improve tests & add emptyobject in chain case

AdguardTeam · Mar 29, 2022 · 6406257 · 6406257
1 parent 5c18130
commit 6406257
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Showing 3 changed files with 46 additions and 6 deletions.
diff --git a/src/helpers/get-property-in-chain.js b/src/helpers/get-property-in-chain.js
@@ -1,3 +1,5 @@
+import { isEmptyObject } from './object-utils';
+
 /**
  * @typedef Chain
  * @property {Object} base
@@ -33,6 +35,11 @@ export function getPropertyInChain(base, chain) {
     const nextBase = base[prop];
     chain = chain.slice(pos + 1);
 
+    if ((base instanceof Object || typeof base === 'object') && isEmptyObject(base)) {
+        // for empty objects in chain
+        return { base, prop, chain };
+    }
+
     if (nextBase === null) {
         return { base, prop, chain };
     }

diff --git a/src/scriptlets/set-constant.js b/src/scriptlets/set-constant.js
@@ -12,6 +12,7 @@ import {
     toRegExp,
     matchStackTrace,
     nativeIsNaN,
+    isEmptyObject,
 } from '../helpers';
 
 /* eslint-disable max-len */
@@ -240,6 +241,11 @@ export function setConstant(source, property, value, stack) {
             return;
         }
 
+        // Empty object prop in chain
+        if ((base instanceof Object || typeof base === 'object') && isEmptyObject(base)) {
+            trapProp(base, prop, true, inChainPropHandler);
+        }
+
         // Defined prop in chain
         const propValue = owner[prop];
         if (propValue instanceof Object || (typeof propValue === 'object' && propValue !== null)) {
@@ -249,7 +255,6 @@ export function setConstant(source, property, value, stack) {
         // Undefined prop in chain
         trapProp(owner, prop, true, inChainPropHandler);
     };
-
     setChainPropAccess(window, property);
 }
 
@@ -278,4 +283,5 @@ setConstant.injections = [
     toRegExp,
     matchStackTrace,
     nativeIsNaN,
+    isEmptyObject,
 ];
diff --git a/tests/scriptlets/set-constant.test.js b/tests/scriptlets/set-constant.test.js
@@ -155,13 +155,39 @@ if (!isSupported) {
         clearGlobalProps(illegalNumberProp);
     });
 
+    test('keep other keys after setting a value', (assert) => {
+        window.testObj = {
+            testChain: null,
+        };
+        runScriptletFromTag('testObj.testChain.testProp', 'true');
+        window.testObj.testChain = {
+            testProp: false,
+            otherProp: 'someValue',
+            testMethod: () => { },
+        };
+        assert.strictEqual(window.testObj.testChain.testProp, true, 'target prop set');
+        assert.strictEqual(window.testObj.testChain.otherProp, 'someValue', 'target prop set');
+        assert.strictEqual(typeof window.testObj.testChain.testMethod, 'function', 'target prop set');
+        clearGlobalProps('testObj');
+    });
+
     test('set value on null prop', (assert) => {
         // end prop is null
-        window.test = null;
-        runScriptletFromTag('test', '15');
-        assert.strictEqual(window.test, 15, 'null end prop changed');
-        clearGlobalProps('test');
+        window.nullProp = null;
+        runScriptletFromTag('nullProp', '15');
+        assert.strictEqual(window.nullProp, 15, 'null end prop changed');
+        clearGlobalProps('nullProp');
+    });
+
+    test('set value through chain with empty object', (assert) => {
+        window.emptyObj = {};
+        runScriptletFromTag('emptyObj.a.prop', 'true');
+        window.emptyObj.a = {};
+        assert.strictEqual(window.emptyObj.a.prop, true, 'target prop set');
+        clearGlobalProps('emptyObj');
+    });
 
+    test('set value through chain with null', (assert) => {
         // null prop in chain
         window.nullChain = {
             nullProp: null,
@@ -170,7 +196,8 @@ if (!isSupported) {
         window.nullChain.nullProp = {
             endProp: false,
         };
-        assert.strictEqual(window.nullChain.nullProp.endProp, true, 'nsdfsdxfhgsd');
+        assert.strictEqual(window.nullChain.nullProp.endProp, true, 'chain with null trapped');
+        clearGlobalProps('nullChain');
     });
 
     test('sets values to the chained properties', (assert) => {