fileprivate_regex.py

import argparse
import fnmatch
import json
import os
import re
import sys

from collections import namedtuple


REGEX = re.compile("""
    fileprivate
    \s+
    (?:var|func|let)
    \s+
    (.+?)
    \s*
    [:(]
""", re.VERBOSE)

USE_REGEX = """
    (?:^|\W)    # Should be prepended by a non-alphanumeric char or SOL
    {variable}  # The variable itself (replaced further down)
    (?:$|\W)   # Should be followed by a non-alphanumeric char or EOL
"""


def find_scopes(content, max_depth=1):
    queue = []
    for i, letter in enumerate(content):
        if letter == "{":
            queue.append((i, "{"))
        elif letter == "}":
            depth = len(queue)
            start, _ = queue.pop()
            if max_depth >= depth:
                yield depth, start, i + 1


def convert(content):
    """
    >>> content = '''
    ... private let global: () -> Void = { print("heh") }
    ... struct Test {
    ...     fileprivate let a: Int = 1
    ...     fileprivate let b: Int = 1
    ...     @IBOutlet fileprivate var c: String
    ...     let d: Int = 1
    ...     fileprivate func test() {}
    ... }
    ...
    ... extension Test {
    ...    fileprivate var something: Int {
    ...        Test().b
    ...        print(a)
    ...        return self.d
    ...    }
    ... }
    ... '''
    >>> expected = '''
    ... private let global: () -> Void = { print("heh") }
    ... struct Test {
    ...     fileprivate let a: Int = 1
    ...     fileprivate let b: Int = 1
    ...     @IBOutlet private var c: String
    ...     let d: Int = 1
    ...     private func test() {}
    ... }
    ...
    ... extension Test {
    ...    private var something: Int {
    ...        Test().b
    ...        print(a)
    ...        return self.d
    ...    }
    ... }
    ... '''
    >>> convert(content) == expected
    True
    """
    replaces = []
    for _, start, end in find_scopes(content):
        scope = content[start:end]
        rest = content[:start] + content[end:]
        for match in REGEX.finditer(scope):
            variable = match.group(1)
            mstart, mend = match.start(), match.start() + len(match.group())
            regex = re.compile(USE_REGEX.format(variable=variable), re.VERBOSE)
            if regex.findall(rest):
                continue

            replaces.append(start + mstart)

    for start in replaces[::-1]:
        end = start + len("fileprivate")
        content = content[:start] + "private" + content[end:]

    return content


def main(args):
    files = [os.path.join(path, filepath)
             for path, dirs, files in os.walk(args.directory)
             for filepath in fnmatch.filter(files, "*.swift")]

    for filepath in files or [args.file]:
        content = open(filepath).read()
        fixed = convert(content)
        open(filepath, "w").write(fixed)


def test():
    import doctest
    doctest.testmod()


if __name__ == "__main__":
    parser = argparse.ArgumentParser(
        description="Migrates fileprivate insanity on a local scope"
    )
    parser.add_argument('-t', help="Run tests", action='store_const',
                        const=True, dest="test")
    parser.add_argument('--file', help="Swift file to fix")
    parser.add_argument('--directory', help="Swift directory to fix")
    args = parser.parse_args()
    if not args.file and not args.directory and not args.test:
        parser.print_help()
        sys.exit(1)

    if args.test:
        test()
    else:
        main(args)