tests: initial test suite for IR compiler

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

tests/lambda_pattern.nix

@@ -0,0 +1,36 @@
+# Test lambda patterns
+let
+  # Basic destructuring
+  f1 = { a, b }: a + b;
+
+  # With default values
+  f2 = { a, b ? 10 }: a + b;
+
+  # With ellipsis (extra fields allowed)
+  f3 = { a, ... }: a * 2;
+
+  # Named pattern
+  f4 = arg@{ a, b }: a + b + arg.c;
+
+  # Simple lambda (not a pattern)
+  f5 = x: x + 1;
+in
+  {
+    # Test basic destructuring
+    test1 = f1 { a = 3; b = 4; };
+
+    # Test with defaults (provide both)
+    test2a = f2 { a = 5; b = 6; };
+
+    # Test with defaults (use default for b)
+    test2b = f2 { a = 5; };
+
+    # Test ellipsis (extra field ignored)
+    test3 = f3 { a = 7; extra = 999; };
+
+    # Test named pattern
+    test4 = f4 { a = 1; b = 2; c = 3; };
+
+    # Test simple lambda
+    test5 = f5 10;
+  }