duckduckgo · dharb · Sep 5, 2024 · Sep 8, 2024 · Sep 8, 2024 · Sep 18, 2024
@@ -30,7 +30,7 @@ test('web compat', async ({ page }, testInfo) => {
 })
 
 export class WebcompatSpec {
-    htmlPage = '/webcompat/index.html'
+    htmlPage = '/webcompat/pages/message-handlers.html'
     config = './integration-test/test-pages/webcompat/config/message-handlers.json'
 
     /**

@@ -94,4 +94,11 @@ describe('Test integration pages', () => {
             `${process.cwd()}/integration-test/test-pages/webcompat/config/shims.json`
         )
     })
+
+    it('Properly modifies localStorage entries', async () => {
+        await testPage(
+            'webcompat/pages/modify-localstorage.html',
+            `${process.cwd()}/integration-test/test-pages/webcompat/config/modify-localstorage.json`
+        )
+    })
 })
@@ -0,0 +1,33 @@
+{
+  "unprotectedTemporary": [],
+  "features": {
+    "webCompat": {
+      "exceptions": [],
+      "state": "enabled",
+      "settings": {
+        "windowSizing": "enabled",
+        "navigatorCredentials": "enabled",
+        "safariObject": "enabled",
+        "modifyLocalStorage": {
+          "state": "enabled",
+          "changes": []
+        },
+        "domains": [
+          {
+            "domain": ["localhost", "privacy-test-pages.site"],
+            "patchSettings": [
+              {
+                "op": "add",
+                "path": "/modifyLocalStorage/changes/-",
+                "value": {
+                  "key": "keyToBeDeleted",
+                  "action": "delete"
+                }
+              }
+            ]
+          }
+        ]
+      }
+    }
+  }
+}
@@ -3,60 +3,15 @@
 <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width">
-    <title>Webcompat</title>
+    <title>Webcompat Interventions</title>
     <link rel="stylesheet" href="../shared/style.css">
 </head>
 <body>
-<script src="../shared/utils.js"></script>
-
-<p>Webcompat, Message Handlers</p>
-<script>
-    test('webkit.messageHandlers - polyfill prevents throw', async () => {
-        let notThrown = true;
-        try {
-            window.webkit.messageHandlers.anythingatall.postMessage({})
-        } catch (e) {
-            notThrown = false
-        }
-        return [
-            { name: 'Error not thrown polyfil', result: notThrown, expected: true },
-        ]
-    })
-    test('webkit.messageHandlers - undefined should throw', async () => {
-        let thrown = false;
-        try {
-            window.webkit.messageHandlers.jsHandler.postMessage({})
-        } catch (e) {
-            thrown = true
-        }
-        return [
-            { name: 'undefined handler should throw', result: thrown, expected: true },
-        ]
-    })
-    test('webkit.messageHandlers - reflected message', async () => {
-        window.webkit.messageHandlers.printHandler = {
-            postMessage() {
-                return { test: "test" }
-            }
-        }
-
-        const value = window.webkit.messageHandlers.printHandler.postMessage({});
-
-        return [
-            { name: 'reflected message should pass through', result: value.test, expected: 'test' },
-        ]
-    })
-    renderResults();
-
-    async function captureError(fn) {
-        try {
-            // ensure Promise.reject is captured
-            return fn().catch(e => e)
-        } catch (e) {
-            return e
-        }
-    }
-
-</script>
+    <p><a href="../../index.html">[Home]</a></p>
+    <ul>
+        <li><a href="./pages/message-handlers.html">Message Handlers</a> - <a href="./config/message-handlers.json">Config</a></li>
+        <li><a href="./pages/shims.html">Shims</a> - <a href="./config/shims.json">Config</a></li>
+        <li><a href="./pages/modify-localstorage.html">Modify localStorage</a> - <a href="./config/modify-localstorage.json">Config</a></li>
+    </ul>
 </body>
 </html>
@@ -0,0 +1,62 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width">
+    <title>Webcompat</title>
+    <link rel="stylesheet" href="../../shared/style.css">
+</head>
+<body>
+<script src="../../shared/utils.js"></script>
+
+<p>Webcompat, Message Handlers</p>
+<script>
+    test('webkit.messageHandlers - polyfill prevents throw', async () => {
+        let notThrown = true;
+        try {
+            window.webkit.messageHandlers.anythingatall.postMessage({})
+        } catch (e) {
+            notThrown = false
+        }
+        return [
+            { name: 'Error not thrown polyfil', result: notThrown, expected: true },
+        ]
+    })
+    test('webkit.messageHandlers - undefined should throw', async () => {
+        let thrown = false;
+        try {
+            window.webkit.messageHandlers.jsHandler.postMessage({})
+        } catch (e) {
+            thrown = true
+        }
+        return [
+            { name: 'undefined handler should throw', result: thrown, expected: true },
+        ]
+    })
+    test('webkit.messageHandlers - reflected message', async () => {
+        window.webkit.messageHandlers.printHandler = {
+            postMessage() {
+                return { test: "test" }
+            }
+        }
+
+        const value = window.webkit.messageHandlers.printHandler.postMessage({});
+
+        return [
+            { name: 'reflected message should pass through', result: value.test, expected: 'test' },
+        ]
+    })
+    renderResults();
+
+    async function captureError(fn) {
+        try {
+            // ensure Promise.reject is captured
+            return fn().catch(e => e)
+        } catch (e) {
+            return e
+        }
+    }
+
+</script>
+</body>
+</html>
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width">
+    <title>Modify localStorage</title>
+    <link rel="stylesheet" href="../../shared/style.css">
+    <script>
+       window.localStorage.setItem('keyToBeDeleted', 'valueToBeDeleted')
+       window.localStorage.setItem('otherKey', 'valueToRemain')
+    </script>
+</head>
+<body>
+    <script src="../../shared/utils.js"></script>
+    <p><a href="../index.html">[WebCompat]</a></p>
+
+    <p>This page verifies that localStorage modifications work properly given the <a href="../config/modify-localstorage.json">config</a>. At this time, only deletion is supported.</p>
+
+    <script>
+        // eslint-disable-next-line no-undef
+        test('Only specified localStorage entry should be removed', async () => {
+            const specifiedKey = window.localStorage.getItem('keyToBeDeleted')
+            const otherKey = window.localStorage.getItem('otherKey')
+
+            return [
+                { name: 'specified localStorage entry deleted', result: specifiedKey, expected: null },
+                { name: 'other localStorage entry untouched', result: otherKey, expected: 'valueToRemain' }
+            ];
+        });
+
+        // eslint-disable-next-line no-undef
+        renderResults();
+    </script>
+</body>
+</html>
@@ -70,7 +70,7 @@
     "@types/chrome": "^0.0.248",
     "@types/jasmine": "^5.1.4",
     "@typescript-eslint/eslint-plugin": "^6.9.1",
-    "config-builder": "github:duckduckgo/privacy-configuration#main",
+    "config-builder": "github:duckduckgo/privacy-configuration#dharb/modify-localstorage-config",
     "esbuild": "^0.19.5",
     "eslint": "^8.57.1",
     "eslint-config-standard": "^17.1.0",

@@ -117,6 +117,10 @@ export class WebCompat extends ContentFeature {
         if (this.getFeatureSettingEnabled('screenLock')) {
             this.screenLockFix()
         }
+
+        if (this.getFeatureSettingEnabled('modifyLocalStorage')) {
+            this.modifyLocalStorage()
+        }
     }
 
     /** Shim Web Share API in Android WebView */
@@ -531,6 +535,24 @@ export class WebCompat extends ContentFeature {
         }
     }
 
+    /**
+     * Support for modifying localStorage entries
+     */
+    modifyLocalStorage () {
+        /** @type {import('../types//webcompat-settings').WebCompatSettings['modifyLocalStorage']} */
+        const settings = this.getFeatureSetting('modifyLocalStorage')
+
+        if (!settings || !settings.changes) return
+
+        settings.changes.forEach((change) => {
+            // @ts-expect-error Property 'action' does not exist on type '{}'
+            if (change.action === 'delete') {
+                // @ts-expect-error Property 'key' does not exist on type '{}'
+                localStorage.removeItem(change.key)
+            }
+        })
+    }
+
     /**
      * Support for proxying `window.webkit.messageHandlers`
      */

@@ -29,7 +29,30 @@ export interface WebCompatSettings {
       undefined: string[];
     };
   };
+  modifyLocalStorage?: {
+    state: State;
+    changes: {}[];
+  };
+  notification?: {
+    state: State;
+  };
+  permissions?: {
+    state: State;
+    supportedPermissions: {};
+  };
+  mediaSession?: State;
+  presentation?: State;
+  webShare?: State;
+  viewportWidth?:
+    | State
+    | {
+        state: State;
+        forcedDesktopValue?: string;
+        forcedMobileValue?: string;
+      };
+  screenLock?: State;
   domains?: Domains;
+  plainTextViewPort?: State;
 }
 export interface Domain {
   /**
@@ -53,5 +76,5 @@ export interface PatchSetting {
   /**
    * The value to replace at the specified path
    */
-  value: string;
+  value: string | unknown[] | {} | number;
 }