fix: remove proxy frames from stack traces

Proxy-related implementation frames were showing up in the stack
traces for failed property assertions. This commit removes them by
setting the proxy getter (instead of the property getter) as the
starting point to remove all implementation frames.

lib/chai/utils/addProperty.js

@@ -6,6 +6,7 @@
 
 var chai = require('../../chai');
 var flag = require('./flag');
+var isProxyEnabled = require('./isProxyEnabled');
 var transferFlags = require('./transferFlags');
 
 /**
@@ -39,10 +40,12 @@ module.exports = function addProperty(ctx, name, getter) {
 
   Object.defineProperty(ctx, name,
     { get: function propertyGetter() {
+        if (!isProxyEnabled()) {
           var keep_ssfi = flag(this, 'keep_ssfi');
           var old_ssfi = flag(this, 'ssfi');
           if (!keep_ssfi && old_ssfi)
             flag(this, 'ssfi', propertyGetter);
+        }
 
         var result = getter.call(this);
         if (result !== undefined)

lib/chai/utils/overwriteProperty.js

@@ -6,6 +6,7 @@
 
 var chai = require('../../chai');
 var flag = require('./flag');
+var isProxyEnabled = require('./isProxyEnabled');
 var transferFlags = require('./transferFlags');
 
 /**
@@ -51,10 +52,12 @@ module.exports = function overwriteProperty(ctx, name, getter) {
 
   Object.defineProperty(ctx, name,
     { get: function overwritingPropertyGetter() {
+        if (!isProxyEnabled()) {
           var keep_ssfi = flag(this, 'keep_ssfi');
           var old_ssfi = flag(this, 'ssfi');
           if (!keep_ssfi && old_ssfi)
             flag(this, 'ssfi', overwritingPropertyGetter);
+        }
 
         flag(this, 'keep_ssfi', true);
         var result = getter(_super).call(this);

lib/chai/utils/proxify.js

@@ -1,4 +1,5 @@
 var config = require('../config');
+var flag = require('./flag');
 var getProperties = require('./getProperties');
 var isProxyEnabled = require('./isProxyEnabled');
 
@@ -27,6 +28,8 @@ var isProxyEnabled = require('./isProxyEnabled');
  * @name proxify
  */
 
+var builtins = ['__flags', '__methods', '_obj', 'assert'];
+
 module.exports = function proxify(obj, nonChainableMethodName) {
   if (!isProxyEnabled()) return obj;
 
@@ -48,7 +51,7 @@ module.exports = function proxify(obj, nonChainableMethodName) {
 
         var orderedProperties = getProperties(target).filter(function(property) {
           return !Object.prototype.hasOwnProperty(property) &&
-            ['__flags', '__methods', '_obj', 'assert'].indexOf(property) === -1;
+            builtins.indexOf(property) === -1;
         }).sort(function(a, b) {
           return stringDistance(property, a) - stringDistance(property, b);
         });
@@ -64,6 +67,10 @@ module.exports = function proxify(obj, nonChainableMethodName) {
         }
       }
 
+      if (builtins.indexOf(property) === -1) {
+        flag(target, 'ssfi', proxyGetter);
+      }
+
       return Reflect.get(target, property);
     }
   });

test/configuration.js

@@ -99,6 +99,10 @@ describe('configuration', function () {
 
         it('should include Chai frames in stack trace', function () {
           expect(caughtErr.stack).to.contain('propertyGetter');
+
+          if (typeof Proxy !== 'undefined' && typeof Reflect !== 'undefined') {
+            expect(caughtErr.stack).to.contain('proxyGetter');
+          }
         });
 
         it('should include user frames in stack trace', function () {
@@ -121,6 +125,10 @@ describe('configuration', function () {
 
         it('should include Chai frames in stack trace', function () {
           expect(caughtErr.stack).to.contain('overwritingPropertyGetter');
+
+          if (typeof Proxy !== 'undefined' && typeof Reflect !== 'undefined') {
+            expect(caughtErr.stack).to.contain('proxyGetter');
+          }
         });
 
         it('should include user frames in stack trace', function () {
@@ -233,6 +241,10 @@ describe('configuration', function () {
 
         it('should not include Chai frames in stack trace', function () {
           expect(caughtErr.stack).to.not.contain('propertyGetter');
+
+          if (typeof Proxy !== 'undefined' && typeof Reflect !== 'undefined') {
+            expect(caughtErr.stack).to.not.contain('proxyGetter');
+          }
         });
 
         it('should include user frames in stack trace', function () {
@@ -255,6 +267,10 @@ describe('configuration', function () {
 
         it('should not include Chai frames in stack trace', function () {
           expect(caughtErr.stack).to.not.contain('overwritingPropertyGetter');
+
+          if (typeof Proxy !== 'undefined' && typeof Reflect !== 'undefined') {
+            expect(caughtErr.stack).to.not.contain('proxyGetter');
+          }
         });
 
         it('should include user frames in stack trace', function () {