Add StringExample for easier examples of String properties

Author: bherbst

src/main/kotlin/com/papsign/ktor/openapigen/annotations/type/string/example/StringExample.kt

@@ -0,0 +1,10 @@
+package com.papsign.ktor.openapigen.annotations.type.string.example
+
+import com.papsign.ktor.openapigen.schema.processor.SchemaProcessorAnnotation
+
+/**
+ * Provide examples for a String property
+ */
+@Target(AnnotationTarget.PROPERTY)
+@SchemaProcessorAnnotation(StringExampleProcessor::class)
+annotation class StringExample(vararg val examples: String)

src/main/kotlin/com/papsign/ktor/openapigen/annotations/type/string/example/StringExampleProcessor.kt

@@ -0,0 +1,23 @@
+package com.papsign.ktor.openapigen.annotations.type.string.example
+
+import com.papsign.ktor.openapigen.model.schema.SchemaModel
+import com.papsign.ktor.openapigen.schema.processor.SchemaProcessor
+import kotlin.reflect.KType
+
+object StringExampleProcessor: SchemaProcessor<StringExample> {
+    override fun process(model: SchemaModel<*>, type: KType, annotation: StringExample): SchemaModel<*> {
+        (model as SchemaModel<String?>).apply {
+            if (annotation.examples.size > 1) {
+                examples = examples?.plus(annotation.examples) ?: annotation.examples.asList()
+            } else {
+                if (example == null) {
+                    example = annotation.examples.getOrNull(0)
+                } else {
+                    examples = examples?.plus(annotation.examples)
+                }
+            }
+        }
+        return model
+    }
+
+}

src/test/kotlin/TestServer.kt

@@ -31,6 +31,7 @@ import com.papsign.ktor.openapigen.annotations.type.number.ConstraintVialoation
 import com.papsign.ktor.openapigen.annotations.type.number.integer.clamp.Clamp
 import com.papsign.ktor.openapigen.annotations.type.number.integer.max.Max
 import com.papsign.ktor.openapigen.annotations.type.number.integer.min.Min
+import com.papsign.ktor.openapigen.annotations.type.string.example.StringExample
 import io.ktor.application.application
 import io.ktor.application.call
 import io.ktor.application.install
@@ -227,7 +228,7 @@ object TestServer {
     data class NameParam(@HeaderParam("A simple Header Param") @OpenAPIName("X-NAME") val name: String)
 
     @Response("A Response for header param example")
-    data class NameGreetingResponse(val str: String)
+    data class NameGreetingResponse(@StringExample("Hi, John!") val str: String)
 
 
     @Response("A String Response")