Auto-dispatch PR conflict resolution from PR poller by chihsuan · Pull Request #57 · Automattic/symphony

chihsuan · 2026-05-21T10:46:36Z

Context

PR review polling needs to detect merge conflicts and dispatch agents to resolve them semantically.

TL;DR

Dispatch agent-owned PR merge conflict resolution from the review poller.

Summary

Fetch PR mergeability and base/head metadata during review polling.
Store conflict context, dedupe by head/base key, and cap repeated dispatches.
Inject conflict-resolution instructions and sanitized metadata into the next prompt.
Clear conflict state when PRs become clean, close, or merge.

Alternatives

Keep conflict handling in CI polling; rejected because mergeability is PR state.
Add new config keys; rejected because existing PR review records can store context.

Test Plan

make all blocked locally by AF_UNIX socket bind :eperm in app-server socket tests.
mix format --check-formatted
mix lint
mix specs.check
mix test prompt safety, prompt builder, PR poller, and GitHub PR tests
MIX_HOME=/private/tmp/symphony-mix-home HEX_HOME=/private/tmp/symphony-hex-home mix dialyzer --format short
git diff --check origin/main..HEAD

Summary: - Fetch GitHub mergeability and base/head metadata during PR review polling. - Persist conflict context, dedupe by head/base identity, enforce a retry cap, and inject conflict instructions into the next prompt. - Add focused coverage for conflict dispatch, dedupe, escalation, cleanup, active-run suppression, prompt text, and GitHub parsing. Rationale: - Merge conflicts are PR review state, not CI state, so the PR review poller should hand semantic conflict resolution back to the normal agent workflow. - Keeping the conflict key in the existing PR review record avoids a new store table or config contract while preventing repeated dispatch loops for the same conflict. Tests: - mix test test/symphony_elixir/pr_review_poller_test.exs test/symphony_elixir/github_pull_request_test.exs test/symphony_elixir/core_test.exs:2263 - mix specs.check - mix lint - git diff --check - make all (fails in full app-server tests with {:mcp_socket_open_failed, :eperm}; coverage then misses the 100% threshold)

Summary: - Remove unreachable non-map fallback clauses from PR conflict helpers. - Cover PR conflict prompt fallback values for string timestamps and invalid retry limits. Rationale: - Dialyzer can prove PR review conflict helpers only receive maps at these call sites, so the defensive catch-all clauses were dead code. - The added prompt assertions exercise fallback branches that CI coverage previously reported as missed. Tests: - mix test test/symphony_elixir/core_test.exs:2268 test/symphony_elixir/pr_review_poller_test.exs test/symphony_elixir/github_pull_request_test.exs - mix specs.check - MIX_HOME=/private/tmp/rsm-3739-mix-home HEX_HOME=/private/tmp/rsm-3739-hex-home mix dialyzer --format short - mix format --check-formatted - mix lint - git diff --check - make all (fails locally: app-server MCP socket setup returns {:mcp_socket_open_failed, :eperm})

Summary: - Let conflict helper functions accept any input shape so Dialyzer no longer reports unreachable fallback clauses. - Cover compact prompt PR conflict instructions and metadata. Rationale: - The PR conflict flow normalizes map-like persisted data at the call sites, so the helper guards were narrower than the inferred types. - Compact prompts share the same conflict section as full prompts and need direct coverage to keep the 100% coverage gate green. Tests: - mix test test/symphony_elixir/pr_review_poller_test.exs test/symphony_elixir/prompt_builder_test.exs test/symphony_elixir/github_pull_request_test.exs test/symphony_elixir/core_test.exs:2263 - mix dialyzer --format short - mix test.coverage - mix specs.check - mix lint - mix format --check-formatted - git diff --check - make all (fails locally: app-server MCP socket setup returns eperm; PromptBuilder reports 100% before coverage fails from those test failures)

chihsuan · 2026-05-21T13:59:56Z

@copilot resolve the merge conflicts in this pull request

Copilot

Pull request overview

This PR extends Symphony’s PR review polling flow to detect GitHub merge conflicts, persist conflict context (including head/base identity), and auto-dispatch an agent-owned conflict-resolution run by moving the Linear issue back to In Progress while injecting conflict instructions/metadata into the next agent prompt.

Changes:

Fetch additional PR mergeability + head/base metadata via gh pr view --json ... and expose it through GitHub.PullRequest.fetch_activity/2.
Add merge-conflict detection/deduping/escalation logic to PrReviewPoller, persist conflict context in PR review records, and expose pending_pr_conflict/2 for prompt injection.
Inject merge-conflict context/instructions into both full and compact prompts, and wire the injection into AgentRunner.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
`lib/symphony_elixir/pr_review_poller.ex`	Detect merge conflicts from PR activity, store conflict context, dedupe by head/base key, dispatch/escalate, and expose `pending_pr_conflict/2`.
`lib/symphony_elixir/github/pull_request.ex`	Extend `gh pr view` fields and normalize mergeability/head/base metadata into activity.
`lib/symphony_elixir/prompt_builder.ex`	Add `pr_conflict` normalization and append a conflict section (instructions + metadata) to prompts.
`lib/symphony_elixir/agent_runner.ex`	Include `pr_conflict` in first-turn prompt options and use it in continuation stopping logic.
`test/symphony_elixir/pr_review_poller_test.exs`	Add coverage for conflict dispatch, dedupe, escalation, active-run suppression, and cleanup behavior.
`test/symphony_elixir/github_pull_request_test.exs`	Update expectations for expanded `gh pr view --json` fields and decoded activity fields.
`test/symphony_elixir/prompt_builder_test.exs`	Assert compact prompt includes conflict instructions and metadata.
`test/symphony_elixir/core_test.exs`	Assert prompt builder injects conflict instructions/metadata and handles partial/missing fields.
`SPEC.md`	Document conflict detection/dispatch behavior in the poller spec.
`docs/configuration.md`	Document merge conflict detection + prompt injection behavior for the PR review poller.

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chihsuan · 2026-05-21T14:12:27Z

@copilot resolve the merge conflicts in this pull request

Co-authored-by: chihsuan <4344253+chihsuan@users.noreply.github.com>

Copilot · 2026-05-21T14:17:40Z

@copilot resolve the merge conflicts in this pull request

Resolved and pushed in commit 9420a44. I merged origin/main into this branch and fixed the three semantic conflicts in lib/symphony_elixir/github/pull_request.ex, lib/symphony_elixir/pr_review_poller.ex, and test/symphony_elixir/github_pull_request_test.exs.

Summary: - Add bounded prompt-safety normalization for inline PR conflict fields. - Apply that normalization before conflict metadata reaches workflow templates or compact prompt rendering. - Cover both render paths with malicious and overlong conflict metadata. Rationale: - PR conflict metadata can include human-authored titles and branch names. Sanitizing it before rendering keeps conflict prompts bounded and avoids confusing control text in untrusted input sections. Tests: - mix test test/symphony_elixir/prompt_safety_test.exs test/symphony_elixir/prompt_builder_test.exs test/symphony_elixir/pr_review_poller_test.exs test/symphony_elixir/github_pull_request_test.exs - mix specs.check - git diff --check - MIX_HOME=/private/tmp/symphony-mix-home HEX_HOME=/private/tmp/symphony-hex-home mix dialyzer --format short - make all (blocked by MCP socket bind returning {:mcp_socket_open_failed, :eperm}; coverage then fails below the 100% threshold)

Copilot · 2026-05-21T14:22:45Z

@copilot resolve the merge conflicts in this pull request

Resolved by merging latest origin/main into this branch and pushing commit 37a50ed, which clears the PR merge conflicts. No UI changes in this PR, so there is no screenshot to share.

@copilot resolve the merge conflicts in this pull request

Done — I merged latest origin/main into this branch and pushed commit 37a50ed to resolve the merge conflicts. No UI changes in this PR, so there is no screenshot to share.

Summary: - Add the formatter-required blank line in the GitHub PR activity test. - Wrap long PR review poller branches and a long AppServer test assertion. - Replace a one-branch cond with if/else in config schema validation. Rationale: - The reviewer-reported format and credo failures blocked the gate. - The additional small style fixes keep the full lint command green without changing runtime behavior. Tests: - mix format --check-formatted - mix test test/symphony_elixir/github_pull_request_test.exs test/symphony_elixir/pr_review_poller_test.exs - mix specs.check - mix lint - mix test test/symphony_elixir/app_server_test.exs:1858 failed locally before the touched assertion with {:mcp_socket_open_failed, :eperm}

Summary: - Restore the event-specific assert_received pattern for malformed command completion recovery messages. - Keep the assertion formatter-friendly without binding the first generic app-server mailbox message. Rationale: - The prior lint rewrite consumed :session_started before the recovery event, which regressed the test assertion and failed CI. Tests: - mix format --check-formatted test/symphony_elixir/app_server_test.exs - mix lint - git diff --check -- test/symphony_elixir/app_server_test.exs - mix test test/symphony_elixir/app_server_test.exs:1858 blocked locally by {:mcp_socket_open_failed, :eperm}

chihsuan · 2026-05-21T16:07:36Z

@copilot resolve the merge conflicts in this pull request

# Conflicts: # test/symphony_elixir/app_server_test.exs Co-authored-by: chihsuan <4344253+chihsuan@users.noreply.github.com>

Copilot · 2026-05-21T16:10:45Z

@copilot resolve the merge conflicts in this pull request

Resolved in commit 0b60ad2 by merging latest origin/main into this branch and fixing the remaining merge conflict in test/symphony_elixir/app_server_test.exs. No UI changes in this PR, so screenshot is not applicable.

chihsuan added 3 commits May 21, 2026 18:44

Copilot started work on behalf of chihsuan May 21, 2026 14:00 View session

chihsuan requested a review from Copilot May 21, 2026 14:01

Copilot started reviewing on behalf of chihsuan May 21, 2026 14:01 View session

Copilot AI reviewed May 21, 2026

View reviewed changes

Comment thread lib/symphony_elixir/prompt_builder.ex Outdated

Copilot started work on behalf of chihsuan May 21, 2026 14:12 View session

Copilot AI and others added 2 commits May 21, 2026 14:12

Merge origin/main into auto/RSM-3739

9420a44

Co-authored-by: chihsuan <4344253+chihsuan@users.noreply.github.com>

Merge remote-tracking branch 'origin/main' into auto/RSM-3739

37a50ed

Co-authored-by: chihsuan <4344253+chihsuan@users.noreply.github.com>

Copilot finished work on behalf of chihsuan May 21, 2026 14:18

Copilot finished work on behalf of chihsuan May 21, 2026 14:23

chihsuan added 2 commits May 21, 2026 22:24

Merge remote-tracking branch 'origin/auto/RSM-3739' into auto/RSM-3739

7f8daec

chihsuan mentioned this pull request May 21, 2026

fix(ci): per-SHA reset and dispatch race fix in CI poller #59

Merged

2 tasks

Copilot started work on behalf of chihsuan May 21, 2026 16:07 View session

Merge remote-tracking branch 'origin/main' into auto/RSM-3739

0b60ad2

# Conflicts: # test/symphony_elixir/app_server_test.exs Co-authored-by: chihsuan <4344253+chihsuan@users.noreply.github.com>

Copilot finished work on behalf of chihsuan May 21, 2026 16:11

style(test): add blank line after recovered-event assertion block

57c1a05

chihsuan merged commit ec435a3 into main May 21, 2026
9 checks passed

chihsuan deleted the auto/RSM-3739 branch May 25, 2026 06:00

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Auto-dispatch PR conflict resolution from PR poller - #57

Auto-dispatch PR conflict resolution from PR poller#57
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