From cdf2eead7ebd9f14e0c20e7e23fa605ad2b8d181 Mon Sep 17 00:00:00 2001
From: EmaToplek <toplek.ema0213@outlook.com>
Date: Fri, 21 Aug 2026 08:32:50 +0200
Subject: [PATCH] test: add coverage for lower-sql-plan.ts literal-unwrap and
 bind-site guard paths

Signed-off-by: EmaToplek <toplek.ema0213@outlook.com>
---
 .../5-runtime/test/lower-sql-plan.test.ts     | 73 +++++++++++++++++++
 packages/2-sql/5-runtime/vitest.config.ts     |  1 -
 2 files changed, 73 insertions(+), 1 deletion(-)
 create mode 100644 packages/2-sql/5-runtime/test/lower-sql-plan.test.ts

diff --git a/packages/2-sql/5-runtime/test/lower-sql-plan.test.ts b/packages/2-sql/5-runtime/test/lower-sql-plan.test.ts
new file mode 100644
index 000000000000..a0d2401e132e
--- /dev/null
+++ b/packages/2-sql/5-runtime/test/lower-sql-plan.test.ts
@@ -0,0 +1,73 @@
+import {
+  BinaryExpr,
+  ColumnRef,
+  ParamRef,
+  PreparedParamRef,
+  ProjectionItem,
+  SelectAst,
+  TableSource,
+} from '@internal/sql-relational-core/ast';
+import type { SqlQueryPlan } from '@internal/sql-relational-core/plan';
+import { describe, expect, it } from 'vitest';
+import { lowerSqlPlan } from '../src/lower-sql-plan';
+import { createStubAdapter, createTestContract } from './utils';
+
+const testContract = createTestContract({ targetFamily: 'sql', target: 'postgres' });
+
+const meta = {
+  target: testContract.target,
+  storageHash: testContract.storage.storageHash,
+  lane: 'dsl' as const,
+};
+
+function buildLiteralPlan(): SqlQueryPlan<{ id: number }> {
+  const users = TableSource.named('users');
+  const ast = SelectAst.from(users)
+    .withProjection([
+      ProjectionItem.of('id', ColumnRef.of('id', 'users'), { codecId: 'pg/int4@1' }),
+    ])
+    .withWhere(
+      BinaryExpr.eq(
+        ColumnRef.of('id', 'users'),
+        ParamRef.of(42, { codec: { codecId: 'pg/int4@1' } }),
+      ),
+    );
+  return Object.freeze({ ast, params: [42], meta });
+}
+
+function buildBindSitePlan(): SqlQueryPlan<{ id: number }> {
+  const users = TableSource.named('users');
+  const ast = SelectAst.from(users)
+    .withProjection([
+      ProjectionItem.of('id', ColumnRef.of('id', 'users'), { codecId: 'pg/int4@1' }),
+    ])
+    .withWhere(
+      BinaryExpr.eq(
+        ColumnRef.of('id', 'users'),
+        PreparedParamRef.of('userId', { codecId: 'pg/int4@1' }),
+      ),
+    );
+  return Object.freeze({ ast, params: [undefined], meta });
+}
+
+describe('lowerSqlPlan', () => {
+  it('unwraps literal slots into a bare-value params array and freezes the result', () => {
+    const adapter = createStubAdapter();
+    const plan = lowerSqlPlan(adapter, testContract, buildLiteralPlan());
+
+    expect(plan.params).toEqual([42]);
+    expect(plan.ast).toBeDefined();
+    expect(plan.meta).toEqual(meta);
+    expect(Object.isFrozen(plan)).toBe(true);
+  });
+
+  it('throws RUNTIME.PREPARE_BIND_ON_ADHOC when a bind-site slot reaches the ad-hoc path', () => {
+    const adapter = createStubAdapter();
+    expect(() => lowerSqlPlan(adapter, testContract, buildBindSitePlan())).toThrowError(
+      expect.objectContaining({
+        code: 'RUNTIME.PREPARE_BIND_ON_ADHOC',
+        details: expect.objectContaining({ name: 'userId' }),
+      }),
+    );
+  });
+});
diff --git a/packages/2-sql/5-runtime/vitest.config.ts b/packages/2-sql/5-runtime/vitest.config.ts
index de0b9e499b71..64e635b6831c 100644
--- a/packages/2-sql/5-runtime/vitest.config.ts
+++ b/packages/2-sql/5-runtime/vitest.config.ts
@@ -18,7 +18,6 @@ export default defineConfig({
         '**/*.test-d.ts',
         '**/*.config.ts',
         '**/exports/**',
-        'src/lower-sql-plan.ts', // TODO(TML-1786): Add tests - currently 0% coverage
         'src/codecs/encoding.ts', // TODO(TML-1786): Add tests - currently 6% coverage
         'src/codecs/decoding.ts', // TODO(TML-1786): Add tests - currently 33% coverage
         'src/codecs/validation.ts', // TODO(TML-1786): Add tests - currently 50% coverage