feat: Drizzle - added support for custom column types in schema conversion (#475)

Author: Chriztiaan

.changeset/lemon-moles-lie.md

@@ -0,0 +1,5 @@
+---
+'@powersync/drizzle-driver': patch
+---
+
+Added support for custom column types when converting a Drizzle schema to a PowerSync app schema.

packages/drizzle-driver/src/utils/schema.ts

@@ -12,6 +12,7 @@ import { CasingCache } from 'drizzle-orm/casing';
 import {
   getTableConfig,
   SQLiteBoolean,
+  SQLiteCustomColumn,
   SQLiteInteger,
   SQLiteReal,
   SQLiteText,
@@ -44,24 +45,7 @@ export function toPowerSyncTable<T extends SQLiteTableWithColumns<any>>(
       continue;
     }
 
-    let mappedType: BaseColumnType<number | string | null>;
-    switch (drizzleColumn.columnType) {
-      case SQLiteText[entityKind]:
-      case SQLiteTextJson[entityKind]:
-        mappedType = column.text;
-        break;
-      case SQLiteInteger[entityKind]:
-      case SQLiteTimestamp[entityKind]:
-      case SQLiteBoolean[entityKind]:
-        mappedType = column.integer;
-        break;
-      case SQLiteReal[entityKind]:
-        mappedType = column.real;
-        break;
-      default:
-        throw new Error(`Unsupported column type: ${drizzleColumn.columnType}`);
-    }
-    columns[name] = mappedType;
+    columns[name] = mapDrizzleColumnToType(drizzleColumn);
   }
   const indexes: IndexShorthand = {};
 
@@ -82,6 +66,34 @@ export function toPowerSyncTable<T extends SQLiteTableWithColumns<any>>(
   return new Table(columns, { ...options, indexes }) as Table<Expand<ExtractPowerSyncColumns<T>>>;
 }
 
+function mapDrizzleColumnToType(drizzleColumn: SQLiteColumn<any, object>): BaseColumnType<number | string | null> {
+  switch (drizzleColumn.columnType) {
+    case SQLiteText[entityKind]:
+    case SQLiteTextJson[entityKind]:
+      return column.text;
+    case SQLiteInteger[entityKind]:
+    case SQLiteTimestamp[entityKind]:
+    case SQLiteBoolean[entityKind]:
+      return column.integer;
+    case SQLiteReal[entityKind]:
+      return column.real;
+    case SQLiteCustomColumn[entityKind]:
+      const sqlName = (drizzleColumn as SQLiteCustomColumn<any>).getSQLType();
+      switch (sqlName) {
+        case 'text':
+          return column.text;
+        case 'integer':
+          return column.integer;
+        case 'real':
+          return column.real;
+        default:
+          throw new Error(`Unsupported custom column type: ${drizzleColumn.columnType}: ${sqlName}`);
+      }
+    default:
+      throw new Error(`Unsupported column type: ${drizzleColumn.columnType}`);
+  }
+}
+
 export type DrizzleTablePowerSyncOptions = Omit<TableV2Options, 'indexes'>;
 
 export type DrizzleTableWithPowerSyncOptions = {

packages/drizzle-driver/tests/sqlite/schema.test.ts

@@ -1,5 +1,5 @@
 import { column, Schema, Table } from '@powersync/common';
-import { index, integer, real, sqliteTable, text } from 'drizzle-orm/sqlite-core';
+import { customType, index, integer, real, sqliteTable, text } from 'drizzle-orm/sqlite-core';
 import { describe, expect, it } from 'vitest';
 import { DrizzleAppSchema, DrizzleTableWithPowerSyncOptions, toPowerSyncTable } from '../../src/utils/schema';
 import { CasingCache } from 'drizzle-orm/casing';
@@ -105,6 +105,61 @@ describe('toPowerSyncTable', () => {
 
     expect(convertedList).toEqual(expectedLists);
   });
+
+  it('custom column conversion', () => {
+    const customSqliteText = customType<{ data: string; driverData: string }>({
+      dataType() {
+        return 'text';
+      },
+      fromDriver(value) {
+        return value;
+      },
+      toDriver(value) {
+        return value;
+      }
+    });
+
+    const customSqliteInteger = customType<{ data: number; driverData: number }>({
+      dataType() {
+        return 'integer';
+      },
+      fromDriver(value) {
+        return Number(value);
+      },
+      toDriver(value) {
+        return value;
+      }
+    });
+
+    const customSqliteReal = customType<{ data: number; driverData: number }>({
+      dataType() {
+        return 'real';
+      },
+      fromDriver(value) {
+        return Number(value);
+      },
+      toDriver(value) {
+        return value;
+      }
+    });
+
+    const lists = sqliteTable('lists', {
+      id: text('id').primaryKey(),
+      text_col: customSqliteText('text_col'),
+      int_col: customSqliteInteger('int_col'),
+      real_col: customSqliteReal('real_col')
+    });
+
+    const convertedList = toPowerSyncTable(lists);
+
+    const expectedLists = new Table({
+      text_col: column.text,
+      int_col: column.integer,
+      real_col: column.real
+    });
+
+    expect(convertedList).toEqual(expectedLists);
+  });
 });
 
 describe('DrizzleAppSchema constructor', () => {