[microsoft-agent-framework-for-go]

Summary

A fan-out edge delivered a message once per entry when its Assigner (or sink list) named the same target more than once, so a target could run twice on one message. selectedTargetIDs in workflow/internal/execution/edgerunner.go now drops repeated IDs, keeping the order in which each target is first named. This matches upstream FanOutEdgeRunner, which applies Distinct(StringComparer.Ordinal) to the resolved target IDs. #706 fixed only the SwitchBuilder per-case path; the runtime path was still unguarded.

Ported .NET PRs

• .NET: Deduplicate fan-out targets so each target runs once agent-framework#9432 (commit ee3628384c10fe887877293c66de0d73805eec7b), inspected at pinned upstream SHA fc3c3c0789378d6902293ec9a5fac8911dce566a. I screened the prepared commit list and inspected this one in depth.
• Source: https://github.com/microsoft/agent-framework/blob/fc3c3c0789378d6902293ec9a5fac8911dce566a/dotnet/src/Microsoft.Agents.AI.Workflows/Execution/FanOutEdgeRunner.cs
• Classification: fix only. It is an internal runtime change with no public API, option, or default change.

Breaking Changes

No. Repeated targets now run once, which is the intended contract.

Tests and Examples

I added TestPrepareDeliveryForFanOutEdge_AssignerRepeatedTargetsDeliveredOnce in workflow/internal/execution/edgerunner_test.go. No example changes were needed. gofmt is clean and go test ./workflow/... passes.

Notes

• The Go counterpart is EdgeRunner.PrepareDeliveryForEdge via selectedTargetIDs.
• I searched for duplicate work before editing and again before publishing. The only related hit was merged PR Deduplicate repeated target indices within a SwitchBuilder case to avoid duplicate delivery #706, which covers the switch builder only. No open claims were found.
• Not run: E2E and benchmark suites.

Generated by .NET to Go Fixes and Test Porting Agent · copilot · auto · 31.5 AIC · ⌖ 0.698 AIC · ⊞ 4.9K · ◷

[github-actions]

API consistency review

Result	Scope
aligned	user-visible behavior

Changed Go contract

selectedTargetIDs (workflow/internal/execution/edgerunner.go) now de-duplicates fan-out targets, keeping first-named order, before applying the envelope target filter. No exported API change.

Upstream evidence reviewed

Implementation	Source	Contract checked
.NET	FanOutEdgeRunner.ChaseEdgeAsync	targetIds.Distinct(StringComparer.Ordinal) before the IsValidTarget filter; no opt-in gate

Assessment

Upstream applies an unconditional ordinal Distinct that preserves first-named order, then filters by the envelope target. Go now does the same (exact-match dedupe, first-occurrence order, envelope filter). Neither side has an option or default to disable it, so enablement matches. No parity issues found.

Generated by Go API Consistency Review Agent for #1336 · copilot · auto · 16.4 AIC · ⌖ 0.615 AIC · ⊞ 4.9K · ◷

[Copilot]

🟢 Approval recommended

There are no active review issues for the runtime fan-out deduplication change.

No open issues 🎉

What changed in this PR

This PR prevents duplicate delivery to repeated fan-out targets at runtime, extending the earlier SwitchBuilder-specific fix in #706.

Changes:

• Deduplicates resolved target IDs while preserving first-occurrence order and target filtering.
• Adds a regression test for an assigner that selects the same targets repeatedly.

File	Description
workflow/​internal/​execution/​edgerunner.go	Deduplicates selected target IDs so each target receives the message once.
workflow/​internal/​execution/​edgerunner_test.go	Adds coverage for repeated target selections from an assigner.

_{Review effort: Balanced}