function format()

in src/platform/packages/shared/kbn-expect/expect.js [617:801]

• 148 lines of code
• 46 McCabe index (conditional complexity)

  function format (value, recurseTimes) {
    // Provide a hook for user-specified inspect functions.
    // Check that value is an object with an inspect function on it
    if (value && typeof value.inspect === 'function' &&
        // Filter out the util module, it's inspect function is special
        value !== exports &&
        // Also filter out any prototype objects using the circular check.
        !(value.constructor && value.constructor.prototype === value)) {
      return value.inspect(recurseTimes);
    }

    // Primitive types cannot have properties
    switch (typeof value) {
      case 'undefined':
        return stylize('undefined', 'undefined');

      case 'string':
        var simple = '\'' + JSON.stringify(value).replace(/^"|"$/g, '')
                                                  .replace(/'/g, "\\'")
                                                  .replace(/\\"/g, '"') + '\'';
        return stylize(simple, 'string');

      case 'number':
        return stylize('' + value, 'number');

      case 'boolean':
        return stylize('' + value, 'boolean');
    }
    // For some reason typeof null is "object", so special case here.
    if (value === null) {
      return stylize('null', 'null');
    }

    // format sets like arrays
    if (value instanceof Set) {
      value = Array.from(value)
    }

    if (isDOMElement(value)) {
      return getOuterHTML(value);
    }

    // Look up the keys of the object.
    var visible_keys = keys(value);
    var $keys = showHidden ? Object.getOwnPropertyNames(value) : visible_keys;

    // Functions without properties can be shortcutted.
    if (typeof value === 'function' && $keys.length === 0) {
      if (isRegExp(value)) {
        return stylize('' + value, 'regexp');
      } else {
        var name = value.name ? ': ' + value.name : '';
        return stylize('[Function' + name + ']', 'special');
      }
    }

    // Dates without properties can be shortcutted
    if (isDate(value) && $keys.length === 0) {
      return stylize(value.toUTCString(), 'date');
    }

    // Error objects can be shortcutted
    if (value instanceof Error) {
      return stylize("["+value.toString()+"]", 'Error');
    }

    var base, type, braces;
    // Determine the object type
    if (isArray(value)) {
      type = 'Array';
      braces = ['[', ']'];
    } else {
      type = 'Object';
      braces = ['{', '}'];
    }

    // Make functions say that they are functions
    if (typeof value === 'function') {
      var n = value.name ? ': ' + value.name : '';
      base = (isRegExp(value)) ? ' ' + value : ' [Function' + n + ']';
    } else {
      base = '';
    }

    // Make dates with properties first say the date
    if (isDate(value)) {
      base = ' ' + value.toUTCString();
    }

    if ($keys.length === 0) {
      return braces[0] + base + braces[1];
    }

    if (recurseTimes < 0) {
      if (isRegExp(value)) {
        return stylize('' + value, 'regexp');
      } else {
        return stylize('[Object]', 'special');
      }
    }

    seen.push(value);

    var output = map($keys, function (key) {
      var name, str;
      if (value.__lookupGetter__) {
        if (value.__lookupGetter__(key)) {
          if (value.__lookupSetter__(key)) {
            str = stylize('[Getter/Setter]', 'special');
          } else {
            str = stylize('[Getter]', 'special');
          }
        } else {
          if (value.__lookupSetter__(key)) {
            str = stylize('[Setter]', 'special');
          }
        }
      }
      if (indexOf(visible_keys, key) < 0) {
        name = '[' + key + ']';
      }
      if (!str) {
        if (indexOf(seen, value[key]) < 0) {
          if (recurseTimes === null) {
            str = format(value[key]);
          } else {
            str = format(value[key], recurseTimes - 1);
          }
          if (str.indexOf('\n') > -1) {
            if (isArray(value)) {
              str = map(str.split('\n'), function (line) {
                return '  ' + line;
              }).join('\n').substr(2);
            } else {
              str = '\n' + map(str.split('\n'), function (line) {
                return '   ' + line;
              }).join('\n');
            }
          }
        } else {
          str = stylize('[Circular]', 'special');
        }
      }
      if (typeof name === 'undefined') {
        if (type === 'Array' && key.match(/^\d+$/)) {
          return str;
        }
        name = JSON.stringify('' + key);
        if (name.match(/^"([a-zA-Z_][a-zA-Z_0-9]*)"$/)) {
          name = name.substr(1, name.length - 2);
          name = stylize(name, 'name');
        } else {
          name = name.replace(/'/g, "\\'")
                      .replace(/\\"/g, '"')
                      .replace(/(^"|"$)/g, "'");
          name = stylize(name, 'string');
        }
      }

      return name + ': ' + str;
    });

    seen.pop();

    var numLinesEst = 0;
    var length = reduce(output, function (prev, cur) {
      numLinesEst++;
      if (indexOf(cur, '\n') >= 0) numLinesEst++;
      return prev + cur.length + 1;
    }, 0);

    if (length > 50) {
      output = braces[0] +
                (base === '' ? '' : base + '\n ') +
                ' ' +
                output.join(',\n  ') +
                ' ' +
                braces[1];

    } else {
      output = braces[0] + base + ' ' + output.join(', ') + ' ' + braces[1];
    }

    return output;
  }