handle set-constant error if some chain prop is null while loading. A…

…G-8269 #128

Merge in ADGUARD-FILTERS/scriptlets from fix/AG-8269 to master

Squashed commit of the following:

commit a96f804
Author: Slava Leleka <v.leleka@adguard.com>
Date:   Fri May 28 14:42:25 2021 +0300

    rebuild dist

commit e182461
Author: Slava Leleka <v.leleka@adguard.com>
Date:   Fri May 28 14:40:56 2021 +0300

    return base if it's null without let nextBase

commit 40aa593
Author: Slava Leleka <v.leleka@adguard.com>
Date:   Thu May 27 19:51:05 2021 +0300

    build dist

commit 5e42baa
Author: Slava Leleka <v.leleka@adguard.com>
Date:   Thu May 27 19:49:34 2021 +0300

    handle set-constant error if some chain prop is null while loading

dist/cjs/scriptlets.cjs.js

@@ -65,7 +65,18 @@ function getPropertyInChain(base, chain) {
     };
   }
 
-  var prop = chain.slice(0, pos);
+  var prop = chain.slice(0, pos); // https://github.com/AdguardTeam/Scriptlets/issues/128
+
+  if (base === null) {
+    // if base is null, return 'null' as base.
+    // it's needed for triggering the reason logging while debugging
+    return {
+      base: base,
+      prop: prop,
+      chain: chain
+    };
+  }
+
   var nextBase = base[prop];
   chain = chain.slice(pos + 1);
 

dist/scriptlets.js

@@ -67,7 +67,18 @@
         };
       }
 
-      var prop = chain.slice(0, pos);
+      var prop = chain.slice(0, pos); // https://github.com/AdguardTeam/Scriptlets/issues/128
+
+      if (base === null) {
+        // if base is null, return 'null' as base.
+        // it's needed for triggering the reason logging while debugging
+        return {
+          base: base,
+          prop: prop,
+          chain: chain
+        };
+      }
+
       var nextBase = base[prop];
       chain = chain.slice(pos + 1);
 

src/helpers/get-property-in-chain.js

@@ -22,6 +22,14 @@ export function getPropertyInChain(base, chain) {
         return { base, prop: chain };
     }
     const prop = chain.slice(0, pos);
+
+    // https://github.com/AdguardTeam/Scriptlets/issues/128
+    if (base === null) {
+        // if base is null, return 'null' as base.
+        // it's needed for triggering the reason logging while debugging
+        return { base, prop, chain };
+    }
+
     const nextBase = base[prop];
     chain = chain.slice(pos + 1);
     if (nextBase !== undefined) {

tests/scriptlets/prevent-window-open.test.js

@@ -1,11 +1,12 @@
-/* eslint-disable no-eval, no-underscore-dangle */
+/* eslint-disable no-eval, no-underscore-dangle, no-console */
 import { clearGlobalProps } from '../helpers';
 
 const { test, module } = QUnit;
 const name = 'prevent-window-open';
 
 const nativeOpen = window.open;
 const nativeSetTimeout = window.setTimeout;
+const nativeConsole = console.log;
 
 /**
  * Runs sctiptlet with given props
@@ -31,6 +32,7 @@ const beforeEach = () => {
 
 const afterEach = () => {
     window.open = nativeOpen;
+    console.log = nativeConsole;
     clearGlobalProps('hit', '__debug');
 };
 

tests/scriptlets/set-constant.test.js

@@ -1,10 +1,13 @@
-/* eslint-disable no-eval, no-underscore-dangle */
+/* eslint-disable no-eval, no-underscore-dangle, no-console */
 import { clearGlobalProps } from '../helpers';
 
 const { test, module } = QUnit;
 const name = 'set-constant';
 
+const nativeConsole = console.log;
+
 const afterEach = () => {
+    console.log = nativeConsole;
     clearGlobalProps('hit', '__debug', 'counter');
 };
 
@@ -223,3 +226,49 @@ test('sets values correctly + no stack match', (assert) => {
     assert.strictEqual(window.counter, undefined);
     clearGlobalProps(property);
 });
+
+test('no value setting if chain is not relevant', (assert) => {
+    window.chain = { property: {} };
+    runScriptlet(['noprop.property.aaa', 'true']);
+    assert.deepEqual(window.chain.property, {}, 'predefined obj was not changed');
+    assert.strictEqual(window.noprop, undefined, '"noprop" was not set');
+    clearGlobalProps('chain');
+});
+
+test('no value setting if some property in chain is undefined while loading', (assert) => {
+    const testObj = { prop: undefined };
+    window.chain = testObj;
+    runScriptlet(['chain.prop.aaa', 'true']);
+    assert.deepEqual(window.chain, testObj, 'predefined obj was not changed');
+    clearGlobalProps('chain');
+});
+
+test('no value setting if first property in chain is null', (assert) => {
+    window.chain = null;
+    runScriptlet(['chain.property.aaa', 'true']);
+    assert.strictEqual(window.chain, null, 'predefined obj was not changed');
+    clearGlobalProps('chain');
+});
+
+// for now the scriptlet does not set the chained property if one of chain prop is null.
+// that might happen, for example, while loading the page.
+// after the needed property is loaded, the scriptlet does not check it and do not set the value
+// https://github.com/AdguardTeam/Scriptlets/issues/128
+test('set value after timeout if it was null earlier', (assert) => {
+    window.chain = null;
+    runScriptlet(['chain.property.aaa', 'true']);
+    assert.strictEqual(window.chain, null, 'predefined obj was not changed');
+
+    const done = assert.async();
+
+    setTimeout(() => {
+        window.chain = { property: {} };
+    }, 50);
+
+    setTimeout(() => {
+        assert.strictEqual(window.chain.property.aaa, undefined, 'chained prop was NOT set after delay');
+        done();
+    }, 100);
+
+    clearGlobalProps('chain');
+});