feat: add test helpers

default args to {}

lib/default.nix

@@ -5,6 +5,8 @@
 }: let
   inherit (lib) evalModules toList;
 in rec {
+  helpers = import ./testHelpers.nix {inherit lib;};
+
   mkBinary = {
     nixtests,
     extraParams,
@@ -46,7 +48,7 @@ in rec {
 
   mkNixtestConfig = {
     modules,
-    args,
+    args ? {},
     ...
   }:
     (evalModules {

lib/scriptHelpers.sh

@@ -0,0 +1,51 @@
+output=
+exit_code=
+
+function assert() {
+  test $1 || { echo "Assertion '$1' failed: $2" >&2; exit 1; }
+}
+function assert_eq() {
+  assert "$1 -eq $2" "$3"
+}
+function assert_not_eq() {
+  assert "$1 -ne $2" "$3"
+}
+function assert_contains() {
+  echo "$1" | grep -q -- "$2" || {
+    echo "Assertion failed: $3. $1 does not contain $2" >&2;
+    exit 1;
+  }
+}
+function assert_not_contains() {
+  echo "$1" | grep -q -- "$2" && {
+    echo "Assertion failed: $3. $1 does contain $2" >&2;
+    exit 1;
+  }
+}
+function assert_file_contains() {
+  grep -q -- "$2" $1 || {
+    echo "Assertion failed: $3. $1 does not contain $2" >&2;
+    exit 1;
+  }
+}
+function assert_file_not_contains() {
+  grep -q -- "$2" $1 && {
+    echo "Assertion failed: $3. $1 does contain $2" >&2;
+    exit 1;
+  }
+}
+
+function tmpdir() {
+  dir=$(mktemp -d)
+  trap "rm -rf $dir" EXIT
+  echo -n "$dir"
+}
+function tmpfile() {
+  file=$(mktemp)
+  trap "rm -f $file" EXIT
+  echo -n "$file"
+}
+function run() {
+  output=$($@ 2>&1)
+  exit_code=$?
+}

lib/testHelpers.nix

@@ -0,0 +1,5 @@
+{lib, ...}: {
+  path = pkgs: "export PATH=${lib.makeBinPath pkgs}";
+  pathAdd = pkgs: "export PATH=$PATH:${lib.makeBinPath pkgs}";
+  scriptHelpers = builtins.readFile ./scriptHelpers.sh;
+}