Resolve issue #2026

src/public/types/keypaths.d.ts

@@ -1,16 +1,17 @@
 export type KeyPaths<T> = {
-  [P in keyof T]: 
-    P extends string 
-      ? T[P] extends Array<infer K>
-        ? K extends object // only drill into the array element if it's an object
-          ? P | `${P}.${number}` | `${P}.${number}.${KeyPaths<K>}` 
-          : P | `${P}.${number}`
-        : T[P] extends (...args: any[]) => any // Method
-           ? never 
-          : T[P] extends object 
-            ? P | `${P}.${KeyPaths<T[P]>}` 
-            : P 
-      : never;
+  [P in keyof T]: P extends string
+    ? T[P] extends Array<infer K>
+      ? K extends any[] // Array of arrays (issue #2026)
+        ? P | `${P}.${number}` | `${P}.${number}.${number}`
+        : K extends object // only drill into the array element if it's an object
+        ? P | `${P}.${number}` | `${P}.${number}.${KeyPaths<K>}`
+        : P | `${P}.${number}`
+      : T[P] extends (...args: any[]) => any // Method
+      ? never
+      : T[P] extends object
+      ? P | `${P}.${KeyPaths<T[P]>}`
+      : P
+    : never;
 }[keyof T];
 
 export type KeyPathValue<T, PATH> = PATH extends `${infer R}.${infer S}`

test/typings-test/test-typings.ts

@@ -268,12 +268,17 @@ import './test-updatespec';
         isGoodFriend: boolean;
         address: {
             city: string;
-        }
+        },
+        matrix: number[][]; // Trigger issue #2026
     }
 
     let db = new Dexie('dbname') as Dexie & {friends: Table<Friend, number>};
 
     db.friends.where({name: 'Kalle'}).modify({name: replacePrefix('K', 'C')});
+
+    // Issue #2026
+    db.friends.update(1, {"address.city": "New York"});
+    db.friends.update(2, {matrix: [[1,2]]});
 }