chore: use kysely_column_metadata (#52)

Author: remiposo

packages/kysely-tailordb-codegen/package.json

@@ -24,12 +24,11 @@
   },
   "devDependencies": {
     "@biomejs/biome": "1.9.4",
-    "@tailor-platform/function-kysely-tailordb": "0.1.2",
     "@tailor-platform/function-types": "0.3.0",
     "@types/fs-extra": "11.0.4",
     "@types/node": "22.15.33",
     "esbuild": "0.25.5",
-    "kysely": "0.27.6",
+    "kysely": "0.28.2",
     "kysely-codegen": "0.18.5",
     "typescript": "5.8.3",
     "unenv": "1.10.0"

packages/kysely-tailordb-codegen/pnpm-lock.yaml

@@ -1,7 +1,6 @@
-import { TailordbDialect } from "@tailor-platform/function-kysely-tailordb";
-import { Kysely } from "kysely";
+import type { TableMetadata } from "kysely";
 import {
-  type PostgresDB,
+  EnumCollection,
   PostgresDialect,
   TypeScriptSerializer,
 } from "kysely-codegen";
@@ -10,11 +9,69 @@ export default async (args: { namespace: string }) => {
   const client = new tailordb.Client({
     namespace: args.namespace,
   });
-  const db = new Kysely<PostgresDB>({
-    dialect: new TailordbDialect(client),
+  const columns = (
+    await client.queryObject<RawColumnMetadata>(
+      // To avoid unstable dependencies on SQL generated by Kysely, issue a SELECT statement to the special metadata table `kysely_column_metadata`.
+      // Tailor Platform must return results corresponding to `RawColumnMetadata` for this SQL.
+      "SELECT * FROM kysely_column_metadata;",
+    )
+  ).rows;
+  const tables = parseTableMetadata(columns);
+  const dialect = new PostgresDialect();
+  const metadata = dialect.introspector.createDatabaseMetadata({
+    tables,
+    domains: [],
+    partitions: [],
+    enums: new EnumCollection(),
   });
-  const dialect = new PostgresDialect({ domains: false });
-  const metadata = await dialect.introspector.introspect({ db });
   const data = new TypeScriptSerializer().serializeFile(metadata, dialect);
   return { data };
 };
+
+// Since Kysely's parseTableMetadata is not exported, it is copied below.
+// https://github.com/kysely-org/kysely/blob/0.28.2/src/dialect/postgres/postgres-introspector.ts#L103
+const parseTableMetadata = (columns: RawColumnMetadata[]): TableMetadata[] => {
+  return columns.reduce<TableMetadata[]>((tables, it) => {
+    let table = tables.find(
+      (tbl) => tbl.name === it.table && tbl.schema === it.schema,
+    );
+
+    if (!table) {
+      table = Object.freeze({
+        name: it.table,
+        isView: it.table_type === "v",
+        schema: it.schema,
+        columns: [],
+      });
+
+      tables.push(table);
+    }
+
+    table.columns.push(
+      Object.freeze({
+        name: it.column,
+        dataType: it.type,
+        dataTypeSchema: it.type_schema,
+        isNullable: !it.not_null,
+        isAutoIncrementing: !!it.auto_incrementing,
+        hasDefaultValue: it.has_default,
+        comment: it.column_description ?? undefined,
+      }),
+    );
+
+    return tables;
+  }, []);
+};
+
+interface RawColumnMetadata {
+  column: string;
+  table: string;
+  table_type: string;
+  schema: string;
+  not_null: boolean;
+  has_default: boolean;
+  type: string;
+  type_schema: string;
+  auto_incrementing: boolean | null;
+  column_description: string | null;
+}