️ Report is 66 commits behind head on main.

Additional details and impacted files

see 24 files with indirect coverage changes

@@            Coverage Diff             @@
##             main   #20837      +/-   ##
==========================================
+ Coverage   69.14%   69.20%   +0.06%     
==========================================
  Files         422      422              
  Lines       34824    34824              
==========================================
+ Hits        24079    24100      +21     
+ Misses       9342     9326      -16     
+ Partials     1403     1398       -5     

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[k8s-ci-robot]

@joshjms: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-etcd-verify	c74838c	link	true	/test pull-etcd-verify
pull-etcd-integration-2-cpu-arm64	c74838c	link	true	/test pull-etcd-integration-2-cpu-arm64
pull-etcd-integration-1-cpu-arm64	c74838c	link	true	/test pull-etcd-integration-1-cpu-arm64
pull-etcd-integration-4-cpu-arm64	c74838c	link	true	/test pull-etcd-integration-4-cpu-arm64
pull-etcd-integration-4-cpu-amd64	c74838c	link	true	/test pull-etcd-integration-4-cpu-amd64
pull-etcd-integration-2-cpu-amd64	c74838c	link	true	/test pull-etcd-integration-2-cpu-amd64
pull-etcd-integration-1-cpu-amd64	c74838c	link	true	/test pull-etcd-integration-1-cpu-amd64
pull-etcd-e2e-amd64	c74838c	link	true	/test pull-etcd-e2e-amd64
pull-etcd-e2e-arm64	c74838c	link	true	/test pull-etcd-e2e-arm64

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[yagikota]

@joshjms

Can you write PR description in more detail? You can refer to my PR for reference.

[yagikota]

@joshjms

The tests/e2e/watch_test.go contains some tests:
First, you need to determine which tests should be migrated to common and which should remain as they are.

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• TestWatchDelayForPeriodicProgressNotification
• TestWatchDelayForManualProgressNotification
• TestWatchDelayForEvent

To understand these tests, you need to read these references:

• #15402 (comment)
• #15431

In my opinion, these tests should not be migrated to common.
As described in the discussion, they validate watch behavior over a single persistent gRPC(HTTP/2) connection. Running them under tests/common would switch the e2e runner to etcdctl-based clients, where each call is executed in a separate process/connection. That masks the very class of bugs we want to catch (e.g., multiple requests over one connection).

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• TestDeleteEventDrop_Issue18089

See #18201 for the backgroud of this test.

It's better to migrate this test to tests/e2e/reproduce_18089_test.go to align with other reproduction purpose tests.

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• TestStartWatcherFromCompactedRevision

See #18274 for the background.

It can probably be migrated to tests/common.

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• TestResumeCompactionOnTombstone

See https://github.com/etcd-io/etcd/pull/191884 for the background.

I'm not sure why this test exists in tests/e2e/watch_test.go. tests/e2e/resume_compaction_tombstone_test.go or something would be better.
Since failpoint injection is used in this test, it's better to keep it in tests/e2e/.

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