fix(runner): stop get_function_line_number clobbering caller extdebug

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 ### Fixed
+- `bashunit::helper::get_function_line_number` no longer disables `extdebug` for its caller: it enables the option only inside a subshell (also dropping an `awk` fork)
 - `--test-timeout` no longer intermittently reports a fast test as timed out; the watchdog now signals by pid and skips a test that already completed
 
 ### Added

src/helpers.sh

@@ -615,12 +615,16 @@ function bashunit::helper::load_bench_files() {
 function bashunit::helper::get_function_line_number() {
   local fn_name=$1
 
-  shopt -s extdebug
-  local line_number
-  line_number=$(declare -F "$fn_name" | awk '{print $2}')
-  shopt -u extdebug
-
-  echo "$line_number"
+  # Enable extdebug only inside the subshell so the caller's setting is not
+  # clobbered. With extdebug, `declare -F` prints "<name> <line> <file>"; parse
+  # the line number with shell word-splitting instead of forking awk.
+  local declaration
+  declaration=$(
+    shopt -s extdebug
+    declare -F "$fn_name"
+  )
+  declaration="${declaration#* }"
+  echo "${declaration%% *}"
 }
 
 # Writes a sanitized, process-unique id into _BASHUNIT_HELPER_ID_OUT.

tests/unit/helpers_test.sh

@@ -586,3 +586,26 @@ function test_find_function_at_line_nonexistent_file() {
   bashunit::helper::find_function_at_line "/nonexistent/file.sh" 10 2>/dev/null || exit_code=$?
   assert_same 1 "$exit_code"
 }
+
+function test_get_function_line_number_returns_the_definition_line() {
+  # shellcheck disable=SC2317  # invoked indirectly via declare -F
+  function _bashunit_line_fixture() { :; }
+
+  local line
+  line="$(bashunit::helper::get_function_line_number _bashunit_line_fixture)"
+
+  assert_matches '^[0-9]+$' "$line"
+}
+
+function test_get_function_line_number_preserves_caller_extdebug() {
+  # extdebug is toggled inside a subshell so the assertion never enables it in
+  # the test runner's shell. The helper must not turn it off for its caller.
+  local state
+  state=$(
+    shopt -s extdebug
+    bashunit::helper::get_function_line_number test_get_function_line_number_preserves_caller_extdebug >/dev/null
+    if shopt -q extdebug; then echo "on"; else echo "off"; fi
+  )
+
+  assert_same "on" "$state"
+}