[Bug] TypeError: undefined is not an object (evaluating 'auth.type')

[randomm]

Problem

Runtime error when accessing auth.type on undefined auth object:

TypeError: undefined is not an object (evaluating 'auth.type')

This error appears repeatedly in the TUI, blocking normal operation.

Root Cause

Code is accessing auth.type without first checking if auth is defined. This is different from issue #37 (race condition) - this is a simple null check missing.

Reproduction

1. Start opencode TUI
2. Error appears in output

Fix Required

Add null/undefined checks before accessing auth.type:

// Before (broken)
if (auth.type === "something")

// After (safe)
if (auth?.type === "something")

Files to Check

• packages/opencode/src/auth/
• packages/opencode/src/provider/
• Any code that reads auth configuration

Priority

Critical - Blocks normal TUI operation

Related

• [Bug] Race condition in auth.json causes provider credentials to disappear #37 (different bug - race condition, already fixed)

[randomm]

Fixed in PR #51 via commit c7fbf11. Comprehensive null checks added:

• Zod validation: .int().nonnegative() for method index
• Bounds check: input.method >= auth.methods.length
• Null check: if (!method) return undefined
• Property checks: if ('key' in result && result.key)

Adversarial review passed with no critical issues.