(Maybe) Fixes #3187 (couldn't repro, but found bugs)

.eslintignore

@@ -0,0 +1 @@
+Gruntfile.js

Gruntfile.js

@@ -190,7 +190,10 @@ module.exports = function (grunt) {
                 command: [
                     'node bin/lessc --clean-css="--s1 --advanced" test/less/lazy-eval.less tmp/lazy-eval.css',
                     'cd lib',
-                    'node ../bin/lessc --clean-css="--s1 --advanced" ../test/less/lazy-eval.less ../tmp/lazy-eval.css'
+                    'node ../bin/lessc --clean-css="--s1 --advanced" ../test/less/lazy-eval.less ../tmp/lazy-eval.css',
+                    'cd ..',
+                    // Test multiple plugins
+                    'node bin/lessc --plugin=clean-css="--s1 --advanced" --plugin=autoprefix="ie 11,Edge >= 13,Chrome >= 47,Firefox >= 45,iOS >= 9.2,Safari >= 9" test/less/lazy-eval.less tmp/lazy-eval.css'
                 ].join(' && ')
             },
             'sourcemap-test': {

dist/less.js

@@ -886,8 +886,7 @@ var AbstractPluginLoader = require('../less/environment/abstract-plugin-loader.j
  */
 var PluginLoader = function(less) {
     this.less = less;
-    // shim for browser require?
-    this.require = require;
+    // Should we shim this.require for browser? Probably not?
 };
 
 PluginLoader.prototype = new AbstractPluginLoader();
@@ -1436,24 +1435,21 @@ var functionRegistry = require('../functions/function-registry'),
     LessError = require('../less-error');
 
 var AbstractPluginLoader = function() {
+    // Implemented by Node.js plugin loader
+    this.require = function() {
+        return null;
+    }
 };
 
-function error(msg, type) {
-    throw new LessError(
-        {
-            type: type || 'Syntax',
-            message: msg
-        }
-    );
-}
 AbstractPluginLoader.prototype.evalPlugin = function(contents, context, imports, pluginOptions, fileInfo) {
 
     var loader,
         registry,
         pluginObj,
         localModule,
         pluginManager,
-        filename;
+        filename,
+        result;
 
     pluginManager = context.pluginManager;
 
@@ -1471,15 +1467,18 @@ AbstractPluginLoader.prototype.evalPlugin = function(contents, context, imports,
         pluginObj = pluginManager.get(filename);
 
         if (pluginObj) {
-            this.trySetOptions(pluginObj, filename, shortname, pluginOptions);
+            result = this.trySetOptions(pluginObj, filename, shortname, pluginOptions);
+            if (result) {
+                return result;
+            }
             try {
                 if (pluginObj.use) {
                     pluginObj.use.call(this.context, pluginObj);
                 }
             }
             catch (e) {
-                e.message = 'Error during @plugin call';
-                return new this.less.LessError(e, imports, filename);
+                e.message = e.message || 'Error during @plugin call';
+                return new LessError(e, imports, filename);
             }
             return pluginObj;
         }
@@ -1497,24 +1496,38 @@ AbstractPluginLoader.prototype.evalPlugin = function(contents, context, imports,
 
     try {
         loader = new Function('module', 'require', 'registerPlugin', 'functions', 'tree', 'less', 'fileInfo', contents);
-        loader(localModule, this.require, registerPlugin, registry, this.less.tree, this.less, fileInfo);
+        loader(localModule, this.require(filename), registerPlugin, registry, this.less.tree, this.less, fileInfo);
     } catch (e) {
-        return new this.less.LessError(e, imports, filename);
+        return new LessError(e, imports, filename);
     }
 
     if (!pluginObj) {
         pluginObj = localModule.exports;
     }
     pluginObj = this.validatePlugin(pluginObj, filename, shortname);
 
+    if (pluginObj instanceof LessError) {
+        return pluginObj;
+    }
+
     if (pluginObj) {
+        // For 2.x back-compatibility - setOptions() before install()
+        pluginObj.imports = imports;
+        pluginObj.filename = filename;
+        result = this.trySetOptions(pluginObj, filename, shortname, pluginOptions);
+        if (result) {
+            return result;
+        }
+
         // Run on first load
         pluginManager.addPlugin(pluginObj, fileInfo.filename, registry);
         pluginObj.functions = registry.getLocalFunctions();
-        pluginObj.imports = imports;
-        pluginObj.filename = filename;
 
-        this.trySetOptions(pluginObj, filename, shortname, pluginOptions);
+        // Need to call setOptions again because the pluginObj might have functions
+        result = this.trySetOptions(pluginObj, filename, shortname, pluginOptions);
+        if (result) {
+            return result;
+        }
 
         // Run every @plugin call
         try {
@@ -1523,32 +1536,31 @@ AbstractPluginLoader.prototype.evalPlugin = function(contents, context, imports,
             }
         }
         catch (e) {
-            e.message = 'Error during @plugin call';
-            return new this.less.LessError(e, imports, filename);
+            e.message = e.message || 'Error during @plugin call';
+            return new LessError(e, imports, filename);
         }
 
     }
     else {
-        return new this.less.LessError({ message: 'Not a valid plugin' });
+        return new LessError({ message: 'Not a valid plugin' }, imports, filename);
     }
 
     return pluginObj;
 
 };
 
 AbstractPluginLoader.prototype.trySetOptions = function(plugin, filename, name, options) {
-    if (options) {
-        if (!plugin.setOptions) {
-            error('Options have been provided but the plugin ' + name + ' does not support any options.');
-            return null;
-        }
-        try {
-            plugin.setOptions(options);
-        }
-        catch (e) {
-            error('Error setting options on plugin ' + name + '\n' + e.message);
-            return null;
-        }
+    if (options && !plugin.setOptions) {
+        return new LessError({
+            message: 'Options have been provided but the plugin ' +
+                name + ' does not support any options.'
+        });
+    }
+    try {
+        plugin.setOptions && plugin.setOptions(options);
+    }
+    catch (e) {
+        return new LessError(e);
     }
 };
 
@@ -1562,8 +1574,10 @@ AbstractPluginLoader.prototype.validatePlugin = function(plugin, filename, name)
 
         if (plugin.minVersion) {
             if (this.compareVersion(plugin.minVersion, this.less.version) < 0) {
-                error('Plugin ' + name + ' requires version ' + this.versionToString(plugin.minVersion));
-                return null;
+                return new LessError({
+                    message: 'Plugin ' + name + ' requires version ' +
+                        this.versionToString(plugin.minVersion)
+                });
             }
         }
         return plugin;

lib/less-browser/plugin-loader.js

@@ -8,8 +8,7 @@ var AbstractPluginLoader = require('../less/environment/abstract-plugin-loader.j
  */
 var PluginLoader = function(less) {
     this.less = less;
-    // shim for browser require?
-    this.require = require;
+    // Should we shim this.require for browser? Probably not?
 };
 
 PluginLoader.prototype = new AbstractPluginLoader();

lib/less-node/plugin-loader.js

@@ -7,8 +7,7 @@ var path = require('path'),
  */
 var PluginLoader = function(less) {
     this.less = less;
-    this.require = require;
-    this.requireRelative = function(prefix) {
+    this.require = function(prefix) {
         prefix = path.dirname(prefix);
         return function(id) {
             var str = id.substr(0, 2);
@@ -25,7 +24,6 @@ var PluginLoader = function(less) {
 PluginLoader.prototype = new AbstractPluginLoader();
 
 PluginLoader.prototype.loadPlugin = function(filename, basePath, context, environment, fileManager) {
-    var self = this;
     var prefix = filename.slice(0, 1);
     var explicit = prefix === '.' || prefix === '/' || filename.slice(-3).toLowerCase() === '.js';
     if (!explicit) {
@@ -36,7 +34,6 @@ PluginLoader.prototype.loadPlugin = function(filename, basePath, context, enviro
         fileManager.loadFile(filename, basePath, context, environment).then(
             function(data) {
                 try {
-                    self.require = self.requireRelative(data.filename);
                     fulfill(data);
                 }
                 catch (e) {

lib/less/environment/abstract-plugin-loader.js

@@ -2,24 +2,21 @@ var functionRegistry = require('../functions/function-registry'),
     LessError = require('../less-error');
 
 var AbstractPluginLoader = function() {
+    // Implemented by Node.js plugin loader
+    this.require = function() {
+        return null;
+    }
 };
 
-function error(msg, type) {
-    throw new LessError(
-        {
-            type: type || 'Syntax',
-            message: msg
-        }
-    );
-}
 AbstractPluginLoader.prototype.evalPlugin = function(contents, context, imports, pluginOptions, fileInfo) {
 
     var loader,
         registry,
         pluginObj,
         localModule,
         pluginManager,
-        filename;
+        filename,
+        result;
 
     pluginManager = context.pluginManager;
 
@@ -37,15 +34,18 @@ AbstractPluginLoader.prototype.evalPlugin = function(contents, context, imports,
         pluginObj = pluginManager.get(filename);
 
         if (pluginObj) {
-            this.trySetOptions(pluginObj, filename, shortname, pluginOptions);
+            result = this.trySetOptions(pluginObj, filename, shortname, pluginOptions);
+            if (result) {
+                return result;
+            }
             try {
                 if (pluginObj.use) {
                     pluginObj.use.call(this.context, pluginObj);
                 }
             }
             catch (e) {
-                e.message = 'Error during @plugin call';
-                return new this.less.LessError(e, imports, filename);
+                e.message = e.message || 'Error during @plugin call';
+                return new LessError(e, imports, filename);
             }
             return pluginObj;
         }
@@ -63,24 +63,38 @@ AbstractPluginLoader.prototype.evalPlugin = function(contents, context, imports,
 
     try {
         loader = new Function('module', 'require', 'registerPlugin', 'functions', 'tree', 'less', 'fileInfo', contents);
-        loader(localModule, this.require, registerPlugin, registry, this.less.tree, this.less, fileInfo);
+        loader(localModule, this.require(filename), registerPlugin, registry, this.less.tree, this.less, fileInfo);
     } catch (e) {
-        return new this.less.LessError(e, imports, filename);
+        return new LessError(e, imports, filename);
     }
 
     if (!pluginObj) {
         pluginObj = localModule.exports;
     }
     pluginObj = this.validatePlugin(pluginObj, filename, shortname);
 
+    if (pluginObj instanceof LessError) {
+        return pluginObj;
+    }
+
     if (pluginObj) {
+        // For 2.x back-compatibility - setOptions() before install()
+        pluginObj.imports = imports;
+        pluginObj.filename = filename;
+        result = this.trySetOptions(pluginObj, filename, shortname, pluginOptions);
+        if (result) {
+            return result;
+        }
+
         // Run on first load
         pluginManager.addPlugin(pluginObj, fileInfo.filename, registry);
         pluginObj.functions = registry.getLocalFunctions();
-        pluginObj.imports = imports;
-        pluginObj.filename = filename;
 
-        this.trySetOptions(pluginObj, filename, shortname, pluginOptions);
+        // Need to call setOptions again because the pluginObj might have functions
+        result = this.trySetOptions(pluginObj, filename, shortname, pluginOptions);
+        if (result) {
+            return result;
+        }
 
         // Run every @plugin call
         try {
@@ -89,32 +103,31 @@ AbstractPluginLoader.prototype.evalPlugin = function(contents, context, imports,
             }
         }
         catch (e) {
-            e.message = 'Error during @plugin call';
-            return new this.less.LessError(e, imports, filename);
+            e.message = e.message || 'Error during @plugin call';
+            return new LessError(e, imports, filename);
         }
 
     }
     else {
-        return new this.less.LessError({ message: 'Not a valid plugin' });
+        return new LessError({ message: 'Not a valid plugin' }, imports, filename);
     }
 
     return pluginObj;
 
 };
 
 AbstractPluginLoader.prototype.trySetOptions = function(plugin, filename, name, options) {
-    if (options) {
-        if (!plugin.setOptions) {
-            error('Options have been provided but the plugin ' + name + ' does not support any options.');
-            return null;
-        }
-        try {
-            plugin.setOptions(options);
-        }
-        catch (e) {
-            error('Error setting options on plugin ' + name + '\n' + e.message);
-            return null;
-        }
+    if (options && !plugin.setOptions) {
+        return new LessError({
+            message: 'Options have been provided but the plugin ' +
+                name + ' does not support any options.'
+        });
+    }
+    try {
+        plugin.setOptions && plugin.setOptions(options);
+    }
+    catch (e) {
+        return new LessError(e);
     }
 };
 
@@ -128,8 +141,10 @@ AbstractPluginLoader.prototype.validatePlugin = function(plugin, filename, name)
 
         if (plugin.minVersion) {
             if (this.compareVersion(plugin.minVersion, this.less.version) < 0) {
-                error('Plugin ' + name + ' requires version ' + this.versionToString(plugin.minVersion));
-                return null;
+                return new LessError({
+                    message: 'Plugin ' + name + ' requires version ' +
+                        this.versionToString(plugin.minVersion)
+                });
             }
         }
         return plugin;