| "use strict"; |
| |
| const declarationValueIndex = require("../../utils/declarationValueIndex"); |
| const functionArgumentsSearch = require("../../utils/functionArgumentsSearch"); |
| const isStandardSyntaxValue = require("../../utils/isStandardSyntaxValue"); |
| const postcss = require("postcss"); |
| const report = require("../../utils/report"); |
| const ruleMessages = require("../../utils/ruleMessages"); |
| const validateOptions = require("../../utils/validateOptions"); |
| const valueParser = require("postcss-value-parser"); |
| |
| const ruleName = "function-linear-gradient-no-nonstandard-direction"; |
| |
| const messages = ruleMessages(ruleName, { |
| rejected: "Unexpected nonstandard direction" |
| }); |
| |
| function isStandardDirection(source, withToPrefix) { |
| const regexp = withToPrefix |
| ? /^to (top|left|bottom|right)(?: (top|left|bottom|right))?$/ |
| : /^(top|left|bottom|right)(?: (top|left|bottom|right))?$/; |
| |
| const 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; |
| } |
| |
| const rule = function(actual) { |
| return (root, result) => { |
| const validOptions = validateOptions(result, ruleName, { actual }); |
| |
| if (!validOptions) { |
| return; |
| } |
| |
| root.walkDecls(decl => { |
| valueParser(decl.value).walk(valueNode => { |
| if (valueNode.type !== "function") { |
| return; |
| } |
| |
| functionArgumentsSearch( |
| valueParser.stringify(valueNode).toLowerCase(), |
| "linear-gradient", |
| (expression, expressionIndex) => { |
| const firstArg = expression.split(",")[0].trim(); |
| |
| // If the first arg is not standard, return early |
| if (!isStandardSyntaxValue(firstArg)) { |
| return; |
| } |
| |
| // 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; |
| } |
| |
| const withToPrefix = !postcss.vendor.prefix(valueNode.value); |
| |
| if (!isStandardDirection(firstArg, withToPrefix)) { |
| complain(); |
| |
| return; |
| } |
| |
| function complain() { |
| report({ |
| message: messages.rejected, |
| node: decl, |
| index: |
| declarationValueIndex(decl) + |
| valueNode.sourceIndex + |
| expressionIndex, |
| result, |
| ruleName |
| }); |
| } |
| } |
| ); |
| }); |
| }); |
| }; |
| }; |
| |
| rule.ruleName = ruleName; |
| rule.messages = messages; |
| module.exports = rule; |