webpack-plugin-serve/lib/client/hmr.js

A Development Server in a Webpack Plugin

/*
  Copyright © 2018 Andrew Powell

  This Source Code Form is subject to the terms of the Mozilla Public
  License, v. 2.0. If a copy of the MPL was not distributed with this
  file, You can obtain one at http://mozilla.org/MPL/2.0/.

  The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of this Source Code Form.
*/
const { error, info, refresh, warn } = require('./log')();

let latest = true;

const hmr = (onFailure) => {
  return {
    onUnaccepted(data) {
      onFailure();
      warn('Change in unaccepted module(s):\n', data);
      warn(data);
    },
    onDeclined(data) {
      onFailure();
      warn('Change in declined module(s):\n', data);
    },
    onErrored(data) {
      onFailure();
      error('Error in module(s):\n', data);
    }
  };
};

const replace = async (buildHash, hash, refreshOnFailure) => {
  const { apply, check, status } = module.hot;

  if (hash) {
    // eslint-disable-next-line no-undef
    latest = hash.includes(buildHash);
  }

  if (!latest) {
    const hmrStatus = status();

    if (hmrStatus === 'abort' || hmrStatus === 'fail') {
      warn(`An HMR update was triggered, but ${hmrStatus}ed. ${refresh}`);
      return;
    }

    let modules;

    try {
      modules = await check(false);
    } catch (e) {
      // noop. this typically happens when a MultiCompiler has more than one compiler that includes
      // this script, and an update happens with a hash that isn't part of the compiler/module this
      // instance was loaded for.
      return;
    }

    if (!modules) {
      warn(`No modules found for replacement. ${refresh}`);
      return;
    }

    modules = await apply(
      hmr(
        refreshOnFailure
          ? () => {
              if (refreshOnFailure) {
                // eslint-disable-next-line no-undef
                location.reload();
              }
            }
          : () => {}
      )
    );

    if (modules) {
      latest = true;
      info(`Build ${hash.slice(0, 7)} replaced:\n`, modules);
    }
  }
};

module.exports = { replace };