fix: improve code generation safety

lib/CodeGenerator.js

@@ -79,7 +79,7 @@ CodeGenerator.prototype.compile = function (namespace) {
     '    $$processScope(scope)',
     '    ' + code,
     '  },',
-    "  code: '" + code + "'",
+    '  code: ' + JSON.stringify(code),
     '}'
   ].join('\n')
 

lib/Interpreter.js

@@ -21,6 +21,11 @@ const Interpreter = function (owner, options) {
     rawCallExpressionElements: false,
     applyFactoryToScope: false
   }, options)
+
+  const factory = this.options.factory
+  if (typeof factory !== 'string' || !/^[a-zA-Z_$][a-zA-Z0-9_$]*(\.[a-zA-Z_$][a-zA-Z0-9_$]*)*$/.test(factory)) {
+    throw new Error('factory must be a valid JS property access path (e.g. "ns.factory")')
+  }
 }
 
 extend(Interpreter.prototype, types)

lib/node/AssignmentNode.js

@@ -1,5 +1,5 @@
 'use strict'
 
 module.exports = function (node) {
-  return 'scope["' + node.name + '"] = ' + this.next(node.expr)
+  return 'scope[' + JSON.stringify(node.name) + '] = ' + this.next(node.expr)
 }

lib/node/ConstantNode.js

@@ -3,5 +3,6 @@ module.exports = function (node) {
   if (this.options.raw) {
     return node.value
   }
-  return this.options.factory + '(' + node.value + ')'
+  const value = node.valueType === 'string' ? JSON.stringify(node.value) : node.value
+  return this.options.factory + '(' + value + ')'
 }

lib/node/FunctionNode.js

@@ -2,7 +2,7 @@
 const SymbolNode = require('mr-parser').nodeTypes.SymbolNode
 
 const functionProxy = function (node) {
-  return '$$mathCodegen.functionProxy(' + this.next(new SymbolNode(node.name)) + ', "' + node.name + '")'
+  return '$$mathCodegen.functionProxy(' + this.next(new SymbolNode(node.name)) + ', ' + JSON.stringify(node.name) + ')'
 }
 
 module.exports = function (node) {

lib/node/SymbolNode.js

@@ -2,5 +2,5 @@
 
 module.exports = function (node) {
   const id = node.name
-  return '$$mathCodegen.getProperty("' + id + '", scope, ns)'
+  return '$$mathCodegen.getProperty(' + JSON.stringify(id) + ', scope, ns)'
 }