fix(codegen-ts): emit type-only Drizzle symbols with import type (verbatimModuleSyntax) (#165) (#166)

The default entityFile() output imported Drizzle's type-only symbols as VALUE
imports: InferSelectModel / InferInsertModel (drizzle-orm) and AnyPgColumn /
AnySQLiteColumn (the *-core package, used only as a .references() return-type
annotation). Under `verbatimModuleSyntax: true` — a common default in modern
Vite/TS app templates — tsc rejects each with TS1484 ("… is a type and must be
imported using a type-only import"), so a generated DAO fails `tsc -b` with
hundreds of errors even though it runs fine under a bundler.

Mark the three symbols type-only via ts-poet's `t:` prefix (the idiom already
used for FastifyInstance/Hono/TPH imports), so they emit as `import type` (or an
inline `type` modifier when mixed with value imports from the same module). This
fixes both the built-in generator and the ADR-0034 scaffold-and-own reference
template, which delegates to the same renderDrizzleSchema / renderInferredTypes
primitives.

Adds a real-tsc compile guard with verbatimModuleSyntax ON over an entity with a
self-referential FK (so AnyPgColumn is exercised); a negative control confirms it
catches the TS1484 regression for all three symbols. Golden snapshots updated
(the only change is value→type imports). TS-only; codegen output, no metamodel
or cross-port impact.


Claude-Session: https://claude.ai/code/session_01Ew1XfYSbEAezxjs9opynAe

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: dmealing

server/typescript/packages/codegen-ts/src/templates/drizzle-schema.ts

@@ -344,7 +344,9 @@ function renderColumn(
     // initializer") under `strict`. The annotation is a harmless explicit supertype
     // for acyclic FKs, so emitting it unconditionally is safe.
     const anyColType = ctx.dialect === "sqlite" ? "AnySQLiteColumn" : "AnyPgColumn";
-    const anyColSym = imp(`${anyColType}@${spec.importModule}`);
+    // Used only as a return-type annotation → type-only import (t:) so it emits
+    // `import type` and doesn't fail tsc under `verbatimModuleSyntax` (TS1484). (#165)
+    const anyColSym = imp(`t:${anyColType}@${spec.importModule}`);
     if (fkInfo.targetEntityName === currentEntityName) {
       // Self-referential FK (e.g. createdBy → this same table): reference the local
       // table const directly — NOT a self-import.

server/typescript/packages/codegen-ts/src/templates/inferred-types.ts

@@ -57,8 +57,10 @@ export function renderInferredTypes(entity: MetaObject, tphBase = false, ctx?: R
   // ctx is optional for bare unit-test calls — those fall back to the default
   // always-pluralize spelling.
   const varName = ctx ? ctx.collectionName(entity.name) : variableNameFromEntity(entity.name);
-  const selectSym = imp("InferSelectModel@drizzle-orm");
-  const insertSym = imp("InferInsertModel@drizzle-orm");
+  // Type-only symbols (t: prefix) so ts-poet emits `import type` — otherwise a
+  // value import of these types fails tsc under `verbatimModuleSyntax` (TS1484). (#165)
+  const selectSym = imp("t:InferSelectModel@drizzle-orm");
+  const insertSym = imp("t:InferInsertModel@drizzle-orm");
   const docs = renderDocsFor(entity);
   const docsPrefix = docs ? `${docs}\n` : "";
   const rowName = tphBase ? `${entity.name}Row` : entity.name;

server/typescript/packages/codegen-ts/test/golden/__snapshots__/package/Tag.ts

@@ -1,9 +1,13 @@
 // @generated by @metaobjectsdev/codegen-ts — DO NOT EDIT.
 // Source metadata: Tag (Tag)
 // Customize via Tag.extra.ts in this directory.
-import { InferInsertModel, InferSelectModel, relations } from "drizzle-orm";
 import {
-  AnySQLiteColumn,
+  type InferInsertModel,
+  type InferSelectModel,
+  relations,
+} from "drizzle-orm";
+import {
+  type AnySQLiteColumn,
   integer,
   sqliteTable,
   text,

server/typescript/packages/codegen-ts/test/golden/__snapshots__/package/shop/commerce/Order.ts

@@ -1,8 +1,16 @@
 // @generated by @metaobjectsdev/codegen-ts — DO NOT EDIT.
 // Source metadata: Order (shop::commerce::Order)
 // Customize via Order.extra.ts in this directory.
-import { InferInsertModel, InferSelectModel, relations } from "drizzle-orm";
-import { AnySQLiteColumn, integer, sqliteTable } from "drizzle-orm/sqlite-core";
+import {
+  type InferInsertModel,
+  type InferSelectModel,
+  relations,
+} from "drizzle-orm";
+import {
+  type AnySQLiteColumn,
+  integer,
+  sqliteTable,
+} from "drizzle-orm/sqlite-core";
 import { z } from "zod";
 import { customers } from "../users/Customer";
 import { products } from "./Product";

server/typescript/packages/codegen-ts/test/golden/__snapshots__/package/shop/commerce/Product.ts

@@ -1,9 +1,13 @@
 // @generated by @metaobjectsdev/codegen-ts — DO NOT EDIT.
 // Source metadata: Product (shop::commerce::Product)
 // Customize via Product.extra.ts in this directory.
-import { InferInsertModel, InferSelectModel, relations } from "drizzle-orm";
 import {
-  AnySQLiteColumn,
+  type InferInsertModel,
+  type InferSelectModel,
+  relations,
+} from "drizzle-orm";
+import {
+  type AnySQLiteColumn,
   integer,
   sqliteTable,
   text,

server/typescript/packages/codegen-ts/test/golden/__snapshots__/package/shop/users/Customer.ts

@@ -1,7 +1,7 @@
 // @generated by @metaobjectsdev/codegen-ts — DO NOT EDIT.
 // Source metadata: Customer (shop::users::Customer)
 // Customize via Customer.extra.ts in this directory.
-import { InferInsertModel, InferSelectModel } from "drizzle-orm";
+import type { InferInsertModel, InferSelectModel } from "drizzle-orm";
 import { integer, sqliteTable, text } from "drizzle-orm/sqlite-core";
 import { z } from "zod";
 

server/typescript/packages/codegen-ts/test/golden/__snapshots__/postgres/Exercise.ts

@@ -1,9 +1,13 @@
 // @generated by @metaobjectsdev/codegen-ts — DO NOT EDIT.
 // Source metadata: Exercise (Exercise)
 // Customize via Exercise.extra.ts in this directory.
-import { InferInsertModel, InferSelectModel, relations } from "drizzle-orm";
 import {
-  AnyPgColumn,
+  type InferInsertModel,
+  type InferSelectModel,
+  relations,
+} from "drizzle-orm";
+import {
+  type AnyPgColumn,
   bigint,
   bigserial,
   integer,

server/typescript/packages/codegen-ts/test/golden/__snapshots__/postgres/Program.ts

@@ -1,7 +1,7 @@
 // @generated by @metaobjectsdev/codegen-ts — DO NOT EDIT.
 // Source metadata: Program (Program)
 // Customize via Program.extra.ts in this directory.
-import { InferInsertModel, InferSelectModel } from "drizzle-orm";
+import type { InferInsertModel, InferSelectModel } from "drizzle-orm";
 import {
   bigserial,
   boolean,

server/typescript/packages/codegen-ts/test/golden/__snapshots__/postgres/Purchase.ts

@@ -1,9 +1,13 @@
 // @generated by @metaobjectsdev/codegen-ts — DO NOT EDIT.
 // Source metadata: Purchase (Purchase)
 // Customize via Purchase.extra.ts in this directory.
-import { InferInsertModel, InferSelectModel, relations } from "drizzle-orm";
 import {
-  AnyPgColumn,
+  type InferInsertModel,
+  type InferSelectModel,
+  relations,
+} from "drizzle-orm";
+import {
+  type AnyPgColumn,
   bigint,
   bigserial,
   integer,

server/typescript/packages/codegen-ts/test/golden/__snapshots__/postgres/Subscriber.ts

@@ -1,7 +1,7 @@
 // @generated by @metaobjectsdev/codegen-ts — DO NOT EDIT.
 // Source metadata: Subscriber (Subscriber)
 // Customize via Subscriber.extra.ts in this directory.
-import { InferInsertModel, InferSelectModel } from "drizzle-orm";
+import type { InferInsertModel, InferSelectModel } from "drizzle-orm";
 import {
   bigserial,
   boolean,