ci: also test on ksh

Makefile

@@ -5,7 +5,7 @@ lint:
 	@find run lib -type f -not -iname '*.*' | xargs shellcheck -s dash
 	@printf "\033[032mLINT OK\033[0m\n\n"
 
-test: lint test-dash test-bash
+test: lint test-dash test-bash test-ksh
 
 test-ash:
 	@cd test && ash ./lib_test.sh
@@ -19,4 +19,8 @@ test-bash:
 	@cd test && bash ./lib_test.sh
 	@cd test && bash ./run_test.sh
 
+test-ksh:
+	@cd test && ksh ./lib_test.sh
+	@cd test && ksh ./run_test.sh
+
 .PHONY: lint test test-dash test-bash

flake.nix

@@ -10,7 +10,12 @@
       rec {
         devShell = pkgs.mkShell {
           buildInputs = with pkgs; [
+            # Shells
+            bash
             dash
+            ksh
+
+            # Tools
             gnumake
             shellcheck
           ];