Support modifying cookies (#1384)

jonathanKingston · web-flow · commit 399ce49c3dc8 · 2025-01-14T17:23:48.000Z
* Support modifying cookies

* Add test for path
diff --git a/injected/integration-test/pages.spec.js b/injected/integration-test/pages.spec.js
@@ -56,4 +56,14 @@ test.describe('Test integration pages', () => {
             `./integration-test/test-pages/webcompat/config/modify-localstorage.json`,
         );
     });
+
+    test('Properly modifies cookies', async ({ page }, testInfo) => {
+        // prettier-ignore
+        await testPage(
+            page,
+            testInfo,
+            'webcompat/pages/modify-cookies.html',
+            `./integration-test/test-pages/webcompat/config/modify-cookies.json`,
+        );
+    });
 });
diff --git a/injected/integration-test/test-pages/webcompat/config/modify-cookies.json b/injected/integration-test/test-pages/webcompat/config/modify-cookies.json
@@ -0,0 +1,55 @@
+{
+  "unprotectedTemporary": [],
+  "features": {
+    "webCompat": {
+      "exceptions": [],
+      "state": "enabled",
+      "settings": {
+        "modifyCookies": {
+          "state": "enabled",
+          "changes": []
+        },
+        "domains": [
+          {
+            "domain": ["localhost", "privacy-test-pages.site"],
+            "patchSettings": [
+              {
+                "op": "add",
+                "path": "/modifyCookies/changes/-",
+                "value": {
+                  "key": "keyToBeDeleted",
+                  "action": "delete"
+                }
+              },
+              {
+                "op": "add",
+                "path": "/modifyCookies/changes/-",
+                "value": {
+                  "key": "pathCookie",
+                  "action": "delete"
+                }
+              },
+              {
+                "op": "add",
+                "path": "/modifyCookies/changes/-",
+                "value": {
+                  "key": "pathCookieWithPath",
+                  "path": "/webcompat/pages/",
+                  "action": "delete"
+                }
+              },
+              {
+                "op": "add",
+                "path": "/modifyCookies/changes/-",
+                "value": {
+                  "key": "nonexistentKey",
+                  "action": "delete"
+                }
+              }
+            ]
+          }
+        ]
+      }
+    }
+  }
+}
diff --git a/injected/integration-test/test-pages/webcompat/pages/modify-cookies.html b/injected/integration-test/test-pages/webcompat/pages/modify-cookies.html
@@ -0,0 +1,53 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width">
+    <title>Modify Cookies</title>
+    <link rel="stylesheet" href="../../shared/style.css">
+    <script>
+        // Current file path
+        let path = '/webcompat/pages/'
+        document.cookie = 'keyToBeDeleted="valueToBeDeleted"'
+        document.cookie = 'pathCookie="valueToBeDeleted"; path=' + path
+        document.cookie = 'pathCookieWithPath="valueToBeDeleted"; path=' + path
+        document.cookie = 'otherKey="valueToRemain"'
+    </script>
+</head>
+<body>
+    <script src="../../shared/utils.js"></script>
+    <p><a href="../index.html">[WebCompat]</a></p>
+
+    <p>This page verifies that cookie modifications work properly given the <a href="../config/modify-cookies.json">config</a>. At this time, only deletion is supported.</p>
+
+    <script>
+        // Copy from: https://stackoverflow.com/a/2144404
+        function hasCookie(name){
+            return document.cookie.split(';').some(c => {
+                return c.trim().startsWith(name + '=');
+            });
+        }
+
+        // eslint-disable-next-line no-undef
+        test('Only specified cookies should be removed', async () => {
+            const specifiedKey = hasCookie('keyToBeDeleted')
+            const pathKey = hasCookie('pathCookie')
+            const pathKey2 = hasCookie('pathCookie2')
+            const pathKey3 = hasCookie('pathCookieWithPath')
+            const nonexistentKey = hasCookie('nonexistentKey')
+            const otherKey = hasCookie('otherKey')
+
+            return [
+                { name: 'specified cookie entry deleted', result: specifiedKey, expected: false },
+                { name: 'specified cookie entry with path not deleted', result: pathKey, expected: true },
+                { name: `specified cookie entry with correct path (${path}) deleted`, result: pathKey3, expected: false },
+                { name: 'specified cookie entry that is not present on page load', result: nonexistentKey, expected: false },
+                { name: 'other cookie entry untouched', result: otherKey, expected: true }
+            ];
+        });
+
+        // eslint-disable-next-line no-undef
+        renderResults();
+    </script>
+</body>
+</html>
diff --git a/injected/src/features/web-compat.js b/injected/src/features/web-compat.js
@@ -122,6 +122,10 @@ export class WebCompat extends ContentFeature {
         if (this.getFeatureSettingEnabled('modifyLocalStorage')) {
             this.modifyLocalStorage();
         }
+
+        if (this.getFeatureSettingEnabled('modifyCookies')) {
+            this.modifyCookies();
+        }
     }
 
     /** Shim Web Share API in Android WebView */
@@ -583,6 +587,24 @@ export class WebCompat extends ContentFeature {
         });
     }
 
+    /**
+     * Support for modifying cookies
+     */
+    modifyCookies() {
+        /** @type {import('@duckduckgo/privacy-configuration/schema/features/webcompat').WebCompatSettings['modifyCookies']} */
+        const settings = this.getFeatureSetting('modifyCookies');
+
+        if (!settings || !settings.changes) return;
+
+        settings.changes.forEach((change) => {
+            if (change.action === 'delete') {
+                const pathValue = change.path ? `; path=${change.path}` : '';
+                const domainValue = change.domain ? `; domain=${change.domain}` : '';
+                document.cookie = `${change.key}=; expires=Thu, 01 Jan 1970 00:00:00 GMT${pathValue}${domainValue}`;
+            }
+        });
+    }
+
     /**
      * Support for proxying `window.webkit.messageHandlers`
      */
diff --git a/injected/src/types/duckplayer-settings.d.ts b/injected/src/types/duckplayer-settings.d.ts
diff --git a/injected/src/types/webcompat-settings.d.ts b/injected/src/types/webcompat-settings.d.ts
diff --git a/tsconfig.json b/tsconfig.json
@@ -29,7 +29,6 @@
     "playwright.config.js",
     "injected",
     "injected/src/globals.d.ts",
-    "injected/src/features/duckplayer/duckplayer-settings.ts",
     "typedoc.js",
     ".github/scripts"
   ],
