fix: custom nullable column (#419)

* fix: custom nullable column

* rename

* format

Author: Newbie012

.changeset/stale-signs-bow.md

@@ -0,0 +1,5 @@
+---
+"@ts-safeql/eslint-plugin": patch
+---
+
+fixed an issue with nullable custom types in insert statements

packages/eslint-plugin/src/rules/check-sql.test.ts

@@ -144,6 +144,10 @@ const runMigrations1 = <TTypes extends Record<string, unknown>>(sql: Sql<TTypes>
     CREATE TABLE test_nullable_boolean (
       colname BOOLEAN
     );
+
+    CREATE TABLE test_nullable_timestamptz (
+      colname TIMESTAMPTZ
+    );
 `);
 
 RuleTester.describe("check-sql", () => {
@@ -1225,16 +1229,48 @@ RuleTester.describe("check-sql", () => {
           type Meta = { is_test: boolean; };
           type Caregiver = { meta: Meta | null };
 
-          await sql<Caregiver[]>\`
-            SELECT
-              CASE WHEN caregiver.id IS NOT NULL
-                THEN jsonb_build_object('is_test', caregiver.first_name LIKE '%test%')
-                ELSE NULL
-              END AS meta
-            FROM
-              caregiver
-          \`;
-        `,
+           await sql<Caregiver[]>\`
+             SELECT
+               CASE WHEN caregiver.id IS NOT NULL
+                 THEN jsonb_build_object('is_test', caregiver.first_name LIKE '%test%')
+                 ELSE NULL
+               END AS meta
+             FROM
+               caregiver
+           \`;
+         `,
+      },
+      {
+        name: 'insert with custom type { timestamptz: "Instant" }',
+        options: withConnection(connections.withTag, {
+          overrides: { types: { timestamptz: "Instant" } },
+        }),
+        code: `
+          class Instant {}
+          function foo(instant: Instant | null) {
+            sql<{ colname: Instant | null }>\`
+              INSERT INTO test_nullable_timestamptz (colname)
+              VALUES (\${instant})
+              RETURNING *
+            \`
+          }
+         `,
+      },
+      {
+        name: 'insert with custom type { timestamptz: "Instant" } - property access',
+        options: withConnection(connections.withTag, {
+          overrides: { types: { timestamptz: "Instant" } },
+        }),
+        code: `
+          class Instant {}
+          function foo(x: { instant: Instant | null }) {
+            sql<{ colname: Instant | null }>\`
+              INSERT INTO test_nullable_timestamptz (colname)
+              VALUES (\${x.instant})
+              RETURNING *
+            \`
+          }
+         `,
       },
     ],
     invalid: [

packages/eslint-plugin/src/utils/ts-pg.utils.ts

@@ -267,6 +267,12 @@ function getPgTypeFromTsType(params: {
     const symbolType = checker.getTypeOfSymbolAtLocation(symbol!, node);
 
     if (TSUtils.isTsUnionType(symbolType)) {
+      // If union is X | null, continue with X
+      const nonNullTypes = symbolType.types.filter((t) => t.flags !== ts.TypeFlags.Null);
+      if (nonNullTypes.length === 1) {
+        return checkType({ checker, type: nonNullTypes[0], options });
+      }
+
       return getPgTypeFromTsTypeUnion({ types: symbolType.types });
     }
 
@@ -316,9 +322,17 @@ function getPgTypeFromTsType(params: {
   // Handle union types
   if (TSUtils.isTsUnionType(type)) {
     const matchingType = type.types.find((t) => t.flags in tsFlagToPgTypeMap);
-    return matchingType
-      ? E.right({ kind: "cast", cast: tsFlagToPgTypeMap[matchingType.flags] })
-      : E.left("Unsupported union type");
+    if (matchingType) {
+      return E.right({ kind: "cast", cast: tsFlagToPgTypeMap[matchingType.flags] });
+    }
+
+    // If union is X | null, continue with X
+    const nonNullTypes = type.types.filter((t) => t.flags !== ts.TypeFlags.Null);
+    if (nonNullTypes.length === 1) {
+      return checkType({ checker, type: nonNullTypes[0], options });
+    }
+
+    return E.left("Unsupported union type");
   }
 
   return checkType({ checker, type, options });