Function stripAddedIndentation

packages/jest-snapshot/src/index.ts:72–112

(inlineSnapshot: string)

};

function stripAddedIndentation(inlineSnapshot: string) {
  // Find indentation if exists.
  const match = inlineSnapshot.match(INDENTATION_REGEX);
  if (!match || !match[1]) {
    // No indentation.
    return inlineSnapshot;
  }

  const indentation = match[1];
  const lines = inlineSnapshot.split('\n');
  if (lines.length <= 2) {
    // Must be at least 3 lines.
    return inlineSnapshot;
  }

  if (lines[0].trim() !== '' || lines.at(-1)!.trim() !== '') {
    // If not blank first and last lines, abort.
    return inlineSnapshot;
  }

  for (let i = 1; i < lines.length - 1; i++) {
    if (lines[i] !== '') {
      if (lines[i].indexOf(indentation) !== 0) {
        // All lines except first and last should either be blank or have the same
        // indent as the first line (or more). If this isn't the case we don't
        // want to touch the snapshot at all.
        return inlineSnapshot;
      }

      lines[i] = lines[i].slice(indentation.length);
    }
  }

  // Last line is a special case because it won't have the same indent as others
  // but may still have been given some indent to line up.
  lines[lines.length - 1] = '';

  // Return inline snapshot, now at indent 0.
  inlineSnapshot = lines.join('\n');
  return inlineSnapshot;
}

const fileExists = (filePath: string, fileSystem: FileSystem): boolean =>
  fileSystem.exists(filePath) || fs.existsSync(filePath);