Added string length validators, string schemamodel

Author: bargergo

src/main/kotlin/com/papsign/ktor/openapigen/annotations/type/string/length/Length.kt

@@ -0,0 +1,9 @@
+package com.papsign.ktor.openapigen.annotations.type.string.length
+
+import com.papsign.ktor.openapigen.schema.processor.SchemaProcessorAnnotation
+import com.papsign.ktor.openapigen.validation.ValidatorAnnotation
+
+@Target(AnnotationTarget.TYPE, AnnotationTarget.PROPERTY)
+@SchemaProcessorAnnotation(LengthProcessor::class)
+@ValidatorAnnotation(LengthProcessor::class)
+annotation class Length(val min: Int, val max: Int, val message: String = "")

src/main/kotlin/com/papsign/ktor/openapigen/annotations/type/string/length/LengthConstraintProcessor.kt

@@ -0,0 +1,75 @@
+package com.papsign.ktor.openapigen.annotations.type.string.length
+
+import com.papsign.ktor.openapigen.classLogger
+import com.papsign.ktor.openapigen.getKType
+import com.papsign.ktor.openapigen.model.schema.SchemaModel
+import com.papsign.ktor.openapigen.schema.processor.SchemaProcessor
+import com.papsign.ktor.openapigen.validation.Validator
+import com.papsign.ktor.openapigen.validation.ValidatorBuilder
+import java.lang.Exception
+import kotlin.reflect.KType
+import kotlin.reflect.full.withNullability
+
+abstract class LengthConstraintProcessor<A: Annotation>(): SchemaProcessor<A>, ValidatorBuilder<A> {
+
+    private val log = classLogger()
+
+    val types = listOf(getKType<String>().withNullability(true), getKType<String>().withNullability(false))
+
+    abstract fun process(model: SchemaModel.SchemaModelString, annotation: A): SchemaModel.SchemaModelString
+
+    abstract fun getConstraint(annotation: A): LengthConstraint
+
+    private class LengthConstraintValidator(private val constraint: LengthConstraint): Validator {
+        override fun <T> validate(subject: T?): T? {
+            if (subject is String?) {
+                val value = subject?.length ?: 0
+                if (constraint.min != null) {
+                    if (value < constraint.min) throw LengthConstraintViolation(value, constraint)
+                }
+                if (constraint.max != null) {
+                    if (value > constraint.max) throw LengthConstraintViolation(value, constraint)
+                }
+            } else {
+                throw NotAStringViolation(subject)
+            }
+            return subject
+        }
+    }
+
+    override fun build(type: KType, annotation: A): Validator {
+        return if (types.contains(type)) {
+            LengthConstraintValidator(getConstraint(annotation))
+        } else {
+            error("${annotation::class} can only be used on types: $types")
+        }
+    }
+
+    override fun process(model: SchemaModel<*>, type: KType, annotation: A): SchemaModel<*> {
+        return if (model is SchemaModel.SchemaModelString && types.contains(type)) {
+            process(model, annotation)
+        } else {
+            log.warn("${annotation::class} can only be used on types: $types")
+            model
+        }
+    }
+}
+
+data class LengthConstraint(val min: Int? = null, val max: Int? = null, val errorMessage: String? = null)
+
+open class ConstraintViolation(message: String, cause: Throwable? = null): Exception(message, cause)
+
+class LengthConstraintViolation(val actual: Number?, val constraint: LengthConstraint): ConstraintViolation(constraint.errorMessage ?: "Constraint violation: the length of the string should be ${
+{
+    val min = "${constraint.min}"
+    val max = "${constraint.max}"
+    when {
+        constraint.min != null && constraint.max != null -> "between $min and $max"
+        constraint.min != null -> "at least $min"
+        constraint.max != null -> "at most $max"
+        else -> "anything"
+    }
+}()
+}, but it is $actual")
+
+class NotAStringViolation(val value: Any?): ConstraintViolation("Constraint violation: $value is not a string")

src/main/kotlin/com/papsign/ktor/openapigen/annotations/type/string/length/LengthProcessor.kt

@@ -0,0 +1,17 @@
+package com.papsign.ktor.openapigen.annotations.type.string.length
+
+import com.papsign.ktor.openapigen.model.schema.SchemaModel
+
+object LengthProcessor : LengthConstraintProcessor<Length>() {
+    override fun process(model: SchemaModel.SchemaModelString, annotation: Length): SchemaModel.SchemaModelString {
+        return model.apply {
+            maxLength = annotation.max
+            minLength = annotation.min
+        }
+    }
+
+    override fun getConstraint(annotation: Length): LengthConstraint {
+        val errorMessage = if (annotation.message.isNotEmpty()) annotation.message else null
+        return LengthConstraint(min = annotation.min, max = annotation.max, errorMessage = errorMessage)
+    }
+}

src/main/kotlin/com/papsign/ktor/openapigen/annotations/type/string/length/MaxLength.kt

@@ -0,0 +1,9 @@
+package com.papsign.ktor.openapigen.annotations.type.string.length
+
+import com.papsign.ktor.openapigen.schema.processor.SchemaProcessorAnnotation
+import com.papsign.ktor.openapigen.validation.ValidatorAnnotation
+
+@Target(AnnotationTarget.TYPE, AnnotationTarget.PROPERTY)
+@SchemaProcessorAnnotation(LengthProcessor::class)
+@ValidatorAnnotation(LengthProcessor::class)
+annotation class MaxLength(val value: Int, val message: String = "")

src/main/kotlin/com/papsign/ktor/openapigen/annotations/type/string/length/MaxLengthProcessor.kt

@@ -0,0 +1,16 @@
+package com.papsign.ktor.openapigen.annotations.type.string.length
+
+import com.papsign.ktor.openapigen.model.schema.SchemaModel
+
+object MaxLengthProcessor : LengthConstraintProcessor<MaxLength>() {
+    override fun process(model: SchemaModel.SchemaModelString, annotation: MaxLength): SchemaModel.SchemaModelString {
+        return model.apply {
+            maxLength = annotation.value
+        }
+    }
+
+    override fun getConstraint(annotation: MaxLength): LengthConstraint {
+        val errorMessage = if (annotation.message.isNotEmpty()) annotation.message else null
+        return LengthConstraint(max = annotation.value, errorMessage = errorMessage)
+    }
+}

src/main/kotlin/com/papsign/ktor/openapigen/annotations/type/string/length/MinLength.kt

@@ -0,0 +1,9 @@
+package com.papsign.ktor.openapigen.annotations.type.string.length
+
+import com.papsign.ktor.openapigen.schema.processor.SchemaProcessorAnnotation
+import com.papsign.ktor.openapigen.validation.ValidatorAnnotation
+
+@Target(AnnotationTarget.TYPE, AnnotationTarget.PROPERTY)
+@SchemaProcessorAnnotation(LengthProcessor::class)
+@ValidatorAnnotation(LengthProcessor::class)
+annotation class MinLength(val value: Int, val message: String = "")

src/main/kotlin/com/papsign/ktor/openapigen/annotations/type/string/length/MinLengthProcessor.kt

@@ -0,0 +1,16 @@
+package com.papsign.ktor.openapigen.annotations.type.string.length
+
+import com.papsign.ktor.openapigen.model.schema.SchemaModel
+
+object MinLengthProcessor : LengthConstraintProcessor<MinLength>() {
+    override fun process(model: SchemaModel.SchemaModelString, annotation: MinLength): SchemaModel.SchemaModelString {
+        return model.apply {
+            minLength = annotation.value
+        }
+    }
+
+    override fun getConstraint(annotation: MinLength): LengthConstraint {
+        val errorMessage = if (annotation.message.isNotEmpty()) annotation.message else null
+        return LengthConstraint(min = annotation.value, errorMessage = errorMessage)
+    }
+}

src/main/kotlin/com/papsign/ktor/openapigen/model/schema/SchemaModel.kt

@@ -60,6 +60,18 @@ sealed class SchemaModel<T>: DataModel {
         override var description: String? = null
     ) : SchemaModel<T>()
 
+    data class SchemaModelString(
+        var type: DataType? = null,
+        var format: DataFormat? = null,
+        var nullable: Boolean = false,
+        var minLength: Int? = null,
+        var maxLength: Int? = null,
+        var pattern: String? = null,
+        override var example: String? = null,
+        override var examples: List<String>? = null,
+        override var description: String? = null
+    ) : SchemaModel<String>()
+
     data class SchemaModelRef<T>(override val `$ref`: String) : SchemaModel<T>(), RefModel<SchemaModel<T>> {
         override var example: T? = null
         override var examples: List<T>? = null