lingui loader

lingui-loader.js

// Modified version of @lingui/loader.
// Current version does not read message catalogs correctly.
// https://github.com/lingui/js-lingui/blob/388464825440b7df3f20a549e425399f8a64c0b7/packages/loader/src/index.js

const path = require("path");
const { getConfig } = require("@lingui/conf");
const { createCompiledCatalog, configureCatalog } = require("@lingui/cli/api");
const loaderUtils = require("loader-utils");

// Check if JavascriptParser and JavascriptGenerator exists -> Webpack 4
let JavascriptParser;
let JavascriptGenerator;
try {
  JavascriptParser = require("webpack/lib/Parser");
  JavascriptGenerator = require("webpack/lib/JavascriptGenerator");
} catch (error) {
  if (error.code !== "MODULE_NOT_FOUND") {
    throw e;
  }
}

exports.default = function(source) {
  const options = loaderUtils.getOptions(this) || {};

  // Webpack 4 uses json-loader automatically, which breaks this loader because it
  // doesn't return JSON, but JS module. This is a temporary workaround before
  // official API is added (https://github.com/webpack/webpack/issues/7057#issuecomment-381883220)
  // See https://github.com/webpack/webpack/issues/7057
  if (JavascriptParser && JavascriptGenerator) {
    this._module.type = "javascript/auto";
    this._module.parser = new JavascriptParser();
    this._module.generator = new JavascriptGenerator();
  }

  const config = getConfig({
    configPath: options.config,
    cwd: path.dirname(this.resourcePath)
  });
  const catalog = configureCatalog(config);

  const locale = catalog.getLocale(this.resourcePath);

  const messages = JSON.parse(source);

  // In production we don't want untranslated strings. It's better to use message
  // keys as a last resort.
  // In development, however, we want to catch missing strings with `missing` parameter
  // of I18nProvider (React) or setupI18n (core) and therefore we need to get
  // empty translations if missing.
  const strict = process.env.NODE_ENV !== "production";
  return createCompiledCatalog(
    locale,
    messages,
    strict,
    config.compileNamespace,
    config.pseudoLocale
  );
};