Add tests for context of filters

lib/plugins/context.js

@@ -19,7 +19,7 @@ function pluginCtx(plugin) {
     error.deprecateField(ctx, 'options', book.config.dump(), '"options" property is deprecated, use config.get(key) instead');
 
     // Loop for template filters/blocks
-    error.deprecateField(ctx, 'book', ctx, '"book" property is deprecated, this directly instead');
+    error.deprecateField(ctx, 'book', ctx, '"book" property is deprecated, use "this" directly instead');
 
     return ctx;
 }

lib/plugins/plugin.js

@@ -270,10 +270,7 @@ BookPlugin.prototype.getFilters = function() {
 
     return _.mapValues(this.content.filters || {}, function(fn, filter) {
         return function() {
-            var ctx = _.extend(
-                this,
-                pluginCtx(that)
-            );
+            var ctx = _.extend(pluginCtx(that), this);
 
             return fn.apply(ctx, arguments);
         };
@@ -289,10 +286,7 @@ BookPlugin.prototype.getBlocks = function() {
 
         var fn = block.exec;
         block.exec = function() {
-            var ctx = _.extend(
-                this,
-                pluginCtx(that)
-            );
+            var ctx = _.extend(pluginCtx(that), this);
 
             return fn.apply(ctx, arguments);
         };

test/node_modules/gitbook-plugin-test-filters/index.js

@@ -0,0 +1,21 @@
+var should = require('should');
+
+module.exports = {
+    filters: {
+        // Simple test
+        hello: function(s) {
+            return 'Hello ' + s + '!';
+        },
+
+        // Test using the conetxt "this"
+        testContext: function(s) {
+            this.should.have.property('config');
+            this.should.have.property('log');
+            this.should.have.property('options');
+            this.should.have.property('resolve').which.is.a.function;
+            this.should.have.property('book').which.equal(this);
+
+            return 'Hello ' + s + '!';
+        }
+    }
+};

test/node_modules/gitbook-plugin-test-filters/package.json

@@ -0,0 +1,7 @@
+{
+    "name": "gitbook-plugin-test-filters",
+    "version": "1.0.0",
+    "engines": {
+        "gitbook": "*"
+    }
+}

test/plugins.js

@@ -1,3 +1,4 @@
+var _ = require('lodash');
 var path = require('path');
 
 var mock = require('./mock');
@@ -124,5 +125,31 @@ describe('Plugins', function() {
             });
         });
     });
+
+    describe('Filters', function() {
+        var plugin, filters;
+
+        before(function() {
+            plugin = new BookPlugin(book, 'test-filters');
+            return plugin.load(PLUGINS_ROOT)
+
+            .then(function() {
+                filters = plugin.getFilters();
+            });
+        });
+
+
+        it('should list all resources for website', function() {
+            _.size(filters).should.equal(2);
+        });
+
+        it('should correctly execute a filter', function() {
+            filters.hello('World').should.equal('Hello World!');
+        });
+
+        it('should correctly set contexts for filter', function() {
+            filters.testContext('Hello');
+        });
+    });
 });