fix(db): dialect helpers dispatch on the platform; lint gate for the repository layer

server/src/db/dialect/sql-functions.ts

@@ -1,13 +1,19 @@
-import { raw, type RawQueryFragment } from '@mikro-orm/core';
+import { raw, type Platform, type RawQueryFragment } from '@mikro-orm/core';
+import { SqlitePlatform } from '@mikro-orm/sql';
 
 /**
  * The only place a repository may spell a database function.
  *
- * Every helper takes an already-qualified column reference (`'t.created_at'`)
- * and returns a fragment for the *current* dialect. The ORM exists so a
- * Postgres driver can follow; when it does, this file gets a second
- * implementation and no repository changes. Values are never interpolated —
- * the day count in `dateAdd` is checked to be an integer before it is spelled.
+ * Every helper takes the MikroORM `Platform` the caller's EntityManager is
+ * running on (`em.getPlatform()`) plus an already-qualified column reference
+ * (`'t.created_at'`), and dispatches on that platform at runtime. TREK ships
+ * one binary and the database is chosen by configuration, so the dialect is a
+ * runtime property of the live connection, not a build-time swap: when the
+ * Postgres driver arrives this file grows a second branch and no repository
+ * changes. An unknown platform fails closed rather than guessing a spelling.
+ *
+ * Values are never interpolated — the day count in `dateAdd` is checked to be
+ * an integer before it is spelled.
  */
 
 function column(ref: string): string {
@@ -17,19 +23,28 @@ function column(ref: string): string {
   return ref;
 }
 
+function unsupported(platform: Platform): never {
+  throw new Error(`sql-functions: no implementation for platform ${platform.constructor.name}`);
+}
+
 /** The calendar date (`YYYY-MM-DD`) of a timestamp column. */
-export function dateOf(ref: string): RawQueryFragment {
-  return raw(`date(${column(ref)})`);
+export function dateOf(platform: Platform, ref: string): RawQueryFragment {
+  if (platform instanceof SqlitePlatform) return raw(`date(${column(ref)})`);
+  return unsupported(platform);
 }
 
 /** The timestamp column shifted by whole days, as a calendar date. */
-export function dateAdd(ref: string, days: number): RawQueryFragment {
+export function dateAdd(platform: Platform, ref: string, days: number): RawQueryFragment {
   if (!Number.isInteger(days)) throw new Error(`sql-functions: dateAdd needs an integer day count, got ${days}`);
-  const sign = days < 0 ? '-' : '+';
-  return raw(`date(${column(ref)}, '${sign}${Math.abs(days)} days')`);
+  if (platform instanceof SqlitePlatform) {
+    const sign = days < 0 ? '-' : '+';
+    return raw(`date(${column(ref)}, '${sign}${Math.abs(days)} days')`);
+  }
+  return unsupported(platform);
 }
 
 /** The database clock, in the same text the column defaults produce. */
-export function currentTimestamp(): RawQueryFragment {
-  return raw('CURRENT_TIMESTAMP');
+export function currentTimestamp(platform: Platform): RawQueryFragment {
+  if (platform instanceof SqlitePlatform) return raw('CURRENT_TIMESTAMP');
+  return unsupported(platform);
 }