How do I add Hilt to a Kotlin project in Android Studio?

I am a beginner with Kotlin and I am following a tutorial that uses Hilt for dependency injection. Even though the tutorial is from 2023, the lines of code used there no longer work for me; I could not find clear instructions on the internet on what to add to which file.

My current version of Kotlin is 232-1.9.0-release-358-AS10227.8.2321.11479570

If it helps, here is what my current build.gradle (Module: app) looks like:

plugins {
    alias(libs.plugins.androidApplication)
    alias(libs.plugins.jetbrainsKotlinAndroid)
}

android {
    namespace = "com.package.myApp"
    compileSdk = 34

    defaultConfig {
        applicationId = "com.package.myApp"
        minSdk = 30
        targetSdk = 34
        versionCode = 1
        versionName = "1.0"

        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
        vectorDrawables {
            useSupportLibrary = true
        }
    }

    buildTypes {
        release {
            isMinifyEnabled = false
            proguardFiles(
                getDefaultProguardFile("proguard-android-optimize.txt"),
                "proguard-rules.pro"
            )
        }
    }
    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_1_8
        targetCompatibility = JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = "1.8"
    }
    buildFeatures {
        compose = true
    }
    composeOptions {
        kotlinCompilerExtensionVersion = "1.5.1"
    }
    packaging {
        resources {
            excludes += "/META-INF/{AL2.0,LGPL2.1}"
        }
    }
}

dependencies {

    implementation(libs.androidx.core.ktx)
    implementation(libs.androidx.lifecycle.runtime.ktx)
    implementation(libs.androidx.activity.compose)
    implementation(platform(libs.androidx.compose.bom))
    implementation(libs.androidx.ui)
    implementation(libs.androidx.ui.graphics)
    implementation(libs.androidx.ui.tooling.preview)
    implementation(libs.androidx.material3)
    implementation(libs.androidx.lifecycle.viewmodel.compose)
    testImplementation(libs.junit)
    androidTestImplementation(libs.androidx.junit)
    androidTestImplementation(libs.androidx.espresso.core)
    androidTestImplementation(platform(libs.androidx.compose.bom))
    androidTestImplementation(libs.androidx.ui.test.junit4)
    debugImplementation(libs.androidx.ui.tooling)
    debugImplementation(libs.androidx.ui.test.manifest)
}

As well as my build.gradle (Project: {app-name}) file:

plugins {
    alias(libs.plugins.androidApplication) apply false
    alias(libs.plugins.jetbrainsKotlinAndroid) apply false
}

Solution

Your project's root build.gradle plugins section needs to have this:

plugins {
  ...
  id 'com.google.dagger.hilt.android' version '2.44' apply false
}
apply plugin: 'dagger.hilt.android.plugin'

Then your app's build.gradle file needs to have this inside depencies:

dependencies {
  implementation "com.google.dagger:hilt-android:$hilt_version"
  implementation "com.google.devtools.ksp:com.google.devtools.ksp.gradle.plugin:<ksp-version>"
}

Lastly, add a ksp {} block under your android {} block:

    ksp { 
arg("dagger.hilt.android.internal.disableAndroidSuperclassValidation", "true")            
        javaSourceCompatibility = "1.8"
      }