Add function and lambda accessor syntax (#65)

Co-authored-by: David Hoepelman <dhoepelman@flexport.com>
Co-authored-by: Jilles van Gurp <jillesvangurp@users.noreply.github.com>
Co-authored-by: David Hoepelman <992153+dhoepelman@users.noreply.github.com>

README.md

@@ -35,7 +35,7 @@ dependencies {
 
 Suppose you have a data class like this:
 
-```Kotlin
+```kotlin
 data class UserProfile(
  val fullName: String,
  val age: Int?
@@ -44,7 +44,7 @@ data class UserProfile(
 
 Using the Konform type-safe DSL you can quickly write up a validation
 
-```Kotlin
+```kotlin
 val validateUser = Validation<UserProfile> {
  UserProfile::fullName {
  minLength(2)
@@ -60,14 +60,14 @@ val validateUser = Validation<UserProfile> {
 
 and apply it to your data
 
-```Kotlin
+```kotlin
 val invalidUser = UserProfile("A", -1)
 val validationResult = validateUser(invalidUser)
 ```
 
 since the validation fails the `validationResult` will be of type `Invalid` and you can get a list of validation errors by indexed access:
 
-```Kotlin
+```kotlin
 validationResult[UserProfile::fullName]
 // yields listOf("must have at least 2 characters")
 
@@ -77,7 +77,7 @@ validationResult[UserProfile::age]
 
 or you can get all validation errors with details as a list:
 
-```Kotlin
+```kotlin
 validationResult.errors
 // yields listOf(
 // ValidationError(dataPath=.fullName, message=must have at least 2 characters),
@@ -87,19 +87,19 @@ validationResult.errors
 
 In case the validation went through successfully you get a result of type `Valid` with the validated value in the `value` field.
 
-```Kotlin
+```kotlin
 val validUser = UserProfile("Alice", 25)
 val validationResult = validateUser(validUser)
 // yields Valid(UserProfile("Alice", 25))
 ```
 
-### Advanced use
+### Detailed usage
 
 #### Hints
 
 You can add custom hints to validations
 
-```Kotlin
+```kotlin
 val validateUser = Validation<UserProfile> {
  UserProfile::age ifPresent {
  minimum(0) hint "Registering before birth is not supported"
@@ -109,7 +109,7 @@ val validateUser = Validation<UserProfile> {
 
 You can use `{value}` to include the `.toString()`-ed data in the hint
 
-```Kotlin
+```kotlin
 val validateUser = Validation<UserProfile> {
  UserProfile::fullName {
  minLength(2) hint "'{value}' is too short a name, must be at least 2 characters long."
@@ -119,40 +119,61 @@ val validateUser = Validation<UserProfile> {
 
 #### Custom validations
 
-You can add custom validations by using `addConstraint`
+You can add custom validations on properties by using `addConstraint`
 
-```Kotlin
+```kotlin
 val validateUser = Validation<UserProfile> {
  UserProfile::fullName {
  addConstraint("Name cannot contain a tab") { !it.contains("\t") }
  }
 }
 ```
 
-#### Nested validations
+You can transform data and then add a validation on the result
 
-You can define validations for nested classes and use them for new validations
+```kotlin
+val validateUser = Validation<UserProfile> {
+ validate("trimmedName", { it.fullName.trim() }) {
+ minLength(5)
+ }
+ // This also required and ifPresent for nullable values
+ required("yourName", /* ...*/) {
+ // your validations, giving an error out if the result is null
+ }
+ ifPresent("yourName", /* ... */) {
+ // your validations, only running if the result is not null
+ }
+}
+```
+
+#### Split validations
 
-```Kotlin
-val ageCheck = Validation<UserProfile> {
- UserProfile::age required {
- minimum(18)
+You can define validations separately and run them from other validations
+
+```kotlin
+val ageCheck = Validation<Int?> {
+ required {
+ minimum(21)
  }
 }
 
 val validateUser = Validation<UserProfile> {
- UserProfile::fullName {
- minLength(2)
- maxLength(100)
+ UserProfile::age {
+ run(ageCheck)
  }
 
- run(ageCheck)
+ // You can also transform the data and then run a validation against the result
+ validate("ageMinus10", { it.age?.let { age -> age - 10 } }) {
+ run(ageCheck)
+ }
 }
 ```
 
+#### Collections
+
 It is also possible to validate nested data classes and properties that are collections (List, Map, etc...)
 
-```Kotlin
+```kotlin
 data class Person(val name: String, val email: String?, val age: Int)
 
 data class Event(
@@ -206,7 +227,7 @@ val validateEvent = Validation<Event> {
 Errors in the `ValidationResult` can also be accessed using the index access method. In case of `Iterables` and `Arrays` you use the
 numerical index and in case of `Maps` you use the key as string.
 
-```Kotlin
+```kotlin
 // get the error messages for the first attendees age if any
 result[Event::attendees, 0, Person::age]
 

build.gradle.kts

@@ -1,7 +1,9 @@
+import org.gradle.internal.extensions.stdlib.capitalized
 import org.jetbrains.kotlin.cli.common.toBooleanLenient
 import org.jetbrains.kotlin.gradle.ExperimentalKotlinGradlePluginApi
 import org.jetbrains.kotlin.gradle.ExperimentalWasmDsl
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+import org.jetbrains.kotlin.gradle.testing.internal.KotlinTestReport
 
 val projectName = "konform"
 val projectGroup = "io.konform"
@@ -95,6 +97,14 @@ kotlin {
  //endregion
 
  sourceSets {
+ val kotestSupported =
+ listOf(
+ appleTest,
+ jsTest,
+ jvmTest,
+ nativeTest,
+ wasmJsTest,
+ )
  // Shared dependencies
  commonMain.dependencies {
  api(kotlin("stdlib"))
@@ -104,9 +114,13 @@ kotlin {
  implementation(kotlin("test"))
  // implementation(kotlin("test-annotations-common"))
  // implementation(kotlin("test-common"))
- // implementation(libs.kotest.assertions.core)
- // implementation(libs.kotest.framework.datatest)
- // implementation(libs.kotest.framework.engine)
+ }
+ kotestSupported.forEach {
+ it.dependencies {
+ implementation(libs.kotest.assertions.core)
+ // implementation(libs.kotest.framework.datatest)
+ // implementation(libs.kotest.framework.engine)
+ }
  }
  jvmTest.dependencies {
  // implementation(libs.kotest.runner.junit5)
@@ -132,6 +146,24 @@ tasks.named<Test>("jvmTest") {
  exceptionFormat = org.gradle.api.tasks.testing.logging.TestExceptionFormat.FULL
  }
 }
+// Disable test tasks for the unsupported source sets
+val kotestUnsupported =
+ listOf(
+ "wasmWasi",
+ )
+kotestUnsupported.forEach {
+ // Disable tests for targets kotest doesn't support yet
+
+ val capitalized = it.capitalized()
+ tasks.named("compileTestKotlin$capitalized") {
+ enabled = false
+ }
+
+ tasks.named<KotlinTestReport>("${it}Test") {
+ enabled = false
+ }
+}
+
 //endregion
 
 //region Publishing configuration

src/commonMain/kotlin/io/konform/validation/ValidationBuilder.kt

@@ -7,6 +7,7 @@ import io.konform.validation.internal.OptionalValidation
 import io.konform.validation.internal.RequiredValidation
 import io.konform.validation.internal.ValidationBuilderImpl
 import kotlin.jvm.JvmName
+import kotlin.reflect.KFunction1
 import kotlin.reflect.KProperty1
 
 @DslMarker
@@ -24,48 +25,106 @@ public abstract class ValidationBuilder<T> {
 
  public abstract infix fun Constraint<T>.hint(hint: String): Constraint<T>
 
- public abstract operator fun <R> KProperty1<T, R>.invoke(init: ValidationBuilder<R>.() -> Unit)
-
  internal abstract fun <R> onEachIterable(
- prop: KProperty1<T, Iterable<R>>,
+ name: String,
+ prop: (T) -> Iterable<R>,
  init: ValidationBuilder<R>.() -> Unit,
  )
 
- @JvmName("onEachIterable")
- public infix fun <R> KProperty1<T, Iterable<R>>.onEach(init: ValidationBuilder<R>.() -> Unit): Unit = onEachIterable(this, init)
-
  internal abstract fun <R> onEachArray(
- prop: KProperty1<T, Array<R>>,
+ name: String,
+ prop: (T) -> Array<R>,
  init: ValidationBuilder<R>.() -> Unit,
  )
 
- @JvmName("onEachArray")
- public infix fun <R> KProperty1<T, Array<R>>.onEach(init: ValidationBuilder<R>.() -> Unit): Unit = onEachArray(this, init)
-
  internal abstract fun <K, V> onEachMap(
- prop: KProperty1<T, Map<K, V>>,
+ name: String,
+ prop: (T) -> Map<K, V>,
  init: ValidationBuilder<Map.Entry<K, V>>.() -> Unit,
  )
 
+ @JvmName("onEachIterable")
+ public infix fun <R> KProperty1<T, Iterable<R>>.onEach(init: ValidationBuilder<R>.() -> Unit): Unit = onEachIterable(name, this, init)
+
+ @JvmName("onEachIterable")
+ public infix fun <R> KFunction1<T, Iterable<R>>.onEach(init: ValidationBuilder<R>.() -> Unit): Unit =
+ onEachIterable("$name()", this, init)
+
+ @JvmName("onEachArray")
+ public infix fun <R> KProperty1<T, Array<R>>.onEach(init: ValidationBuilder<R>.() -> Unit): Unit = onEachArray(name, this, init)
+
+ @JvmName("onEachArray")
+ public infix fun <R> KFunction1<T, Array<R>>.onEach(init: ValidationBuilder<R>.() -> Unit): Unit = onEachArray("$name()", this, init)
+
  @JvmName("onEachMap")
  public infix fun <K, V> KProperty1<T, Map<K, V>>.onEach(init: ValidationBuilder<Map.Entry<K, V>>.() -> Unit): Unit =
- onEachMap(this, init)
+ onEachMap(name, this, init)
+
+ @JvmName("onEachMap")
+ public infix fun <K, V> KFunction1<T, Map<K, V>>.onEach(init: ValidationBuilder<Map.Entry<K, V>>.() -> Unit): Unit =
+ onEachMap("$name()", this, init)
 
- public abstract infix fun <R> KProperty1<T, R?>.ifPresent(init: ValidationBuilder<R>.() -> Unit)
+ public operator fun <R> KProperty1<T, R>.invoke(init: ValidationBuilder<R>.() -> Unit): Unit = validate(name, this, init)
 
- public abstract infix fun <R> KProperty1<T, R?>.required(init: ValidationBuilder<R>.() -> Unit)
+ public operator fun <R> KFunction1<T, R>.invoke(init: ValidationBuilder<R>.() -> Unit): Unit = validate("$name()", this, init)
 
+ public infix fun <R> KProperty1<T, R?>.ifPresent(init: ValidationBuilder<R>.() -> Unit): Unit = ifPresent(name, this, init)
+
+ public infix fun <R> KFunction1<T, R?>.ifPresent(init: ValidationBuilder<R>.() -> Unit): Unit = ifPresent("$name()", this, init)
+
+ public infix fun <R> KProperty1<T, R?>.required(init: ValidationBuilder<R>.() -> Unit): Unit = required(name, this, init)
+
+ public infix fun <R> KFunction1<T, R?>.required(init: ValidationBuilder<R>.() -> Unit): Unit = required("$name()", this, init)
+
+ /**
+ * Calculate a value from the input and run a validation on it.
+ * @param name The name that should be reported in validation errors. Must be a valid kotlin name, optionally followed by ().
+ * @param f The function for which you want to validate the result of
+ * @see run
+ */
+ public abstract fun <R> validate(
+ name: String,
+ f: (T) -> R,
+ init: ValidationBuilder<R>.() -> Unit,
+ )
+
+ /**
+ * Calculate a value from the input and run a validation on it, but only if the value is not null.
+ */
+ public abstract fun <R> ifPresent(
+ name: String,
+ f: (T) -> R?,
+ init: ValidationBuilder<R>.() -> Unit,
+ )
+
+ /**
+ * Calculate a value from the input and run a validation on it, and give an error if the result is null.
+ */
+ public abstract fun <R> required(
+ name: String,
+ f: (T) -> R?,
+ init: ValidationBuilder<R>.() -> Unit,
+ )
+
+ /** Run an arbitrary other validation. */
  public abstract fun run(validation: Validation<T>)
 
  public abstract val <R> KProperty1<T, R>.has: ValidationBuilder<R>
+ public abstract val <R> KFunction1<T, R>.has: ValidationBuilder<R>
 }
 
+/**
+ * Run a validation if the property is not-null, and allow nulls.
+ */
 public fun <T : Any> ValidationBuilder<T?>.ifPresent(init: ValidationBuilder<T>.() -> Unit) {
  val builder = ValidationBuilderImpl<T>()
  init(builder)
  run(OptionalValidation(builder.build()))
 }
 
+/**
+ * Run a validation on a nullable property, giving an error on nulls.
+ */
 public fun <T : Any> ValidationBuilder<T?>.required(init: ValidationBuilder<T>.() -> Unit) {
  val builder = ValidationBuilderImpl<T>()
  init(builder)
@@ -84,8 +143,7 @@ public fun <S, T : Iterable<S>> ValidationBuilder<T>.onEach(init: ValidationBuil
 public fun <T> ValidationBuilder<Array<T>>.onEach(init: ValidationBuilder<T>.() -> Unit) {
  val builder = ValidationBuilderImpl<T>()
  init(builder)
- @Suppress("UNCHECKED_CAST")
- run(ArrayValidation(builder.build()) as Validation<Array<T>>)
+ run(ArrayValidation(builder.build()))
 }
 
 @JvmName("onEachMap")

src/commonMain/kotlin/io/konform/validation/ValidationResult.kt

@@ -1,6 +1,6 @@
 package io.konform.validation
 
-import kotlin.reflect.KProperty1
+import io.konform.validation.kotlin.Path
 
 public interface ValidationError {
  public val dataPath: String
@@ -43,14 +43,7 @@ public sealed class ValidationResult<out T> {
 public data class Invalid(
  internal val internalErrors: Map<String, List<String>>,
 ) : ValidationResult<Nothing>() {
- override fun get(vararg propertyPath: Any): List<String>? = internalErrors[propertyPath.joinToString("", transform = ::toPathSegment)]
-
- private fun toPathSegment(it: Any): String =
- when (it) {
- is KProperty1<*, *> -> ".${it.name}"
- is Int -> "[$it]"
- else -> ".$it"
- }
+ override fun get(vararg propertyPath: Any): List<String>? = internalErrors[Path.toPath(*propertyPath)]
 
  override val errors: List<ValidationError> by lazy {
  internalErrors.flatMap { (path, errors) ->