Improve tests

tests/test_plugin_installation_legacy.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+
+CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+source $CURRENT_DIR/helpers.sh
+
+test_plugin_installation() {
+	set_tmux_conf_helper <<- HERE
+	set -g @tpm_plugins "tmux-plugins/tmux-example-plugin"
+	run-shell "$PWD/tpm"
+	HERE
+
+	# opens tmux and test it with `expect`
+	$CURRENT_DIR/expect_successful_plugin_download ||
+		fail_helper "Tmux plugin installation fails"
+
+	# check plugin dir exists after download
+	check_dir_exists_helper "$HOME/.tmux/plugins/tmux-example-plugin/" ||
+		fail_helper "Plugin download fails"
+
+	teardown_helper
+}
+
+main() {
+	test_plugin_installation
+	exit_value_helper
+}
+main