fix(apiv3): Sort dependency links for deterministic ordering

[lopster568]

Which problem is this PR solving?

• Fixes [Bug]: api_v3 GetDependencies returns dependency links in nondeterministic order #9126

Description of the changes

apiv3.Handler.GetDependencies returned links in the order the storage layer produced them, which is built from a map and therefore not stable across queries. This sorts them by parent then child before building the response, so repeated queries return the same order. Same approach as the HTTP handler (#9119) and the MCP tool (#8403).

How was this change tested?

• New TestGetDependenciesSortsLinks: feeds the mock reader unsorted links and asserts the response is sorted. Fails on main, passes with the change.
• make fmt, make lint (0 issues), make test (4073 tests, 0 failures) all pass. GetDependencies is at 100% coverage.

Checklist

• I have read https://github.com/jaegertracing/jaeger/blob/main/CONTRIBUTING_GUIDELINES.md
• I have signed all commits
• I have added unit tests for the new functionality
• I have run lint and test steps successfully: make lint test

AI Usage in this PR (choose one)

See AI Usage Policy.

• None: No AI tools were used in creating this PR
• Light: AI provided minor assistance (formatting, simple suggestions)
• Moderate: AI helped with code generation or debugging specific parts
• Heavy: AI generated most or all of the code changes

[Copilot]

Pull request overview

This PR fixes nondeterministic ordering in the api_v3 gRPC GetDependencies response by sorting dependency links before returning them, ensuring repeated identical queries produce a stable link order (aligning behavior with the HTTP handler and the MCP tool).

Changes:

• Sort dependency links by parent then child in apiv3.Handler.GetDependencies to make response ordering deterministic.
• Add a unit test that feeds unsorted dependency links via a mock reader and asserts the returned order is sorted.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
cmd/jaeger/internal/extension/jaegerquery/internal/apiv3/grpc_handler.go	Sorts dependency links (parent, then child) before building the api_v3 response to ensure deterministic ordering.
cmd/jaeger/internal/extension/jaegerquery/internal/apiv3/grpc_handler_test.go	Adds a regression test asserting GetDependencies returns links in sorted order even when storage returns an unsorted slice.

[github-actions]

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✅ Coverage 98% (baseline 98%)

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2026-07-27 20:03:49 UTC

[yurishkuro]

@lopster568 why does the sorting need to be done in the transport later (grpc handler)? Query Service is the business layer, the data should not look different depending on whether you hit HTTP or GRPC endpoints.