keepNanPayloads should look for a sign bit also

Author: hildjj

package.json

@@ -79,7 +79,7 @@
     "c8": "10.1.3",
     "cbor-edn": "0.2.2",
     "eslint": "9.39.2",
-    "eslint-plugin-jsdoc": "62.4.0",
+    "eslint-plugin-jsdoc": "62.4.1",
     "package-extract": "3.1.3",
     "rimraf": "^6.1.2",
     "tsup": "8.5.1",

pnpm-lock.yaml

@@ -228,7 +228,7 @@ export class CBORcontainer {
                 throw new Error(`Invalid NaN encoding: "${u8toHex(buf)}"`);
               }
             } else if (opts.keepNanPayloads) {
-              if (val.payload) {
+              if (val.payload || val.sign === -1) {
                 if (opts.rejectLongFloats && !val.isShortestEncoding) {
                   throw new Error(`NaN should have been encoded shorter: ${value}`);
                 }

src/container.ts

@@ -1,6 +1,7 @@
 import '../lib/types.js';
 import * as cases from './cases.js';
 import {CBORcontainer} from '../lib/container.js';
+import {NAN} from '../lib/float.js';
 import {TAG} from '../lib/constants.js';
 import {Tag} from '../lib/tag.js';
 import assert from 'node:assert/strict';
@@ -235,6 +236,9 @@ test('ignoreGlobalTags', () => {
 });
 
 test('keep nan payloads', () => {
+  testAll([
+    [new NAN(-0), '', 'f9fe00'],
+  ], {keepNanPayloads: true});
   failAll([
     '0xFB7FF1000000000000',
   ], {rejectLongFloats: true, keepNanPayloads: true});