fix: #8686, deprecate `plugin.json/library` (#8705)

and also fix deprecated hooks with no alternative

src/plugins/hooks.js

@@ -35,12 +35,15 @@ module.exports = function (Plugins) {
 			return;
 		}
 
-		if (Plugins.deprecatedHooks[data.hook]) {
-			winston.warn('[plugins/' + id + '] Hook `' + data.hook + '` is deprecated, ' +
-				(Plugins.deprecatedHooks[data.hook] ?
-					'please use `' + Plugins.deprecatedHooks[data.hook] + '` instead.' :
-					'there is no alternative.'
-				));
+		// `hasOwnProperty` needed for hooks with no alternative (set to null)
+		if (Plugins.deprecatedHooks.hasOwnProperty(data.hook)) {
+			const deprecated = Plugins.deprecatedHooks[data.hook];
+
+			if (deprecated) {
+				winston.warn(`[plugins/${id}] Hook "${data.hook}" is deprecated, please use "${deprecated}" instead.`);
+			} else {
+				winston.warn(`[plugins/${id}] Hook "${data.hook}" is deprecated, there is no alternative.`);
+			}
 		}
 
 		data.id = id;

src/plugins/index.js

@@ -41,8 +41,28 @@ Plugins.loadedPlugins = [];
 
 Plugins.initialized = false;
 
-Plugins.requireLibrary = function (pluginID, libraryPath) {
-	Plugins.libraries[pluginID] = require(libraryPath);
+Plugins.requireLibrary = function (pluginData) {
+	let libraryPath;
+	// attempt to load a plugin directly with `require("nodebb-plugin-*")`
+	// Plugins should define their entry point in the standard `main` property of `package.json`
+	try {
+		libraryPath = pluginData.path;
+		Plugins.libraries[pluginData.id] = require(libraryPath);
+	} catch (e) {
+		// DEPRECATED: @1.15.0, remove in version >=1.17
+		// for backwards compatibility
+		// if that fails, fall back to `pluginData.library`
+		if (pluginData.library) {
+			winston.warn(`   [plugins/${pluginData.id}] The plugin.json field "library" is deprecated. Please use the package.json field "main" instead.`);
+			winston.verbose(`[plugins/${pluginData.id}] See https://github.com/NodeBB/NodeBB/issues/8686`);
+
+			libraryPath = path.join(pluginData.path, pluginData.library);
+			Plugins.libraries[pluginData.id] = require(libraryPath);
+		} else {
+			throw e;
+		}
+	}
+
 	Plugins.libraryPaths.push(libraryPath);
 };
 

src/plugins/load.js

@@ -1,6 +1,5 @@
 'use strict';
 
-const path = require('path');
 const semver = require('semver');
 const async = require('async');
 const winston = require('winston');
@@ -156,22 +155,16 @@ module.exports = function (Plugins) {
 	}
 
 	function registerHooks(pluginData) {
-		if (!pluginData.library) {
-			return;
-		}
-
-		const libraryPath = path.join(pluginData.path, pluginData.library);
-
 		try {
 			if (!Plugins.libraries[pluginData.id]) {
-				Plugins.requireLibrary(pluginData.id, libraryPath);
+				Plugins.requireLibrary(pluginData);
 			}
 
 			if (Array.isArray(pluginData.hooks)) {
 				pluginData.hooks.forEach(hook => Plugins.registerHook(pluginData.id, hook));
 			}
 		} catch (err) {
-			winston.warn('[plugins] Unable to parse library for: ' + pluginData.id);
+			winston.warn('[plugins] Unable to load library for: ' + pluginData.id);
 			throw err;
 		}
 	}