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2020-11-01 22:46:04 +00:00

111 lines
2.8 KiB
JavaScript

// @ts-nocheck
'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;
}
function rule(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();
}
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;