add concept of LanguageModel to CompletionProvider

crates/assistant/src/assistant_panel.rs

@@ -328,6 +328,7 @@ impl AssistantPanel {
 
         let inline_assist_id = post_inc(&mut self.next_inline_assist_id);
         let provider = Arc::new(OpenAICompletionProvider::new(
+            "gpt-4",
             api_key,
             cx.background().clone(),
         ));

crates/assistant/src/codegen.rs

@@ -335,6 +335,7 @@ fn strip_markdown_codeblock(
 #[cfg(test)]
 mod tests {
     use super::*;
+    use ai::{models::LanguageModel, test::FakeLanguageModel};
     use futures::{
         future::BoxFuture,
         stream::{self, BoxStream},
@@ -638,6 +639,10 @@ mod tests {
     }
 
     impl CompletionProvider for TestCompletionProvider {
+        fn base_model(&self) -> Box<dyn LanguageModel> {
+            let model: Box<dyn LanguageModel> = Box::new(FakeLanguageModel { capacity: 8190 });
+            model
+        }
         fn complete(
             &self,
             _prompt: Box<dyn CompletionRequest>,