stylelint-high-performance-animation/index.js

Stylelint rule for preventing the use of low performance animation and transition properties.

"use strict";

const declarationValueIndex = require("./utils/declarationValueIndex");
const stylelint = require("stylelint");
const valueParser = require("postcss-value-parser");

const ruleName = "plugin/no-low-performance-animation-properties";

const messages = stylelint.utils.ruleMessages(ruleName, {
  rejected: (type, prop) =>
    `Unexpected use of low performance ${type} property (${prop}).`,
});

const isString = (s) => typeof s === "string";

// https://drafts.csswg.org/css-timing/
const cssLinearTimingFunctions = ["linear"];
const cssCubicBezierTimingFunctions = [
  "ease",
  "ease-in",
  "ease-out",
  "ease-in-out",
  "cubic-bezier",
];
const cssStepTimingFunctions = ["step-start", "step-end", "steps"];
const cssFramesTimingFunctions = ["frames"];
const cssTimingFunctions = [].concat(
  cssLinearTimingFunctions,
  cssCubicBezierTimingFunctions,
  cssStepTimingFunctions,
  cssFramesTimingFunctions,
);
const cssTimingFunctionsRE = new RegExp(
  "^(" + cssTimingFunctions.join("|") + ").*",
);

const propsThatCauseLayout = [
  "position",
  "top",
  "bottom",
  "left",
  "right",
  "inset-block-start",
  "inset-block-end",
  "inset-inline-start",
  "inset-inline-end",
  "width",
  "height",
  "inline-size",
  "block-size",
  "min-height",
  "max-height",
  "max-width",
  "min-width",
  "min-block-size",
  "max-block-size",
  "min-inline-size",
  "max-inline-size",
  "padding",
  "padding-bottom",
  "padding-left",
  "padding-right",
  "padding-top",
  "padding-block-end",
  "padding-inline-start",
  "padding-inline-end",
  "padding-block-start",
  "margin",
  "margin-bottom",
  "margin-left",
  "margin-right",
  "margin-top",
  "margin-block-end",
  "margin-inline-start",
  "margin-inline-end",
  "margin-block-start",
  "display",
  "border-width",
  "border-spacing",
  "border-collapse",
  "border",
  "font",
  "font-size",
  "font-family",
  "font-weight",
  "font-style",
  "float",
  "overflow-y",
  "overflow-x",
  "overflow",
  "overflow-block",
  "overflow-inline",
  "line-height",
  "vertical-align",
  "clear",
  "white-space",
  "list-style",
  "list-style-type",
  "zoom",
  "content",
  "box-sizing",
  "text-shadow",
  "text-align",
  "text-indent",
  "text-transform",
  "text-overflow",
  "word-wrap",
  "letter-spacing",
  "appearance",
  "direction",
];

const propsThatCausePaint = [
  "color",
  "border-color",
  "border-style",
  "border-radius",
  "visibility",
  "text-decoration",
  "background",
  "background-color",
  "background-size",
  "background-image",
  "background-position",
  "background-repeat",
  "outline",
  "outline-style",
  "outline-width",
  "outline-color",
  "box-shadow",
];

const getBlacklist = (ignore) => {
  if (ignore === "paint-properties") {
    return propsThatCauseLayout;
  }
  return propsThatCauseLayout.concat(propsThatCausePaint);
};

/**
 * Returns the input string stripped of its vendor prefix.
 *
 * @param {string} prop String with or without vendor prefix.
 *
 * @return {string} String name without vendor prefixes.
 *
 * @example
 * unprefixed('-moz-tab-size') //=> 'tab-size'
 */
const unprefixed = (prop) => {
  return prop.replace(/^-\w+-/, "");
};

module.exports = stylelint.createPlugin(
  ruleName,
  (actual, options) => (cssRoot, result) => {
    const validOptions = stylelint.utils.validateOptions(
      result,
      ruleName,
      { actual },
      {
        actual: options,
        possible: {
          ignore: ["paint-properties"],
          ignoreProperties: [isString],
        },
        optional: true,
      },
    );

    if (!validOptions) return;

    const blacklist = getBlacklist(options && options.ignore);
    const ignored =
      options && options.ignoreProperties ? options.ignoreProperties : [];

    cssRoot.walkDecls("transition-property", (decl) => {
      valueParser(decl.value).walk((node) => {
        const val = unprefixed(node.value);
        if (
          node.type === "word" &&
          ignored.indexOf(val) === -1 &&
          (blacklist.indexOf(val) > -1 || val === "all")
        ) {
          const index = declarationValueIndex(decl) + node.sourceIndex;
          const endIndex = index + node.value.length;
          stylelint.utils.report({
            ruleName,
            result,
            node: decl,
            message: messages.rejected("transition", node.value),
            index,
            endIndex,
          });
        }
      });
    });

    cssRoot.walkDecls("transition", (decl) => {
      let next = decl.next();

      while (next) {
        if (next.prop && next.prop === "transition-property") {
          return;
        }
        next = next.next();
      }

      const nodes = [];

      valueParser(decl.value).walk((node) => {
        if (node.type === "word" || node.type === "function")
          nodes.push({
            index: node.sourceIndex,
            value: node.value,
          });
        return false;
      });

      if (ignored.indexOf("all") === -1) {
        const transitionProp = nodes.filter((node) => {
          const isUnit = valueParser.unit(node.value);
          const isTimingFunction = cssTimingFunctionsRE.test(node.value);
          if (isUnit || isTimingFunction) {
            return false;
          }
          return node;
        });

        if (nodes.length && transitionProp.length === 0) {
          const index = declarationValueIndex(decl) + nodes[0].index;
          const endIndex = index + nodes[0].value.length;
          stylelint.utils.report({
            ruleName,
            result,
            node: decl,
            message: messages.rejected("transition", "all"),
            index,
            endIndex,
          });
          return;
        }
      }

      for (const prop of nodes) {
        const index = declarationValueIndex(decl) + prop.index;
        const endIndex = index + prop.value.length;
        const val = unprefixed(prop.value);
        if (
          ignored.indexOf(val) === -1 &&
          (blacklist.indexOf(val) > -1 || val === "all")
        ) {
          stylelint.utils.report({
            ruleName,
            result,
            node: decl,
            message: messages.rejected("transition", prop.value),
            index,
            endIndex,
          });
        }
      }
    });

    cssRoot.walkAtRules(/^keyframes$/i, (atRuleKeyframes) => {
      atRuleKeyframes.walkDecls((decl) => {
        const val = unprefixed(decl.prop);
        if (ignored.indexOf(val) === -1 && blacklist.indexOf(val) > -1) {
          stylelint.utils.report({
            ruleName,
            result,
            node: decl,
            message: messages.rejected("animation", decl.prop),
          });
        }
      });
    });
  },
);

module.exports.ruleName = ruleName;
module.exports.messages = messages;