Fix strict_variables issues

src/twig.core.js

@@ -1239,7 +1239,7 @@ module.exports = function (Twig) {
         //            options:  {
         //                Compiler/parser options
         //
-        //                strictVariables: true/false
+        //                strict_variables: true/false
         //                    Should missing variable/keys emit an error message. If false, they default to null.
         //            }
         //     }

src/twig.exports.js

@@ -19,7 +19,7 @@ module.exports = function (Twig) {
         'use strict';
         const {id} = params;
         const options = {
-            strictVariables: params.strictVariables || false,
+            strictVariables: params.strict_variables || false,
             // TODO: turn autoscape on in the next major version
             autoescape: (params.autoescape !== null && params.autoescape) || false,
             allowInlineIncludes: params.allowInlineIncludes || false,

src/twig.expression.js

@@ -846,6 +846,10 @@ module.exports = function (Twig) {
                 // Get the variable from the context
                 return Twig.expression.resolveAsync.call(state, context[token.value], context)
                     .then(value => {
+                        if (state.template.options.strictVariables && value === undefined) {
+                            throw new Twig.Error('Variable "' + token.value + '" does not exist.');
+                        }
+
                         stack.push(value);
                     });
             }
@@ -869,14 +873,19 @@ module.exports = function (Twig) {
                 const object = stack.pop();
                 let value;
 
+                if (object && !Object.prototype.hasOwnProperty.call(object, key) && state.template.options.strictVariables) {
+                    const keys = Object.keys(object);
+                    if (keys.length > 0) {
+                        throw new Twig.Error('Key "' + key + '" for object with keys "' + Object.keys(object).join(', ') + '" does not exist.');
+                    } else {
+                        throw new Twig.Error('Key "' + key + '" does not exist as the object is empty.');
+                    }
+                }
+
                 return parseParams(state, token.params, context)
                     .then(params => {
                         if (object === null || object === undefined) {
-                            if (state.template.options.strict_variables) {
-                                throw new Twig.Error('Can\'t access a key ' + key + ' on an null or undefined object.');
-                            } else {
-                                value = undefined;
-                            }
+                            value = undefined;
                         } else {
                             const capitalize = function (value) {
                                 return value.substr(0, 1).toUpperCase() + value.substr(1);
@@ -935,12 +944,15 @@ module.exports = function (Twig) {
                     .then(key => {
                         object = stack.pop();
 
-                        if (object === null || object === undefined) {
-                            if (state.template.options.strict_variables) {
-                                throw new Twig.Error('Can\'t access a key ' + key + ' on an null or undefined object.');
+                        if (object && !Object.prototype.hasOwnProperty.call(object, key) && state.template.options.strictVariables) {
+                            const keys = Object.keys(object);
+                            if (keys.length > 0) {
+                                throw new Twig.Error('Key "' + key + '" for array with keys "' + keys.join(', ') + '" does not exist.');
                             } else {
-                                return null;
+                                throw new Twig.Error('Key "' + key + '" does not exist as the array is empty.');
                             }
+                        } else if (object === null || object === undefined) {
+                            return null;
                         }
 
                         // Get the variable from the context

test/test.options.js

@@ -17,5 +17,69 @@ describe('Twig.js Optional Functionality ->', function () {
 
         output.should.equal('template with another template');
     });
-});
 
+    describe('should throw an error when `strict_variables` set to `true`', function () {
+        const variable = twig({
+            rethrow: true,
+            strict_variables: true,
+            data: '{{ test }}'
+        });
+
+        const object = twig({
+            rethrow: true,
+            strict_variables: true,
+            data: '{{ test.10 }}'
+        });
+
+        const array = twig({
+            rethrow: true,
+            strict_variables: true,
+            data: '{{ test[10] }}'
+        });
+
+        it('For undefined variables', function () {
+            try {
+                variable.render();
+                throw new Error('should have thrown an error.');
+            } catch (error) {
+                error.message.should.equal('Variable "test" does not exist.');
+            }
+        });
+
+        it('For empty objects', function () {
+            try {
+                object.render({test: {}});
+                throw new Error('should have thrown an error.');
+            } catch (error) {
+                error.message.should.equal('Key "10" does not exist as the object is empty.');
+            }
+        });
+
+        it('For undefined object keys', function () {
+            try {
+                object.render({test: {1: 'value', 2: 'value', 3: 'value'}});
+                throw new Error('should have thrown an error.');
+            } catch (error) {
+                error.message.should.equal('Key "10" for object with keys "1, 2, 3" does not exist.');
+            }
+        });
+
+        it('For empty arrays', function () {
+            try {
+                array.render({test: []});
+                throw new Error('should have thrown an error.');
+            } catch (error) {
+                error.message.should.equal('Key "10" does not exist as the array is empty.');
+            }
+        });
+
+        it('For undefined array keys', function () {
+            try {
+                array.render({test: [1, 2, 3]});
+                throw new Error('should have thrown an error.');
+            } catch (error) {
+                error.message.should.equal('Key "10" for array with keys "0, 1, 2" does not exist.');
+            }
+        });
+    });
+});