Fix GenTypes.kt

GeneratorScripts/src/main/kotlin/autogenscripts/GenTypes.kt

@@ -75,18 +75,15 @@ val fileFieldEnumOverrides = mapOf(
 // ============================================================
 
 // Sealed interfaces that are not generated by dukat but must exist in the datatypes package.
-// Maps the interface name to its @JsonClassDiscriminator field, and whether it needs @Serializable.
-data class SealedInterface(val discriminator: String, val serializable: Boolean = false)
-
-// Interfaces that are deserialized polymorphically (as response fields) must be @Serializable,
-// otherwise the class discriminator is not resolved at runtime.
-// TODO refactor
+// Maps the interface name to its @JsonClassDiscriminator field.
+// They are always generated as @Serializable, otherwise the class discriminator
+// is not resolved when they are deserialized polymorphically (as response fields).
 val sealedInterfaces = mapOf(
-    "PostOrCommentOrPrivateMessage" to SealedInterface("type_", serializable = true),
-    "ResolveObjectView"            to SealedInterface("type_", serializable = true),
-    "ReportCombinedView"            to SealedInterface("type_", serializable = true),
-    "NotificationData"              to SealedInterface("type_", serializable = true),
-    "PostCommentCombinedView"       to SealedInterface("type_", serializable = true),
+    "PostOrCommentOrPrivateMessage" to "type_",
+    "ResolveObjectView" to "type_",
+    "ReportCombinedView" to "type_",
+    "NotificationData" to "type_",
+    "PostCommentCombinedView" to "type_",
 )
 
 // Which data classes implement which sealed interfaces and what @SerialName they carry.
@@ -218,19 +215,18 @@ fun addSealedInterfaceImpl(content: String, fileName: String, imports: MutableSe
 
 /** Generates a sealed interface .kt file for each entry in sealedInterfaces. */
 fun writeSealedInterfaces(datatypesDir: File, packageName: String) {
-    for ((name, info) in sealedInterfaces) {
-        val serializableImport = if (info.serializable) "\nimport kotlinx.serialization.Serializable" else ""
-        val serializableAnnotation = if (info.serializable) "\n@Serializable" else ""
-
+    for ((name, discriminator) in sealedInterfaces) {
         File(datatypesDir, "$name.kt").writeText(
             """
             package $packageName
 
-            import kotlinx.serialization.ExperimentalSerializationApi$serializableImport
+            import kotlinx.serialization.ExperimentalSerializationApi
+            import kotlinx.serialization.Serializable
             import kotlinx.serialization.json.JsonClassDiscriminator
 
-            @OptIn(ExperimentalSerializationApi::class)$serializableAnnotation
-            @JsonClassDiscriminator("${info.discriminator}")
+            @OptIn(ExperimentalSerializationApi::class)
+            @Serializable
+            @JsonClassDiscriminator("$discriminator")
             internal sealed interface $name
             """.trimIndent() + "\n"
         )
@@ -265,7 +261,8 @@ fun processDukatFile(typeFile: File, fileName: String, packageName: String, root
         if (!body.endsWith("\n")) appendLine()
     })
 
-    typeFile.delete()
+    // Older dukat versions emit `.d.kt` files, newer ones emit `.kt`, which is overwritten above.
+    if (typeFile.canonicalPath != outputFile.canonicalPath) typeFile.delete()
 }
 
 // ============================================================
@@ -311,8 +308,10 @@ fun downloadTypes(
     println("Starting Dukat process...")
     val proc = ProcessBuilder("bash", "-ic", "dukat temp/*.ts", "exit")
         .directory(datatypesDir)
+        .redirectErrorStream(true)
         .start()
     println(String(proc.inputStream.readAllBytes()))
+    check(proc.waitFor() == 0) { "Dukat failed" }
 
     // Process each dukat-generated .d.kt → clean .kt
     datatypesDir.listFiles()!!.forEach { typeFile ->

app/src/commonMain/kotlin/it/vercruysse/lemmyapi/datatypes/NotificationData.kt

@@ -3,9 +3,11 @@ package it.vercruysse.lemmyapi.datatypes
 import it.vercruysse.lemmyapi.CommonParcelize
 import it.vercruysse.lemmyapi.DatatypeRoot
 import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.Serializable
 import kotlinx.serialization.json.JsonClassDiscriminator
 
 @CommonParcelize
 @OptIn(ExperimentalSerializationApi::class)
+@Serializable
 @JsonClassDiscriminator("type_")
 sealed interface NotificationData : DatatypeRoot

app/src/commonMain/kotlin/it/vercruysse/lemmyapi/datatypes/PostCommentCombinedView.kt

@@ -3,9 +3,11 @@ package it.vercruysse.lemmyapi.datatypes
 import it.vercruysse.lemmyapi.CommonParcelize
 import it.vercruysse.lemmyapi.DatatypeRoot
 import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.Serializable
 import kotlinx.serialization.json.JsonClassDiscriminator
 
 @CommonParcelize
 @OptIn(ExperimentalSerializationApi::class)
+@Serializable
 @JsonClassDiscriminator("type_")
 sealed interface PostCommentCombinedView : DatatypeRoot

app/src/commonMain/kotlin/it/vercruysse/lemmyapi/datatypes/PostOrCommentOrPrivateMessage.kt

@@ -3,9 +3,11 @@ package it.vercruysse.lemmyapi.datatypes
 import it.vercruysse.lemmyapi.CommonParcelize
 import it.vercruysse.lemmyapi.DatatypeRoot
 import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.Serializable
 import kotlinx.serialization.json.JsonClassDiscriminator
 
 @CommonParcelize
 @OptIn(ExperimentalSerializationApi::class)
+@Serializable
 @JsonClassDiscriminator("type_")
 sealed interface PostOrCommentOrPrivateMessage : DatatypeRoot

app/src/commonMain/kotlin/it/vercruysse/lemmyapi/datatypes/ReportCombinedView.kt

@@ -3,9 +3,11 @@ package it.vercruysse.lemmyapi.datatypes
 import it.vercruysse.lemmyapi.CommonParcelize
 import it.vercruysse.lemmyapi.DatatypeRoot
 import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.Serializable
 import kotlinx.serialization.json.JsonClassDiscriminator
 
 @CommonParcelize
 @OptIn(ExperimentalSerializationApi::class)
+@Serializable
 @JsonClassDiscriminator("type_")
 sealed interface ReportCombinedView : DatatypeRoot

app/src/commonMain/kotlin/it/vercruysse/lemmyapi/datatypes/ResolveObjectView.kt

@@ -3,9 +3,11 @@ package it.vercruysse.lemmyapi.datatypes
 import it.vercruysse.lemmyapi.CommonParcelize
 import it.vercruysse.lemmyapi.DatatypeRoot
 import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.Serializable
 import kotlinx.serialization.json.JsonClassDiscriminator
 
 @CommonParcelize
 @OptIn(ExperimentalSerializationApi::class)
+@Serializable
 @JsonClassDiscriminator("type_")
 sealed interface ResolveObjectView : DatatypeRoot

app/src/jvmTest/kotlin/SealedInterfaceSerializationTest.kt

@@ -0,0 +1,66 @@
+import it.vercruysse.lemmyapi.IGNORE_UNKNOWN_KEYS_JSON
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertIs
+import kotlin.test.assertTrue
+import it.vercruysse.lemmyapi.datatypes.PersonView as UniPersonView
+import it.vercruysse.lemmyapi.datatypes.ResolveObjectView as UniResolveObjectView
+import it.vercruysse.lemmyapi.datatypes.SearchResponse as UniSearchResponse
+import it.vercruysse.lemmyapi.v1.x0.x0.datatypes.PersonView as V1PersonView
+import it.vercruysse.lemmyapi.v1.x0.x0.datatypes.ResolveObjectView as V1ResolveObjectView
+import it.vercruysse.lemmyapi.v1.x0.x0.datatypes.SearchResponse as V1SearchResponse
+
+class SealedInterfaceSerializationTest {
+    private val searchResponseJson =
+        """
+        {
+          "resolve": {
+            "type_": "person",
+            "person": {
+              "id": 1, "name": "name", "published_at": "2025-01-01T00:00:00Z", "ap_id": "https://example.com/u/name",
+              "local": true, "last_refreshed_at": "2025-01-01T00:00:00Z", "deleted": false, "bot_account": false,
+              "instance_id": 1, "post_count": 0, "comment_count": 0
+            },
+            "is_admin": false,
+            "banned": false
+          },
+          "comments": [], "posts": [], "communities": [], "persons": [], "multi_communities": []
+        }
+        """.trimIndent()
+
+    @Test
+    fun `generated v1 sealed interface is resolved by its class discriminator`() {
+        val response = IGNORE_UNKNOWN_KEYS_JSON.decodeFromString<V1SearchResponse>(searchResponseJson)
+
+        val resolved = assertIs<V1PersonView>(response.resolve)
+        assertEquals("name", resolved.person.name)
+    }
+
+    @Test
+    fun `generated v1 sealed interface is encoded with its class discriminator`() {
+        val response = IGNORE_UNKNOWN_KEYS_JSON.decodeFromString<V1SearchResponse>(searchResponseJson)
+
+        val encoded = IGNORE_UNKNOWN_KEYS_JSON.encodeToString<V1ResolveObjectView>(response.resolve!!)
+
+        assertTrue("\"type_\":\"person\"" in encoded, encoded)
+    }
+
+    @Test
+    fun `unified sealed interface is resolved by its class discriminator`() {
+        val response = IGNORE_UNKNOWN_KEYS_JSON.decodeFromString<UniSearchResponse>(searchResponseJson)
+
+        val resolved = assertIs<UniPersonView>(response.resolve)
+        assertEquals("name", resolved.person.name)
+    }
+
+    @Test
+    fun `unified sealed interface survives a round trip`() {
+        val response = IGNORE_UNKNOWN_KEYS_JSON.decodeFromString<UniSearchResponse>(searchResponseJson)
+
+        val roundTripped =
+            IGNORE_UNKNOWN_KEYS_JSON.decodeFromString<UniSearchResponse>(IGNORE_UNKNOWN_KEYS_JSON.encodeToString(response))
+
+        assertEquals(response, roundTripped)
+        assertIs<UniResolveObjectView>(roundTripped.resolve)
+    }
+}