Entrace unexpected errors in snapshots

[hadley]

This ensures that their backtraces point to the source of the error, not the internals of expect_snapshot()

Fixes #2277

[claude]

Claude finished @hadley's task —— View job

---

Reviewing PR: Entrace unexpected errors in snapshots

Todo List:

• Read repository guidelines (CLAUDE.md)
• Examine core changes in R/verify-output.R
• Review test changes and snapshot updates
• Analyze for potential bugs or issues
• Provide review feedback

Review Analysis

The core change in R/verify-output.R:89 adds rlang::entrace(cnd) to the error handler in verify_exec(). This ensures error backtraces in snapshots point to the source rather than expect_snapshot() internals.

Key observations:

1. Correct implementation: The change properly adds calling_handlers = list(error = function(cnd) rlang::entrace(cnd)) to the evaluate::new_output_handler()
2. Dependencies satisfied: rlang is imported globally via @import rlang in testthat-package.R:89
3. Test coverage: New test case validates the fix with a clear call chain (f() -> g() -> h())
4. Snapshot updates: All affected snapshots correctly updated to show improved backtraces

Issues found:

• Line numbers in test snapshots shifted but updates look correct
• Error condition type changed from simpleError to rlang_error in snapshots - expected behavior with entracing

LGTM

[Copilot]

Pull Request Overview

This PR enhances error handling in snapshot testing by ensuring that unexpected errors within expect_snapshot() produce backtraces that point to the source of the error rather than the internals of the snapshot mechanism. This is achieved by adding error entracing via rlang::entrace() in the verify_exec handler.

Key Changes:

• Added error entracing to the verify_exec() function's output handler to capture meaningful backtraces for errors occurring within snapshots
• Added a test case to verify that errors in snapshots produce useful backtraces
• Updated snapshot test outputs to reflect the new error handling behavior

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
R/verify-output.R	Added rlang::entrace() as an error handler in the evaluate output handler to capture backtraces
tests/testthat/reporters/backtraces.R	Added test case demonstrating error backtrace behavior in snapshots
tests/testthat/test-reporter-progress.R	Set TESTTHAT_MAX_FAILS to Inf to ensure all test failures are captured
tests/testthat/_snaps/reporter-progress.md	Updated snapshot to include the new test case and adjusted line numbers
tests/testthat/_snaps/snapshot.md	Changed error class from simpleError to rlang_error due to entracing
tests/testthat/_snaps/snapshot-reporter.md	Updated error message format to include "Error:" prefix
NEWS.md	Documented the improvement to snapshot error backtraces

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Corrected spelling of 'Entrace' to 'Entrance' in PR title; however, the term should be 'Entraces' (verb form) to match the technical usage in the code.

[lionel-]

LG!