webpack-cli.js

const fs = require("fs");
const path = require("path");
const { pathToFileURL } = require("url");
const Module = require("module");

const { program, Option } = require("commander");
const utils = require("./utils");

const WEBPACK_PACKAGE = process.env.WEBPACK_PACKAGE || "webpack";
const WEBPACK_DEV_SERVER_PACKAGE = process.env.WEBPACK_DEV_SERVER_PACKAGE || "webpack-dev-server";

class WebpackCLI {
  constructor() {
    this.logger = utils.logger;
    this.utils = utils;

    // Initialize program
    this.program = program;
    this.program.name("webpack");
    this.program.configureOutput({
      writeErr: this.logger.error,
      outputError: (str, write) =>
        write(`Error: ${this.utils.capitalizeFirstLetter(str.replace(/^error:/, "").trim())}`),
    });
  }

  async tryRequireThenImport(module, handleError = true) {
    let result;

    try {
      result = require(module);
    } catch (error) {
      let previousModuleCompile;

      // TODO Workaround https://github.com/zertosh/v8-compile-cache/issues/30
      if (this._originalModuleCompile) {
        previousModuleCompile = Module.prototype._compile;

        Module.prototype._compile = this._originalModuleCompile;
      }

      const dynamicImportLoader = this.utils.dynamicImportLoader();

      if (this._originalModuleCompile) {
        Module.prototype._compile = previousModuleCompile;
      }

      if (
        (error.code === "ERR_REQUIRE_ESM" || process.env.WEBPACK_CLI_FORCE_LOAD_ESM_CONFIG) &&
        pathToFileURL &&
        dynamicImportLoader
      ) {
        const urlForConfig = pathToFileURL(module);

        result = await dynamicImportLoader(urlForConfig);
        result = result.default;

        return result;
      }

      if (handleError) {
        this.logger.error(error);
        process.exit(2);
      } else {
        throw error;
      }
    }

    // For babel/typescript
    if (result && result.default) {
      result = result.default;
    }

    // Treat undefined configuration for zero-config
    if (!result) {
      this.logger.info(
        "Configuration file provided didn't export any configuration, using defaults to build.",
      );
      result = {};
    }

    return result;
  }

  loadJSONFile(pathToFile, handleError = true) {
    let result;

    try {
      result = require(pathToFile);
    } catch (error) {
      if (handleError) {
        this.logger.error(error);
        process.exit(2);
      } else {
        throw error;
      }
    }

    return result;
  }

  async loadWebpack(handleError = true) {
    return this.tryRequireThenImport(WEBPACK_PACKAGE, handleError);
  }

  async makeCommand(commandOptions, options, action) {
    const alreadyLoaded = this.program.commands.find(
      (command) =>
        command.name() === commandOptions.name.split(" ")[0] ||
        command.aliases().includes(commandOptions.alias),
    );

    if (alreadyLoaded) {
      return;
    }

    const command = this.program.command(commandOptions.name, {
      noHelp: commandOptions.noHelp,
      hidden: commandOptions.hidden,
      isDefault: commandOptions.isDefault,
    });

    if (commandOptions.description) {
      command.description(commandOptions.description, commandOptions.argsDescription);
    }

    if (commandOptions.usage) {
      command.usage(commandOptions.usage);
    }

    if (Array.isArray(commandOptions.alias)) {
      command.aliases(commandOptions.alias);
    } else {
      command.alias(commandOptions.alias);
    }

    if (commandOptions.pkg) {
      command.pkg = commandOptions.pkg;
    } else {
      command.pkg = "webpack-cli";
    }

    const { forHelp } = this.program;

    let allDependenciesInstalled = true;

    if (commandOptions.dependencies && commandOptions.dependencies.length > 0) {
      for (const dependency of commandOptions.dependencies) {
        const { packageExists } = this.utils;
        const isPkgExist = packageExists(dependency);

        if (isPkgExist) {
          continue;
        } else if (!isPkgExist && forHelp) {
          allDependenciesInstalled = false;
          continue;
        }

        let skipInstallation = false;

        // Allow to use `./path/to/webpack.js` outside `node_modules`
        if (dependency === WEBPACK_PACKAGE && fs.existsSync(WEBPACK_PACKAGE)) {
          skipInstallation = true;
        }

        // Allow to use `./path/to/webpack-dev-server.js` outside `node_modules`
        if (dependency === WEBPACK_DEV_SERVER_PACKAGE && fs.existsSync(WEBPACK_PACKAGE)) {
          skipInstallation = true;
        }

        if (skipInstallation) {
          continue;
        }

        await this.utils.promptInstallation(dependency, () => {
          this.logger.error(
            `For using '${this.utils.colors.green(
              commandOptions.name.split(" ")[0],
            )}' command you need to install: '${this.utils.colors.green(dependency)}' package.`,
          );
        });
      }
    }

    if (options) {
      if (typeof options === "function") {
        if (forHelp && !allDependenciesInstalled) {
          command.description(
            `${
              commandOptions.description
            } To see all available options you need to install ${commandOptions.dependencies
              .map((dependency) => `'${dependency}'`)
              .join(", ")}.`,
          );
          options = [];
        } else {
          options = await options();
        }
      }

      options.forEach((optionForCommand) => {
        this.makeOption(command, optionForCommand);
      });
    }

    command.action(action);

    return command;
  }

  makeOption(command, option) {
    let mainOption;
    let negativeOption;

    if (option.configs) {
      let needNegativeOption = false;
      const mainOptionType = new Set();

      option.configs.forEach((config) => {
        // Possible value: "enum" | "string" | "path" | "number" | "boolean" | "RegExp" | "reset"
        switch (config.type) {
          case "reset":
            mainOptionType.add(Boolean);
            break;
          case "boolean":
            if (!needNegativeOption) {
              needNegativeOption = true;
            }

            mainOptionType.add(Boolean);
            break;
          case "number":
            mainOptionType.add(Number);
            break;
          case "string":
          case "path":
          case "RegExp":
            mainOptionType.add(String);
            break;
          case "enum": {
            let hasFalseEnum = false;

            const enumTypes = config.values.map((value) => {
              switch (typeof value) {
                case "string":
                  mainOptionType.add(String);
                  break;
                case "number":
                  mainOptionType.add(Number);
                  break;
                case "boolean":
                  if (!hasFalseEnum && value === false) {
                    hasFalseEnum = true;
                    break;
                  }

                  mainOptionType.add(Boolean);
                  break;
              }
            });

            if (!needNegativeOption) {
              needNegativeOption = hasFalseEnum;
            }

            return enumTypes;
          }
        }
      });

      mainOption = {
        flags: option.alias ? `-${option.alias}, --${option.name}` : `--${option.name}`,
        description: option.description || "",
        type: mainOptionType,
        multiple: option.multiple,
        defaultValue: option.defaultValue,
      };

      if (needNegativeOption) {
        negativeOption = {
          flags: `--no-${option.name}`,
          description: option.negatedDescription
            ? option.negatedDescription
            : `Negative '${option.name}' option.`,
        };
      }
    } else {
      mainOption = {
        flags: option.alias ? `-${option.alias}, --${option.name}` : `--${option.name}`,
        // TODO `describe` used by `webpack-dev-server@3`
        description: option.description || option.describe || "",
        type: option.type
          ? new Set(Array.isArray(option.type) ? option.type : [option.type])
          : new Set([Boolean]),
        multiple: option.multiple,
        defaultValue: option.defaultValue,
      };

      if (option.negative) {
        negativeOption = {
          flags: `--no-${option.name}`,
          description: option.negatedDescription
            ? option.negatedDescription
            : `Negative '${option.name}' option.`,
        };
      }
    }

    if (mainOption.type.size > 1 && mainOption.type.has(Boolean)) {
      mainOption.flags = `${mainOption.flags} [value${mainOption.multiple ? "..." : ""}]`;
    } else if (mainOption.type.size > 0 && !mainOption.type.has(Boolean)) {
      mainOption.flags = `${mainOption.flags} <value${mainOption.multiple ? "..." : ""}>`;
    }

    if (mainOption.type.size === 1) {
      if (mainOption.type.has(Number)) {
        let skipDefault = true;

        const optionForCommand = new Option(mainOption.flags, mainOption.description)
          .argParser((value, prev = []) => {
            if (mainOption.defaultValue && mainOption.multiple && skipDefault) {
              prev = [];
              skipDefault = false;
            }

            return mainOption.multiple ? [].concat(prev).concat(Number(value)) : Number(value);
          })
          .default(mainOption.defaultValue);

        optionForCommand.helpLevel = option.helpLevel;

        command.addOption(optionForCommand);
      } else if (mainOption.type.has(String)) {
        let skipDefault = true;

        const optionForCommand = new Option(mainOption.flags, mainOption.description)
          .argParser((value, prev = []) => {
            if (mainOption.defaultValue && mainOption.multiple && skipDefault) {
              prev = [];
              skipDefault = false;
            }

            return mainOption.multiple ? [].concat(prev).concat(value) : value;
          })
          .default(mainOption.defaultValue);

        optionForCommand.helpLevel = option.helpLevel;

        command.addOption(optionForCommand);
      } else if (mainOption.type.has(Boolean)) {
        const optionForCommand = new Option(mainOption.flags, mainOption.description).default(
          mainOption.defaultValue,
        );

        optionForCommand.helpLevel = option.helpLevel;

        command.addOption(optionForCommand);
      } else {
        const optionForCommand = new Option(mainOption.flags, mainOption.description)
          .argParser(Array.from(mainOption.type)[0])
          .default(mainOption.defaultValue);

        optionForCommand.helpLevel = option.helpLevel;

        command.addOption(optionForCommand);
      }
    } else if (mainOption.type.size > 1) {
      let skipDefault = true;

      const optionForCommand = new Option(
        mainOption.flags,
        mainOption.description,
        mainOption.defaultValue,
      )
        .argParser((value, prev = []) => {
          if (mainOption.defaultValue && mainOption.multiple && skipDefault) {
            prev = [];
            skipDefault = false;
          }

          if (mainOption.type.has(Number)) {
            const numberValue = Number(value);

            if (!isNaN(numberValue)) {
              return mainOption.multiple ? [].concat(prev).concat(numberValue) : numberValue;
            }
          }

          if (mainOption.type.has(String)) {
            return mainOption.multiple ? [].concat(prev).concat(value) : value;
          }

          return value;
        })
        .default(mainOption.defaultValue);

      optionForCommand.helpLevel = option.helpLevel;

      command.addOption(optionForCommand);
    } else if (mainOption.type.size === 0 && negativeOption) {
      const optionForCommand = new Option(mainOption.flags, mainOption.description);

      // Hide stub option
      optionForCommand.hideHelp();
      optionForCommand.helpLevel = option.helpLevel;

      command.addOption(optionForCommand);
    }

    if (negativeOption) {
      const optionForCommand = new Option(negativeOption.flags, negativeOption.description);

      optionForCommand.helpLevel = option.helpLevel;

      command.addOption(optionForCommand);
    }
  }

  getBuiltInOptions() {
    if (this.builtInOptionsCache) {
      return this.builtInOptionsCache;
    }

    const minimumHelpFlags = [
      "config",
      "config-name",
      "merge",
      "env",
      "mode",
      "watch",
      "watch-options-stdin",
      "stats",
      "devtool",
      "entry",
      "target",
      "progress",
      "json",
      "name",
      "output-path",
      "node-env",
    ];

    const builtInFlags = [
      // For configs
      {
        name: "config",
        alias: "c",
        configs: [
          {
            type: "string",
          },
        ],
        multiple: true,
        description: "Provide path to a webpack configuration file e.g. ./webpack.config.js.",
      },
      {
        name: "config-name",
        configs: [
          {
            type: "string",
          },
        ],
        multiple: true,
        description: "Name of the configuration to use.",
      },
      {
        name: "merge",
        alias: "m",
        configs: [
          {
            type: "enum",
            values: [true],
          },
        ],
        description: "Merge two or more configurations using 'webpack-merge'.",
      },
      // Complex configs
      {
        name: "env",
        type: (value, previous = {}) => {
          // for https://github.com/webpack/webpack-cli/issues/2642
          if (value.endsWith("=")) {
            value.concat('""');
          }

          // This ensures we're only splitting by the first `=`
          const [allKeys, val] = value.split(/=(.+)/, 2);
          const splitKeys = allKeys.split(/\.(?!$)/);

          let prevRef = previous;

          splitKeys.forEach((someKey, index) => {
            if (!prevRef[someKey]) {
              prevRef[someKey] = {};
            }

            if (typeof prevRef[someKey] === "string") {
              prevRef[someKey] = {};
            }

            if (index === splitKeys.length - 1) {
              if (typeof val === "string") {
                prevRef[someKey] = val;
              } else {
                prevRef[someKey] = true;
              }
            }

            prevRef = prevRef[someKey];
          });

          return previous;
        },
        multiple: true,
        description: "Environment passed to the configuration when it is a function.",
      },
      {
        name: "node-env",
        configs: [
          {
            type: "string",
          },
        ],
        multiple: false,
        description: "Sets process.env.NODE_ENV to the specified value.",
      },

      // Adding more plugins
      {
        name: "hot",
        alias: "h",
        configs: [
          {
            type: "string",
          },
          {
            type: "boolean",
          },
        ],
        negative: true,
        description: "Enables Hot Module Replacement",
        negatedDescription: "Disables Hot Module Replacement.",
      },
      {
        name: "analyze",
        configs: [
          {
            type: "enum",
            values: [true],
          },
        ],
        multiple: false,
        description: "It invokes webpack-bundle-analyzer plugin to get bundle information.",
      },
      {
        name: "progress",
        configs: [
          {
            type: "string",
          },
          {
            type: "enum",
            values: [true],
          },
        ],
        description: "Print compilation progress during build.",
      },
      {
        name: "prefetch",
        configs: [
          {
            type: "string",
          },
        ],
        description: "Prefetch this request.",
      },

      // Output options
      {
        name: "json",
        configs: [
          {
            type: "string",
          },
          {
            type: "enum",
            values: [true],
          },
        ],
        alias: "j",
        description: "Prints result as JSON or store it in a file.",
      },

      // For webpack@4
      {
        name: "entry",
        configs: [
          {
            type: "string",
          },
        ],
        multiple: true,
        description: "The entry point(s) of your application e.g. ./src/main.js.",
      },
      {
        name: "output-path",
        alias: "o",
        configs: [
          {
            type: "string",
          },
        ],
        description: "Output location of the file generated by webpack e.g. ./dist/.",
      },
      {
        name: "target",
        alias: "t",
        configs: [
          {
            type: "string",
          },
        ],
        multiple: this.webpack.cli !== undefined,
        description: "Sets the build target e.g. node.",
      },
      {
        name: "devtool",
        configs: [
          {
            type: "string",
          },
          {
            type: "enum",
            values: [false],
          },
        ],
        negative: true,
        alias: "d",
        description: "Determine source maps to use.",
        negatedDescription: "Do not generate source maps.",
      },
      {
        name: "mode",
        configs: [
          {
            type: "string",
          },
        ],
        description: "Defines the mode to pass to webpack.",
      },
      {
        name: "name",
        configs: [
          {
            type: "string",
          },
        ],
        description: "Name of the configuration. Used when loading multiple configurations.",
      },
      {
        name: "stats",
        configs: [
          {
            type: "string",
          },
          {
            type: "boolean",
          },
        ],
        negative: true,
        description: "It instructs webpack on how to treat the stats e.g. verbose.",
        negatedDescription: "Disable stats output.",
      },
      {
        name: "watch",
        configs: [
          {
            type: "boolean",
          },
        ],
        negative: true,
        alias: "w",
        description: "Watch for files changes.",
        negatedDescription: "Do not watch for file changes.",
      },
      {
        name: "watch-options-stdin",
        configs: [
          {
            type: "boolean",
          },
        ],
        negative: true,
        description: "Stop watching when stdin stream has ended.",
        negatedDescription: "Do not stop watching when stdin stream has ended.",
      },
    ];

    // Extract all the flags being exported from core.
    // A list of cli flags generated by core can be found here https://github.com/webpack/webpack/blob/master/test/__snapshots__/Cli.test.js.snap
    const coreFlags = this.webpack.cli
      ? Object.entries(this.webpack.cli.getArguments()).map(([flag, meta]) => {
          const inBuiltIn = builtInFlags.find((builtInFlag) => builtInFlag.name === flag);

          if (inBuiltIn) {
            return {
              ...meta,
              name: flag,
              group: "core",
              ...inBuiltIn,
              configs: meta.configs || [],
            };
          }

          return { ...meta, name: flag, group: "core" };
        })
      : [];

    const options = []
      .concat(
        builtInFlags.filter(
          (builtInFlag) => !coreFlags.find((coreFlag) => builtInFlag.name === coreFlag.name),
        ),
      )
      .concat(coreFlags)
      .map((option) => {
        option.helpLevel = minimumHelpFlags.includes(option.name) ? "minimum" : "verbose";

        return option;
      });

    this.builtInOptionsCache = options;

    return options;
  }

  applyNodeEnv(options) {
    if (typeof options.nodeEnv === "string") {
      process.env.NODE_ENV = options.nodeEnv;
    }
  }

  async run(args, parseOptions) {
    // Built-in internal commands
    const buildCommandOptions = {
      name: "build [entries...]",
      alias: ["bundle", "b"],
      description: "Run webpack (default command, can be omitted).",
      usage: "[entries...] [options]",
      dependencies: [WEBPACK_PACKAGE],
    };
    const watchCommandOptions = {
      name: "watch [entries...]",
      alias: "w",
      description: "Run webpack and watch for files changes.",
      usage: "[entries...] [options]",
      dependencies: [WEBPACK_PACKAGE],
    };
    const versionCommandOptions = {
      name: "version [commands...]",
      alias: "v",
      description:
        "Output the version number of 'webpack', 'webpack-cli' and 'webpack-dev-server' and commands.",
    };
    const helpCommandOptions = {
      name: "help [command] [option]",
      alias: "h",
      description: "Display help for commands and options.",
    };
    // Built-in external commands
    const externalBuiltInCommandsInfo = [
      {
        name: "serve [entries...]",
        alias: ["server", "s"],
        pkg: "@webpack-cli/serve",
      },
      {
        name: "info",
        alias: "i",
        pkg: "@webpack-cli/info",
      },
      {
        name: "init",
        alias: ["create", "new", "c", "n"],
        pkg: "@webpack-cli/generators",
      },
      {
        name: "loader",
        alias: "l",
        pkg: "@webpack-cli/generators",
      },
      {
        name: "plugin",
        alias: "p",
        pkg: "@webpack-cli/generators",
      },
      {
        name: "migrate",
        alias: "m",
        pkg: "@webpack-cli/migrate",
      },
      {
        name: "configtest [config-path]",
        alias: "t",
        pkg: "@webpack-cli/configtest",
      },
    ];

    const knownCommands = [
      buildCommandOptions,
      watchCommandOptions,
      versionCommandOptions,
      helpCommandOptions,
      ...externalBuiltInCommandsInfo,
    ];
    const getCommandName = (name) => name.split(" ")[0];
    const isKnownCommand = (name) =>
      knownCommands.find(
        (command) =>
          getCommandName(command.name) === name ||
          (Array.isArray(command.alias) ? command.alias.includes(name) : command.alias === name),
      );
    const isCommand = (input, commandOptions) => {
      const longName = getCommandName(commandOptions.name);

      if (input === longName) {
        return true;
      }

      if (commandOptions.alias) {
        if (Array.isArray(commandOptions.alias)) {
          return commandOptions.alias.includes(input);
        } else {
          return commandOptions.alias === input;
        }
      }

      return false;
    };
    const findCommandByName = (name) =>
      this.program.commands.find(
        (command) => name === command.name() || command.aliases().includes(name),
      );
    const isOption = (value) => value.startsWith("-");
    const isGlobalOption = (value) =>
      value === "--color" ||
      value === "--no-color" ||
      value === "-v" ||
      value === "--version" ||
      value === "-h" ||
      value === "--help";

    const loadCommandByName = async (commandName, allowToInstall = false) => {
      const isBuildCommandUsed = isCommand(commandName, buildCommandOptions);
      const isWatchCommandUsed = isCommand(commandName, watchCommandOptions);

      if (isBuildCommandUsed || isWatchCommandUsed) {
        await this.makeCommand(
          isBuildCommandUsed ? buildCommandOptions : watchCommandOptions,
          async () => {
            this.webpack = await this.loadWebpack();

            return isWatchCommandUsed
              ? this.getBuiltInOptions().filter((option) => option.name !== "watch")
              : this.getBuiltInOptions();
          },
          async (entries, options) => {
            if (entries.length > 0) {
              options.entry = [...entries, ...(options.entry || [])];
            }

            await this.runWebpack(options, isWatchCommandUsed);
          },
        );
      } else if (isCommand(commandName, helpCommandOptions)) {
        // Stub for the `help` command
        this.makeCommand(helpCommandOptions, [], () => {});
      } else if (isCommand(commandName, versionCommandOptions)) {
        // Stub for the `version` command
        this.makeCommand(versionCommandOptions, [], () => {});
      } else {
        const builtInExternalCommandInfo = externalBuiltInCommandsInfo.find(
          (externalBuiltInCommandInfo) =>
            getCommandName(externalBuiltInCommandInfo.name) === commandName ||
            (Array.isArray(externalBuiltInCommandInfo.alias)
              ? externalBuiltInCommandInfo.alias.includes(commandName)
              : externalBuiltInCommandInfo.alias === commandName),
        );

        let pkg;

        if (builtInExternalCommandInfo) {
          ({ pkg } = builtInExternalCommandInfo);
        } else {
          pkg = commandName;
        }

        if (pkg !== "webpack-cli" && !this.utils.packageExists(pkg)) {
          if (!allowToInstall) {
            return;
          }

          const { promptInstallation, colors } = this.utils;

          pkg = await promptInstallation(pkg, () => {
            this.logger.error(
              `For using this command you need to install: '${colors.green(pkg)}' package.`,
            );
          });
        }

        let loadedCommand;

        try {
          loadedCommand = await this.tryRequireThenImport(pkg, false);
        } catch (error) {
          // Ignore, command is not installed

          return;
        }

        let command;

        try {
          command = new loadedCommand();

          await command.apply(this);
        } catch (error) {
          this.logger.error(`Unable to load '${pkg}' command`);
          this.logger.error(error);
          process.exit(2);
        }
      }
    };

    // Register own exit
    this.program.exitOverride(async (error) => {
      if (error.exitCode === 0) {
        process.exit(0);
      }

      if (error.code === "executeSubCommandAsync") {
        process.exit(2);
      }

      if (error.code === "commander.help") {
        process.exit(0);
      }

      if (error.code === "commander.unknownOption") {
        let name = error.message.match(/'(.+)'/);

        if (name) {
          name = name[1].substr(2);

          if (name.includes("=")) {
            name = name.split("=")[0];
          }

          const { operands } = this.program.parseOptions(this.program.args);
          const operand =
            typeof operands[0] !== "undefined"
              ? operands[0]
              : getCommandName(buildCommandOptions.name);

          if (operand) {
            const command = findCommandByName(operand);

            if (!command) {
              this.logger.error(`Can't find and load command '${operand}'`);
              this.logger.error("Run 'webpack --help' to see available commands and options");
              process.exit(2);
            }

            command.options.forEach((option) => {
              if (
                !option.hidden &&
                this.utils.levenshtein.distance(name, option.long.slice(2)) < 3
              ) {
                this.logger.error(`Did you mean '--${option.name()}'?`);
              }
            });
          }
        }
      }

      // Codes:
      // - commander.unknownCommand
      // - commander.missingArgument
      // - commander.missingMandatoryOptionValue
      // - commander.optionMissingArgument

      this.logger.error("Run 'webpack --help' to see available commands and options");
      process.exit(2);
    });

    // Default `--color` and `--no-color` options
    const cli = this;
    this.program.option("--color", "Enable colors on console.");
    this.program.on("option:color", function () {
      const { color } = this.opts();

      cli.utils.colors.options.changed = true;
      cli.utils.colors.options.enabled = color;
    });
    this.program.option("--no-color", "Disable colors on console.");
    this.program.on("option:no-color", function () {
      const { color } = this.opts();

      cli.utils.colors.options.changed = true;
      cli.utils.colors.options.enabled = color;
    });

    // Make `-v, --version` options
    // Make `version|v [commands...]` command
    const outputVersion = async (options) => {
      // Filter `bundle`, `watch`, `version` and `help` commands
      const possibleCommandNames = options.filter(
        (option) =>
          !isCommand(option, buildCommandOptions) &&
          !isCommand(option, watchCommandOptions) &&
          !isCommand(option, versionCommandOptions) &&
          !isCommand(option, helpCommandOptions),
      );

      possibleCommandNames.forEach((possibleCommandName) => {
        if (!isOption(possibleCommandName)) {
          return;
        }

        this.logger.error(`Unknown option '${possibleCommandName}'`);
        this.logger.error("Run 'webpack --help' to see available commands and options");
        process.exit(2);
      });

      if (possibleCommandNames.length > 0) {
        await Promise.all(
          possibleCommandNames.map((possibleCommand) => loadCommandByName(possibleCommand)),
        );

        for (const possibleCommandName of possibleCommandNames) {
          const foundCommand = findCommandByName(possibleCommandName);

          if (!foundCommand) {
            this.logger.error(`Unknown command '${possibleCommandName}'`);
            this.logger.error("Run 'webpack --help' to see available commands and options");
            process.exit(2);
          }

          try {
            const { name, version } = this.loadJSONFile(`${foundCommand.pkg}/package.json`);

            this.logger.raw(`${name} ${version}`);
          } catch (e) {
            this.logger.error(`Error: External package '${foundCommand.pkg}' not found`);
            process.exit(2);
          }
        }
      }

      let webpack;

      try {
        webpack = await this.loadWebpack(false);
      } catch (_error) {
        // Nothing
      }

      this.logger.raw(`webpack: ${webpack ? webpack.version : "not installed"}`);

      const pkgJSON = this.loadJSONFile("../package.json");

      this.logger.raw(`webpack-cli: ${pkgJSON.version}`);

      let devServer;

      try {
        devServer = await this.loadJSONFile("webpack-dev-server/package.json", false);
      } catch (_error) {
        // Nothing
      }

      this.logger.raw(`webpack-dev-server ${devServer ? devServer.version : "not installed"}`);

      process.exit(0);
    };
    this.program.option(
      "-v, --version",
      "Output the version number of 'webpack', 'webpack-cli' and 'webpack-dev-server' and commands.",
    );

    const outputHelp = async (options, isVerbose, isHelpCommandSyntax, program) => {
      const { bold } = this.utils.colors;

      const outputIncorrectUsageOfHelp = () => {
        this.logger.error("Incorrect use of help");
        this.logger.error(
          "Please use: 'webpack help [command] [option]' | 'webpack [command] --help'",
        );
        this.logger.error("Run 'webpack --help' to see available commands and options");
        process.exit(2);
      };

      const isGlobalHelp = options.length === 0;
      const isCommandHelp = options.length === 1 && !isOption(options[0]);

      if (isGlobalHelp || isCommandHelp) {
        program.configureHelp({
          sortSubcommands: true,
          // Support multiple aliases
          commandUsage: (command) => {
            let parentCmdNames = "";

            for (let parentCmd = command.parent; parentCmd; parentCmd = parentCmd.parent) {
              parentCmdNames = `${parentCmd.name()} ${parentCmdNames}`;
            }

            if (isGlobalHelp) {
              return `${parentCmdNames}${command.usage()}\n${this.utils.colors.bold(
                "Alternative usage to run commands:",
              )} ${parentCmdNames}[command] [options]`;
            }

            return `${parentCmdNames}${command.name()}|${command
              .aliases()
              .join("|")} ${command.usage()}`;
          },
          // Support multiple aliases
          subcommandTerm: (command) => {
            const humanReadableArgumentName = (argument) => {
              const nameOutput = argument.name + (argument.variadic === true ? "..." : "");

              return argument.required ? "<" + nameOutput + ">" : "[" + nameOutput + "]";
            };
            const args = command._args.map((arg) => humanReadableArgumentName(arg)).join(" ");

            return `${command.name()}|${command.aliases().join("|")}${args ? ` ${args}` : ""}${
              command.options.length > 0 ? " [options]" : ""
            }`;
          },
          visibleOptions: function visibleOptions(command) {
            return command.options.filter((option) => {
              if (option.hidden) {
                return false;
              }

              switch (option.helpLevel) {
                case "verbose":
                  return isVerbose;
                case "minimum":
                default:
                  return true;
              }
            });
          },
          padWidth(command, helper) {
            return Math.max(
              helper.longestArgumentTermLength(command, helper),
              helper.longestOptionTermLength(command, helper),
              // For global options
              helper.longestOptionTermLength(program, helper),
              helper.longestSubcommandTermLength(isGlobalHelp ? program : command, helper),
            );
          },
          formatHelp: (command, helper) => {
            const termWidth = helper.padWidth(command, helper);
            const helpWidth = helper.helpWidth || process.env.WEBPACK_CLI_HELP_WIDTH || 80;
            const itemIndentWidth = 2;
            const itemSeparatorWidth = 2; // between term and description

            const formatItem = (term, description) => {
              if (description) {
                const fullText = `${term.padEnd(termWidth + itemSeparatorWidth)}${description}`;

                return helper.wrap(
                  fullText,
                  helpWidth - itemIndentWidth,
                  termWidth + itemSeparatorWidth,
                );
              }

              return term;
            };

            const formatList = (textArray) =>
              textArray.join("\n").replace(/^/gm, " ".repeat(itemIndentWidth));

            // Usage
            let output = [`${bold("Usage:")} ${helper.commandUsage(command)}`, ""];

            // Description
            const commandDescription = isGlobalHelp
              ? "The build tool for modern web applications."
              : helper.commandDescription(command);

            if (commandDescription.length > 0) {
              output = output.concat([commandDescription, ""]);
            }

            // Arguments
            const argumentList = helper
              .visibleArguments(command)
              .map((argument) => formatItem(argument.term, argument.description));

            if (argumentList.length > 0) {
              output = output.concat([bold("Arguments:"), formatList(argumentList), ""]);
            }

            // Options
            const optionList = helper
              .visibleOptions(command)
              .map((option) =>
                formatItem(helper.optionTerm(option), helper.optionDescription(option)),
              );

            if (optionList.length > 0) {
              output = output.concat([bold("Options:"), formatList(optionList), ""]);
            }

            // Global options
            const globalOptionList = program.options.map((option) =>
              formatItem(helper.optionTerm(option), helper.optionDescription(option)),
            );

            if (globalOptionList.length > 0) {
              output = output.concat([bold("Global options:"), formatList(globalOptionList), ""]);
            }

            // Commands
            const commandList = helper
              .visibleCommands(isGlobalHelp ? program : command)
              .map((command) =>
                formatItem(helper.subcommandTerm(command), helper.subcommandDescription(command)),
              );

            if (commandList.length > 0) {
              output = output.concat([bold("Commands:"), formatList(commandList), ""]);
            }

            return output.join("\n");
          },
        });

        if (isGlobalHelp) {
          await Promise.all(
            knownCommands.map((knownCommand) => {
              return loadCommandByName(getCommandName(knownCommand.name));
            }),
          );

          const buildCommand = findCommandByName(getCommandName(buildCommandOptions.name));

          this.logger.raw(buildCommand.helpInformation());
        } else {
          const name = options[0];

          await loadCommandByName(name);

          const command = findCommandByName(name);

          if (!command) {
            const builtInCommandUsed = externalBuiltInCommandsInfo.find(
              (command) => command.name.includes(name) || name === command.alias,
            );
            if (typeof builtInCommandUsed !== "undefined") {
              this.logger.error(
                `For using '${name}' command you need to install '${builtInCommandUsed.pkg}' package.`,
              );
            } else {
              this.logger.error(`Can't find and load command '${name}'`);
              this.logger.error("Run 'webpack --help' to see available commands and options.");
            }
            process.exit(2);
          }

          this.logger.raw(command.helpInformation());
        }
      } else if (isHelpCommandSyntax) {
        let isCommandSpecified = false;
        let commandName = getCommandName(buildCommandOptions.name);
        let optionName;

        if (options.length === 1) {
          optionName = options[0];
        } else if (options.length === 2) {
          isCommandSpecified = true;
          commandName = options[0];
          optionName = options[1];

          if (isOption(commandName)) {
            outputIncorrectUsageOfHelp();
          }
        } else {
          outputIncorrectUsageOfHelp();
        }

        await loadCommandByName(commandName);

        const command = isGlobalOption(optionName) ? program : findCommandByName(commandName);

        if (!command) {
          this.logger.error(`Can't find and load command '${commandName}'`);
          this.logger.error("Run 'webpack --help' to see available commands and options");
          process.exit(2);
        }

        const option = command.options.find(
          (option) => option.short === optionName || option.long === optionName,
        );

        if (!option) {
          this.logger.error(`Unknown option '${optionName}'`);
          this.logger.error("Run 'webpack --help' to see available commands and options");
          process.exit(2);
        }

        const nameOutput =
          option.flags.replace(/^.+[[<]/, "").replace(/(\.\.\.)?[\]>].*$/, "") +
          (option.variadic === true ? "..." : "");
        const value = option.required
          ? "<" + nameOutput + ">"
          : option.optional
          ? "[" + nameOutput + "]"
          : "";

        this.logger.raw(
          `${bold("Usage")}: webpack${isCommandSpecified ? ` ${commandName}` : ""} ${option.long}${
            value ? ` ${value}` : ""
          }`,
        );

        if (option.short) {
          this.logger.raw(
            `${bold("Short:")} webpack${isCommandSpecified ? ` ${commandName}` : ""} ${
              option.short
            }${value ? ` ${value}` : ""}`,
          );
        }

        if (option.description) {
          this.logger.raw(`${bold("Description:")} ${option.description}`);
        }

        if (!option.negate && option.defaultValue) {
          this.logger.raw(`${bold("Default value:")} ${JSON.stringify(option.defaultValue)}`);
        }

        const flag = this.getBuiltInOptions().find((flag) => option.long === `--${flag.name}`);

        if (flag && flag.configs) {
          const possibleValues = flag.configs.reduce((accumulator, currentValue) => {
            if (currentValue.values) {
              return accumulator.concat(currentValue.values);
            } else {
              return accumulator;
            }
          }, []);

          if (possibleValues.length > 0) {
            this.logger.raw(
              `${bold("Possible values:")} ${JSON.stringify(possibleValues.join(" | "))}`,
            );
          }
        }

        this.logger.raw("");

        // TODO implement this after refactor cli arguments
        // logger.raw('Documentation: https://webpack.js.org/option/name/');
      } else {
        outputIncorrectUsageOfHelp();
      }

      this.logger.raw(
        "To see list of all supported commands and options run 'webpack --help=verbose'.\n",
      );
      this.logger.raw(`${bold("Webpack documentation:")} https://webpack.js.org/.`);
      this.logger.raw(`${bold("CLI documentation:")} https://webpack.js.org/api/cli/.`);
      this.logger.raw(`${bold("Made with ♥ by the webpack team")}.`);
      process.exit(0);
    };
    this.program.helpOption(false);
    this.program.addHelpCommand(false);
    this.program.option("-h, --help [verbose]", "Display help for commands and options.");

    let isInternalActionCalled = false;

    // Default action
    this.program.usage("[options]");
    this.program.allowUnknownOption(true);
    this.program.action(async (options, program) => {
      if (!isInternalActionCalled) {
        isInternalActionCalled = true;
      } else {
        this.logger.error("No commands found to run");
        process.exit(2);
      }

      // Command and options
      const { operands, unknown } = this.program.parseOptions(program.args);
      const defaultCommandToRun = getCommandName(buildCommandOptions.name);
      const hasOperand = typeof operands[0] !== "undefined";
      const operand = hasOperand ? operands[0] : defaultCommandToRun;
      const isHelpOption = typeof options.help !== "undefined";
      const isHelpCommandSyntax = isCommand(operand, helpCommandOptions);

      if (isHelpOption || isHelpCommandSyntax) {
        let isVerbose = false;

        if (isHelpOption) {
          if (typeof options.help === "string") {
            if (options.help !== "verbose") {
              this.logger.error("Unknown value for '--help' option, please use '--help=verbose'");
              process.exit(2);
            }

            isVerbose = true;
          }
        }

        this.program.forHelp = true;

        const optionsForHelp = []
          .concat(isHelpOption && hasOperand ? [operand] : [])
          // Syntax `webpack help [command]`
          .concat(operands.slice(1))
          // Syntax `webpack help [option]`
          .concat(unknown)
          .concat(
            isHelpCommandSyntax && typeof options.color !== "undefined"
              ? [options.color ? "--color" : "--no-color"]
              : [],
          )
          .concat(
            isHelpCommandSyntax && typeof options.version !== "undefined" ? ["--version"] : [],
          );

        await outputHelp(optionsForHelp, isVerbose, isHelpCommandSyntax, program);
      }

      const isVersionOption = typeof options.version !== "undefined";
      const isVersionCommandSyntax = isCommand(operand, versionCommandOptions);

      if (isVersionOption || isVersionCommandSyntax) {
        const optionsForVersion = []
          .concat(isVersionOption ? [operand] : [])
          .concat(operands.slice(1))
          .concat(unknown);

        await outputVersion(optionsForVersion, program);
      }

      let commandToRun = operand;
      let commandOperands = operands.slice(1);

      if (isKnownCommand(commandToRun)) {
        await loadCommandByName(commandToRun, true);
      } else {
        const isEntrySyntax = fs.existsSync(operand);

        if (isEntrySyntax) {
          commandToRun = defaultCommandToRun;
          commandOperands = operands;

          await loadCommandByName(commandToRun);
        } else {
          this.logger.error(`Unknown command or entry '${operand}'`);

          const found = knownCommands.find(
            (commandOptions) =>
              this.utils.levenshtein.distance(operand, getCommandName(commandOptions.name)) < 3,
          );

          if (found) {
            this.logger.error(
              `Did you mean '${getCommandName(found.name)}' (alias '${
                Array.isArray(found.alias) ? found.alias.join(", ") : found.alias
              }')?`,
            );
          }

          this.logger.error("Run 'webpack --help' to see available commands and options");
          process.exit(2);
        }
      }

      await this.program.parseAsync([commandToRun, ...commandOperands, ...unknown], {
        from: "user",
      });
    });

    await this.program.parseAsync(args, parseOptions);
  }

  async loadConfig(configPath, argv = {}) {
    const { interpret } = this.utils;
    const ext = path.extname(configPath);
    const interpreted = Object.keys(interpret.jsVariants).find((variant) => variant === ext);

    if (interpreted) {
      const { rechoir } = this.utils;

      try {
        rechoir.prepare(interpret.extensions, configPath);
      } catch (error) {
        if (error.failures) {
          this.logger.error(`Unable load '${configPath}'`);
          this.logger.error(error.message);

          error.failures.forEach((failure) => {
            this.logger.error(failure.error.message);
          });
          this.logger.error("Please install one of them");
          process.exit(2);
        }

        this.logger.error(error);
        process.exit(2);
      }
    }

    let options;

    try {
      options = await this.tryRequireThenImport(configPath, false);
    } catch (error) {
      this.logger.error(`Failed to load '${configPath}' config`);

      if (this.isValidationError(error)) {
        this.logger.error(error.message);
      } else {
        this.logger.error(error);
      }

      process.exit(2);
    }

    if (Array.isArray(options)) {
      await Promise.all(
        options.map(async (_, i) => {
          if (typeof options[i].then === "function") {
            options[i] = await options[i];
          }

          // `Promise` may return `Function`
          if (typeof options[i] === "function") {
            // when config is a function, pass the env from args to the config function
            options[i] = await options[i](argv.env, argv);
          }
        }),
      );
    } else {
      if (typeof options.then === "function") {
        options = await options;
      }

      // `Promise` may return `Function`
      if (typeof options === "function") {
        // when config is a function, pass the env from args to the config function
        options = await options(argv.env, argv);
      }
    }

    const isObject = (value) => typeof value === "object" && value !== null;

    if (!isObject(options) && !Array.isArray(options)) {
      this.logger.error(`Invalid configuration in '${configPath}'`);

      process.exit(2);
    }

    return { options, path: configPath };
  }

  async resolveConfig(options) {
    const config = { options: {}, path: new WeakMap() };

    if (options.config && options.config.length > 0) {
      const loadedConfigs = await Promise.all(
        options.config.map((configPath) => this.loadConfig(path.resolve(configPath), options.argv)),
      );

      config.options = [];

      loadedConfigs.forEach((loadedConfig) => {
        const isArray = Array.isArray(loadedConfig.options);

        // TODO we should run webpack multiple times when the `--config` options have multiple values with `--merge`, need to solve for the next major release
        if (config.options.length === 0) {
          config.options = loadedConfig.options;
        } else {
          if (!Array.isArray(config.options)) {
            config.options = [config.options];
          }

          if (isArray) {
            loadedConfig.options.forEach((item) => {
              config.options.push(item);
            });
          } else {
            config.options.push(loadedConfig.options);
          }
        }

        if (isArray) {
          loadedConfig.options.forEach((options) => {
            config.path.set(options, loadedConfig.path);
          });
        } else {
          config.path.set(loadedConfig.options, loadedConfig.path);
        }
      });

      config.options = config.options.length === 1 ? config.options[0] : config.options;
    } else {
      const { interpret } = this.utils;

      // Order defines the priority, in decreasing order
      const defaultConfigFiles = [
        "webpack.config",
        ".webpack/webpack.config",
        ".webpack/webpackfile",
      ]
        .map((filename) =>
          // Since .cjs is not available on interpret side add it manually to default config extension list
          [...Object.keys(interpret.extensions), ".cjs"].map((ext) => ({
            path: path.resolve(filename + ext),
            ext: ext,
            module: interpret.extensions[ext],
          })),
        )
        .reduce((accumulator, currentValue) => accumulator.concat(currentValue), []);

      let foundDefaultConfigFile;

      for (const defaultConfigFile of defaultConfigFiles) {
        if (!fs.existsSync(defaultConfigFile.path)) {
          continue;
        }

        foundDefaultConfigFile = defaultConfigFile;
        break;
      }

      if (foundDefaultConfigFile) {
        const loadedConfig = await this.loadConfig(foundDefaultConfigFile.path, options.argv);

        config.options = loadedConfig.options;

        if (Array.isArray(config.options)) {
          config.options.forEach((item) => {
            config.path.set(item, loadedConfig.path);
          });
        } else {
          config.path.set(loadedConfig.options, loadedConfig.path);
        }
      }
    }

    if (options.configName) {
      const notFoundConfigNames = [];

      config.options = options.configName.map((configName) => {
        let found;

        if (Array.isArray(config.options)) {
          found = config.options.find((options) => options.name === configName);
        } else {
          found = config.options.name === configName ? config.options : undefined;
        }

        if (!found) {
          notFoundConfigNames.push(configName);
        }

        return found;
      });

      if (notFoundConfigNames.length > 0) {
        this.logger.error(
          notFoundConfigNames
            .map((configName) => `Configuration with the name "${configName}" was not found.`)
            .join(" "),
        );
        process.exit(2);
      }
    }

    if (options.merge) {
      const merge = await this.tryRequireThenImport("webpack-merge");

      // we can only merge when there are multiple configurations
      // either by passing multiple configs by flags or passing a
      // single config exporting an array
      if (!Array.isArray(config.options) || config.options.length <= 1) {
        this.logger.error("At least two configurations are required for merge.");
        process.exit(2);
      }

      const mergedConfigPaths = [];

      config.options = config.options.reduce((accumulator, options) => {
        const configPath = config.path.get(options);
        const mergedOptions = merge(accumulator, options);

        mergedConfigPaths.push(configPath);

        return mergedOptions;
      }, {});
      config.path.set(config.options, mergedConfigPaths);
    }

    return config;
  }

  runFunctionOnOptions(options, fn) {
    if (Array.isArray(options)) {
      for (let item of options) {
        item = fn(item);
      }
    } else {
      options = fn(options);
    }

    return options;
  }

  // TODO refactor
  async applyOptions(config, options) {
    if (options.analyze) {
      if (!this.utils.packageExists("webpack-bundle-analyzer")) {
        const { promptInstallation, colors } = this.utils;

        await promptInstallation("webpack-bundle-analyzer", () => {
          this.logger.error(
            `It looks like ${colors.yellow("webpack-bundle-analyzer")} is not installed.`,
          );
        });

        this.logger.success(
          `${colors.yellow("webpack-bundle-analyzer")} was installed successfully.`,
        );
      }
    }

    if (typeof options.progress === "string" && options.progress !== "profile") {
      this.logger.error(
        `'${options.progress}' is an invalid value for the --progress option. Only 'profile' is allowed.`,
      );
      process.exit(2);
    }

    if (typeof options.hot === "string" && options.hot !== "only") {
      this.logger.error(
        `'${options.hot}' is an invalid value for the --hot option. Use 'only' instead.`,
      );
      process.exit(2);
    }

    const outputHints = (configOptions) => {
      if (
        configOptions.watch &&
        options.argv &&
        options.argv.env &&
        (options.argv.env["WEBPACK_WATCH"] || options.argv.env["WEBPACK_SERVE"])
      ) {
        this.logger.warn(
          `No need to use the '${
            options.argv.env["WEBPACK_WATCH"] ? "watch" : "serve"
          }' command together with '{ watch: true }' configuration, it does not make sense.`,
        );

        if (options.argv.env["WEBPACK_SERVE"]) {
          configOptions.watch = false;
        }
      }

      return configOptions;
    };

    this.runFunctionOnOptions(config.options, outputHints);

    if (this.webpack.cli) {
      const processArguments = (configOptions) => {
        const args = this.getBuiltInOptions()
          .filter((flag) => flag.group === "core")
          .reduce((accumulator, flag) => {
            accumulator[flag.name] = flag;

            return accumulator;
          }, {});

        const values = Object.keys(options).reduce((accumulator, name) => {
          if (name === "argv") {
            return accumulator;
          }

          const kebabName = this.utils.toKebabCase(name);

          if (args[kebabName]) {
            accumulator[kebabName] = options[name];
          }

          return accumulator;
        }, {});

        const problems = this.webpack.cli.processArguments(args, configOptions, values);

        if (problems) {
          const groupBy = (xs, key) => {
            return xs.reduce((rv, x) => {
              (rv[x[key]] = rv[x[key]] || []).push(x);

              return rv;
            }, {});
          };
          const problemsByPath = groupBy(problems, "path");

          for (const path in problemsByPath) {
            const problems = problemsByPath[path];

            problems.forEach((problem) => {
              this.logger.error(
                `${this.utils.capitalizeFirstLetter(problem.type.replace(/-/g, " "))}${
                  problem.value ? ` '${problem.value}'` : ""
                } for the '--${problem.argument}' option${
                  problem.index ? ` by index '${problem.index}'` : ""
                }`,
              );

              if (problem.expected) {
                this.logger.error(`Expected: '${problem.expected}'`);
              }
            });
          }

          process.exit(2);
        }

        return configOptions;
      };

      this.runFunctionOnOptions(config.options, processArguments);

      const setupDefaultOptions = (configOptions) => {
        // No need to run for webpack@4
        if (configOptions.cache && configOptions.cache.type === "filesystem") {
          const configPath = config.path.get(configOptions);

          if (configPath) {
            if (!configOptions.cache.buildDependencies) {
              configOptions.cache.buildDependencies = {};
            }

            if (!configOptions.cache.buildDependencies.defaultConfig) {
              configOptions.cache.buildDependencies.defaultConfig = [];
            }

            if (Array.isArray(configPath)) {
              configPath.forEach((item) => {
                configOptions.cache.buildDependencies.defaultConfig.push(item);
              });
            } else {
              configOptions.cache.buildDependencies.defaultConfig.push(configPath);
            }
          }
        }

        return configOptions;
      };

      this.runFunctionOnOptions(config.options, setupDefaultOptions);
    }

    // Logic for webpack@4
    // TODO remove after drop webpack@4
    const processLegacyArguments = (configOptions) => {
      if (options.entry) {
        configOptions.entry = options.entry;
      }

      if (options.outputPath) {
        configOptions.output = {
          ...configOptions.output,
          ...{ path: path.resolve(options.outputPath) },
        };
      }

      if (options.target) {
        configOptions.target = options.target;
      }

      if (typeof options.devtool !== "undefined") {
        configOptions.devtool = options.devtool;
      }

      if (options.mode) {
        configOptions.mode = options.mode;
      } else if (
        !configOptions.mode &&
        process.env &&
        process.env.NODE_ENV &&
        (process.env.NODE_ENV === "development" ||
          process.env.NODE_ENV === "production" ||
          process.env.NODE_ENV === "none")
      ) {
        configOptions.mode = process.env.NODE_ENV;
      }

      if (options.name) {
        configOptions.name = options.name;
      }

      if (typeof options.stats !== "undefined") {
        configOptions.stats = options.stats;
      }

      if (typeof options.watch !== "undefined") {
        configOptions.watch = options.watch;
      }

      if (typeof options.watchOptionsStdin !== "undefined") {
        configOptions.watchOptions = {
          ...configOptions.watchOptions,
          ...{ stdin: options.watchOptionsStdin },
        };
      }

      return configOptions;
    };

    this.runFunctionOnOptions(config.options, processLegacyArguments);

    // Apply `stats` and `stats.colors` options
    const applyStatsOption = (configOptions) => {
      // TODO remove after drop webpack@4
      const statsForWebpack4 = this.webpack.Stats && this.webpack.Stats.presetToOptions;

      if (statsForWebpack4) {
        if (typeof configOptions.stats === "undefined") {
          configOptions.stats = {};
        } else if (
          typeof configOptions.stats === "boolean" ||
          typeof configOptions.stats === "string"
        ) {
          if (
            typeof configOptions.stats === "string" &&
            configOptions.stats !== "none" &&
            configOptions.stats !== "verbose" &&
            configOptions.stats !== "detailed" &&
            configOptions.stats !== "minimal" &&
            configOptions.stats !== "errors-only" &&
            configOptions.stats !== "errors-warnings"
          ) {
            return configOptions;
          }

          configOptions.stats = this.webpack.Stats.presetToOptions(configOptions.stats);
        }
      } else {
        if (typeof configOptions.stats === "undefined") {
          configOptions.stats = { preset: "normal" };
        } else if (typeof configOptions.stats === "boolean") {
          configOptions.stats = configOptions.stats ? { preset: "normal" } : { preset: "none" };
        } else if (typeof configOptions.stats === "string") {
          configOptions.stats = { preset: configOptions.stats };
        }
      }

      let colors;

      // From arguments
      if (typeof this.utils.colors.options.changed !== "undefined") {
        colors = Boolean(this.utils.colors.options.enabled);
      }
      // From stats
      else if (typeof configOptions.stats.colors !== "undefined") {
        colors = configOptions.stats.colors;
      }
      // Default
      else {
        colors = Boolean(this.utils.colors.options.enabled);
      }

      configOptions.stats.colors = colors;

      return configOptions;
    };

    this.runFunctionOnOptions(config.options, applyStatsOption);

    return config;
  }

  async applyCLIPlugin(config, cliOptions) {
    const CLIPlugin = await this.tryRequireThenImport("./plugins/CLIPlugin");

    const addCLIPlugin = (options) => {
      if (!options.plugins) {
        options.plugins = [];
      }

      options.plugins.unshift(
        new CLIPlugin({
          configPath: config.path.get(options),
          helpfulOutput: !cliOptions.json,
          hot: cliOptions.hot,
          progress: cliOptions.progress,
          prefetch: cliOptions.prefetch,
          analyze: cliOptions.analyze,
        }),
      );

      return options;
    };

    this.runFunctionOnOptions(config.options, addCLIPlugin);

    return config;
  }

  needWatchStdin(compiler) {
    if (compiler.compilers) {
      return compiler.compilers.some(
        (compiler) => compiler.options.watchOptions && compiler.options.watchOptions.stdin,
      );
    }

    return compiler.options.watchOptions && compiler.options.watchOptions.stdin;
  }

  isValidationError(error) {
    // https://github.com/webpack/webpack/blob/master/lib/index.js#L267
    // https://github.com/webpack/webpack/blob/v4.44.2/lib/webpack.js#L90
    const ValidationError =
      this.webpack.ValidationError || this.webpack.WebpackOptionsValidationError;

    return error instanceof ValidationError || error.name === "ValidationError";
  }

  async createCompiler(options, callback) {
    this.applyNodeEnv(options);

    let config = await this.resolveConfig(options);

    config = await this.applyOptions(config, options);
    config = await this.applyCLIPlugin(config, options);

    let compiler;

    try {
      compiler = this.webpack(
        config.options,
        callback
          ? (error, stats) => {
              if (error && this.isValidationError(error)) {
                this.logger.error(error.message);
                process.exit(2);
              }

              callback(error, stats);
            }
          : callback,
      );
    } catch (error) {
      if (this.isValidationError(error)) {
        this.logger.error(error.message);
      } else {
        this.logger.error(error);
      }

      process.exit(2);
    }

    // TODO webpack@4 return Watching and MultiWatching instead Compiler and MultiCompiler, remove this after drop webpack@4
    if (compiler && compiler.compiler) {
      compiler = compiler.compiler;
    }

    return compiler;
  }

  async runWebpack(options, isWatchCommand) {
    // eslint-disable-next-line prefer-const
    let compiler;
    let createJsonStringifyStream;

    if (options.json) {
      const jsonExt = await this.tryRequireThenImport("@discoveryjs/json-ext");

      createJsonStringifyStream = jsonExt.stringifyStream;
    }

    const callback = (error, stats) => {
      if (error) {
        this.logger.error(error);
        process.exit(2);
      }

      if (stats.hasErrors()) {
        process.exitCode = 1;
      }

      if (!compiler) {
        return;
      }

      const statsOptions = compiler.compilers
        ? {
            children: compiler.compilers.map((compiler) =>
              compiler.options ? compiler.options.stats : undefined,
            ),
          }
        : compiler.options
        ? compiler.options.stats
        : undefined;

      // TODO webpack@4 doesn't support `{ children: [{ colors: true }, { colors: true }] }` for stats
      const statsForWebpack4 = this.webpack.Stats && this.webpack.Stats.presetToOptions;

      if (compiler.compilers && statsForWebpack4) {
        statsOptions.colors = statsOptions.children.some((child) => child.colors);
      }

      if (options.json && createJsonStringifyStream) {
        const handleWriteError = (error) => {
          this.logger.error(error);
          process.exit(2);
        };

        if (options.json === true) {
          createJsonStringifyStream(stats.toJson(statsOptions))
            .on("error", handleWriteError)
            .pipe(process.stdout)
            .on("error", handleWriteError)
            .on("close", () => process.stdout.write("\n"));
        } else {
          createJsonStringifyStream(stats.toJson(statsOptions))
            .on("error", handleWriteError)
            .pipe(fs.createWriteStream(options.json))
            .on("error", handleWriteError)
            // Use stderr to logging
            .on("close", () =>
              process.stderr.write(
                `[webpack-cli] ${this.utils.colors.green(
                  `stats are successfully stored as json to ${options.json}`,
                )}\n`,
              ),
            );
        }
      } else {
        const printedStats = stats.toString(statsOptions);

        // Avoid extra empty line when `stats: 'none'`
        if (printedStats) {
          this.logger.raw(printedStats);
        }
      }
    };

    const env =
      isWatchCommand || options.watch
        ? { WEBPACK_WATCH: true, ...options.env }
        : { WEBPACK_BUNDLE: true, WEBPACK_BUILD: true, ...options.env };

    options.argv = { ...options, env };

    if (isWatchCommand) {
      options.watch = true;
    }

    compiler = await this.createCompiler(options, callback);

    if (!compiler) {
      return;
    }

    const isWatch = (compiler) =>
      compiler.compilers
        ? compiler.compilers.some((compiler) => compiler.options.watch)
        : compiler.options.watch;

    if (isWatch(compiler) && this.needWatchStdin(compiler)) {
      process.stdin.on("end", () => {
        process.exit(0);
      });
      process.stdin.resume();
    }
  }
}

module.exports = WebpackCLI;