Resolve required modules in subdirectories via caller-side basename

The top module's directory is already folded into template_dirs by
get_template_directories, so passing the full filename to plain_file_parser
double-counted the directory. Normalize the top module to its basename at the
call sites instead, and keep plain_file_parser preserving relative subdirectory
prefixes so required/imported modules (e.g. 'dir_name/b') resolve correctly.

Replaces the earlier stem-only fix, which broke required modules in
subdirectories. Add PlainModule-tree and parser-level regression tests.

Author: pedjaradenkovic

plain2code.py

@@ -165,7 +165,7 @@ def render(args, run_state: RunState, event_bus: EventBus, default_log_level: st
     render_range = None
     if args.render_range or args.render_from:
         # Parse the plain file to get the plain_source for FRID extraction
-        _, plain_source, _ = plain_file.plain_file_parser(args.filename, template_dirs)
+        _, plain_source, _ = plain_file.plain_file_parser(os.path.basename(args.filename), template_dirs)
         render_range = plain_spec.compute_render_range(args, plain_source)
 
     codeplainAPI = codeplain_api.CodeplainAPI(args.api_key, console)
@@ -179,7 +179,7 @@ def render(args, run_state: RunState, event_bus: EventBus, default_log_level: st
     signal.signal(signal.SIGTERM, lambda _signum, _frame: stop_event.set())
 
     plain_module = plain_modules.PlainModule(
-        args.filename,
+        os.path.basename(args.filename),
         args.build_folder,
         args.conformance_tests_folder,
         template_dirs,
@@ -323,7 +323,7 @@ def main():  # noqa: C901
 
             if args.dry_run:
                 console.info("Printing dry run output...\n")
-                _, plain_source_tree, _ = plain_file.plain_file_parser(args.filename, template_dirs)
+                _, plain_source_tree, _ = plain_file.plain_file_parser(os.path.basename(args.filename), template_dirs)
                 render_range = plain_spec.compute_render_range(args, plain_source_tree)
                 print_dry_run_output(plain_source_tree, render_range)
                 return

plain_file.py

@@ -651,7 +651,11 @@ def plain_file_parser(  # noqa: C901
             f"Plain syntax error: Invalid plain file extension: {plain_source_file_path.suffix}. Expected: {PLAIN_SOURCE_FILE_EXTENSION}."
         )
 
-    module_name = plain_source_file_path.stem
+    module_name = (
+        plain_source_file_path.stem
+        if plain_source_file_path.is_absolute()
+        else plain_source_file_path.with_suffix("").as_posix()
+    )
 
     code_variables = {}
 

tests/data/requires_subdir/main_in_subdir.plain

@@ -0,0 +1,12 @@
+---
+requires:
+  - nested/leaf
+---
+
+***implementation reqs***
+
+- Main implementation requirement.
+
+***functional specs***
+
+- Display "hello, world"

tests/data/requires_subdir/nested/leaf.plain

@@ -0,0 +1,7 @@
+***implementation reqs***
+
+- Base implementation requirement for the leaf.
+
+***functional specs***
+
+- A base functionality from the leaf.

tests/test_plainfileparser.py

@@ -27,17 +27,30 @@ def test_regular_plain_source(get_test_data_path):
     }
 
 
-def test_relative_subdirectory_path_resolves(get_test_data_path):
-    # Regression: the CLI passes the full path as the filename and its directory as template_dirs[0].
-    # For a relative path with subdirectories, module_name must be the bare stem; otherwise the
-    # subdirectory prefix double-joins with template_dirs[0] and the module is reported as missing.
-    data_dir = get_test_data_path("data/plainfileparser")
-    rel_file = os.path.relpath(os.path.join(data_dir, "regular_plain_source.plain"))
-    assert os.sep in rel_file  # ensure the relative path actually has a subdirectory prefix
+def test_parser_keeps_subdirectory_in_module_name(get_test_data_path):
+    # A template-relative filename with a subdirectory (as passed for required/imported modules)
+    # must keep its subdirectory prefix in the module name so it resolves under template_dirs.
+    data_dir = get_test_data_path("data/requires_subdir")
 
-    module_name, _, _ = plain_file.plain_file_parser(rel_file, [os.path.dirname(rel_file)])
+    module_name, _, required = plain_file.plain_file_parser("nested/leaf.plain", [data_dir])
 
-    assert module_name == "regular_plain_source"
+    assert module_name == "nested/leaf"
+    assert required == []
+
+
+def test_requires_module_in_subdirectory_resolves(get_test_data_path):
+    # Regression: rendering a top module (referenced by basename, its dir supplied via
+    # template_dirs) that `requires` a module in a subdirectory must build the full PlainModule
+    # tree without a "Module does not exist" error, preserving the subdirectory in build paths.
+    import plain_modules
+
+    data_dir = get_test_data_path("data/requires_subdir")
+
+    module = plain_modules.PlainModule("main_in_subdir.plain", "build", "conformance", [data_dir])
+
+    assert module.module_name == "main_in_subdir"
+    assert [m.module_name for m in module.required_modules] == ["nested/leaf"]
+    assert [m.module_build_folder for m in module.required_modules] == [os.path.join("build", "nested/leaf")]
 
 
 def test_unknown_section():