Improve set-constant adg->ubo conversion

fix by @gorhill
uBlockOrigin/uBlock-issues#2411

* commit '993c7648279c7c6c7eb7ee8f3ef92724fe584651':
  add related issue link to changelog
  update changelog
  add few simple tests
  fix converter comments
  fix readme
  Fix converter for uBO's `[]`/`{}` in `set-constant` scriptlet

Author: slavaleleka

CHANGELOG.md

@@ -1,11 +1,20 @@
 # Scriptlets and Redirect Resources Changelog
 
+
+## v1.7.14
+
+### Added
+
+* `set-constant` ADG→UBO conversion for [`emptyArr` and `emptyObj`](https://github.com/uBlockOrigin/uBlock-issues/issues/2411)
+
+
 ## v1.7.13
 
-### Fixed 
+### Fixed
 
 * `isEmptyObject` helper not counting `prototype` as an object property
 
+
 ## v1.7.10
 
 ### Added
@@ -19,6 +28,7 @@
 * spread of args bug at `getXhrData` call for `trusted-replace-xhr-response`
 * request properties array not being served to `getRequestData` and `parseMatchProps` helpers
 
+
 ## v1.7.3
 
 ### Added

README.md

@@ -1,4 +1,4 @@
-# AdGuard Scriptlets and Redirect resources
+# AdGuard Scriptlets and Redirect Resources
 
 AdGuard's Scriptlets and Redirect resources library which provides extended capabilities for content blocking.
 

src/helpers/converter.js

@@ -42,7 +42,11 @@ const ADG_XHR_TYPE = 'xmlhttprequest';
 
 const ADG_SET_CONSTANT_NAME = 'set-constant';
 const ADG_SET_CONSTANT_EMPTY_STRING = '';
+const ADG_SET_CONSTANT_EMPTY_ARRAY = 'emptyArr';
+const ADG_SET_CONSTANT_EMPTY_OBJECT = 'emptyObj';
 const UBO_SET_CONSTANT_EMPTY_STRING = '\'\'';
+const UBO_SET_CONSTANT_EMPTY_ARRAY = '[]';
+const UBO_SET_CONSTANT_EMPTY_OBJECT = '{}';
 
 const ADG_PREVENT_FETCH_NAME = 'prevent-fetch';
 const ADG_PREVENT_FETCH_EMPTY_STRING = '';
@@ -246,10 +250,17 @@ export const convertAdgScriptletToUbo = (rule) => {
         const { name: parsedName, args: parsedParams } = parseRule(rule);
 
         let preparedParams;
-        // https://github.com/AdguardTeam/FiltersCompiler/issues/102
         if (parsedName === ADG_SET_CONSTANT_NAME
+            // https://github.com/AdguardTeam/FiltersCompiler/issues/102
             && parsedParams[1] === ADG_SET_CONSTANT_EMPTY_STRING) {
             preparedParams = [parsedParams[0], UBO_SET_CONSTANT_EMPTY_STRING];
+        } else if (parsedName === ADG_SET_CONSTANT_NAME
+            // https://github.com/uBlockOrigin/uBlock-issues/issues/2411
+            && parsedParams[1] === ADG_SET_CONSTANT_EMPTY_ARRAY) {
+            preparedParams = [parsedParams[0], UBO_SET_CONSTANT_EMPTY_ARRAY];
+        } else if (parsedName === ADG_SET_CONSTANT_NAME
+            && parsedParams[1] === ADG_SET_CONSTANT_EMPTY_OBJECT) {
+            preparedParams = [parsedParams[0], UBO_SET_CONSTANT_EMPTY_OBJECT];
         } else if (parsedName === ADG_PREVENT_FETCH_NAME
             // https://github.com/AdguardTeam/Scriptlets/issues/109
             && (parsedParams[0] === ADG_PREVENT_FETCH_WILDCARD

tests/lib-tests/index.test.js

@@ -246,6 +246,16 @@ test('Test SCRIPTLET converting - ADG -> UBO', (assert) => {
     inputAdg = 'example.com#%#//scriptlet(\'close-window\')';
     expectedUbo = 'example.com##+js(window-close-if)';
     assert.strictEqual(convertAdgScriptletToUbo(inputAdg), expectedUbo);
+
+    // emptyArr as set-constant parameter
+    inputAdg = "example.org#%#//scriptlet('set-constant', 'adUnits', 'emptyArr')";
+    expectedUbo = 'example.org##+js(set-constant, adUnits, [])';
+    assert.strictEqual(convertAdgScriptletToUbo(inputAdg), expectedUbo);
+
+    // emptyObj as set-constant parameter
+    inputAdg = "example.org#%#//scriptlet('set-constant', 'adUnits', 'emptyObj')";
+    expectedUbo = 'example.org##+js(set-constant, adUnits, {})';
+    assert.strictEqual(convertAdgScriptletToUbo(inputAdg), expectedUbo);
 });
 
 test('Test $redirect validation', (assert) => {