Fix global filter with wildcard columns (#66)

- Implement `resolveQueryColumns` in `WasmDatabaseEngine` to dynamically fetch column names when `columns` is `['*']` and `globalFilter` is used.
- Update `fetchTableData` and `fetchTableCount` to use `resolveQueryColumns`.
- Add unit tests in `tests/unit/sqlite-db.test.ts` to verify the fix.

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

Author: zknpr

package-lock.json

@@ -549,6 +549,17 @@ class WasmDatabaseEngine implements DatabaseOperations {
     }
   }
 
+  /**
+   * Helper to resolve wildcard columns to explicit column names when using global filter.
+   */
+  private async resolveQueryColumns(table: string, columns: string[] | undefined, globalFilter: string | undefined): Promise<string[] | undefined> {
+    if (globalFilter && (!columns || (columns.length === 1 && columns[0] === '*'))) {
+      const tableInfo = await this.getTableInfo(table);
+      return tableInfo.map(c => c.identifier);
+    }
+    return columns;
+  }
+
   /**
    * Create a new table.
    */
@@ -691,7 +702,10 @@ class WasmDatabaseEngine implements DatabaseOperations {
    * The query builder enforces these limits, making timeout unnecessary here.
    */
   async fetchTableData(table: string, options: TableQueryOptions): Promise<QueryResultSet> {
-    const { sql, params } = buildSelectQuery(table, options);
+    const queryOptions = { ...options };
+    queryOptions.columns = await this.resolveQueryColumns(table, queryOptions.columns, queryOptions.globalFilter);
+
+    const { sql, params } = buildSelectQuery(table, queryOptions);
 
     // Use prepare/step/get to avoid overhead of exec() which builds intermediate objects
     // and to allow for potentially better memory management in the future
@@ -727,7 +741,10 @@ class WasmDatabaseEngine implements DatabaseOperations {
    * Fetch table row count using options.
    */
   async fetchTableCount(table: string, options: TableCountOptions): Promise<number> {
-    const { sql, params } = buildCountQuery(table, options);
+    const queryOptions = { ...options };
+    queryOptions.columns = await this.resolveQueryColumns(table, queryOptions.columns, queryOptions.globalFilter);
+
+    const { sql, params } = buildCountQuery(table, queryOptions);
     const result = await this.executeQuery(sql, params);
     if (result && result.length > 0 && result[0].rows.length > 0) {
       const count = result[0].rows[0][0];

src/core/sqlite-db.ts

@@ -80,4 +80,35 @@ describe('WasmDatabaseEngine', () => {
       }
     });
   });
+
+  describe('fetchTableData', () => {
+    it('should correctly filter with globalFilter and implicit columns (*)', async () => {
+      // Create a test table for this case
+      await engine.executeQuery("CREATE TABLE items (id INTEGER PRIMARY KEY, name TEXT, description TEXT)");
+      await engine.insertRow('items', { id: 1, name: 'Apple', description: 'Red fruit' });
+      await engine.insertRow('items', { id: 2, name: 'Banana', description: 'Yellow fruit' });
+
+      const result = await engine.fetchTableData('items', {
+        columns: ['*'],
+        globalFilter: 'Yellow'
+      });
+
+      assert.strictEqual(result.rows.length, 1);
+      assert.strictEqual(result.rows[0][1], 'Banana');
+    });
+
+    it('should correctly count with globalFilter and implicit columns (*)', async () => {
+       const count = await engine.fetchTableCount('items', {
+         columns: ['*'],
+         globalFilter: 'fruit'
+       });
+       assert.strictEqual(count, 2);
+
+       const countYellow = await engine.fetchTableCount('items', {
+        columns: ['*'],
+        globalFilter: 'Yellow'
+      });
+      assert.strictEqual(countYellow, 1);
+    });
+  });
 });