graphql/language/blockString.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.dedentBlockStringValue = dedentBlockStringValue;
exports.getBlockStringIndentation = getBlockStringIndentation;
exports.printBlockString = printBlockString;

/**
 * Produces the value of a block string from its parsed raw value, similar to
 * CoffeeScript's block string, Python's docstring trim or Ruby's strip_heredoc.
 *
 * This implements the GraphQL spec's BlockStringValue() static algorithm.
 *
 * @internal
 */
function dedentBlockStringValue(rawString) {
  // Expand a block string's raw value into independent lines.
  var lines = rawString.split(/\r\n|[\n\r]/g); // Remove common indentation from all lines but first.

  var commonIndent = getBlockStringIndentation(rawString);

  if (commonIndent !== 0) {
    for (var i = 1; i < lines.length; i++) {
      lines[i] = lines[i].slice(commonIndent);
    }
  } // Remove leading and trailing blank lines.


  var startLine = 0;

  while (startLine < lines.length && isBlank(lines[startLine])) {
    ++startLine;
  }

  var endLine = lines.length;

  while (endLine > startLine && isBlank(lines[endLine - 1])) {
    --endLine;
  } // Return a string of the lines joined with U+000A.


  return lines.slice(startLine, endLine).join('\n');
}

function isBlank(str) {
  for (var i = 0; i < str.length; ++i) {
    if (str[i] !== ' ' && str[i] !== '\t') {
      return false;
    }
  }

  return true;
}
/**
 * @internal
 */


function getBlockStringIndentation(value) {
  var _commonIndent;

  var isFirstLine = true;
  var isEmptyLine = true;
  var indent = 0;
  var commonIndent = null;

  for (var i = 0; i < value.length; ++i) {
    switch (value.charCodeAt(i)) {
      case 13:
        //  \r
        if (value.charCodeAt(i + 1) === 10) {
          ++i; // skip \r\n as one symbol
        }

      // falls through

      case 10:
        //  \n
        isFirstLine = false;
        isEmptyLine = true;
        indent = 0;
        break;

      case 9: //   \t

      case 32:
        //  <space>
        ++indent;
        break;

      default:
        if (isEmptyLine && !isFirstLine && (commonIndent === null || indent < commonIndent)) {
          commonIndent = indent;
        }

        isEmptyLine = false;
    }
  }

  return (_commonIndent = commonIndent) !== null && _commonIndent !== void 0 ? _commonIndent : 0;
}
/**
 * Print a block string in the indented block form by adding a leading and
 * trailing blank line. However, if a block string starts with whitespace and is
 * a single-line, adding a leading blank line would strip that whitespace.
 *
 * @internal
 */


function printBlockString(value) {
  var indentation = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : '';
  var preferMultipleLines = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : false;
  var isSingleLine = value.indexOf('\n') === -1;
  var hasLeadingSpace = value[0] === ' ' || value[0] === '\t';
  var hasTrailingQuote = value[value.length - 1] === '"';
  var hasTrailingSlash = value[value.length - 1] === '\\';
  var printAsMultipleLines = !isSingleLine || hasTrailingQuote || hasTrailingSlash || preferMultipleLines;
  var result = ''; // Format a multi-line block quote to account for leading space.

  if (printAsMultipleLines && !(isSingleLine && hasLeadingSpace)) {
    result += '\n' + indentation;
  }

  result += indentation ? value.replace(/\n/g, '\n' + indentation) : value;

  if (printAsMultipleLines) {
    result += '\n';
  }

  return '"""' + result.replace(/"""/g, '\\"""') + '"""';
}