Derive schema/property descriptions from KDocs by default

create-plugin/src/main/kotlin/io/github/tabilzad/ktor/KtorDocsCommandLineProcessor.kt

@@ -6,6 +6,7 @@ import io.github.tabilzad.ktor.SwaggerConfigurationKeys.ARG_ENABLED
 import io.github.tabilzad.ktor.SwaggerConfigurationKeys.ARG_FORMAT
 import io.github.tabilzad.ktor.SwaggerConfigurationKeys.ARG_HIDE_PRIVATE
 import io.github.tabilzad.ktor.SwaggerConfigurationKeys.ARG_HIDE_TRANSIENTS
+import io.github.tabilzad.ktor.SwaggerConfigurationKeys.ARG_KDOCS
 import io.github.tabilzad.ktor.SwaggerConfigurationKeys.ARG_PATH
 import io.github.tabilzad.ktor.SwaggerConfigurationKeys.ARG_REQUEST_FEATURE
 import io.github.tabilzad.ktor.SwaggerConfigurationKeys.ARG_SERVERS
@@ -21,6 +22,7 @@ import io.github.tabilzad.ktor.SwaggerConfigurationKeys.OPTION_PATH
 import io.github.tabilzad.ktor.SwaggerConfigurationKeys.OPTION_REQUEST_BODY
 import io.github.tabilzad.ktor.SwaggerConfigurationKeys.OPTION_SERVERS
 import io.github.tabilzad.ktor.SwaggerConfigurationKeys.OPTION_TITLE
+import io.github.tabilzad.ktor.SwaggerConfigurationKeys.OPTION_USE_KDOCS
 import io.github.tabilzad.ktor.SwaggerConfigurationKeys.OPTION_VER
 import org.jetbrains.kotlin.compiler.plugin.AbstractCliOption
 import org.jetbrains.kotlin.compiler.plugin.CliOption
@@ -40,6 +42,7 @@ object SwaggerConfigurationKeys {
     const val OPTION_HIDE_TRANSIENT = "hideTransientFields"
     const val OPTION_HIDE_PRIVATE = "hidePrivateAndInternalFields"
     const val OPTION_DERIVE_PROP_REQ = "deriveFieldRequirementFromTypeNullability"
+    const val OPTION_USE_KDOCS = "useKDocs"
     const val OPTION_SERVERS = "servers"
     const val OPTION_FORMAT = "format"
 
@@ -54,6 +57,7 @@ object SwaggerConfigurationKeys {
     val ARG_DERIVE_PROP_REQ = CompilerConfigurationKey.create<Boolean>(OPTION_DERIVE_PROP_REQ)
     val ARG_FORMAT = CompilerConfigurationKey.create<String>(OPTION_FORMAT)
     val ARG_SERVERS = CompilerConfigurationKey.create<List<String>>(OPTION_SERVERS)
+    val ARG_KDOCS = CompilerConfigurationKey.create<Boolean>(OPTION_USE_KDOCS)
 }
 
 @OptIn(ExperimentalCompilerApi::class)
@@ -113,6 +117,12 @@ class KtorDocsCommandLineProcessor : CommandLineProcessor {
             "Automatically derive object properties' requirement from the type nullability",
             false
         )
+        val useKDocs = CliOption(
+            OPTION_USE_KDOCS,
+            "true opts for using kdocs for schema descriptions",
+            "Resolve schema descriptions from kdocs",
+            false
+        )
         val formatOption = CliOption(
             OPTION_FORMAT,
             "Specification format",
@@ -144,7 +154,8 @@ class KtorDocsCommandLineProcessor : CommandLineProcessor {
             hidePrivateAndInternalFields,
             derivePropRequirement,
             formatOption,
-            serverUrls
+            serverUrls,
+            useKDocs
         )
 
 
@@ -174,6 +185,8 @@ class KtorDocsCommandLineProcessor : CommandLineProcessor {
 
             hidePrivateAndInternalFields -> configuration.put(ARG_HIDE_PRIVATE, value.toBooleanStrictOrNull() ?: true)
 
+            useKDocs -> configuration.put(ARG_KDOCS, value.toBooleanStrictOrNull() ?: true)
+
             serverUrls -> configuration.put(ARG_SERVERS, value.split("||").filter { it.isNotBlank() })
 
             else -> throw IllegalArgumentException("Unexpected config option ${option.optionName}")

create-plugin/src/main/kotlin/io/github/tabilzad/ktor/PluginConfiguration.kt

@@ -12,7 +12,8 @@ internal data class PluginConfiguration(
     val hideTransients: Boolean,
     val hidePrivateFields: Boolean,
     val servers: List<String>,
-    val deriveFieldRequirementFromTypeNullability: Boolean
+    val deriveFieldRequirementFromTypeNullability: Boolean,
+    val useKDocsForDescriptions: Boolean
 ) {
     companion object {
         fun createDefault(
@@ -27,6 +28,7 @@ internal data class PluginConfiguration(
             hidePrivateFields: Boolean? = null,
             servers: List<String>? = null,
             deriveFieldRequirementFromTypeNullability: Boolean? = null,
+            useKDocsForDescriptions: Boolean? = null
         ): PluginConfiguration = PluginConfiguration(
             isEnabled = isEnabled ?: true,
             format = format ?: "yaml",
@@ -39,6 +41,7 @@ internal data class PluginConfiguration(
             hidePrivateFields = hidePrivateFields ?: true,
             deriveFieldRequirementFromTypeNullability = deriveFieldRequirementFromTypeNullability ?: true,
             servers = servers ?: emptyList(),
+            useKDocsForDescriptions = useKDocsForDescriptions ?: true
         )
     }
 }

create-plugin/src/main/kotlin/io/github/tabilzad/ktor/Utils.kt

@@ -4,10 +4,13 @@ import io.github.tabilzad.ktor.k2.ClassIds.TRANSIENT_ANNOTATION_FQ
 import io.github.tabilzad.ktor.output.OpenApiSpec
 import org.jetbrains.kotlin.config.CompilerConfiguration
 import org.jetbrains.kotlin.descriptors.PropertyDescriptor
+import org.jetbrains.kotlin.fir.declarations.FirDeclaration
+import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.resolve.descriptorUtil.isEffectivelyPublicApi
 import org.jetbrains.kotlin.resolve.scopes.DescriptorKindFilter
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
 import org.jetbrains.kotlin.resolve.scopes.getDescriptorsFiltered
+import org.jetbrains.kotlin.util.getChildren
 import java.io.OutputStream
 
 fun Boolean.byFeatureFlag(flag: Boolean): Boolean = if (flag) {
@@ -176,6 +179,32 @@ private fun addPostBody(it: KtorRouteSpec): OpenApiSpec.RequestBody? {
     }
 }
 
+internal fun FirDeclaration.getKDocComments(configuration: PluginConfiguration): String? {
+
+    if(!configuration.useKDocsForDescriptions) return null
+
+    fun String.sanitizeKDoc(): String {
+        val lines = trim().lines().map { it.trim() }
+        return lines.filter { it.isNotEmpty() && it != "*" }
+            .joinToString("\n") { line ->
+                when {
+                    line.startsWith("/**") -> line.removePrefix("/**").trim()
+                    line.startsWith("*/") -> ""
+                    else -> line.trimMargin("*").trim()
+                }
+            }
+            .trim()
+    }
+
+    return source?.treeStructure?.let {
+        source?.lighterASTNode?.getChildren(it)
+            ?.firstOrNull { it.tokenType == KtTokens.DOC_COMMENT }
+            ?.toString()
+            ?.sanitizeKDoc()
+    }
+}
+
+
 private fun OpenApiSpec.ObjectType.isPrimitive() = listOf("string", "number", "integer").contains(type)
 
 internal fun CompilerConfiguration?.buildPluginConfiguration(): PluginConfiguration = PluginConfiguration.createDefault(

create-plugin/src/main/kotlin/io/github/tabilzad/ktor/k2/ExpressionsVisitorK2.kt

@@ -3,12 +3,9 @@ package io.github.tabilzad.ktor.k2
 import io.github.tabilzad.ktor.*
 import io.github.tabilzad.ktor.annotations.KtorDescription
 import io.github.tabilzad.ktor.annotations.KtorResponds
-import io.github.tabilzad.ktor.k2.visitors.*
-import io.github.tabilzad.ktor.k2.visitors.ClassDescriptorVisitorK2
-import io.github.tabilzad.ktor.k2.visitors.ResourceClassVisitor
-import io.github.tabilzad.ktor.k2.visitors.RespondsAnnotationVisitor
 import io.github.tabilzad.ktor.k1.visitors.KtorDescriptionBag
 import io.github.tabilzad.ktor.k1.visitors.toSwaggerType
+import io.github.tabilzad.ktor.k2.visitors.*
 import io.github.tabilzad.ktor.output.OpenApiSpec
 import org.jetbrains.kotlin.fir.FirElement
 import org.jetbrains.kotlin.fir.FirSession
@@ -20,6 +17,7 @@ import org.jetbrains.kotlin.fir.references.resolved
 import org.jetbrains.kotlin.fir.references.toResolvedFunctionSymbol
 import org.jetbrains.kotlin.fir.resolve.firClassLike
 import org.jetbrains.kotlin.fir.resolve.fqName
+import org.jetbrains.kotlin.fir.resolve.toFirRegularClass
 import org.jetbrains.kotlin.fir.symbols.SymbolInternals
 import org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
 import org.jetbrains.kotlin.fir.types.*
@@ -104,14 +102,21 @@ internal class ExpressionsVisitorK2(
     }
 
 
+    @OptIn(SymbolInternals::class)
     private fun ConeKotlinType.generateTypeAndVisitMemberDescriptors(): OpenApiSpec.ObjectType {
 
         val jetTypeFqName = fqNameStr()
 
+        val kdocs = this.toRegularClassSymbol(session)
+            ?.toLookupTag()
+            ?.toFirRegularClass(session)
+            ?.getKDocComments(config)
+
         val objectType = OpenApiSpec.ObjectType(
             type = "object",
             properties = mutableMapOf(),
             fqName = jetTypeFqName,
+            description = kdocs,
             contentBodyRef = "#/components/schemas/${jetTypeFqName}",
         )
         if (!classNames.names.contains(jetTypeFqName)) {

create-plugin/src/main/kotlin/io/github/tabilzad/ktor/k2/visitors/ClassDescriptorVisitorK2.kt

@@ -1,15 +1,16 @@
 package io.github.tabilzad.ktor.k2.visitors
 
-import io.github.tabilzad.ktor.output.OpenApiSpec
-import io.github.tabilzad.ktor.output.OpenApiSpec.ObjectType
 import io.github.tabilzad.ktor.PluginConfiguration
 import io.github.tabilzad.ktor.annotations.KtorDescription
 import io.github.tabilzad.ktor.annotations.KtorFieldDescription
+import io.github.tabilzad.ktor.getKDocComments
+import io.github.tabilzad.ktor.k1.visitors.KtorDescriptionBag
+import io.github.tabilzad.ktor.k1.visitors.toSwaggerType
 import io.github.tabilzad.ktor.k2.*
 import io.github.tabilzad.ktor.k2.JsonNameResolver.getCustomNameFromAnnotation
 import io.github.tabilzad.ktor.names
-import io.github.tabilzad.ktor.k1.visitors.KtorDescriptionBag
-import io.github.tabilzad.ktor.k1.visitors.toSwaggerType
+import io.github.tabilzad.ktor.output.OpenApiSpec
+import io.github.tabilzad.ktor.output.OpenApiSpec.ObjectType
 import org.jetbrains.kotlin.fir.FirElement
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
@@ -27,7 +28,8 @@ import org.jetbrains.kotlin.util.PrivateForInline
 import org.jetbrains.kotlin.util.getValueOrNull
 
 data class GenericParameter(
-    val genericName: String, val genericTypeRef: ConeKotlinType?
+    val genericName: String,
+    val genericTypeRef: ConeKotlinType?
 )
 
 internal class ClassDescriptorVisitorK2(
@@ -41,7 +43,6 @@ internal class ClassDescriptorVisitorK2(
 
     @OptIn(SealedClassInheritorsProviderInternals::class, SymbolInternals::class)
     override fun visitProperty(property: FirProperty, data: ObjectType): ObjectType {
-
         val coneTypeOrNull = property.returnTypeRef.coneTypeOrNull!!
         val type = if (coneTypeOrNull is ConeTypeParameterType && genericParameters.isNotEmpty()) {
             genericParameters.find { it.genericName == coneTypeOrNull.renderReadable() }?.genericTypeRef!!
@@ -314,6 +315,7 @@ internal class ClassDescriptorVisitorK2(
     }
 
     private fun ObjectType.addProperty(fir: FirProperty, objectType: ObjectType?, session: FirSession) {
+        val kdoc = fir.getKDocComments(config)
         val resolvedDescription = fir.findDocsDescription(session)
         val docsDescription = resolvedDescription.let { it?.summary ?: it?.descr }
         val name = fir.findName()
@@ -324,7 +326,7 @@ internal class ClassDescriptorVisitorK2(
             properties?.put(name, spec)
         }
 
-        objectType?.description = docsDescription
+        objectType?.description = docsDescription ?: kdoc
 
         val isRequiredFromExplicitDesc = resolvedDescription?.isRequired
         if (isRequiredFromExplicitDesc != null && isRequiredFromExplicitDesc) {

create-plugin/src/test/kotlin/io/github/tabilzad/ktor/K2StabilityTest.kt

@@ -244,23 +244,35 @@ class K2StabilityTest {
     @Test
     fun `should include private fields or ones annotated with @Transient`() {
         val (source, expected) = loadSourceAndExpected("PrivateFieldsNegation")
-        generateCompilerTest(testFile, source, PluginConfiguration.createDefault(hideTransients = false, hidePrivateFields = false))
+        generateCompilerTest(
+            testFile,
+            source,
+            PluginConfiguration.createDefault(hideTransients = false, hidePrivateFields = false)
+        )
         val result = testFile.readText()
         result.assertWith(expected)
     }
 
     @Test
     fun `should generate response correct response bodies when explicitly specified`() {
         val (source, expected) = loadSourceAndExpected("ResponseBody")
-        generateCompilerTest(testFile, source, PluginConfiguration.createDefault(hideTransients = false, hidePrivateFields = false))
+        generateCompilerTest(
+            testFile,
+            source,
+            PluginConfiguration.createDefault(hideTransients = false, hidePrivateFields = false)
+        )
         val result = testFile.readText()
         result.assertWith(expected)
     }
 
     @Test
     fun `should correctly resolve complex descriptions specified on response annotations`() {
         val (source, expected) = loadSourceAndExpected("ResponseBody2")
-        generateCompilerTest(testFile, source, PluginConfiguration.createDefault(hideTransients = false, hidePrivateFields = false))
+        generateCompilerTest(
+            testFile,
+            source,
+            PluginConfiguration.createDefault(hideTransients = false, hidePrivateFields = false)
+        )
         val result = testFile.readText()
         result.assertWith(expected)
     }
@@ -289,6 +301,14 @@ class K2StabilityTest {
         result.assertWith(expected)
     }
 
+    @Test
+    fun `should use kdocs as property or schema descriptions by default`() {
+        val (source, expected) = loadSourceAndExpected("KDocs")
+        generateCompilerTest(testFile, source, PluginConfiguration.createDefault())
+        val result = testFile.readText()
+        result.assertWith(expected)
+    }
+
     @Test
     fun `should resolve request body schema directly from http method parameter if it's not a resource`() {
         val (source, expected) = loadSourceAndExpected("RequestBodyParam")
@@ -323,7 +343,7 @@ class K2StabilityTest {
 
     @Test
     fun `should append servers from gradle config`() {
-        val source  = loadSourceCodeFrom("BlankSource")
+        val source = loadSourceCodeFrom("BlankSource")
         val input = listOf("server1", "server2")
         val expectation = input.map { OpenApiSpec.Server(it) }
         generateCompilerTest(testFile, source, PluginConfiguration.createDefault(servers = input))
@@ -333,13 +353,13 @@ class K2StabilityTest {
 
     @Test
     fun `should not append servers from gradle config if not specified`() {
-        val source  = loadSourceCodeFrom("BlankSource")
+        val source = loadSourceCodeFrom("BlankSource")
         generateCompilerTest(testFile, source, PluginConfiguration.createDefault())
         val result = testFile.parseSpec()
         assertThat(result.servers).isNull()
     }
 
-    private fun String?.assertWith(expected: String){
+    private fun String?.assertWith(expected: String) {
         assertThat(this).isNotNull.withFailMessage {
             "swagger file was not generated"
         }

create-plugin/src/test/resources/expected/KDocs-expected.json

@@ -0,0 +1,54 @@
+{
+  "openapi" : "3.1.0",
+  "info" : {
+    "title" : "Open API Specification",
+    "description" : "test",
+    "version" : "1.0.0"
+  },
+  "paths" : {
+    "/v1/action" : {
+      "post" : {
+        "requestBody" : {
+          "required" : true,
+          "content" : {
+            "application/json" : {
+              "schema" : {
+                "$ref" : "#/components/schemas/sources.KDocsClass"
+              }
+            }
+          }
+        }
+      }
+    }
+  },
+  "components" : {
+    "schemas" : {
+      "sources.KDocsClass" : {
+        "type" : "object",
+        "properties" : {
+          "kdocsConstructorDerivedProperty" : {
+            "type" : "string",
+            "description" : "This field is called [kdocsConstructorDerivedProperty]."
+          },
+          "kdocsConstructorParameter" : {
+            "type" : "string",
+            "description" : "This field is called [kdocsConstructorParameter].\nTis is another line with\n* This is another line with extra *\n* This \\is another \\*line with extra *"
+          },
+          "kdocsLateinitVar" : {
+            "type" : "string",
+            "description" : "This field is called [kdocsLateinitVar]."
+          },
+          "kdocsProperty" : {
+            "type" : "string",
+            "description" : "This field is called [kdocsProperty]."
+          },
+          "noKdocs" : {
+            "type" : "string"
+          }
+        },
+        "description" : "This class contains fields with kdocs.",
+        "required" : [ "kdocsConstructorParameter", "noKdocs", "kdocsConstructorDerivedProperty", "kdocsLateinitVar" ]
+      }
+    }
+  }
+}