Write compiled AST to temp file when CGX_DEBUG is set

collagraph/sfc/__init__.py

@@ -1,6 +1,6 @@
 from collagraph import Component
 
-from .compiler import construct_ast
+from .compiler import DEBUG, construct_ast, format_code
 
 
 def load(path, namespace=None):
@@ -43,7 +43,19 @@ def load_from_string(template, path=None, namespace=None):
     tree, name = construct_ast(path=path, template=template)
 
     # Compile the tree into a code object (module)
-    code = compile(tree, filename=str(path), mode="exec")
+    # When CGX_DEBUG is set, write the AST to a temporary Python file
+    # and reparse it so that debuggers can step through the generated
+    # source with correct line numbers.
+    filename = str(path)
+    if DEBUG:  # pragma: no cover
+        debug_file, source = _write_debug_file(tree, path)
+        if debug_file:
+            import ast
+
+            filename = str(debug_file)
+            tree = ast.parse(source, filename=filename)
+
+    code = compile(tree, filename=filename, mode="exec")
     # Execute the code as module and pass a dictionary that will capture
     # the global and local scope of the module
     if namespace is None:
@@ -60,3 +72,45 @@ def load_from_string(template, path=None, namespace=None):
     namespace["__component_class"] = component_class
     namespace["__component_name"] = name
     return component_class, namespace
+
+
+def _write_debug_file(tree, path):  # pragma: no cover
+    """Write the compiled AST to a temporary Python file for debugging.
+
+    Returns a tuple of (path, formatted_source), or (None, None) if writing fails.
+    """
+    import ast
+    import logging
+    import tempfile
+    from pathlib import Path
+
+    logger = logging.getLogger(__name__)
+
+    try:
+        plain_result = ast.unparse(tree)
+        formatted = format_code(plain_result)
+
+        # Create a meaningful filename based on the source .cgx file
+        source_name = Path(path).stem if path else "template"
+        debug_file = Path(tempfile.mktemp(prefix=f"cgx_{source_name}_", suffix=".py"))
+        debug_file.write_text(formatted, encoding="utf-8")
+        logger.debug("CGX debug file written to: %s", debug_file)
+
+        try:
+            from rich.console import Console
+            from rich.syntax import Syntax
+
+            console = Console()
+            syntax = Syntax(formatted, "python")
+            console.print(f"#---{path}---")
+            console.print(syntax)
+            console.print(f"[dim]Debug file: {debug_file}[/dim]")
+        except ImportError:
+            print(f"#---{path}---")  # noqa: T201
+            print(formatted)  # noqa: T201
+            print(f"Debug file: {debug_file}")  # noqa: T201
+
+        return debug_file, formatted
+    except Exception as e:
+        logger.warning("Could not write AST debug file", exc_info=e)
+        return None, None

collagraph/sfc/compiler.py

@@ -94,11 +94,6 @@ class definition as `render` function.
     # method to fix any `lineno` and `col_offset` attributes of the nodes
     ast.fix_missing_locations(script_tree)
 
-    if DEBUG:  # pragma: no cover
-        try:
-            _print_ast_tree_as_code(script_tree, path)
-        except Exception as e:
-            logger.warning("Could not unparse AST", exc_info=e)
     return script_tree, component_def.name
 
 
@@ -1008,19 +1003,6 @@ def check_parsed_tree(node: Element):
         )
 
 
-def _print_ast_tree_as_code(tree, path):  # pragma: no cover
-    """Handy function for debugging an ast tree"""
-    from rich.console import Console
-    from rich.syntax import Syntax
-
-    plain_result = ast.unparse(tree)
-    formatted = format_code(plain_result)
-    console = Console()
-    syntax = Syntax(formatted, "python")
-    console.print(f"#---{path}---")
-    console.print(syntax)
-
-
 def format_code(code):  # pragma: no cover
     """
     Format the given code string with ruff