Function printMyersDiff

lib/internal/assert/myers_diff.js:146–189

(diff, operator)

}

function printMyersDiff(diff, operator) {
  let message = '';
  let skipped = false;
  let nopCount = 0;

  for (let diffIdx = diff.length - 1; diffIdx >= 0; diffIdx--) {
    const { 0: operation, 1: value } = diff[diffIdx];
    const previousOperation = diffIdx < diff.length - 1 ? diff[diffIdx + 1][0] : null;

    // Avoid grouping if only one line would have been grouped otherwise
    if (previousOperation === kOperations.NOP && operation !== previousOperation) {
      if (nopCount === kNopLinesToCollapse + 1) {
        message += `${colors.white}  ${diff[diffIdx + 1][1]}\n`;
      } else if (nopCount === kNopLinesToCollapse + 2) {
        message += `${colors.white}  ${diff[diffIdx + 2][1]}\n`;
        message += `${colors.white}  ${diff[diffIdx + 1][1]}\n`;
      } else if (nopCount >= kNopLinesToCollapse + 3) {
        message += `${colors.blue}...${colors.white}\n`;
        message += `${colors.white}  ${diff[diffIdx + 1][1]}\n`;
        skipped = true;
      }
      nopCount = 0;
    }

    if (operation === kOperations.INSERT) {
      if (operator === 'partialDeepStrictEqual') {
        message += `${colors.gray}${colors.hasColors ? ' ' : '+'} ${value}${colors.white}\n`;
      } else {
        message += `${colors.green}+${colors.white} ${value}\n`;
      }
    } else if (operation === kOperations.DELETE) {
      message += `${colors.red}-${colors.white} ${value}\n`;
    } else if (operation === kOperations.NOP) {
      if (nopCount < kNopLinesToCollapse) {
        message += `${colors.white}  ${value}\n`;
      }
      nopCount++;
    }
  }

  message = message.trimEnd();

  return { message: `\n${message}`, skipped };
}

module.exports = { myersDiff, printMyersDiff, printSimpleMyersDiff };