fix: handle BigInt correctly. (#16640)

Co-authored-by: Chris Breiding <chrisbreiding@users.noreply.github.com>

packages/driver/cypress/integration/commands/assertions_spec.js

@@ -848,6 +848,20 @@ describe('src/cy/commands/assertions', () => {
       })
     })
 
+    // https://github.com/cypress-io/cypress/issues/16570
+    it('handles BigInt correctly', (done) => {
+      cy.on('log:added', (attrs, log) => {
+        if (attrs.name === 'assert') {
+          cy.removeAllListeners('log:added')
+          expect(log.get('message')).to.eq('expected **2n** to equal **2n**')
+
+          done()
+        }
+      })
+
+      expect(2n).to.equal(2n)
+    })
+
     it('#consoleProps for regular objects', (done) => {
       cy.on('log:added', (attrs, log) => {
         if (attrs.name === 'assert') {

packages/driver/src/cy/chai/inspect.js

@@ -255,6 +255,10 @@ module.exports = {
 
         case 'symbol':
           return ctx.stylize(value.toString(), 'symbol')
+
+        case 'bigint':
+          return ctx.stylize(`${value.toString() }n`, 'bigint')
+
         default:
           null
       }