fix(test): typed-feedback entry-return ordering assertion compared unrelated sites

[TheHypnoo]

What

typed_feedback_trace_dump_runs_before_entry_return in
crates/perry-codegen/tests/typed_feedback.rs has been red on main
(reproduced at 8b2c736, macOS arm64).

Codegen is not the problem. add_pre_return_void_call in
crates/perry-codegen/src/codegen/entry.rs:469 splices
call void @js_typed_feedback_maybe_dump_trace() in front of every ret in
main, via the return-site rewrite in crates/perry-codegen/src/function.rs:499.
It still does.

The test was measuring the wrong thing. It compared two rfinds over the whole
module text:

let dump_pos = ir.rfind("call void @js_typed_feedback_maybe_dump_trace()")…;
let ret_pos  = ir.rfind("ret i32 0")…;
assert!(dump_pos < ret_pos);

main has more than one return. The emitted IR:

event_loop.host_return.3:
  call void @js_typed_feedback_maybe_dump_trace()
  ret i32 0
…
event_loop.exit.5:
  …
  %r38 = call i32 @js_process_pending_exit_code()
  call void @js_typed_feedback_maybe_dump_trace()
  ret i32 %r38

The host-return early exit is the one that returns a literal i32 0; the
event-loop exit returns the pending exit code. So rfind("ret i32 0") landed on
the first return and rfind(dump) on the second dump — two unrelated sites. The
assertion failed while the property it names held.

Change

Slice the IR to main's body and check every return site: each ret must be
immediately preceded by the dump call. That covers both returns instead of one,
and it is the ordering the epilogue actually guarantees.

Verification

• cargo test -p perry-codegen --test typed_feedback — 15/15 pass.
• Negative check: deleting the add_pre_return_void_call at entry.rs:469
  fails the new test. The old shape could not guarantee that.

Integration suites under crates/*/tests/ don't run per-PR (#5960), which is why
this sat red. Sibling stale test native_proof_buffer_views is fixed in #6839;
this one is untouched there.

Summary by CodeRabbit

• Tests

  • Improved coverage to verify that typed-feedback trace dumps occur before every application entry-point return.
  • Updated validation to focus specifically on the entry-point function and detect ordering issues more reliably.

• Documentation

  • Added a changelog entry describing the corrected test coverage and trace-dump ordering validation.

[coderabbitai]

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Review details

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: e778a0af-611e-4045-a15d-f5af42ba3ec4

📥 Commits

Reviewing files that changed from the base of the PR and between 396a485 and 55f21fc.

📒 Files selected for processing (2)

• changelog.d/6840-typed-feedback-entry-return-ordering.md
• crates/perry-codegen/src/loop_purity.rs

📝 Walkthrough

Walkthrough

The test now extracts main from compiled IR and verifies that js_typed_feedback_maybe_dump_trace() immediately precedes every return instruction. The changelog documents the corrected validation strategy and existing codegen behavior.

Changes

Typed feedback validation

Layer / File(s)	Summary
Main return ordering validation crates/perry-codegen/tests/typed_feedback.rs, changelog.d/6840-typed-feedback-entry-return-ordering.md	The test isolates main, checks every return site for the preceding trace-dump call, and documents the corrected assertion strategy.

Estimated code review effort: 2 (Simple) | ~10 minutes

Suggested reviewers: proggeramlug, andrewtdiz

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and accurately summarizes the main fix to the typed-feedback test assertion.
Description check	✅ Passed	It covers the summary, concrete changes, and verification, though it omits the template's Related issue and checklist sections.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/typed-feedback-entry-return-ordering

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[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (1)

crates/perry-codegen/tests/typed_feedback.rs (1)

222-245: 📐 Maintainability & Code Quality | 🔵 Trivial | 🏗️ Heavy lift

Keep this regression check in a PR-visible unit-test path.

This remains an integration test under crates/*/tests/*.rs. Per repository guidance, add equivalent acceptance coverage in a cargo test-visible unit-test module so the regression is exercised by default.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@crates/perry-codegen/tests/typed_feedback.rs` around lines 222 - 245, Move or
duplicate this typed-feedback return-order regression check into a cargo
test-visible unit-test module, while preserving coverage of every return in main
via entry_fn_body and the existing assertions. Keep the integration test only if
needed, but ensure the equivalent check runs by default through the repository’s
unit-test path.

Source: Coding guidelines

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@changelog.d/6840-typed-feedback-entry-return-ordering.md`:
- Around line 19-20: Update the CI explanation in the changelog entry to remove
the stale claim that crates/*/tests/ integration suites do not run per PR;
describe that changed suites are now selected by the PR e2e-scoped job, or
clearly frame the omission as historical context.

---

Nitpick comments:
In `@crates/perry-codegen/tests/typed_feedback.rs`:
- Around line 222-245: Move or duplicate this typed-feedback return-order
regression check into a cargo test-visible unit-test module, while preserving
coverage of every return in main via entry_fn_body and the existing assertions.
Keep the integration test only if needed, but ensure the equivalent check runs
by default through the repository’s unit-test path.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 39fc0c21-12ba-4ca1-b27e-d1f7d85cfbcc

📥 Commits

Reviewing files that changed from the base of the PR and between 82486d6 and 396a485.

📒 Files selected for processing (2)

• changelog.d/6840-typed-feedback-entry-return-ordering.md
• crates/perry-codegen/tests/typed_feedback.rs