fix: stop reporting expected function errors

[byrichardpowell]

Summary

sendErrorToBugsnag reports all Error instances regardless of their classification. This means AbortError — whose docstring says "shouldn't be reported as a bug" — still gets sent, generating significant noise in Observe.

This PR adds an early return when exitMode === 'expected_error', making the reporting layer respect the classification that shouldReportErrorAsUnexpected already computes correctly.

Problem

The Observe error group Build step "Build Function" failed: Failed to build function. has ~12k events/month across all CLI versions (3.82.0+). Investigation showed:

• The error group appeared in Observe on April 2 because 3.93.0 introduced a client-steps.ts wrapper that changed the message format, creating a new grouping hash
• The underlying errors are user code compilation failures (broken Rust/JS function code), not CLI bugs
• buildFunctionExtension wraps these in AbortError with the comment "To avoid random user-code errors being reported as CLI bugs" — but sendErrorToBugsnag ignores that and reports them anyway

The classification chain works correctly:

AbortError (type=Abort) → shouldReportErrorAsUnexpected() returns false
  → exitMode='expected_error' → sendErrorToBugsnag() ignores exitMode, reports anyway

Fix

5-line early return in sendErrorToBugsnag:

if (exitMode === 'expected_error') {
  outputDebug(`Skipping Bugsnag report for expected error`)
  return {reported: false, error, unhandled: false}
}

Impact

6 callsites use sendErrorToBugsnag. 5 use hardcoded exitMode, 1 computes it dynamically:

Callsite	exitMode	After change
Main error handler (errorHandler)	dynamic	AbortError/ExternalError → skipped. BugError/plain Error → still reported
Analytics flush errors	expected_error	Skipped (telemetry plumbing, not bugs)
Notification system errors	unexpected_error	Still reported
Metadata provider errors	unexpected_error	Still reported
Auto-upgrade errors	expected_error	Skipped (tracked separately via analytics metadata env_auto_upgrade_success)
Notification list errors	expected_error	Skipped (hidden command)

Every callsite that stops reporting was already explicitly classified as expected_error — either by shouldReportErrorAsUnexpected or by the developer hardcoding it. No signal is lost that isn't tracked through other channels.

Test plan

• Updated existing test: processes AbortErrors as handled → skips reporting for expected errors
• All 25 error-handler tests pass

🤖 Generated with Claude Code

Closes shop/issues#32997

[Copilot]

Pull request overview

Updates CLI Kit’s Bugsnag reporting behavior to respect the already-computed error classification, preventing “expected” (non-bug) errors from being sent to Bugsnag/Observe.

Changes:

• Add an early return in sendErrorToBugsnag when exitMode === 'expected_error' to skip reporting.
• Update the existing test to assert that expected errors are not reported.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
packages/cli-kit/src/public/node/error-handler.ts	Skips Bugsnag notification when the error is classified as expected_error.
packages/cli-kit/src/public/node/error-handler.test.ts	Updates the relevant test to ensure expected errors are not reported.

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[craigmichaelmartin]

Thank you!!