tests: initial test suite for IR compiler

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I70cd1dfa45add9df58a44add69fbd30a6a6a6964

tests/string_interp.nix

@@ -0,0 +1,19 @@
+# Test string interpolation
+let
+  name = "world";
+  x = 42;
+  bool_val = true;
+in
+  {
+    # Simple interpolation
+    greeting = "Hello ${name}!";
+
+    # Multiple interpolations
+    multi = "x is ${x} and name is ${name}";
+
+    # Nested expression
+    nested = "Result: ${if bool_val then "yes" else "no"}";
+
+    # Just a string (no interpolation)
+    plain = "plain text";
+  }