dev: Make the tests command able to select which test to launch

The `tests` command can either launch all tests (without any arguments),
a specific test with `-t/--test` or choose a test with `-i/--interactive`

flake-modules/dev/default.nix

@@ -34,6 +34,7 @@
           };
           statix.enable = true;
           stylua.enable = true;
+          shfmt.enable = true;
           taplo.enable = true;
         };
 

flake-modules/dev/devshell.nix

@@ -32,10 +32,20 @@
             {
               name = "tests";
               help = "Run nixvim tests";
-              command = ''
-                echo "=> Running nixvim tests for the '${system}' architecture..."
+              command =
+                let
+                  launchTest = pkgs.writeShellApplication {
+                    name = "launch-tests";
+                    runtimeInputs = with pkgs; [
+                      jq
+                      fzf
+                    ];
 
-                ${nix} build .#checks.${system}.tests "$@"
+                    text = builtins.readFile ./launch-test.sh;
+                  };
+                in
+                ''
+                  NIXVIM_SYSTEM=${system} NIXVIM_NIX_COMMAND=${nix} ${lib.getExe launchTest} "$@"
                 '';
             }
             {

flake-modules/dev/launch-test.sh

@@ -0,0 +1,83 @@
+#!/usr/bin/env bash
+
+: "${NIXVIM_NIX_COMMAND:=nix}"
+if [[ -z ${NIXVIM_SYSTEM+x} ]]; then
+	NIXVIM_SYSTEM=$(nix eval --raw --impure --expr "builtins.currentSystem")
+fi
+
+help() {
+	cat <<EOF
+Usage: tests [OPTIONS] [tests...]
+
+If tests are passed on the command line only these will be launched
+
+Options:
+	-h, --help: Display this help message and exit
+	-l, --list: Display the list of tests and exit
+	-i, --interactive: Pick interactively the tests. Can't be supplied if tests where passed.
+EOF
+}
+
+if ! OPTS=$(getopt -o "hli" -l "help,list,interactive" -- "$@"); then
+	echo "Invalid options" >&2
+	help
+	exit 1
+fi
+
+eval set -- "$OPTS"
+
+specified_tests=()
+interactive=false
+
+mk_test_list() {
+	nix eval ".#checks.${NIXVIM_SYSTEM}" --apply builtins.attrNames --json |
+		jq -r 'map(select(startswith("test-")))[]'
+}
+
+while true; do
+	case "$1" in
+	-h | --help)
+		help
+		exit 0
+		;;
+	-l | --list)
+		mk_test_list
+		exit 0
+		;;
+	-i | --interactive)
+		interactive=true
+		shift
+		;;
+	--)
+		shift
+		specified_tests=("$@")
+		break
+		;;
+	esac
+done
+
+run_tests() {
+	# Add the prefix "checks.${system}." to each argument
+	if ! "${NIXVIM_NIX_COMMAND}" build --no-link --file . "${@/#/checks.${NIXVIM_SYSTEM}.}"; then
+		echo "Test failure" >&2
+		exit 1
+	fi
+}
+
+if [[ $interactive = true && ${#specified_tests[@]} -ne 0 ]]; then
+	echo "Can't use --interactive with tests on the command line" >&2
+	exit 1
+fi
+
+if [[ $interactive = true ]]; then
+	test_name=$(mk_test_list | fzf) || exit $?
+	specified_tests+=("$test_name")
+fi
+
+if [[ ${#specified_tests[@]} -eq 0 ]]; then
+	readarray -t complete_test_list < <(mk_test_list)
+	run_tests "${complete_test_list[@]}"
+else
+	echo "Running ${#specified_tests[@]} tests: ${specified_tests[*]}" >&2
+	run_tests "${specified_tests[@]}"
+fi

tests/default.nix

@@ -48,7 +48,7 @@ builtins.listToAttrs (
       dontRunModule = case: case.tests.dontRun or false;
     in
     {
-      inherit name;
+      name = "test-${name}";
       value = mkTestDerivationFromNixvimModule {
         inherit name;
         tests = builtins.map (