support multiple interfaces (#247)

Author: hauner

openapi-processor-core/src/main/kotlin/io/openapiprocessor/core/model/datatypes/AllOfObjectDataType.kt

@@ -14,7 +14,9 @@ class AllOfObjectDataType(
     private val items: List<DataType> = emptyList(),
     override val deprecated: Boolean = false
 ): ModelDataType {
-    override var implementsDataType: InterfaceDataType? = null
+    private val _implementsDataTypes: MutableCollection<InterfaceDataType> = mutableListOf()
+    override val implementsDataTypes: Collection<InterfaceDataType>
+        get() = _implementsDataTypes.toList()
 
     override fun getName(): String {
         return name.id
@@ -55,6 +57,10 @@ class AllOfObjectDataType(
         return constraints?.isRequired(prop) ?: false
     }
 
+    override fun addInterface(implement: InterfaceDataType) {
+        _implementsDataTypes.add(implement)
+    }
+
     override fun forEach(action: (property: String, dataType: DataType) -> Unit) {
         properties.forEach {
             action(it.key, it.value)

openapi-processor-core/src/main/kotlin/io/openapiprocessor/core/model/datatypes/ModelDataType.kt

@@ -7,9 +7,9 @@ package io.openapiprocessor.core.model.datatypes
 
 interface ModelDataType: DataType {
     /**
-     * implements this interface.
+     * implements interfaces.
      */
-    var implementsDataType: InterfaceDataType?
+    val implementsDataTypes: Collection<InterfaceDataType>
 
     /**
      * loop object properties.
@@ -18,4 +18,5 @@ interface ModelDataType: DataType {
 
     fun isRequired(prop: String): Boolean
 
+    fun addInterface(implement: InterfaceDataType)
 }

openapi-processor-core/src/main/kotlin/io/openapiprocessor/core/model/datatypes/ObjectDataType.kt

@@ -19,7 +19,9 @@ open class ObjectDataType(
     override val deprecated: Boolean = false,
     override val documentation: Documentation? = null
 ): ModelDataType {
-    override var implementsDataType: InterfaceDataType? = null
+    private val _implementsDataTypes: MutableCollection<InterfaceDataType> = mutableListOf()
+    override val implementsDataTypes: Collection<InterfaceDataType>
+        get() = _implementsDataTypes.toList()
 
     override fun getName(): String {
         return name.id
@@ -58,6 +60,10 @@ open class ObjectDataType(
         return constraints?.isRequired(prop) ?: false
     }
 
+    override fun addInterface(implement: InterfaceDataType) {
+        _implementsDataTypes.add(implement)
+    }
+
     override fun forEach(action: (property: String, dataType: DataType) -> Unit) {
         for (p in properties) action(p.key, p.value)
     }
@@ -72,6 +78,9 @@ open class ObjectDataType(
 
     private val implementsImports: Set<String>
         get() {
-            return implementsDataType?.getImports() ?: emptySet()
+            return implementsDataTypes
+                .map { it.getImports() }
+                .flatten()
+                .toSet()
         }
 }

openapi-processor-core/src/main/kotlin/io/openapiprocessor/core/writer/java/DataTypeWriterPojo.kt

@@ -7,6 +7,7 @@ package io.openapiprocessor.core.writer.java
 
 import io.openapiprocessor.core.converter.ApiOptions
 import io.openapiprocessor.core.model.datatypes.DataType
+import io.openapiprocessor.core.model.datatypes.InterfaceDataType
 import io.openapiprocessor.core.model.datatypes.ModelDataType
 import io.openapiprocessor.core.model.datatypes.NullDataType
 import io.openapiprocessor.core.support.capitalizeFirstChar
@@ -41,8 +42,8 @@ class DataTypeWriterPojo(
     }
 
     private fun writeClassOpen(target: Writer, dataType: ModelDataType) {
-        val implements: DataType? = dataType.implementsDataType
-        if (implements != null) {
+        val implements: Collection<InterfaceDataType> = dataType.implementsDataTypes
+        if (implements.isNotEmpty()) {
             writeClassImplementsHeader(target, dataType, implements)
         } else {
             writeClassHeader(target, dataType)
@@ -90,9 +91,13 @@ class DataTypeWriterPojo(
     private fun writeClassImplementsHeader(
         target: Writer,
         dataType: ModelDataType,
-        implements: DataType
+        implements: Collection<InterfaceDataType>
     ) {
-        target.write("public class ${dataType.getTypeName()} implements ${implements.getTypeName()} {\n\n")
+        var result = "public class ${dataType.getTypeName()} implements "
+        result += implements.joinToString(", ") { it.getTypeName() }
+        result += " {\n\n"
+
+        target.write(result)
     }
 
     private fun writeClassHeader(

openapi-processor-core/src/main/kotlin/io/openapiprocessor/core/writer/java/DataTypeWriterRecord.kt

@@ -7,6 +7,7 @@ package io.openapiprocessor.core.writer.java
 
 import io.openapiprocessor.core.converter.ApiOptions
 import io.openapiprocessor.core.model.datatypes.DataType
+import io.openapiprocessor.core.model.datatypes.InterfaceDataType
 import io.openapiprocessor.core.model.datatypes.ModelDataType
 import io.openapiprocessor.core.writer.Identifier
 import java.io.Writer
@@ -68,9 +69,11 @@ class DataTypeWriterRecord(
     }
 
     private fun writeRecordImplements(target: Writer, dataType: ModelDataType) {
-        val implements: DataType? = dataType.implementsDataType
-        if (implements != null) {
-            target.write(" implements ${implements.getTypeName()}")
+        val implements: Collection<InterfaceDataType> = dataType.implementsDataTypes
+        if (implements.isNotEmpty()) {
+            var result = " implements "
+            result += implements.joinToString(", ") { it.getTypeName() }
+            target.write(result)
         }
     }
 

openapi-processor-core/src/test/kotlin/io/openapiprocessor/core/converter/DataTypeConverterOneOfSpec.kt

@@ -6,6 +6,7 @@
 package io.openapiprocessor.core.converter
 
 import io.kotest.core.spec.style.StringSpec
+import io.kotest.matchers.collections.shouldContainExactly
 import io.kotest.matchers.shouldBe
 import io.openapiprocessor.core.model.DataTypes
 import io.openapiprocessor.core.parser.HttpMethod
@@ -82,7 +83,7 @@ class DataTypeConverterOneOfSpec: StringSpec({
         ifDataType.getName() shouldBe "GenericProperties"
         ifDataType.items.size shouldBe 2
         ifDataType.items.forEach {
-            (it as ModelDataType).implementsDataType shouldBe ifDataType
+            (it as ModelDataType).implementsDataTypes shouldContainExactly listOf(ifDataType)
         }
     }
 

openapi-processor-core/src/test/kotlin/io/openapiprocessor/core/writer/java/DataTypeWriterPojoSpec.kt

@@ -214,14 +214,40 @@ class DataTypeWriterPojoSpec: StringSpec({
         val ifDataType = InterfaceDataType(
             DataTypeName("MarkerInterface"), "pkg", listOf(dataType))
 
-        dataType.implementsDataType = ifDataType
+        dataType.addInterface(ifDataType)
 
         // when:
         createWriter().write (target, dataType)
 
         target.toString() shouldContain ("public class Foo implements MarkerInterface {")
     }
 
+    "writes class with multiple implements" {
+        options.oneOfInterface = true
+
+        val dataType = ObjectDataType ("Foo", "pkg", linkedMapOf(
+            "foo" to PropertyDataType (
+                readOnly = false,
+                writeOnly = false,
+                dataType = StringDataType (),
+                documentation = Documentation()
+            )
+        ))
+
+        val ifDataTypeA = InterfaceDataType(
+            DataTypeName("MarkerInterfaceA"), "pkg", listOf(dataType))
+        val ifDataTypeB = InterfaceDataType(
+            DataTypeName("MarkerInterfaceB"), "pkg", listOf(dataType))
+
+        dataType.addInterface(ifDataTypeA)
+        dataType.addInterface(ifDataTypeB)
+
+        // when:
+        createWriter().write (target, dataType)
+
+        target.toString() shouldContain ("public class Foo implements MarkerInterfaceA, MarkerInterfaceB {")
+    }
+
     "writes additional object annotation import from annotation mapping" {
         val opts = parseOptions(
             """