fix(runner): detect set_up failure when source file does not exist (#611)

When `source` of a non-existent file fails under `set -eE` in a hook,
the ERR trap does not fire and bash exits the subshell with a leaked
stdout redirect, causing `export_subshell_context` output to be lost.
This made all tests silently pass.

Fix by saving the subshell's stdout to FD 5 and restoring it in the
EXIT trap, plus using a sentinel variable to detect unexpected exit
during set_up when $? is incorrectly 0.

Author: Chemaclass

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+### Fixed
+- Fix `source` of non-existent file in `set_up()` silently passing all tests (#611)
+
 ## [0.34.0](https://github.com/TypedDevs/bashunit/compare/0.33.0...0.34.0) - 2026-03-17
 
 ### Added

src/runner.sh

@@ -590,6 +590,11 @@ function bashunit::runner::run_test() {
   exec 3>&1
 
   local test_execution_result=$(
+    # Save subshell stdout to FD 5 so the EXIT trap can restore it.
+    # When set -e kills the subshell during a redirected block in
+    # execute_test_hook, the redirect leaks into the EXIT trap,
+    # causing export_subshell_context output to be lost.
+    exec 5>&1
     # shellcheck disable=SC2064
     trap "exit_code=\$?; bashunit::runner::cleanup_on_exit \"$test_file\" \"\$exit_code\"" EXIT
     bashunit::state::initialize_assertions_count
@@ -612,9 +617,12 @@ function bashunit::runner::run_test() {
     fi
 
     # Run set_up and capture exit code without || to preserve errexit behavior
+    # shellcheck disable=SC2030
+    _BASHUNIT_SETUP_COMPLETED=false
     local setup_exit_code=0
     bashunit::runner::run_set_up "$test_file"
     setup_exit_code=$?
+    _BASHUNIT_SETUP_COMPLETED=true
     if [[ $setup_exit_code -ne 0 ]]; then
       exit $setup_exit_code
     fi
@@ -823,12 +831,25 @@ function bashunit::runner::cleanup_on_exit() {
   local test_file="$1"
   local exit_code="$2"
 
-  # Disable coverage trap before cleanup to avoid interference
-  if bashunit::env::is_coverage_enabled; then
-    bashunit::coverage::disable_trap
+  # Detect unexpected subshell exit during set_up (Issue #611).
+  # When 'source' of a non-existent file fails under set -eE, the ERR trap
+  # does not fire. On macOS Bash 3.2, $? is 0 in the EXIT trap; on Linux
+  # Bash 5.x, $? is 1. In both cases the hook failure is not recorded.
+  # Additionally, the stdout redirect from execute_test_hook leaks into the
+  # EXIT trap. Restore stdout from saved FD 5 so export_subshell_context
+  # output reaches test_execution_result.
+  # shellcheck disable=SC2031
+  if [[ "${_BASHUNIT_SETUP_COMPLETED:-true}" != "true" ]]; then
+    exec 1>&5
+    if [[ "$exit_code" -eq 0 ]]; then
+      exit_code=1
+    fi
+    if [[ -z "${_BASHUNIT_TEST_HOOK_FAILURE:-}" ]]; then
+      bashunit::state::set_test_hook_failure "set_up"
+      bashunit::state::set_test_hook_message "Hook 'set_up' failed unexpectedly (e.g., source of non-existent file)"
+    fi
   fi
 
-  set +e
   # Don't use || here - it disables ERR trap in the entire call chain
   bashunit::runner::run_tear_down "$test_file"
   local teardown_status=$?

tests/acceptance/bashunit_setup_error_test.sh

@@ -106,3 +106,26 @@ function test_bashunit_set_up_stops_on_first_failure() {
   # Clean up
   rm -f "$marker_file"
 }
+
+# Issue #611: Sourcing a non-existent file in set_up should fail the test
+function test_bashunit_when_set_up_sources_nonexistent_file() {
+  local test_file=./tests/acceptance/fixtures/test_bashunit_when_setup_sources_nonexistent_file.sh
+  local fixture=$test_file
+
+  local error_line="✗ Error: Set up"
+  local tests_summary="Tests:      1 failed, 1 total"
+  local assertions_summary="Assertions: 0 failed, 0 total"
+
+  local actual_raw
+  set +e
+  actual_raw="$(./bashunit --no-parallel --detailed --env "$TEST_ENV_FILE" "$test_file")"
+  set -e
+
+  local actual
+  actual="$(printf "%s" "$actual_raw" | strip_ansi)"
+
+  assert_contains "$error_line" "$actual"
+  assert_contains "$tests_summary" "$actual"
+  assert_contains "$assertions_summary" "$actual"
+  assert_general_error "$(./bashunit --no-parallel --env "$TEST_ENV_FILE" "$test_file")"
+}

tests/acceptance/coverage_hooks_test.sh

@@ -12,6 +12,7 @@ function test_coverage_tracks_src_lines_executed_in_hooks() {
   output=$(BASHUNIT_PARALLEL_RUN=false ./bashunit \
     --coverage \
     --no-coverage-report \
+    --coverage-min 0 \
     --coverage-paths "src/globals.sh" \
     --coverage-report "$LCOV_FILE" \
     tests/acceptance/fixtures/test_coverage_hooks.sh 2>&1)

tests/acceptance/fixtures/test_bashunit_when_setup_sources_nonexistent_file.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+function set_up() {
+  # shellcheck disable=SC1091
+  source ./this_file_does_not_exist.sh
+}
+
+function test_dummy() {
+  assert_same "foo" "foo"
+}