Split out support code that is specific to source tests out of

importlib.test.support to importlib.test.source.util.

Lib/importlib/test/source/util.py

@@ -0,0 +1,88 @@
+from .. import support as util
+import contextlib
+import imp
+import os
+import os.path
+import sys
+import tempfile
+from test import support as support
+
+
+def writes_bytecode(fxn):
+    """Decorator that returns the function if writing bytecode is enabled, else
+    a stub function that accepts anything and simply returns None."""
+    if sys.dont_write_bytecode:
+        return lambda *args, **kwargs: None
+    else:
+        return fxn
+
+
+def bytecode_path(source_path):
+    for suffix, _, type_ in imp.get_suffixes():
+        if type_ == imp.PY_COMPILED:
+            bc_suffix = suffix
+            break
+    else:
+        raise ValueError("no bytecode suffix is defined")
+    return os.path.splitext(source_path)[0] + bc_suffix
+
+
+@contextlib.contextmanager
+def create_modules(*names):
+    """Temporarily create each named module with an attribute (named 'attr')
+    that contains the name passed into the context manager that caused the
+    creation of the module.
+
+    All files are created in a temporary directory specified by
+    tempfile.gettempdir(). This directory is inserted at the beginning of
+    sys.path. When the context manager exits all created files (source and
+    bytecode) are explicitly deleted.
+
+    No magic is performed when creating packages! This means that if you create
+    a module within a package you must also create the package's __init__ as
+    well.
+
+    """
+    source = 'attr = {0!r}'
+    created_paths = []
+    mapping = {}
+    try:
+        temp_dir = tempfile.gettempdir()
+        mapping['.root'] = temp_dir
+        import_names = set()
+        for name in names:
+            if not name.endswith('__init__'):
+                import_name = name
+            else:
+                import_name = name[:-len('.__init__')]
+            import_names.add(import_name)
+            if import_name in sys.modules:
+                del sys.modules[import_name]
+            name_parts = name.split('.')
+            file_path = temp_dir
+            for directory in name_parts[:-1]:
+                file_path = os.path.join(file_path, directory)
+                if not os.path.exists(file_path):
+                    os.mkdir(file_path)
+                    created_paths.append(file_path)
+            file_path = os.path.join(file_path, name_parts[-1] + '.py')
+            with open(file_path, 'w') as file:
+                file.write(source.format(name))
+            created_paths.append(file_path)
+            mapping[name] = file_path
+        uncache_manager = util.uncache(*import_names)
+        uncache_manager.__enter__()
+        state_manager = util.import_state(path=[temp_dir])
+        state_manager.__enter__()
+        yield mapping
+    finally:
+        state_manager.__exit__(None, None, None)
+        uncache_manager.__exit__(None, None, None)
+        # Reverse the order for path removal to unroll directory creation.
+        for path in reversed(created_paths):
+            if file_path.endswith('.py'):
+                support.unlink(path)
+                support.unlink(path + 'c')
+                support.unlink(path + 'o')
+            else:
+                os.rmdir(path)