style: enable ‘no-prototype-builtins’ lint check

.eslintrc.js

@@ -60,8 +60,5 @@ module.exports = {
     'prefer-arrow-callback': 'error',
     'prefer-const': 'error',
     'prefer-destructuring': ['error', {object: true, array: false}],
-
-    // ----- Temporary exceptions -----
-    'no-prototype-builtins': 'off',
   },
 };

examples/ecmascript/compile.js

@@ -39,6 +39,8 @@ function loadModule(name) {
 
 /* eslint-disable no-console */
 
+const hasOwnProperty = (x, prop) => Object.prototype.hasOwnProperty.call(x, prop);
+
 function compile(args) {
   const filenames = [];
   const opts = {
@@ -51,7 +53,7 @@ function compile(args) {
   for (let i = 0; i < args.length; ++i) {
     if (args[i] === '-g') {
       opts.grammar = args[++i];
-    } else if (args[i][0] === '-' && opts.hasOwnProperty(args[i][1])) {
+    } else if (args[i][0] === '-' && hasOwnProperty(opts, args[i][1])) {
       opts[args[i][1]] = true;
     } else {
       filenames.push(args[i]);

packages/ohm-js/extras/semantics-toAST.js

@@ -22,7 +22,7 @@ const defaultOperation = {
     const {mapping} = this.args;
 
     // without customization
-    if (!mapping.hasOwnProperty(ctorName)) {
+    if (!Object.prototype.hasOwnProperty.call(mapping, ctorName)) {
       // intermediate node
       if (this._node instanceof pexprs.Alt || this._node instanceof pexprs.Apply) {
         return children[0].toAST(mapping);

packages/ohm-js/src/Semantics.js

@@ -19,6 +19,8 @@ const globalActionStack = [];
 let prototypeGrammar;
 let prototypeGrammarSemantics;
 
+const hasOwnProperty = (x, prop) => Object.prototype.hasOwnProperty.call(x, prop);
+
 // ----------------- Wrappers -----------------
 
 // Wrappers decorate CST nodes with all of the functionality (i.e., operations and attributes)
@@ -473,7 +475,7 @@ Semantics.prototype.extendOperationOrAttribute = function(type, name, actionDict
         ' with that name'
     );
   }
-  if (Object.prototype.hasOwnProperty.call(this[typePlural], name)) {
+  if (hasOwnProperty(this[typePlural], name)) {
     throw new Error('Cannot extend ' + type + " '" + name + "' again");
   }
 
@@ -497,7 +499,7 @@ Semantics.prototype.extendOperationOrAttribute = function(type, name, actionDict
 };
 
 Semantics.prototype.assertNewName = function(name, type) {
-  if (Wrapper.prototype.hasOwnProperty(name)) {
+  if (hasOwnProperty(Wrapper.prototype, name)) {
     throw new Error('Cannot add ' + type + " '" + name + "': that's a reserved name");
   }
   if (name in this.operations) {
@@ -694,7 +696,7 @@ class Attribute extends Operation {
   execute(semantics, nodeWrapper) {
     const node = nodeWrapper._node;
     const key = semantics.attributeKeys[this.name];
-    if (!node.hasOwnProperty(key)) {
+    if (!hasOwnProperty(node, key)) {
       // The following is a super-send -- isn't JS beautiful? :/
       node[key] = Operation.prototype.execute.call(this, semantics, nodeWrapper);
     }