sqlite: validate backup() source is a Database

backup() only checked that the source argument was a BaseObject before
casting it to Database, so passing a Statement or Session caused a
type confusion. Check against the Database constructor template
instead.

Signed-off-by: Guilherme Araújo <arauujogui@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/66797
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

test/parallel/test-sqlite-backup.mjs

@@ -48,10 +48,26 @@ describe('backup()', () => {
       backup();
     }, {
       code: 'ERR_INVALID_ARG_TYPE',
-      message: 'The "sourceDb" argument must be an object.'
+      message: 'The "sourceDb" argument must be an instance of Database.'
     });
   });
 
+  test('throws if the source is not an instance of Database', (t) => {
+    const database = makeSourceDb();
+    for (const source of [
+      {},
+      database.prepare('SELECT 1'),
+      database.createSession(),
+    ]) {
+      t.assert.throws(() => {
+        backup(source, 'out.db');
+      }, {
+        code: 'ERR_INVALID_ARG_TYPE',
+        message: 'The "sourceDb" argument must be an instance of Database.'
+      });
+    }
+  });
+
   test('throws if path is not a string, URL, or Buffer', (t) => {
     const database = makeSourceDb();