Use kotlin's explicit API in vertexAI (#6313)

This option forces you to define the visibility of your code in Kotlin,
ignoring the default visibility of `public`

For more context, see


https://kotlinlang.org/docs/whatsnew14.html#explicit-api-mode-for-library-authors

https://umang91.medium.com/explicit-api-mode-kotlin-a527843d94f3

Author: rlazo

firebase-vertexai/firebase-vertexai.gradle.kts

@@ -16,6 +16,9 @@
 
 @file:Suppress("UnstableApiUsage")
 
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
+
 plugins {
   id("firebase-library")
   id("kotlin-android")
@@ -66,6 +69,21 @@ android {
   }
 }
 
+// Enable Kotlin "Explicit API Mode". This causes the Kotlin compiler to fail if any
+// classes, methods, or properties have implicit `public` visibility. This check helps
+// avoid  accidentally leaking elements into the public API, requiring that any public
+// element be explicitly declared as `public`.
+// https://github.com/Kotlin/KEEP/blob/master/proposals/explicit-api-mode.md
+// https://chao2zhang.medium.com/explicit-api-mode-for-kotlin-on-android-b8264fdd76d1
+tasks.withType<KotlinCompile>().all {
+  if (!name.contains("test", ignoreCase = true)) {
+    if (!kotlinOptions.freeCompilerArgs.contains("-Xexplicit-api=strict")) {
+      kotlinOptions.freeCompilerArgs += "-Xexplicit-api=strict"
+    }
+  }
+}
+
+
 dependencies {
   val ktorVersion = "2.3.2"
 

firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/Chat.kt

@@ -42,7 +42,10 @@ import kotlinx.coroutines.flow.onEach
  * @param model The model to use for the interaction
  * @property history The previous interactions with the model
  */
-class Chat(private val model: GenerativeModel, val history: MutableList<Content> = ArrayList()) {
+public class Chat(
+  private val model: GenerativeModel,
+  public val history: MutableList<Content> = ArrayList()
+) {
   private var lock = Semaphore(1)
 
   /**
@@ -53,7 +56,7 @@ class Chat(private val model: GenerativeModel, val history: MutableList<Content>
    * @throws InvalidStateException if the prompt is not coming from the 'user' role
    * @throws InvalidStateException if the [Chat] instance has an active request.
    */
-  suspend fun sendMessage(prompt: Content): GenerateContentResponse {
+  public suspend fun sendMessage(prompt: Content): GenerateContentResponse {
     prompt.assertComesFromUser()
     attemptLock()
     try {
@@ -72,7 +75,7 @@ class Chat(private val model: GenerativeModel, val history: MutableList<Content>
    * @param prompt The text to be converted into a single piece of [Content] to send to the model.
    * @throws InvalidStateException if the [Chat] instance has an active request.
    */
-  suspend fun sendMessage(prompt: String): GenerateContentResponse {
+  public suspend fun sendMessage(prompt: String): GenerateContentResponse {
     val content = content { text(prompt) }
     return sendMessage(content)
   }
@@ -83,7 +86,7 @@ class Chat(private val model: GenerativeModel, val history: MutableList<Content>
    * @param prompt The image to be converted into a single piece of [Content] to send to the model.
    * @throws InvalidStateException if the [Chat] instance has an active request.
    */
-  suspend fun sendMessage(prompt: Bitmap): GenerateContentResponse {
+  public suspend fun sendMessage(prompt: Bitmap): GenerateContentResponse {
     val content = content { image(prompt) }
     return sendMessage(content)
   }
@@ -96,7 +99,7 @@ class Chat(private val model: GenerativeModel, val history: MutableList<Content>
    * @throws InvalidStateException if the prompt is not coming from the 'user' role
    * @throws InvalidStateException if the [Chat] instance has an active request.
    */
-  fun sendMessageStream(prompt: Content): Flow<GenerateContentResponse> {
+  public fun sendMessageStream(prompt: Content): Flow<GenerateContentResponse> {
     prompt.assertComesFromUser()
     attemptLock()
 
@@ -149,7 +152,7 @@ class Chat(private val model: GenerativeModel, val history: MutableList<Content>
    * @return A [Flow] which will emit responses as they are returned from the model.
    * @throws InvalidStateException if the [Chat] instance has an active request.
    */
-  fun sendMessageStream(prompt: String): Flow<GenerateContentResponse> {
+  public fun sendMessageStream(prompt: String): Flow<GenerateContentResponse> {
     val content = content { text(prompt) }
     return sendMessageStream(content)
   }
@@ -161,7 +164,7 @@ class Chat(private val model: GenerativeModel, val history: MutableList<Content>
    * @return A [Flow] which will emit responses as they are returned from the model.
    * @throws InvalidStateException if the [Chat] instance has an active request.
    */
-  fun sendMessageStream(prompt: Bitmap): Flow<GenerateContentResponse> {
+  public fun sendMessageStream(prompt: Bitmap): Flow<GenerateContentResponse> {
     val content = content { image(prompt) }
     return sendMessageStream(content)
   }

firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/FirebaseVertexAI.kt

@@ -31,7 +31,7 @@ import com.google.firebase.vertexai.type.Tool
 import com.google.firebase.vertexai.type.ToolConfig
 
 /** Entry point for all _Vertex AI for Firebase_ functionality. */
-class FirebaseVertexAI
+public class FirebaseVertexAI
 internal constructor(
   private val firebaseApp: FirebaseApp,
   private val location: String,
@@ -51,7 +51,7 @@ internal constructor(
    * @param systemInstruction contains a [Content] that directs the model to behave a certain way
    */
   @JvmOverloads
-  fun generativeModel(
+  public fun generativeModel(
     modelName: String,
     generationConfig: GenerationConfig? = null,
     safetySettings: List<SafetySetting>? = null,
@@ -77,13 +77,13 @@ internal constructor(
     )
   }
 
-  companion object {
+  public companion object {
     /** The [FirebaseVertexAI] instance for the default [FirebaseApp] */
     @JvmStatic
-    val instance: FirebaseVertexAI
+    public val instance: FirebaseVertexAI
       get() = getInstance(location = "us-central1")
 
-    @JvmStatic fun getInstance(app: FirebaseApp): FirebaseVertexAI = getInstance(app)
+    @JvmStatic public fun getInstance(app: FirebaseApp): FirebaseVertexAI = getInstance(app)
 
     /**
      * Returns the [FirebaseVertexAI] instance for the provided [FirebaseApp] and [location]
@@ -93,19 +93,19 @@ internal constructor(
      */
     @JvmStatic
     @JvmOverloads
-    fun getInstance(app: FirebaseApp = Firebase.app, location: String): FirebaseVertexAI {
+    public fun getInstance(app: FirebaseApp = Firebase.app, location: String): FirebaseVertexAI {
       val multiResourceComponent = app[FirebaseVertexAIMultiResourceComponent::class.java]
       return multiResourceComponent.get(location)
     }
   }
 }
 
 /** Returns the [FirebaseVertexAI] instance of the default [FirebaseApp]. */
-val Firebase.vertexAI: FirebaseVertexAI
+public val Firebase.vertexAI: FirebaseVertexAI
   get() = FirebaseVertexAI.instance
 
 /** Returns the [FirebaseVertexAI] instance of a given [FirebaseApp]. */
-fun Firebase.vertexAI(
+public fun Firebase.vertexAI(
   app: FirebaseApp = Firebase.app,
   location: String = "us-central1"
 ): FirebaseVertexAI = FirebaseVertexAI.getInstance(app, location)

firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/GenerativeModel.kt

@@ -50,7 +50,7 @@ import kotlinx.coroutines.tasks.await
 /**
  * A controller for communicating with the API of a given multimodal model (for example, Gemini).
  */
-class GenerativeModel
+public class GenerativeModel
 internal constructor(
   private val modelName: String,
   private val generationConfig: GenerationConfig? = null,
@@ -128,7 +128,7 @@ internal constructor(
    * @return A [GenerateContentResponse]. Function should be called within a suspend context to
    * properly manage concurrency.
    */
-  suspend fun generateContent(vararg prompt: Content): GenerateContentResponse =
+  public suspend fun generateContent(vararg prompt: Content): GenerateContentResponse =
     try {
       controller.generateContent(constructRequest(*prompt)).toPublic().validate()
     } catch (e: Throwable) {
@@ -141,7 +141,7 @@ internal constructor(
    * @param prompt [Content] to send to the model.
    * @return A [Flow] which will emit responses as they are returned from the model.
    */
-  fun generateContentStream(vararg prompt: Content): Flow<GenerateContentResponse> =
+  public fun generateContentStream(vararg prompt: Content): Flow<GenerateContentResponse> =
     controller
       .generateContentStream(constructRequest(*prompt))
       .catch { throw FirebaseVertexAIException.from(it) }
@@ -154,7 +154,7 @@ internal constructor(
    * @return A [GenerateContentResponse] after some delay. Function should be called within a
    * suspend context to properly manage concurrency.
    */
-  suspend fun generateContent(prompt: String): GenerateContentResponse =
+  public suspend fun generateContent(prompt: String): GenerateContentResponse =
     generateContent(content { text(prompt) })
 
   /**
@@ -163,7 +163,7 @@ internal constructor(
    * @param prompt The text to be converted into a single piece of [Content] to send to the model.
    * @return A [Flow] which will emit responses as they are returned from the model.
    */
-  fun generateContentStream(prompt: String): Flow<GenerateContentResponse> =
+  public fun generateContentStream(prompt: String): Flow<GenerateContentResponse> =
     generateContentStream(content { text(prompt) })
 
   /**
@@ -173,7 +173,7 @@ internal constructor(
    * @return A [GenerateContentResponse] after some delay. Function should be called within a
    * suspend context to properly manage concurrency.
    */
-  suspend fun generateContent(prompt: Bitmap): GenerateContentResponse =
+  public suspend fun generateContent(prompt: Bitmap): GenerateContentResponse =
     generateContent(content { image(prompt) })
 
   /**
@@ -182,19 +182,20 @@ internal constructor(
    * @param prompt The image to be converted into a single piece of [Content] to send to the model.
    * @return A [Flow] which will emit responses as they are returned from the model.
    */
-  fun generateContentStream(prompt: Bitmap): Flow<GenerateContentResponse> =
+  public fun generateContentStream(prompt: Bitmap): Flow<GenerateContentResponse> =
     generateContentStream(content { image(prompt) })
 
   /** Creates a [Chat] instance which internally tracks the ongoing conversation with the model */
-  fun startChat(history: List<Content> = emptyList()): Chat = Chat(this, history.toMutableList())
+  public fun startChat(history: List<Content> = emptyList()): Chat =
+    Chat(this, history.toMutableList())
 
   /**
    * Counts the amount of tokens in a prompt.
    *
    * @param prompt A group of [Content] to count tokens of.
    * @return A [CountTokensResponse] containing the amount of tokens in the prompt.
    */
-  suspend fun countTokens(vararg prompt: Content): CountTokensResponse {
+  public suspend fun countTokens(vararg prompt: Content): CountTokensResponse {
     try {
       return controller.countTokens(constructCountTokensRequest(*prompt)).toPublic()
     } catch (e: Throwable) {
@@ -208,7 +209,7 @@ internal constructor(
    * @param prompt The text to be converted to a single piece of [Content] to count the tokens of.
    * @return A [CountTokensResponse] containing the amount of tokens in the prompt.
    */
-  suspend fun countTokens(prompt: String): CountTokensResponse {
+  public suspend fun countTokens(prompt: String): CountTokensResponse {
     return countTokens(content { text(prompt) })
   }
 
@@ -218,7 +219,7 @@ internal constructor(
    * @param prompt The image to be converted to a single piece of [Content] to count the tokens of.
    * @return A [CountTokensResponse] containing the amount of tokens in the prompt.
    */
-  suspend fun countTokens(prompt: Bitmap): CountTokensResponse {
+  public suspend fun countTokens(prompt: Bitmap): CountTokensResponse {
     return countTokens(content { image(prompt) })
   }
 
@@ -247,7 +248,7 @@ internal constructor(
       ?.let { throw ResponseStoppedException(this) }
   }
 
-  companion object {
+  private companion object {
     private val TAG = GenerativeModel::class.java.simpleName
   }
 }

firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/common/shared/Types.kt

@@ -41,7 +41,7 @@ internal enum class HarmCategory {
   @SerialName("HARM_CATEGORY_DANGEROUS_CONTENT") DANGEROUS_CONTENT
 }
 
-typealias Base64 = String
+internal typealias Base64 = String
 
 @ExperimentalSerializationApi
 @Serializable

firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/java/ChatFutures.kt

@@ -29,25 +29,25 @@ import org.reactivestreams.Publisher
  *
  * @see from
  */
-abstract class ChatFutures internal constructor() {
+public abstract class ChatFutures internal constructor() {
 
   /**
    * Generates a response from the backend with the provided [Content], and any previous ones
    * sent/returned from this chat.
    *
    * @param prompt A [Content] to send to the model.
    */
-  abstract fun sendMessage(prompt: Content): ListenableFuture<GenerateContentResponse>
+  public abstract fun sendMessage(prompt: Content): ListenableFuture<GenerateContentResponse>
 
   /**
    * Generates a streaming response from the backend with the provided [Content].
    *
    * @param prompt A [Content] to send to the model.
    */
-  abstract fun sendMessageStream(prompt: Content): Publisher<GenerateContentResponse>
+  public abstract fun sendMessageStream(prompt: Content): Publisher<GenerateContentResponse>
 
   /** Returns the [Chat] instance that was used to create this instance */
-  abstract fun getChat(): Chat
+  public abstract fun getChat(): Chat
 
   private class FuturesImpl(private val chat: Chat) : ChatFutures() {
     override fun sendMessage(prompt: Content): ListenableFuture<GenerateContentResponse> =
@@ -59,9 +59,9 @@ abstract class ChatFutures internal constructor() {
     override fun getChat(): Chat = chat
   }
 
-  companion object {
+  public companion object {
 
     /** @return a [ChatFutures] created around the provided [Chat] */
-    @JvmStatic fun from(chat: Chat): ChatFutures = FuturesImpl(chat)
+    @JvmStatic public fun from(chat: Chat): ChatFutures = FuturesImpl(chat)
   }
 }

firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/java/GenerativeModelFutures.kt

@@ -31,41 +31,45 @@ import org.reactivestreams.Publisher
  *
  * @see from
  */
-abstract class GenerativeModelFutures internal constructor() {
+public abstract class GenerativeModelFutures internal constructor() {
 
   /**
    * Generates a response from the backend with the provided [Content].
    *
    * @param prompt A group of [Content] to send to the model.
    */
-  abstract fun generateContent(vararg prompt: Content): ListenableFuture<GenerateContentResponse>
+  public abstract fun generateContent(
+    vararg prompt: Content
+  ): ListenableFuture<GenerateContentResponse>
 
   /**
    * Generates a streaming response from the backend with the provided [Content].
    *
    * @param prompt A group of [Content] to send to the model.
    */
-  abstract fun generateContentStream(vararg prompt: Content): Publisher<GenerateContentResponse>
+  public abstract fun generateContentStream(
+    vararg prompt: Content
+  ): Publisher<GenerateContentResponse>
 
   /**
    * Counts the number of tokens used in a prompt.
    *
    * @param prompt A group of [Content] to count tokens of.
    */
-  abstract fun countTokens(vararg prompt: Content): ListenableFuture<CountTokensResponse>
+  public abstract fun countTokens(vararg prompt: Content): ListenableFuture<CountTokensResponse>
 
   /** Creates a chat instance which internally tracks the ongoing conversation with the model */
-  abstract fun startChat(): ChatFutures
+  public abstract fun startChat(): ChatFutures
 
   /**
    * Creates a chat instance which internally tracks the ongoing conversation with the model
    *
    * @param history an existing history of context to use as a starting point
    */
-  abstract fun startChat(history: List<Content>): ChatFutures
+  public abstract fun startChat(history: List<Content>): ChatFutures
 
   /** Returns the [GenerativeModel] instance that was used to create this object */
-  abstract fun getGenerativeModel(): GenerativeModel
+  public abstract fun getGenerativeModel(): GenerativeModel
 
   private class FuturesImpl(private val model: GenerativeModel) : GenerativeModelFutures() {
     override fun generateContent(
@@ -86,9 +90,9 @@ abstract class GenerativeModelFutures internal constructor() {
     override fun getGenerativeModel(): GenerativeModel = model
   }
 
-  companion object {
+  public companion object {
 
     /** @return a [GenerativeModelFutures] created around the provided [GenerativeModel] */
-    @JvmStatic fun from(model: GenerativeModel): GenerativeModelFutures = FuturesImpl(model)
+    @JvmStatic public fun from(model: GenerativeModel): GenerativeModelFutures = FuturesImpl(model)
   }
 }