stylelint/dist/rules/function-linear-gradient-no-nonstandard-direction/index.js

A mighty, modern CSS linter.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.messages = exports.ruleName = undefined;

exports.default = function (actual) {
  return function (root, result) {
    var validOptions = (0, _utils.validateOptions)(result, ruleName, { actual: actual });
    if (!validOptions) {
      return;
    }

    root.walkDecls(function (decl) {
      (0, _utils.functionArgumentsSearch)(decl.toString().toLowerCase(), "linear-gradient", function (expression, expressionIndex) {
        var firstArg = expression.split(",")[0].trim();

        // If the first character is a number, we can assume the user intends an angle
        if (/[\d\.]/.test(firstArg[0])) {
          if (/^[\d\.]+(?:deg|grad|rad|turn)$/.test(firstArg)) {
            return;
          }
          complain();
          return;
        }

        // The first argument may not be a direction: it may be an angle,
        // or a color stop (in which case user gets default direction, "to bottom")
        // cf. https://drafts.csswg.org/css-images-3/#linear-gradient-syntax
        if (!/left|right|top|bottom/.test(firstArg)) {
          return;
        }

        var withToPrefix = !_postcss.vendor.prefix(decl.value);
        if (!isStandardDirection(firstArg, withToPrefix)) {
          complain();
          return;
        }

        function complain() {
          (0, _utils.report)({
            message: messages.rejected,
            node: decl,
            index: expressionIndex,
            result: result,
            ruleName: ruleName
          });
        }
      });
    });
  };
};

var _utils = require("../../utils");

var _postcss = require("postcss");

var ruleName = exports.ruleName = "function-linear-gradient-no-nonstandard-direction";

var messages = exports.messages = (0, _utils.ruleMessages)(ruleName, {
  rejected: "Unexpected nonstandard direction"
});

function isStandardDirection(source, withToPrefix) {
  var regexp = withToPrefix ? /^to (top|left|bottom|right)(?: (top|left|bottom|right))?$/ : /^(top|left|bottom|right)(?: (top|left|bottom|right))?$/;

  var matches = source.match(regexp);
  if (!matches) {
    return false;
  }
  if (matches.length === 2) {
    return true;
  }
  // Cannot repeat side-or-corner, e.g. "to top top"
  if (matches.length === 3 && matches[1] !== matches[2]) {
    return true;
  }
  return false;
}