import { describe, it, expect } from 'vitest'
import { safeErrorMessage } from './safe-error-message'

describe('safeErrorMessage', () => {
  it('extracts the message from an Error', () => {
    expect(safeErrorMessage(new Error('boom'))).toBe('boom')
  })

  it('stringifies non-Error values', () => {
    expect(safeErrorMessage('plain string')).toBe('plain string')
    expect(safeErrorMessage(42)).toBe('42')
  })

  it('never throws for a throwing toString()', () => {
    const evil = {
      toString(): string {
        throw new Error('poisoned toString')
      }
    }
    expect(safeErrorMessage(evil)).toBe('Unreadable error object')
  })

  it('never throws for a poisoned message getter', () => {
    const evil = new Error('real')
    Object.defineProperty(evil, 'message', {
      get() {
        throw new Error('poisoned message')
      }
    })
    expect(safeErrorMessage(evil)).toBe('Unreadable error object')
  })

  it('caps a huge message so dedup keys stay bounded', () => {
    const out = safeErrorMessage(new Error('x'.repeat(10_000)))
    expect(out).toHaveLength(500)
  })
})