feat: Ability to control newline placement around comma when seperating multiple columns/tables

Add option that can control if the newline is present after the comma or before the comma when listing multiple columns/tables

Author: helloswayamshah

test/options/commaNewline.ts

@@ -0,0 +1,37 @@
+import dedent from 'dedent-js';
+
+import { FormatFn } from '../../src/sqlFormatter.js';
+
+export default function supportsCommaNewline(format: FormatFn) {
+  it('by default adds newline after comma', () => {
+    const result = format(`SELECT id, first_name, last_name, email FROM users;`);
+    expect(result).toBe(
+      dedent`
+      SELECT
+        id,
+        first_name,
+        last_name,
+        email
+      FROM
+        users;
+    `
+    );
+  });
+
+  it('supports newline before comma', () => {
+    const result = format(`SELECT id, first_name, last_name, email FROM users;`, {
+      commaNewline: 'before',
+    });
+    expect(result).toBe(
+      dedent`
+      SELECT
+        id
+        , first_name
+        , last_name
+        , email
+      FROM
+        users;
+    `
+    );
+  });
+}