Error Handling Patterns

Patterns for detecting, reporting, and recovering from failures.

Core Principle

Fail fast on precondition failures. Degrade gracefully on runtime failures.

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Overview

Error handling is about when and how your automation responds to problems.

Pattern	When to Use	Strategy
Fail Fast	Invalid input, missing config	Stop immediately, report clearly
Prerequisite Checks	Complex preconditions	Validate all upfront before work
Graceful Degradation	Fallbacks exist	Degrade to safer state, continue

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Decision Flow

flowchart TD
    A[Error Detected] --> B{Can recover?}
    B -->|No| C[Fail Fast]
    B -->|Yes| D{Before work started?}
    D -->|Yes| E[Prerequisite Check]
    D -->|No| F[Graceful Degradation]

    %% Ghostty Hardcore Theme
    style A fill:#f92572,color:#1b1d1e
    style B fill:#fd971e,color:#1b1d1e
    style C fill:#f92572,color:#1b1d1e
    style D fill:#fd971e,color:#1b1d1e
    style E fill:#65d9ef,color:#1b1d1e
    style F fill:#a7e22e,color:#1b1d1e

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Quick Reference

Scenario	Pattern	Reasoning
Missing required config	Fail Fast	Can't continue safely
Invalid user input	Fail Fast	User error, report immediately
Complex deployment requirements	Prerequisite Checks	Validate tools, access, state
API timeout	Graceful Degradation	Retry or use backup
Service unavailable	Graceful Degradation	Fall back to alternatives

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Fail fast when you can't recover. Degrade gracefully when you can.

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