add stub compile function and basic integration tests (#9)

src/lib.rs

@@ -2,3 +2,13 @@ mod error;
 mod lexer;
 mod scanner;
 mod token;
+
+use std::error::Error;
+
+pub fn compile(_template: &str) -> Result<String, Box<dyn Error>> {
+    todo!("Implement compilation process")
+}
+
+// re-export important types or functions from modules here, e.g.
+// pub use lexer::Lexer;
+// that should be part of the public API

tests/compile.rs

@@ -0,0 +1,45 @@
+use django_template_ast::compile;
+
+#[test]
+#[should_panic]
+fn test_empty_template() {
+    let result = compile("");
+    assert!(result.is_ok());
+    assert_eq!(result.unwrap(), "");
+}
+
+#[test]
+#[should_panic]
+fn test_simple_template() {
+    let result = compile("Hello, {{ name }}!");
+    assert!(result.is_ok());
+    // You'll need to adjust this expected output based on your actual implementation
+    assert_eq!(result.unwrap(), "Hello, {{ name }}!");
+}
+
+#[test]
+#[should_panic]
+fn test_invalid_template() {
+    let result = compile("{% invalid %}");
+    assert!(result.is_err());
+}
+
+#[test]
+#[should_panic]
+fn test_complex_template() {
+    let template = r#"
+        {% if user.is_authenticated %}
+            Hello, {{ user.name }}!
+        {% else %}
+            Please log in.
+        {% endif %}
+    "#;
+    let result = compile(template);
+    assert!(result.is_ok());
+
+    if let Ok(compiled) = result {
+        assert!(compiled.contains("Hello") && compiled.contains("Please log in"));
+    } else {
+        panic!("Compilation failed unexpectedly");
+    }
+}