fix uuid toString

api/src/values/DuckDBUUIDValue.ts

@@ -6,14 +6,16 @@ export class DuckDBUUIDValue {
   }
 
   public toString(): string {
+    // UUID values are stored with their MSB flipped so their numeric ordering matches their string ordering.
+    const flipped = this.hugeint ^ 0x80000000000000000000000000000000n
     // Truncate to 32 hex digits, then prepend with a hex 1, before converting to a hex string.
     // This ensures the trailing 32 characters are the hex digits we want, left padded with zeros as needed.
-    const hex = ((this.hugeint & 0xffffffffffffffffffffffffffffffffn) | 0x100000000000000000000000000000000n).toString(16);
+    const hex = ((flipped & 0xffffffffffffffffffffffffffffffffn) | 0x100000000000000000000000000000000n).toString(16);
     return `${hex.substring(1, 9)}-${hex.substring(9, 13)}-${hex.substring(13, 17)}-${hex.substring(17, 21)}-${hex.substring(21, 33)}`;
   }
 
-  public static readonly Max = new DuckDBUUIDValue(2n ** 127n - 1n);
-  public static readonly Min = new DuckDBUUIDValue(-(2n ** 127n));
+  public static readonly Max = new DuckDBUUIDValue(2n ** 127n - 1n); //  7fffffffffffffffffffffffffffffff
+  public static readonly Min = new DuckDBUUIDValue(-(2n ** 127n));   //  80000000000000000000000000000000
 }
 
 export function uuidValue(hugeint: bigint): DuckDBUUIDValue {

api/test/api.test.ts

@@ -115,7 +115,6 @@ import {
   timestampTZValue,
   timestampValue,
   unionValue,
-  uuidValue,
   version
 } from '../src';
 
@@ -920,8 +919,8 @@ describe('api', () => {
     assert.equal(unionValue('b', 'duck').toString(), 'duck');
 
     // uuid
-    assert.equal(uuidValue(0n).toString(), '00000000-0000-0000-0000-000000000000');
-    assert.equal(uuidValue(2n ** 128n - 1n).toString(), 'ffffffff-ffff-ffff-ffff-ffffffffffff');
+    assert.equal(DuckDBUUIDValue.Min.toString(), '00000000-0000-0000-0000-000000000000');
+    assert.equal(DuckDBUUIDValue.Max.toString(), 'ffffffff-ffff-ffff-ffff-ffffffffffff');
   });
   test('date isFinite', () => {
     assert.isTrue(DuckDBDateValue.Epoch.isFinite);