Throw error if lib is imported twice (#863)

The lib library was written with the assumption that there's only one
copy of it in the whole application and everything imports that one
copy.  Unfortunately there are quite a few circumstances were package
managers end up installing multiple copies of lib and then different
parts use different versions of the library.

This causes Clusterio to break with strange and hard to track down
errors.  Most notably permissions and link messages for a plugin may get
registered to one copy of lib while the controller uses a different copy
and thus does not see or register that what the plugin added exists.

Detect this condition when importing @clusterio/lib and throw an error
when it has been imported twice in order to prevent the broken
installation from causing future hard to debug issues.

packages/controller/controller.ts

@@ -490,7 +490,7 @@ I           version of clusterio.  Expect things to break. I
 `
 	);
 	startup().catch(err => {
-		if (err instanceof lib.StartupError) {
+		if (err instanceof lib.StartupError || err.code === "InstallationError") {
 			logger.fatal(`
 +-------------------------------+
 | Unable to to start controller |

packages/controller/src/Controller.ts

@@ -1068,6 +1068,9 @@ export default class Controller {
 				this.plugins.set(pluginInfo.name, controllerPlugin);
 
 			} catch (err: any) {
+				if (err.code === "InstallationError") {
+					throw err;
+				}
 				throw new lib.PluginError(pluginInfo.name, err);
 			}
 

packages/host/host.ts

@@ -299,7 +299,7 @@ I           version of clusterio.  Expect things to break. I
 		if (err instanceof lib.WebSocketError) {
 			// Already handled by connector.on("error") within Host
 
-		} else if (err instanceof lib.StartupError) {
+		} else if (err instanceof lib.StartupError || err.code === "InstallationError") {
 			logger.fatal(`
 +----------------------------------+
 | Unable to to start clusteriohost |

packages/host/src/Host.ts

@@ -440,6 +440,9 @@ export default class Host extends lib.Link {
 				this.plugins.set(pluginInfo.name, hostPlugin);
 
 			} catch (err: any) {
+				if (err.code === "InstallationError") {
+					throw err;
+				}
 				throw new lib.PluginError(pluginInfo.name, err);
 			}
 

packages/lib/browser.ts

@@ -16,3 +16,6 @@ export * from "./src/subscriptions";
 export { default as ExponentialBackoff } from "./src/ExponentialBackoff";
 export { default as RateLimiter } from "./src/RateLimiter";
 export { default as ValueCache } from "./src/ValueCache";
+
+import { checkSingletonImport } from "./src/check_singleton_import";
+checkSingletonImport(import.meta.url);

packages/lib/index.ts

@@ -38,3 +38,6 @@ export { default as ExponentialBackoff } from "./src/ExponentialBackoff";
 export { default as ModStore } from "./src/ModStore";
 export { default as RateLimiter } from "./src/RateLimiter";
 export { default as ValueCache } from "./src/ValueCache";
+
+import { checkSingletonImport } from "./src/check_singleton_import";
+checkSingletonImport(__filename);

packages/lib/src/check_singleton_import.ts

@@ -0,0 +1,21 @@
+import { InstallationError } from "./errors";
+declare global {
+	// eslint-disable-next-line vars-on-top
+	var _clusterioLibImportedFrom: string;
+}
+
+export function checkSingletonImport(location: string) {
+	if (!global._clusterioLibImportedFrom) {
+		global._clusterioLibImportedFrom = location;
+	} else {
+		throw new InstallationError(`Attempt to import duplicate copy of @clusterio/lib
+
+Importing more than one copy of @clusterio/lib into the same runtime
+will break Clusterio. This typically happens when the package
+manager has installed two different versions of @clusterio/lib
+and assigned different ones to different components of Clusterio.
+
+Previously imported @clusterio/lib was located at ${_clusterioLibImportedFrom}
+This copy of @clusterio/lib is located at ${location}`);
+	}
+}

packages/lib/src/errors.ts

@@ -10,6 +10,13 @@ export class CommandError extends Error {
 	code = "CommandError";
 }
 
+/**
+ * Thrown if the installation is broken, such as when multiple copies of lib is imported
+ */
+export class InstallationError extends Error {
+	code = "InstallationError";
+}
+
 /**
  * Thrown from requests sent when an error occured handling it
  */

packages/lib/src/plugin_loader.ts

@@ -45,6 +45,9 @@ export async function loadPluginInfos(pluginList: Map<string, string>) {
 			pluginInfo = require(pluginPath).plugin;
 			pluginPackage = require(path.posix.join(pluginPath, "package.json"));
 		} catch (err: any) {
+			if (err.code === "InstallationError") {
+				throw err;
+			}
 			throw new libErrors.PluginError(pluginName, err);
 		}
 

packages/lib/tsconfig.browser.json

@@ -7,6 +7,7 @@
 		"./src/config/*.ts",
 		"./src/data/*.ts",
 		"./src/external/*.ts",
+		"./src/check_singleton_import.ts",
 		"./src/datastore.ts",
 		"./src/errors.ts",
 		"./src/factorio/exchange_string.ts",

packages/lib/tsconfig.node.json

@@ -1,6 +1,6 @@
 {
 	"extends": "../../tsconfig.node.json",
-	"include": ["index.ts", "browser.ts", "build_mod.js", "src/**/*.ts", "src/**/*.js"],
+	"include": ["index.ts", "build_mod.js", "src/**/*.ts", "src/**/*.js"],
 	"compilerOptions": {
 		"allowJs": true,
 	},

test/lib/check_singleton_import.test.js

@@ -0,0 +1,16 @@
+const assert = require("assert").strict;
+const { checkSingletonImport } = require("@clusterio/lib/dist/node/src/check_singleton_import");
+// Import lib so it sets the global indicating lib has been imported.
+require("@clusterio/lib");
+
+describe("lib/check_singleton_import", function() {
+	it("Should throw an installation error if called twice", function() {
+		assert.throws(
+			() => checkSingletonImport(__filename),
+			{
+				message: /Attempt to import duplicate copy of @clusterio\/lib/,
+				code: "InstallationError",
+			}
+		);
+	});
+});