настройка webpack

node_modules/webpack/lib/EnvironmentPlugin.js

@@ -0,0 +1,72 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Authors Simen Brekken @simenbrekken, Einar Löve @einarlove
+*/
+
+"use strict";
+
+/** @typedef {import("./Compiler")} Compiler */
+
+const WebpackError = require("./WebpackError");
+const DefinePlugin = require("./DefinePlugin");
+
+const needsEnvVarFix =
+	["8", "9"].indexOf(process.versions.node.split(".")[0]) >= 0 &&
+	process.platform === "win32";
+
+class EnvironmentPlugin {
+	constructor(...keys) {
+		if (keys.length === 1 && Array.isArray(keys[0])) {
+			this.keys = keys[0];
+			this.defaultValues = {};
+		} else if (keys.length === 1 && keys[0] && typeof keys[0] === "object") {
+			this.keys = Object.keys(keys[0]);
+			this.defaultValues = keys[0];
+		} else {
+			this.keys = keys;
+			this.defaultValues = {};
+		}
+	}
+
+	/**
+	 * @param {Compiler} compiler webpack compiler instance
+	 * @returns {void}
+	 */
+	apply(compiler) {
+		const definitions = this.keys.reduce((defs, key) => {
+			// TODO remove once the fix has made its way into Node 8.
+			// Work around https://github.com/nodejs/node/pull/18463,
+			// affecting Node 8 & 9 by performing an OS-level
+			// operation that always succeeds before reading
+			// environment variables:
+			if (needsEnvVarFix) require("os").cpus();
+
+			const value =
+				process.env[key] !== undefined
+					? process.env[key]
+					: this.defaultValues[key];
+
+			if (value === undefined) {
+				compiler.hooks.thisCompilation.tap("EnvironmentPlugin", compilation => {
+					const error = new WebpackError(
+						`EnvironmentPlugin - ${key} environment variable is undefined.\n\n` +
+							"You can pass an object with default values to suppress this warning.\n" +
+							"See https://webpack.js.org/plugins/environment-plugin for example."
+					);
+
+					error.name = "EnvVariableNotDefinedError";
+					compilation.warnings.push(error);
+				});
+			}
+
+			defs[`process.env.${key}`] =
+				value === undefined ? "undefined" : JSON.stringify(value);
+
+			return defs;
+		}, {});
+
+		new DefinePlugin(definitions).apply(compiler);
+	}
+}
+
+module.exports = EnvironmentPlugin;