Safe Internet Access Checker

SafeInternetAccessChecker is a Detekt rule designed to enforce safe internet access in Kotlin applications. It is implemented based on the notion of an effect system, a static system used to track the side effects of functions. It ensures that risky internet connection function calls do not exist inside targeted functions.

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Checking Rules:

The checker operates using an effect system consisting of two effects:

1. @Safe (Default Effect)

   • All functions are assumed safe unless explicitly annotated otherwise.
   • No internet connection or only safe calls are present.

2. @HasRiskyInternetConnection (Explicit Effect)

   • Contain function calls that initiate internet connections without exception handling.
   • Must be explicitly marked by the developer.

The core rule of this checker is:

Inside @Safe functions, there should be no calls to @HasRiskyInternetConnection functions without a try-catch block.

This ensures that risky internet operations are either explicitly handled or safely encapsulated, reducing the likelihood of unhandled network errors.

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Example Usage

import java.io.IOException
import java.net.URL
import java.net.URLConnection

// Risky function without try-catch - should be marked with @HasRiskyInternetConnection
@HasRiskyInternetConnection
fun fetchDataFromAPI() {
    val url = URL("https://example.com")
    val connection: URLConnection = url.openConnection()
    connection.connect()
}

// Safe function with proper try-catch handling
fun fetchDataSafely() {
    try {
        val url = URL("https://example.com")
        val connection: URLConnection = url.openConnection()
        connection.connect()
    } catch (e: IOException) {
        println("Connection failed: ${e.message}")
    }
}

fun main() {
    fetchDataFromAPI() // 🚨 The checker will flag this as unsafe and raise a warning.
}

fun processDataSafely() {
    fetchDataSafely() // ✅ This is safe and does not trigger a warning
}

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Usage Instructions

Step 1: Add Dependencies

To begin with, add Detekt to your project.

To use this checker, add the following to your settings.gradle.kts file:

dependencyResolutionManagement {
    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
    repositories {
        mavenCentral()
        maven { url 'https://jitpack.io' }
    }
}

Then, add the dependency to your build.gradle.kts:

dependencies {
   detektPlugins("com.github.LoiNguyenCS:SafeInternetAccessChecker:v1.2.4") 
   compileOnly("com.github.LoiNguyenCS:SafeInternetAccessChecker:v1.2.4")
}

Step 2: Configure Detekt

Add the following to your detekt.yml configuration file in order for Detekt to apply the checker:

SafeInternetAccessRule:
  ConnectToInternetEffectRule:
    active: true

Step 3: Annotate Your Functions

Mark functions that initiate internet connections without proper error handling with @HasRiskyInternetConnection. Keep in mind that Detekt is a static analysis tool and cannot handle dependency injection, so annotate functions broadly, particularly the root-level ones.

Step 4: Run Detekt

Execute the following command to analyze your project and see the report:

./gradlew detektMain

Example Project:

To see an example of how an Android project can be configured and annotated to apply SafeInternetAccessChecker, consult the internet-unsafe branch of this project.

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Summary

✅ Ensures safer internet connections in critical functions.
✅ Uses a lightweight annotation-based effect system.

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Future Work

To reduce the burden of manually annotating functions, we plan to develop an effect inference algorithm. This algorithm will automatically infer the appropriate effect annotations for some functions, reducing developer effort.