jupyterlab/buildutils/src/webpack-plugins.ts

/*-----------------------------------------------------------------------------
| Copyright (c) Jupyter Development Team.
| Distributed under the terms of the Modified BSD License.
|----------------------------------------------------------------------------*/

import * as webpack from 'webpack';
import * as fs from 'fs-extra';

export namespace WPPlugin {
  /**
   * A WebPack Plugin that copies the assets to the static directory
   */
  export class FrontEndPlugin {
    constructor(buildDir: string, staticDir: string) {
      this.buildDir = buildDir;
      this.staticDir = staticDir;

      this._first = true;
    }

    apply(compiler: any) {
      compiler.hooks.afterEmit.tap('FrontEndPlugin', () => {
        // bail if no staticDir
        if (!this.staticDir) {
          return;
        }

        // ensure a clean static directory on the first emit
        if (this._first && fs.existsSync(this.staticDir)) {
          fs.removeSync(this.staticDir);
        }
        this._first = false;

        fs.copySync(this.buildDir, this.staticDir);
      });
    }

    buildDir: string;
    staticDir: string;

    private _first: boolean;
  }

  /**
   * A WebPack Plugin that ignores files that are filtered by a callback
   */
  export class FilterIgnorePlugin extends webpack.IgnorePlugin {
    constructor(ignored: (path: string) => boolean) {
      super({});

      // ignored should be a callback function that filters the build files
      this.ignored = ignored;
    }

    checkIgnore(result: any): any | null {
      if (!result) {
        return result;
      }
      return this.ignored(result.resource) ? result : null;
    }

    ignored: (path: string) => boolean;
  }

  /**
   * A helper class for the WatchIgnoreFilterPlugin. This is a close copy of
   * (the non-exported) webpack.IgnoringWatchFileSystem
   */
  class FilterIgnoringWatchFileSystem {
    constructor(wfs: any, ignored: (path: string) => boolean) {
      this.wfs = wfs;

      // ignored should be a callback function that filters the build files
      this.ignored = ignored;
    }

    watch(
      files: any,
      dirs: any,
      missing: any,
      startTime: any,
      options: any,
      callback: any,
      callbackUndelayed: any
    ) {
      const notIgnored = (path: string) => !this.ignored(path);

      const ignoredFiles = files.filter(this.ignored);
      const ignoredDirs = dirs.filter(this.ignored);

      const watcher = this.wfs.watch(
        files.filter(notIgnored),
        dirs.filter(notIgnored),
        missing,
        startTime,
        options,
        (
          err: any,
          filesModified: any,
          dirsModified: any,
          missingModified: any,
          fileTimestamps: any,
          dirTimestamps: any,
          removedFiles: any
        ) => {
          if (err) {
            return callback(err);
          }
          for (const path of ignoredFiles) {
            fileTimestamps.set(path, 1);
          }

          for (const path of ignoredDirs) {
            dirTimestamps.set(path, 1);
          }

          callback(
            err,
            filesModified,
            dirsModified,
            missingModified,
            fileTimestamps,
            dirTimestamps,
            removedFiles
          );
        },
        callbackUndelayed
      );

      return {
        close: () => watcher.close(),
        pause: () => watcher.pause(),
        getContextTimestamps: () => {
          const dirTimestamps = watcher.getContextTimestamps();
          for (const path of ignoredDirs) {
            dirTimestamps.set(path, 1);
          }
          return dirTimestamps;
        },
        getFileTimestamps: () => {
          const fileTimestamps = watcher.getFileTimestamps();
          for (const path of ignoredFiles) {
            fileTimestamps.set(path, 1);
          }
          return fileTimestamps;
        }
      };
    }

    ignored: (path: string) => boolean;
    wfs: any;
  }

  /**
   * A WebPack Plugin that ignores files files that are filtered
   * by a callback during a `--watch` build
   */
  export class FilterWatchIgnorePlugin {
    constructor(ignored: (path: string) => boolean) {
      this.ignored = ignored;
    }

    apply(compiler: any) {
      compiler.hooks.afterEnvironment.tap('FilterWatchIgnorePlugin', () => {
        compiler.watchFileSystem = new FilterIgnoringWatchFileSystem(
          compiler.watchFileSystem,
          this.ignored
        );
      });
    }

    ignored: (path: string) => boolean;
  }
}