fix(unit): stabilize backend unit tests

[ntny]

The Test_executeV2_publishLogs/retry_required_-_component_success case had an implicit dependency on artifact map iteration order. When executor-logs was not processed in the expected order, the retry path could miss uploading logs and fail randomly with: blob (key "executor-logs-0") (code=NotFound): blob not found

The fake metadata client now fails the executor-logs artifact explicitly, so the test no longer depends on which artifact is processed first.

failed tests:

testoutput
E0612 21:06:16.100891   27196 launcher_v2.go:449] Component failed to execute successfully: exit status 1
=== RUN   Test_executeV2_publishLogs/retry_required_-_component_success
testoutput
    launcher_v2_test.go:312: 
        	Error Trace:	/home/runner/work/pipelines/pipelines/backend/src/v2/component/launcher_v2_test.go:312
        	Error:      	Expected nil, but got: blob (key "executor-logs-0") (code=NotFound): blob not found
        	Test:       	Test_executeV2_publishLogs/retry_required_-_component_success
        	Messages:   	Expected executor-logs to be readable at key "executor-logs-0"
    launcher_v2_test.go:313: 
        	Error Trace:	/home/runner/work/pipelines/pipelines/backend/src/v2/component/launcher_v2_test.go:313
        	Error:      	Not equal: 
        	            	expected: "testoutput\n"
        	            	actual  : ""
        	            	
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -1,2 +1 @@
        	            	-testoutput
        	            	 
        	Test:       	Test_executeV2_publishLogs/retry_required_-_component_success

https://github.com/kubeflow/pipelines/actions/runs/27442866956/job/81120877056?pr=13171

[google-oss-prow]

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[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

This PR updates the v2 metadata fake client and related launcher tests to make RecordArtifact failures deterministic per output name (avoiding flaky behavior due to map iteration order).

Changes:

• Extend RecordArtifactFailureFakeClient to track call counts per outputName and optionally fail only for a specific output.
• Add a new constructor to configure failures for a single output name.
• Update Test_executeV2_publishLogs assertions to validate retries specifically for executor-logs.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
backend/src/v2/metadata/client_fake.go	Adds per-output failure configuration and per-output call counting in the fake metadata client.
backend/src/v2/component/launcher_v2_test.go	Updates tests to use output-specific failure fake and assert retry counts deterministically.

[ntny]

NewRecordArtifactFailureFakeClientForOutput is the sole constructor that always initializes OutputNameCalls

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

[ntny]

/retest