Event Library Helper Plugin

IntelliJ IDEA inspections and quick-fixes for Event Library

This plugin provides compile-time validation, clear diagnostics, and safe quick fixes for Event Library handlers across Kotlin, Java, and Scala 3.

It helps you catch mistakes before runtime, without changing the behavior or design of the Event Library itself.

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✨ Features

✅ @EventHandler Validation

The plugin verifies that every @EventHandler method:

• Has exactly one parameter
• That parameter is assignable to Event
• Returns Unit / void / scala.Unit

Invalid handlers are highlighted with precise error locations.

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✅ @ExceptionHandler Validation

The plugin enforces all supported @ExceptionHandler shapes.

Supported signatures:

@ExceptionHandler
fun onFailure(event: MyEvent, t: Throwable)

@ExceptionHandler
fun onFailure(event: MyEvent)

@ExceptionHandler
fun onFailure(t: Throwable)

What the plugin checks:

• Parameter count must be 1 or 2
• Parameters must be assignable to Event and/or Throwable
• Two-parameter handlers must be ordered as (Event, Throwable)

Smart quick fix:

If parameters are reversed, the plugin offers a safe swap quick fix.

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✏️ Return Type Inspection + Quick Fix

Handlers must not return values.

If a handler returns a value, the plugin reports an error and offers a one-click fix:

Language	Fix
Java	Change return type to void
Kotlin	Remove return type or replace with Unit
Scala 3	Insert or replace return type with Unit

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🌍 Multi-Language Support

Works across:

• Kotlin
• Java
• Scala 3

Inspections and quick fixes are language-aware and highlight the most relevant PSI element.

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🧪 Example

Invalid handler:

@EventHandler
fun onEvent(event: MyEvent): Int {
    return 42
}

Error: > Event Library handler methods must return void / Unit

Quick fix: > Change return type to void / Unit

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📦 Installation

From JetBrains Marketplace:

1. Open Settings / Preferences
2. Go to Plugins
3. Search for Event Library Helper
4. Click Install
5. Restart IDE

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📜 License

Apache 2.0 — see the LICENSE file for details.