fix(messages): content as image file (#313)

Author: aallam

CHANGELOG.md

@@ -4,6 +4,10 @@
 
 - **Audio**: add `timestampGranularities` (thanks @mxwell)
 
+### Fixed
+
+- **Messages**: nullable field `MessageContent.Image#fileId` (#313)
+
 ## 3.7.0
 
 ### Added

openai-core/src/commonMain/kotlin/com.aallam.openai.api/message/ImageFile.kt

@@ -0,0 +1,16 @@
+package com.aallam.openai.api.message
+
+import com.aallam.openai.api.file.FileId
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+/**
+ * References an image File in the content of a message.
+ */
+@Serializable
+public data class ImageFile(
+    /**
+     * The File ID of the image in the message content.
+     */
+    @SerialName("file_id") val fileId: FileId
+)

openai-core/src/commonMain/kotlin/com.aallam.openai.api/message/MessageContent.kt

@@ -35,7 +35,7 @@ public sealed interface MessageContent {
         /**
          * The File ID of the image in the message content.
          */
-        @SerialName("file_id") val fileId: FileId
+        @SerialName("image_file") val imageFile: ImageFile
     ) : MessageContent
 
 }

openai-core/src/commonMain/kotlin/com.aallam.openai.api/message/MessageFile.kt

@@ -2,6 +2,7 @@ package com.aallam.openai.api.message
 
 import com.aallam.openai.api.BetaOpenAI
 import com.aallam.openai.api.file.FileId
+import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 
 /**
@@ -13,13 +14,13 @@ public data class MessageFile(
     /**
      * The identifier, which can be referenced in API endpoints.
      */
-    val id: FileId,
+    @SerialName("id") val id: FileId,
     /**
      * The Unix timestamp (in seconds) for when the message file was created.
      */
-    val createdAt: Int? = null,
+    @SerialName("created_at") val createdAt: Int? = null,
     /**
      * The ID of the message that the File is attached to.
      */
-    val messageId: MessageId? = null,
+    @SerialName("message_id") val messageId: MessageId? = null,
 )