Merge pull request #1 from Workiva/initial-migrater

Add migrater

README.md

@@ -1 +1,9 @@
-# over_react_codemod
+# over_react_codemod
+
+A tool to convert Over React components from Dart 1 to Dart 2. Uses the
+[Codemod](https://github.com/Facebook/codemod) library.
+
+The script requires a [custom branch](https://github.com/georgelesica-wf/codemod/tree/dart-convert)
+of `codemod`. Install it however you want (virtual environment, or whatever).
+
+To use, just run the Python script in the Dart repo you want to update.

migrater.py

@@ -0,0 +1,168 @@
+#!/usr/bin/env python2
+
+import os
+import re
+
+import codemod
+
+IGNORE_GENERATED_URI_COMMENT_LINE = '// ignore: uri_does_not_exist\n'
+GENERATED_PART_EXTENSION = '.generated.dart'
+
+def get_factory_name(line):
+    """
+    Get the factory name from a line that is known to include a factory
+    definition.
+
+    >>> get_factory_name('UiFactory<DemoProps> Demo;')
+    'Demo'
+    """
+    name = re.search(r' (\w+);', line).group(1)
+    return name
+
+
+def get_part_name(path):
+    """
+    Get the expected part name from a file path.
+
+    >>> get_part_name('./foo/bar/baz.dart')
+    'baz'
+    """
+    name = os.path.split(path)[-1].replace('.dart', '')
+    return name
+
+def get_part_path(path):
+    """
+    Get the expected part name from a file path.
+
+    >>> get_part_name('./foo/bar/baz.dart')
+    'baz'
+    """
+    split_path = os.path.split(path)
+    directory = os.path.join(*split_path[:-1])
+    name = split_path[-1].replace('.dart', GENERATED_PART_EXTENSION)
+    return os.path.join(directory, name)
+
+def get_last_directive_line_number(lines):
+    last_directive_line_number = -1
+    for line_number, line in enumerate(lines):
+        match = re.search(r'''^(?:(?:(?:part|import|export)\s+['"])|library\s+\w)''', line)
+        if match:
+            last_directive_line_number = line_number
+    return last_directive_line_number
+
+def get_line_number_to_insert_part(lines):
+    last_directive_line_number = get_last_directive_line_number(lines)
+    if last_directive_line_number != -1:
+        return last_directive_line_number + 1
+    return len(lines)
+
+# Maps library identifiers (foo.bar) to the parts that
+# must be added to them (baz.g.dart).
+part_paths_by_library_name = {}
+
+
+def collect_library(lines, part_path):
+    """
+    Determine which library the current file is a part of and remember it.
+
+    >>> result = collect_library([
+    ...     'foo bar baz',
+    ...     'part of foo.bar;',
+    ...     'something'
+    ... ], 'part')
+    >>> result
+    True
+    >>> libraries['foo.bar']
+    'part'
+    """
+    for line in lines:
+        name = re.search(r'part of ([_\w\.]+);', line)
+        if name is not None:
+            name = name.group(1)
+            part_paths_by_library_name.setdefault(name, []).append(part_path)
+            return True
+    return False
+
+
+def suggest(lines, path):
+    patches = []
+    need_part = False
+
+    for line_number, line in enumerate(lines):
+        if line.startswith('UiFactory'):
+            need_part = True
+
+            factory_name = get_factory_name(line)
+            ignore_line = '// ignore: undefined_identifier\n'
+            new_line = line.replace(';\n', ' = $%s;\n' % (factory_name))
+
+            patches.append(codemod.Patch(line_number, new_lines=[
+                ignore_line,
+                new_line,
+            ]))
+
+    if need_part:
+        part_name = get_part_name(path)
+        part_path = get_part_path(path)
+        part_filename = '%s%s' % (part_name, GENERATED_PART_EXTENSION)
+
+        get_last_directive_line_number
+
+        # If we're not a part then we just need to declare our part.
+        # Otherwise we'll need to make another pass and declare our
+        # part in the library we are a part of.
+        if not collect_library(lines, part_path):
+            part_line = 'part \'%s\';\n' % part_filename
+
+            insert_line_number = get_line_number_to_insert_part(lines)
+            patches.append(codemod.Patch(insert_line_number,
+                end_line_number=insert_line_number,
+                new_lines=[
+                    IGNORE_GENERATED_URI_COMMENT_LINE,
+                    part_line,
+                ]))
+
+    for patch in patches:
+        yield patch
+
+
+def use_path(path):
+    """
+    Determines if the given path is a Dart file.
+
+    >>> use_path('foo/bar.dart')
+    True
+    >>> use_path('bar/baz.py')
+    False
+    """
+    return path.endswith('.dart')
+
+
+def parts_suggest(lines, _path):
+    library_name = None
+    for line_number, line in enumerate(lines):
+        match = re.search(r'library ([\w.]+);', line)
+        if match is not None:
+            library_name = match.group(1)
+            break
+
+    if library_name is not None and part_paths_by_library_name.has_key(library_name):
+        new_lines = []
+        for part_path in part_paths_by_library_name[library_name]:
+            containing_dir_path = os.path.join(*os.path.split(_path)[:-1])
+            # This path needs to be relative from the libary
+            relative_part_path = os.path.relpath(part_path, containing_dir_path)
+            new_lines.append('part \'%s\'; %s' % (relative_part_path, IGNORE_GENERATED_URI_COMMENT_LINE))
+
+        insert_line_number = get_line_number_to_insert_part(lines)
+        # Parts need to go after all other directives; add them after the last part, or at the end of the file
+        yield codemod.Patch(insert_line_number,
+            end_line_number=insert_line_number,
+            new_lines=new_lines)
+
+q0 = codemod.Query(suggest, path_filter=use_path)
+q1 = codemod.Query(parts_suggest, path_filter=use_path)
+
+if __name__ == '__main__':
+    codemod.run_interactive(q0)
+    codemod.run_interactive(q1)