postcss-url-parser.js

import valueParser from "postcss-value-parser";

import {
  normalizeUrl,
  requestify,
  resolveRequests,
  isUrlRequestable,
  WEBPACK_IGNORE_COMMENT_REGEXP,
} from "../utils";

const isUrlFunc = /url/i;
const isImageSetFunc = /^(?:-webkit-)?image-set$/i;
const needParseDeclaration = /(?:url|(?:-webkit-)?image-set)\(/i;

function getNodeFromUrlFunc(node) {
  return node.nodes && node.nodes[0];
}

function getWebpackIgnoreCommentValue(index, nodes, inBetween) {
  if (index === 0 && typeof inBetween !== "undefined") {
    return inBetween;
  }

  let prevValueNode = nodes[index - 1];

  if (!prevValueNode) {
    // eslint-disable-next-line consistent-return
    return;
  }

  if (prevValueNode.type === "space") {
    if (!nodes[index - 2]) {
      // eslint-disable-next-line consistent-return
      return;
    }

    prevValueNode = nodes[index - 2];
  }

  if (prevValueNode.type !== "comment") {
    // eslint-disable-next-line consistent-return
    return;
  }

  const matched = prevValueNode.value.match(WEBPACK_IGNORE_COMMENT_REGEXP);

  return matched && matched[2] === "true";
}

function shouldHandleURL(url, declaration, result) {
  if (url.length === 0) {
    result.warn(`Unable to find uri in '${declaration.toString()}'`, {
      node: declaration,
    });

    return false;
  }

  if (!isUrlRequestable(url)) {
    return false;
  }

  return true;
}

function parseDeclaration(declaration, key, result) {
  if (!needParseDeclaration.test(declaration[key])) {
    return;
  }

  const parsed = valueParser(
    declaration.raws && declaration.raws.value && declaration.raws.value.raw
      ? declaration.raws.value.raw
      : declaration[key]
  );

  let inBetween;

  if (declaration.raws && declaration.raws.between) {
    const lastCommentIndex = declaration.raws.between.lastIndexOf("/*");

    const matched = declaration.raws.between
      .slice(lastCommentIndex)
      .match(WEBPACK_IGNORE_COMMENT_REGEXP);

    if (matched) {
      inBetween = matched[2] === "true";
    }
  }

  let isIgnoreOnDeclaration = false;

  const prevNode = declaration.prev();

  if (prevNode && prevNode.type === "comment") {
    const matched = prevNode.text.match(WEBPACK_IGNORE_COMMENT_REGEXP);

    if (matched) {
      isIgnoreOnDeclaration = matched[2] === "true";
    }
  }

  let needIgnore;

  const parsedURLs = [];

  parsed.walk((valueNode, index, valueNodes) => {
    if (valueNode.type !== "function") {
      return;
    }

    if (isUrlFunc.test(valueNode.value)) {
      needIgnore = getWebpackIgnoreCommentValue(index, valueNodes, inBetween);

      if (
        (isIgnoreOnDeclaration && typeof needIgnore === "undefined") ||
        needIgnore
      ) {
        if (needIgnore) {
          // eslint-disable-next-line no-undefined
          needIgnore = undefined;
        }

        return;
      }

      const { nodes } = valueNode;
      const isStringValue = nodes.length !== 0 && nodes[0].type === "string";
      let url = isStringValue ? nodes[0].value : valueParser.stringify(nodes);
      url = normalizeUrl(url, isStringValue);

      // Do not traverse inside `url`
      if (!shouldHandleURL(url, declaration, result)) {
        // eslint-disable-next-line consistent-return
        return false;
      }

      const queryParts = url.split("!");
      let prefix;

      if (queryParts.length > 1) {
        url = queryParts.pop();
        prefix = queryParts.join("!");
      }

      parsedURLs.push({
        declaration,
        parsed,
        node: getNodeFromUrlFunc(valueNode),
        prefix,
        url,
        needQuotes: false,
      });

      // eslint-disable-next-line consistent-return
      return false;
    } else if (isImageSetFunc.test(valueNode.value)) {
      for (const [innerIndex, nNode] of valueNode.nodes.entries()) {
        const { type, value } = nNode;

        if (type === "function" && isUrlFunc.test(value)) {
          needIgnore = getWebpackIgnoreCommentValue(
            innerIndex,
            valueNode.nodes
          );

          if (
            (isIgnoreOnDeclaration && typeof needIgnore === "undefined") ||
            needIgnore
          ) {
            if (needIgnore) {
              // eslint-disable-next-line no-undefined
              needIgnore = undefined;
            }

            // eslint-disable-next-line no-continue
            continue;
          }

          const { nodes } = nNode;
          const isStringValue =
            nodes.length !== 0 && nodes[0].type === "string";
          let url = isStringValue
            ? nodes[0].value
            : valueParser.stringify(nodes);
          url = normalizeUrl(url, isStringValue);

          // Do not traverse inside `url`
          if (!shouldHandleURL(url, declaration, result)) {
            // eslint-disable-next-line consistent-return
            return false;
          }

          const queryParts = url.split("!");
          let prefix;

          if (queryParts.length > 1) {
            url = queryParts.pop();
            prefix = queryParts.join("!");
          }

          parsedURLs.push({
            declaration,
            parsed,
            node: getNodeFromUrlFunc(nNode),
            prefix,
            url,
            needQuotes: false,
          });
        } else if (type === "string") {
          needIgnore = getWebpackIgnoreCommentValue(
            innerIndex,
            valueNode.nodes
          );

          if (
            (isIgnoreOnDeclaration && typeof needIgnore === "undefined") ||
            needIgnore
          ) {
            if (needIgnore) {
              // eslint-disable-next-line no-undefined
              needIgnore = undefined;
            }

            // eslint-disable-next-line no-continue
            continue;
          }

          let url = normalizeUrl(value, true);

          // Do not traverse inside `url`
          if (!shouldHandleURL(url, declaration, result)) {
            // eslint-disable-next-line consistent-return
            return false;
          }

          const queryParts = url.split("!");
          let prefix;

          if (queryParts.length > 1) {
            url = queryParts.pop();
            prefix = queryParts.join("!");
          }

          parsedURLs.push({
            declaration,
            parsed,
            node: nNode,
            prefix,
            url,
            needQuotes: true,
          });
        }
      }

      // Do not traverse inside `image-set`
      // eslint-disable-next-line consistent-return
      return false;
    }
  });

  // eslint-disable-next-line consistent-return
  return parsedURLs;
}

const plugin = (options = {}) => {
  return {
    postcssPlugin: "postcss-url-parser",
    prepare(result) {
      const parsedDeclarations = [];

      return {
        Declaration(declaration) {
          const parsedURL = parseDeclaration(declaration, "value", result);

          if (!parsedURL) {
            return;
          }

          parsedDeclarations.push(...parsedURL);
        },
        async OnceExit() {
          if (parsedDeclarations.length === 0) {
            return;
          }

          const resolvedDeclarations = await Promise.all(
            parsedDeclarations.map(async (parsedDeclaration) => {
              const { url } = parsedDeclaration;

              if (options.filter) {
                const needKeep = await options.filter(url);

                if (!needKeep) {
                  return null;
                }
              }

              const splittedUrl = url.split(/(\?)?#/);
              const [pathname, query, hashOrQuery] = splittedUrl;

              let hash = query ? "?" : "";
              hash += hashOrQuery ? `#${hashOrQuery}` : "";

              const request = requestify(pathname, options.rootContext);

              const { resolver, context } = options;
              const resolvedUrl = await resolveRequests(resolver, context, [
                ...new Set([request, url]),
              ]);

              return { ...parsedDeclaration, url: resolvedUrl, hash };
            })
          );

          const results = await Promise.all(resolvedDeclarations);

          const urlToNameMap = new Map();
          const urlToReplacementMap = new Map();

          let hasUrlImportHelper = false;

          for (let index = 0; index <= results.length - 1; index++) {
            const item = results[index];

            if (!item) {
              // eslint-disable-next-line no-continue
              continue;
            }

            if (!hasUrlImportHelper) {
              options.imports.push({
                importName: "___CSS_LOADER_GET_URL_IMPORT___",
                url: options.urlHandler(
                  require.resolve("../runtime/getUrl.js")
                ),
                index: -1,
              });

              hasUrlImportHelper = true;
            }

            const { url, prefix } = item;
            const newUrl = prefix ? `${prefix}!${url}` : url;
            let importName = urlToNameMap.get(newUrl);

            if (!importName) {
              importName = `___CSS_LOADER_URL_IMPORT_${urlToNameMap.size}___`;
              urlToNameMap.set(newUrl, importName);

              options.imports.push({
                importName,
                url: options.urlHandler(newUrl),
                index,
              });
            }

            const { hash, needQuotes } = item;
            const replacementKey = JSON.stringify({ newUrl, hash, needQuotes });
            let replacementName = urlToReplacementMap.get(replacementKey);

            if (!replacementName) {
              replacementName = `___CSS_LOADER_URL_REPLACEMENT_${urlToReplacementMap.size}___`;
              urlToReplacementMap.set(replacementKey, replacementName);

              options.replacements.push({
                replacementName,
                importName,
                hash,
                needQuotes,
              });
            }

            // eslint-disable-next-line no-param-reassign
            item.node.type = "word";
            // eslint-disable-next-line no-param-reassign
            item.node.value = replacementName;
            // eslint-disable-next-line no-param-reassign
            item.declaration.value = item.parsed.toString();
          }
        },
      };
    },
  };
};

plugin.postcss = true;

export default plugin;