ShipItRepo.php

<?hh
/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

/**
 * This file was moved from fbsource to www. View old history in diffusion:
 * https://fburl.com/mxrtk0pl
 */
namespace Facebook\ShipIt;

use namespace HH\Lib\{C, Regex, Str}; // @oss-enable

class ShipItRepoException extends \Exception {
  public function __construct(?IShipItRepo $repo, string $message) {
    if ($repo !== null) {
      $message = \get_class($repo).": $message";
    }
    parent::__construct($message);
  }
}

/**
 * Repo handler interface
 * For agnostic communication with git, hg, etc...
 */
abstract class ShipItRepo implements ShipItSourceRepo, ShipItDestinationRepo {
  /**
   * @param $path the path to the repository
   */
  public function __construct(
    private IShipItLock $lock,
    protected string $path,
  ) {}

  protected function getSharedLock(): IShipItLock {
    return $this->lock;
  }

  public function getPath(): string {
    return $this->path;
  }

  final public static async function genTypedOpen<
    <<__Enforceable>> reify Trepo as IShipItRepo,
  >(IShipItLock $lock, string $path, string $branch): Awaitable<Trepo> {
    $repo = await ShipItRepo::genOpen($lock, $path, $branch);
    invariant(
      $repo is Trepo,
      '%s is a %s, needed a %s',
      $path,
      \get_class($repo),
      Trepo::class,
    );
    return $repo as Trepo;
  }

  /**
   * Factory
   */
  final public static async function genOpen(
    IShipItLock $lock,
    string $path,
    string $branch,
  ): Awaitable<IShipItRepo> {
    if (PHP\file_exists($path.'/.git')) {
      $repo = new ShipItRepoGIT($lock, $path);
      await $repo->genSetBranch($branch);
      return $repo;
    }
    if (PHP\file_exists($path.'/.hg')) {
      $repo = new ShipItRepoHG($lock, $path);
      await $repo->genSetBranch($branch);
      return $repo;
    }
    throw
      new ShipItRepoException(null, "Can't determine type of repo at ".$path);
  }

  /**
   * Convert a hunk to a ShipItDiff shape
   */
  public static function parseDiffHunk(string $hunk): ?ShipItDiff {
    list($header, $body) = Str\split($hunk, "\n", 2);
    $matches = Regex\first_match(
      Str\trim($header),
      re'@^diff --git ("?)[ab]/(.*?)"? ("?)[ab]/(.*?)"?$@',
    );
    if ($matches is null) {
      return null;
    }
    $path = $matches[2] as string;
    $new_path = $matches[4] !== '' ? $matches[4] : null;
    if ($matches[1] === '"') {
      // Quoted paths may contain escaped characters.
      $path = PHP\stripslashes($path);
    }

    if ($new_path is nonnull && $path !== $new_path) {
      if ($matches[3] === '"') {
        $new_path = PHP\stripslashes($new_path);
      }
      return shape(
        'path' => $path,
        'body' => $body,
        'operation' => ShipItDiffOperation::RENAME,
        'new_path' => $new_path,
      );
    } else {
      return shape(
        'path' => $path,
        'body' => $body,
        'operation' => ShipItDiffOperation::CHANGE,
      );
    }
  }

  final public static function getCommitMessage(
    ShipItChangeset $changeset,
  ): string {
    return $changeset->getSubject()."\n\n".$changeset->getMessage();
  }

  final public static function fixInlinePatchesInCommitMessage(
    string $message,
  ): string {
    /* Insert a space before patterns that will make `git am` think that a
     * line in the commit message is the start of a patch, which is an artifact
     * of the way `git am` tries to tell where the message ends and the diffs
     * begin. This fix is a hack; a better fix might be to use `git apply` and
     * `git commit` directly instead of `git am`, but this is an edge-case so
     * it's not worth it right now.
     *
     * https://github.com/git/git/blob/77bd3ea9f54f1584147b594abc04c26ca516d987/builtin/mailinfo.c#L701
     */
    return
      Regex\replace($message, re"/^(diff -|Index: |---(?:\s\S|\s*$))/m", ' $1');
  }

  protected bool $useNativeRenames = false;

  final public function setUseNativeRenames(bool $use_native_renames): void {
    $this->useNativeRenames = $use_native_renames;
  }

  /*
   * Generator yielding patch sections of the diff blocks (individually)
   * and finally the footer.
   */
  public static function parsePatch(string $patch): Iterator<string> {
    $contents = '';

    $minus_lines = 0;
    $plus_lines = 0;
    $seen_range_header = false;

    foreach (Str\split($patch, "\n") as $line) {
      $line = Regex\replace($line, re"/(\r\n|\n)/", "\n");

      if (
        Regex\matches(
          Str\trim_right($line),
          re"@^diff --git \"?[ab]/(.*?)\"? \"?[ab]/(.*?)\"?$@",
        )
      ) {
        if ($contents !== '') {
          yield $contents;
        }
        $seen_range_header = false;
        $contents = $line."\n";
        continue;
      }
      $matches = Regex\first_match(
        $line,
        re"/^@@ -\d+(,(?<minus_lines>\d+))? \+\d+(,(?<plus_lines>\d+))? @@/",
      );
      if ($matches !== null) {
        $minus_lines = $matches['minus_lines'] ?? '';
        $minus_lines = $minus_lines === '' ? 1 : (int)$minus_lines;
        $plus_lines = $matches['plus_lines'] ?? '';
        $plus_lines = $plus_lines === '' ? 1 : (int)$plus_lines;

        $contents .= $line."\n";
        $seen_range_header = true;
        continue;
      }

      if (!$seen_range_header) {
        $contents .= $line."\n";
        continue;
      }

      $leftmost = Str\slice($line, 0, 1);
      if ($leftmost === "\\") {
        $contents .= $line."\n";
        // Doesn't count as a + or - line whatever happens; if NL at EOF
        // changes, there is a + and - for the last line of content
        continue;
      }

      if ($minus_lines <= 0 && $plus_lines <= 0) {
        continue;
      }

      $leftmost = Str\slice($line, 0, 1);
      if ($leftmost === '+') {
        --$plus_lines;
      } else if ($leftmost === '-') {
        --$minus_lines;
      } else if ($leftmost === ' ') {
        // Context goes from both.
        --$plus_lines;
        --$minus_lines;
      } else {
        invariant_violation("Can't parse hunk line: %s", $line);
      }
      $contents .= $line."\n";
    }

    if ($contents !== '') {
      // If we got the patch from git-diff, there won't be the signature line
      // from format-patch
      yield $contents;
    }
  }
}