src/utils.js

/*
  MIT License http://www.opensource.org/licenses/mit-license.php
  Author Tobias Koppers @sokra
*/
import { fileURLToPath } from "url";
import path from "path";

import { urlToRequest, interpolateName } from "loader-utils";
import modulesValues from "postcss-modules-values";
import localByDefault from "postcss-modules-local-by-default";
import extractImports from "postcss-modules-extract-imports";
import modulesScope from "postcss-modules-scope";
import camelCase from "camelcase";

const WEBPACK_IGNORE_COMMENT_REGEXP = /webpackIgnore:(\s+)?(true|false)/;

// eslint-disable-next-line no-useless-escape
const regexSingleEscape = /[ -,.\/:-@[\]\^`{-~]/;
const regexExcessiveSpaces = /(^|\\+)?(\\[A-F0-9]{1,6})\x20(?![a-fA-F0-9\x20])/g;

function escape(string) {
  let output = "";
  let counter = 0;

  while (counter < string.length) {
    // eslint-disable-next-line no-plusplus
    const character = string.charAt(counter++);

    let value;

    // eslint-disable-next-line no-control-regex
    if (/[\t\n\f\r\x0B]/.test(character)) {
      const codePoint = character.charCodeAt();

      value = `\\${codePoint.toString(16).toUpperCase()} `;
    } else if (character === "\\" || regexSingleEscape.test(character)) {
      value = `\\${character}`;
    } else {
      value = character;
    }

    output += value;
  }

  const firstChar = string.charAt(0);

  if (/^-[-\d]/.test(output)) {
    output = `\\-${output.slice(1)}`;
  } else if (/\d/.test(firstChar)) {
    output = `\\3${firstChar} ${output.slice(1)}`;
  }

  // Remove spaces after `\HEX` escapes that are not followed by a hex digit,
  // since they’re redundant. Note that this is only possible if the escape
  // sequence isn’t preceded by an odd number of backslashes.
  output = output.replace(regexExcessiveSpaces, ($0, $1, $2) => {
    if ($1 && $1.length % 2) {
      // It’s not safe to remove the space, so don’t.
      return $0;
    }

    // Strip the space.
    return ($1 || "") + $2;
  });

  return output;
}

function gobbleHex(str) {
  const lower = str.toLowerCase();
  let hex = "";
  let spaceTerminated = false;

  // eslint-disable-next-line no-undefined
  for (let i = 0; i < 6 && lower[i] !== undefined; i++) {
    const code = lower.charCodeAt(i);
    // check to see if we are dealing with a valid hex char [a-f|0-9]
    const valid = (code >= 97 && code <= 102) || (code >= 48 && code <= 57);
    // https://drafts.csswg.org/css-syntax/#consume-escaped-code-point
    spaceTerminated = code === 32;

    if (!valid) {
      break;
    }

    hex += lower[i];
  }

  if (hex.length === 0) {
    // eslint-disable-next-line no-undefined
    return undefined;
  }

  const codePoint = parseInt(hex, 16);

  const isSurrogate = codePoint >= 0xd800 && codePoint <= 0xdfff;
  // Add special case for
  // "If this number is zero, or is for a surrogate, or is greater than the maximum allowed code point"
  // https://drafts.csswg.org/css-syntax/#maximum-allowed-code-point
  if (isSurrogate || codePoint === 0x0000 || codePoint > 0x10ffff) {
    return ["\uFFFD", hex.length + (spaceTerminated ? 1 : 0)];
  }

  return [
    String.fromCodePoint(codePoint),
    hex.length + (spaceTerminated ? 1 : 0),
  ];
}

const CONTAINS_ESCAPE = /\\/;

function unescape(str) {
  const needToProcess = CONTAINS_ESCAPE.test(str);

  if (!needToProcess) {
    return str;
  }

  let ret = "";

  for (let i = 0; i < str.length; i++) {
    if (str[i] === "\\") {
      const gobbled = gobbleHex(str.slice(i + 1, i + 7));

      // eslint-disable-next-line no-undefined
      if (gobbled !== undefined) {
        ret += gobbled[0];
        i += gobbled[1];

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

      // Retain a pair of \\ if double escaped `\\\\`
      // https://github.com/postcss/postcss-selector-parser/commit/268c9a7656fb53f543dc620aa5b73a30ec3ff20e
      if (str[i + 1] === "\\") {
        ret += "\\";
        i += 1;

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

      // if \\ is at the end of the string retain it
      // https://github.com/postcss/postcss-selector-parser/commit/01a6b346e3612ce1ab20219acc26abdc259ccefb
      if (str.length === i + 1) {
        ret += str[i];
      }

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

    ret += str[i];
  }

  return ret;
}

function normalizePath(file) {
  return path.sep === "\\" ? file.replace(/\\/g, "/") : file;
}

// eslint-disable-next-line no-control-regex
const filenameReservedRegex = /[<>:"/\\|?*]/g;
// eslint-disable-next-line no-control-regex
const reControlChars = /[\u0000-\u001f\u0080-\u009f]/g;

function escapeLocalIdent(localident) {
  // TODO simplify in the next major release
  return escape(
    localident
      // For `[hash]` placeholder
      .replace(/^((-?[0-9])|--)/, "_$1")
      .replace(filenameReservedRegex, "-")
      .replace(reControlChars, "-")
      .replace(/\./g, "-")
  );
}

function defaultGetLocalIdent(
  loaderContext,
  localIdentName,
  localName,
  options
) {
  let relativeMatchResource = "";

  // eslint-disable-next-line no-underscore-dangle
  if (loaderContext._module && loaderContext._module.matchResource) {
    relativeMatchResource = `${normalizePath(
      // eslint-disable-next-line no-underscore-dangle
      path.relative(options.context, loaderContext._module.matchResource)
    )}\x00`;
  }

  const relativeResourcePath = normalizePath(
    path.relative(options.context, loaderContext.resourcePath)
  );

  // eslint-disable-next-line no-param-reassign
  options.content = `${options.hashPrefix}${relativeMatchResource}${relativeResourcePath}\x00${localName}`;

  return interpolateName(loaderContext, localIdentName, options);
}

const NATIVE_WIN32_PATH = /^[A-Z]:[/\\]|^\\\\/i;

function normalizeUrl(url, isStringValue) {
  let normalizedUrl = url
    .replace(/^( |\t\n|\r\n|\r|\f)*/g, "")
    .replace(/( |\t\n|\r\n|\r|\f)*$/g, "");

  if (isStringValue && /\\(\n|\r\n|\r|\f)/.test(normalizedUrl)) {
    normalizedUrl = normalizedUrl.replace(/\\(\n|\r\n|\r|\f)/g, "");
  }

  if (NATIVE_WIN32_PATH.test(url)) {
    try {
      normalizedUrl = decodeURI(normalizedUrl);
    } catch (error) {
      // Ignore
    }

    return normalizedUrl;
  }

  normalizedUrl = unescape(normalizedUrl);

  try {
    normalizedUrl = decodeURI(normalizedUrl);
  } catch (error) {
    // Ignore
  }

  return normalizedUrl;
}

function requestify(url, rootContext) {
  if (/^file:/i.test(url)) {
    return fileURLToPath(url);
  }

  return url.charAt(0) === "/"
    ? urlToRequest(url, rootContext)
    : urlToRequest(url);
}

function getFilter(filter, resourcePath) {
  return (...args) => {
    if (typeof filter === "function") {
      return filter(...args, resourcePath);
    }

    return true;
  };
}

function getValidLocalName(localName, exportLocalsConvention) {
  if (exportLocalsConvention === "dashesOnly") {
    return dashesCamelCase(localName);
  }

  return camelCase(localName);
}

const moduleRegExp = /\.module(s)?\.\w+$/i;
const icssRegExp = /\.icss\.\w+$/i;

function getModulesOptions(rawOptions, loaderContext) {
  const resourcePath =
    // eslint-disable-next-line no-underscore-dangle
    (loaderContext._module && loaderContext._module.matchResource) ||
    loaderContext.resourcePath;

  let isIcss;

  if (typeof rawOptions.modules === "undefined") {
    const isModules = moduleRegExp.test(resourcePath);

    if (!isModules) {
      isIcss = icssRegExp.test(resourcePath);
    }

    if (!isModules && !isIcss) {
      return false;
    }
  } else if (
    typeof rawOptions.modules === "boolean" &&
    rawOptions.modules === false
  ) {
    return false;
  }

  let modulesOptions = {
    compileType: isIcss ? "icss" : "module",
    auto: true,
    mode: "local",
    exportGlobals: false,
    localIdentName: "[hash:base64]",
    localIdentContext: loaderContext.rootContext,
    localIdentHashPrefix: "",
    // eslint-disable-next-line no-undefined
    localIdentRegExp: undefined,
    // eslint-disable-next-line no-undefined
    getLocalIdent: undefined,
    namedExport: false,
    exportLocalsConvention: "asIs",
    exportOnlyLocals: false,
  };

  if (
    typeof rawOptions.modules === "boolean" ||
    typeof rawOptions.modules === "string"
  ) {
    modulesOptions.mode =
      typeof rawOptions.modules === "string" ? rawOptions.modules : "local";
  } else {
    if (rawOptions.modules) {
      if (typeof rawOptions.modules.auto === "boolean") {
        const isModules =
          rawOptions.modules.auto && moduleRegExp.test(resourcePath);

        if (!isModules) {
          return false;
        }
      } else if (rawOptions.modules.auto instanceof RegExp) {
        const isModules = rawOptions.modules.auto.test(resourcePath);

        if (!isModules) {
          return false;
        }
      } else if (typeof rawOptions.modules.auto === "function") {
        const isModule = rawOptions.modules.auto(resourcePath);

        if (!isModule) {
          return false;
        }
      }

      if (
        rawOptions.modules.namedExport === true &&
        typeof rawOptions.modules.exportLocalsConvention === "undefined"
      ) {
        modulesOptions.exportLocalsConvention = "camelCaseOnly";
      }
    }

    modulesOptions = { ...modulesOptions, ...(rawOptions.modules || {}) };
  }

  if (typeof modulesOptions.mode === "function") {
    modulesOptions.mode = modulesOptions.mode(loaderContext.resourcePath);
  }

  if (modulesOptions.namedExport === true) {
    if (rawOptions.esModule === false) {
      throw new Error(
        'The "modules.namedExport" option requires the "esModules" option to be enabled'
      );
    }

    if (
      modulesOptions.exportLocalsConvention !== "camelCaseOnly" &&
      modulesOptions.exportLocalsConvention !== "dashesOnly"
    ) {
      throw new Error(
        'The "modules.namedExport" option requires the "modules.exportLocalsConvention" option to be "camelCaseOnly" or "dashesOnly"'
      );
    }
  }

  if (/\[emoji(?::(\d+))?\]/i.test(modulesOptions.localIdentName)) {
    loaderContext.emitWarning(
      "Emoji is deprecated and will be removed in next major release."
    );
  }

  return modulesOptions;
}

function normalizeOptions(rawOptions, loaderContext) {
  const modulesOptions = getModulesOptions(rawOptions, loaderContext);

  return {
    url: typeof rawOptions.url === "undefined" ? true : rawOptions.url,
    import: typeof rawOptions.import === "undefined" ? true : rawOptions.import,
    modules: modulesOptions,
    sourceMap:
      typeof rawOptions.sourceMap === "boolean"
        ? rawOptions.sourceMap
        : loaderContext.sourceMap,
    importLoaders:
      typeof rawOptions.importLoaders === "string"
        ? parseInt(rawOptions.importLoaders, 10)
        : rawOptions.importLoaders,
    esModule:
      typeof rawOptions.esModule === "undefined" ? true : rawOptions.esModule,
  };
}

function shouldUseImportPlugin(options) {
  if (options.modules.exportOnlyLocals) {
    return false;
  }

  if (typeof options.import === "boolean") {
    return options.import;
  }

  return true;
}

function shouldUseURLPlugin(options) {
  if (options.modules.exportOnlyLocals) {
    return false;
  }

  if (typeof options.url === "boolean") {
    return options.url;
  }

  return true;
}

function shouldUseModulesPlugins(options) {
  return options.modules.compileType === "module";
}

function shouldUseIcssPlugin(options) {
  return options.icss === true || Boolean(options.modules);
}

function getModulesPlugins(options, loaderContext) {
  const {
    mode,
    getLocalIdent,
    localIdentName,
    localIdentContext,
    localIdentHashPrefix,
    localIdentRegExp,
  } = options.modules;

  let plugins = [];

  try {
    plugins = [
      modulesValues,
      localByDefault({ mode }),
      extractImports(),
      modulesScope({
        generateScopedName(exportName) {
          let localIdent;

          if (typeof getLocalIdent !== "undefined") {
            localIdent = getLocalIdent(
              loaderContext,
              localIdentName,
              unescape(exportName),
              {
                context: localIdentContext,
                hashPrefix: localIdentHashPrefix,
                regExp: localIdentRegExp,
              }
            );
          }

          // A null/undefined value signals that we should invoke the default
          // getLocalIdent method.
          if (typeof localIdent === "undefined" || localIdent === null) {
            localIdent = defaultGetLocalIdent(
              loaderContext,
              localIdentName,
              unescape(exportName),
              {
                context: localIdentContext,
                hashPrefix: localIdentHashPrefix,
                regExp: localIdentRegExp,
              }
            );

            return escapeLocalIdent(localIdent).replace(
              /\\\[local\\]/gi,
              exportName
            );
          }

          return escapeLocalIdent(localIdent);
        },
        exportGlobals: options.modules.exportGlobals,
      }),
    ];
  } catch (error) {
    loaderContext.emitError(error);
  }

  return plugins;
}

const IS_NATIVE_WIN32_PATH = /^[a-z]:[/\\]|^\\\\/i;
const ABSOLUTE_SCHEME = /^[a-z0-9+\-.]+:/i;

function getURLType(source) {
  if (source[0] === "/") {
    if (source[1] === "/") {
      return "scheme-relative";
    }

    return "path-absolute";
  }

  if (IS_NATIVE_WIN32_PATH.test(source)) {
    return "path-absolute";
  }

  return ABSOLUTE_SCHEME.test(source) ? "absolute" : "path-relative";
}

function normalizeSourceMap(map, resourcePath) {
  let newMap = map;

  // Some loader emit source map as string
  // Strip any JSON XSSI avoidance prefix from the string (as documented in the source maps specification), and then parse the string as JSON.
  if (typeof newMap === "string") {
    newMap = JSON.parse(newMap);
  }

  delete newMap.file;

  const { sourceRoot } = newMap;

  delete newMap.sourceRoot;

  if (newMap.sources) {
    // Source maps should use forward slash because it is URLs (https://github.com/mozilla/source-map/issues/91)
    // We should normalize path because previous loaders like `sass-loader` using backslash when generate source map
    newMap.sources = newMap.sources.map((source) => {
      // Non-standard syntax from `postcss`
      if (source.indexOf("<") === 0) {
        return source;
      }

      const sourceType = getURLType(source);

      // Do no touch `scheme-relative` and `absolute` URLs
      if (sourceType === "path-relative" || sourceType === "path-absolute") {
        const absoluteSource =
          sourceType === "path-relative" && sourceRoot
            ? path.resolve(sourceRoot, normalizePath(source))
            : normalizePath(source);

        return path.relative(path.dirname(resourcePath), absoluteSource);
      }

      return source;
    });
  }

  return newMap;
}

function getPreRequester({ loaders, loaderIndex }) {
  const cache = Object.create(null);

  return (number) => {
    if (cache[number]) {
      return cache[number];
    }

    if (number === false) {
      cache[number] = "";
    } else {
      const loadersRequest = loaders
        .slice(
          loaderIndex,
          loaderIndex + 1 + (typeof number !== "number" ? 0 : number)
        )
        .map((x) => x.request)
        .join("!");

      cache[number] = `-!${loadersRequest}!`;
    }

    return cache[number];
  };
}

function getImportCode(imports, options) {
  let code = "";

  for (const item of imports) {
    const { importName, url, icss } = item;

    if (options.esModule) {
      if (icss && options.modules.namedExport) {
        code += `import ${
          options.modules.exportOnlyLocals ? "" : `${importName}, `
        }* as ${importName}_NAMED___ from ${url};\n`;
      } else {
        code += `import ${importName} from ${url};\n`;
      }
    } else {
      code += `var ${importName} = require(${url});\n`;
    }
  }

  return code ? `// Imports\n${code}` : "";
}

function normalizeSourceMapForRuntime(map, loaderContext) {
  const resultMap = map ? map.toJSON() : null;

  if (resultMap) {
    delete resultMap.file;

    resultMap.sourceRoot = "";

    resultMap.sources = resultMap.sources.map((source) => {
      // Non-standard syntax from `postcss`
      if (source.indexOf("<") === 0) {
        return source;
      }

      const sourceType = getURLType(source);

      if (sourceType !== "path-relative") {
        return source;
      }

      const resourceDirname = path.dirname(loaderContext.resourcePath);
      const absoluteSource = path.resolve(resourceDirname, source);
      const contextifyPath = normalizePath(
        path.relative(loaderContext.rootContext, absoluteSource)
      );

      return `webpack://./${contextifyPath}`;
    });
  }

  return JSON.stringify(resultMap);
}

function getModuleCode(result, api, replacements, options, loaderContext) {
  if (options.modules.exportOnlyLocals === true) {
    return "";
  }

  const sourceMapValue = options.sourceMap
    ? `,${normalizeSourceMapForRuntime(result.map, loaderContext)}`
    : "";

  let code = JSON.stringify(result.css);

  let beforeCode = `var ___CSS_LOADER_EXPORT___ = ___CSS_LOADER_API_IMPORT___(${
    options.sourceMap
      ? "___CSS_LOADER_API_SOURCEMAP_IMPORT___"
      : "function(i){return i[1]}"
  });\n`;

  for (const item of api) {
    const { url, media, dedupe } = item;

    beforeCode += url
      ? `___CSS_LOADER_EXPORT___.push([module.id, ${JSON.stringify(
          `@import url(${url});`
        )}${media ? `, ${JSON.stringify(media)}` : ""}]);\n`
      : `___CSS_LOADER_EXPORT___.i(${item.importName}${
          media ? `, ${JSON.stringify(media)}` : dedupe ? ', ""' : ""
        }${dedupe ? ", true" : ""});\n`;
  }

  for (const item of replacements) {
    const { replacementName, importName, localName } = item;

    if (localName) {
      code = code.replace(new RegExp(replacementName, "g"), () =>
        options.modules.namedExport
          ? `" + ${importName}_NAMED___[${JSON.stringify(
              getValidLocalName(
                localName,
                options.modules.exportLocalsConvention
              )
            )}] + "`
          : `" + ${importName}.locals[${JSON.stringify(localName)}] + "`
      );
    } else {
      const { hash, needQuotes } = item;
      const getUrlOptions = []
        .concat(hash ? [`hash: ${JSON.stringify(hash)}`] : [])
        .concat(needQuotes ? "needQuotes: true" : []);
      const preparedOptions =
        getUrlOptions.length > 0 ? `, { ${getUrlOptions.join(", ")} }` : "";

      beforeCode += `var ${replacementName} = ___CSS_LOADER_GET_URL_IMPORT___(${importName}${preparedOptions});\n`;
      code = code.replace(
        new RegExp(replacementName, "g"),
        () => `" + ${replacementName} + "`
      );
    }
  }

  return `${beforeCode}// Module\n___CSS_LOADER_EXPORT___.push([module.id, ${code}, ""${sourceMapValue}]);\n`;
}

function dashesCamelCase(str) {
  return str.replace(/-+(\w)/g, (match, firstLetter) =>
    firstLetter.toUpperCase()
  );
}

function getExportCode(exports, replacements, options) {
  let code = "// Exports\n";
  let localsCode = "";

  const addExportToLocalsCode = (name, value) => {
    if (options.modules.namedExport) {
      localsCode += `export const ${name} = ${JSON.stringify(value)};\n`;
    } else {
      if (localsCode) {
        localsCode += `,\n`;
      }

      localsCode += `\t${JSON.stringify(name)}: ${JSON.stringify(value)}`;
    }
  };

  for (const { name, value } of exports) {
    switch (options.modules.exportLocalsConvention) {
      case "camelCase": {
        addExportToLocalsCode(name, value);

        const modifiedName = camelCase(name);

        if (modifiedName !== name) {
          addExportToLocalsCode(modifiedName, value);
        }
        break;
      }
      case "camelCaseOnly": {
        addExportToLocalsCode(camelCase(name), value);
        break;
      }
      case "dashes": {
        addExportToLocalsCode(name, value);

        const modifiedName = dashesCamelCase(name);

        if (modifiedName !== name) {
          addExportToLocalsCode(modifiedName, value);
        }
        break;
      }
      case "dashesOnly": {
        addExportToLocalsCode(dashesCamelCase(name), value);
        break;
      }
      case "asIs":
      default:
        addExportToLocalsCode(name, value);
        break;
    }
  }

  for (const item of replacements) {
    const { replacementName, localName } = item;

    if (localName) {
      const { importName } = item;

      localsCode = localsCode.replace(new RegExp(replacementName, "g"), () => {
        if (options.modules.namedExport) {
          return `" + ${importName}_NAMED___[${JSON.stringify(
            getValidLocalName(localName, options.modules.exportLocalsConvention)
          )}] + "`;
        } else if (options.modules.exportOnlyLocals) {
          return `" + ${importName}[${JSON.stringify(localName)}] + "`;
        }

        return `" + ${importName}.locals[${JSON.stringify(localName)}] + "`;
      });
    } else {
      localsCode = localsCode.replace(
        new RegExp(replacementName, "g"),
        () => `" + ${replacementName} + "`
      );
    }
  }

  if (options.modules.exportOnlyLocals) {
    code += options.modules.namedExport
      ? localsCode
      : `${
          options.esModule ? "export default" : "module.exports ="
        } {\n${localsCode}\n};\n`;

    return code;
  }

  if (localsCode) {
    code += options.modules.namedExport
      ? localsCode
      : `___CSS_LOADER_EXPORT___.locals = {\n${localsCode}\n};\n`;
  }

  code += `${
    options.esModule ? "export default" : "module.exports ="
  } ___CSS_LOADER_EXPORT___;\n`;

  return code;
}

async function resolveRequests(resolve, context, possibleRequests) {
  return resolve(context, possibleRequests[0])
    .then((result) => result)
    .catch((error) => {
      const [, ...tailPossibleRequests] = possibleRequests;

      if (tailPossibleRequests.length === 0) {
        throw error;
      }

      return resolveRequests(resolve, context, tailPossibleRequests);
    });
}

function isUrlRequestable(url) {
  // Protocol-relative URLs
  if (/^\/\//.test(url)) {
    return false;
  }

  // `file:` protocol
  if (/^file:/i.test(url)) {
    return true;
  }

  // Absolute URLs
  if (/^[a-z][a-z0-9+.-]*:/i.test(url) && !NATIVE_WIN32_PATH.test(url)) {
    return false;
  }

  // `#` URLs
  if (/^#/.test(url)) {
    return false;
  }

  return true;
}

function sort(a, b) {
  return a.index - b.index;
}

function combineRequests(preRequest, url) {
  const idx = url.indexOf("!=!");

  return idx !== -1
    ? url.slice(0, idx + 3) + preRequest + url.slice(idx + 3)
    : preRequest + url;
}

export {
  normalizeOptions,
  shouldUseModulesPlugins,
  shouldUseImportPlugin,
  shouldUseURLPlugin,
  shouldUseIcssPlugin,
  normalizeUrl,
  requestify,
  getFilter,
  getModulesOptions,
  getModulesPlugins,
  normalizeSourceMap,
  getPreRequester,
  getImportCode,
  getModuleCode,
  getExportCode,
  resolveRequests,
  isUrlRequestable,
  sort,
  WEBPACK_IGNORE_COMMENT_REGEXP,
  combineRequests,
};