Add some tests for shell scripts

Makefile

@@ -41,15 +41,18 @@ sanitize:
 	#
 	#
 
-build: test submodules bin/resh-collect bin/resh-daemon bin/resh-evaluate bin/resh-sanitize
+build: test_go submodules bin/resh-collect bin/resh-daemon bin/resh-evaluate bin/resh-sanitize
 
-test:
+test_go:
 	# Running tests
 	@for dir in {cmd,pkg}/* ; do \
 		echo $$dir ; \
 		go test $$dir/*.go ; \
 	done
 
+test:
+	scripts/test.sh
+
 rebuild:
 	make clean
 	make build

scripts/test.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+[ "${BASH_SOURCE[0]}" != "scripts/test.sh" ] && echo 'Run this script using `make test`' && exit 1 
+
+for f in scripts/*.sh; do
+    echo "Running shellcheck on $f ..."
+    shellcheck $f --shell=bash --severity=error || exit 1
+done
+
+echo "Checking Zsh syntax of scripts/shellrc.sh ..."
+! zsh -n scripts/shellrc.sh && echo "Zsh syntax check failed!" && exit 1
+
+for sh in bash zsh; do
+    echo "Running functions in scripts/shellrc.sh using $sh ..."
+    ! $sh -c ". scripts/shellrc.sh; __resh_preexec; __resh_precmd" && echo "Error while running functions!" && exit 1
+done
+
+# TODO: test installation
+
+exit 0