add bash-it

dot_bash_it/test/executable_run

@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+test_directory="$(cd "$(dirname "$0")" && pwd)"
+bats_executable="${test_directory}/../test_lib/bats-core/bin/bats"
+
+# Locate ourselves for easy reference.
+export MAIN_BASH_IT_DIR="${test_directory%/*}"
+export MAIN_BASH_IT_GITDIR="${MAIN_BASH_IT_DIR}/.git"
+
+# Make sure BATS is available:
+git submodule init && git submodule update
+
+# Warn user that tests run from the current git HEAD
+if ! git diff --quiet; then
+	echo "${BASH_SOURCE##*/}: your worktree is dirty; uncommitted changes will *not* be tested!"
+fi
+
+# Which tests do we run?
+if [[ $# -eq '0' ]]; then
+	test_dirs=("${test_directory}"/{bash_it,completion,install,lib,plugins,themes})
+else
+	test_dirs=("$@")
+fi
+
+# Make sure that the `parallel` command is installed,
+# AND that it is the GNU version of `parallel`.
+# If that is the case, try to guess the number of CPU cores,
+# so we can run `bats` in parallel processing mode, which is a lot faster.
+if command -v parallel &> /dev/null \
+	&& parallel -V &> /dev/null \
+	&& { parallel -V 2> /dev/null | grep -q '^GNU\>'; }; then
+	# Expect to run at least on a dual-core CPU; slightly degraded performance
+	# shouldn't matter otherwise.
+	declare -i -r test_jobs_default=2
+	# shellcheck disable=SC2155
+	declare -i -r test_jobs_effective="$(
+		if [[ "${TEST_JOBS:-detect}" = "detect" ]] \
+			&& command -v nproc &> /dev/null; then
+			nproc
+		elif [[ -n "${TEST_JOBS}" ]] \
+			&& [[ "${TEST_JOBS}" != "detect" ]]; then
+			echo "${TEST_JOBS}"
+		else
+			echo "${test_jobs_default}"
+		fi
+	)"
+	exec "$bats_executable" "${CI:+--tap}" --jobs "${test_jobs_effective}" \
+		--no-parallelize-within-files "${test_dirs[@]}"
+else
+	# Run `bats` in single-threaded mode.
+	exec "$bats_executable" "${CI:+--tap}" "${test_dirs[@]}"
+fi