Make this a better library (#7)

Some additions to make this more useful as a library
- Move testing only dependencies into dev-dependencies
- The library itself now uses surf instead of reqwest, which is more flexible over runtimes
- Add some crate features to allow configuring which backend to use
- Add logging for requests and responses

Cargo.toml

@@ -10,17 +10,23 @@ repository = "https://github.com/deontologician/openai-api-rust/"
 keywords = ["openai", "gpt3"]
 categories = ["api-bindings", "asynchronous"]
 
+[features]
+default = ["hyper"]
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+hyper = ["surf/hyper-client"]
+curl = ["surf/curl-client"]
+h1 = ["surf/h1-client"]
 
 [dependencies]
-reqwest = { version = "0.10.9", features = ["json"] }
+surf = { version = "^2.1.0", default-features = false }
 thiserror = "^1.0.22"
 serde = { version = "^1.0.117", features = ["derive"] }
-tokio = { version = "^0.2.5", features = ["full"]}
-serde_json = "^1.0"
-derive_builder = "0.9.0"
+derive_builder = "^0.9.0"
+log = "^0.4.11"
 
 [dev-dependencies]
 mockito = "0.28.0"
 maplit = "1.0.2"
+tokio = { version = "^0.2.5", features = ["full"]}
+serde_json = "^1.0"
+env_logger = "0.8.2"

src/lib.rs

@@ -1,8 +1,7 @@
-///! OpenAI API client library
+///! `OpenAI` API client library
 #[macro_use]
 extern crate derive_builder;
 
-use reqwest::header::HeaderMap;
 use thiserror::Error;
 
 type Result<T> = std::result::Result<T, OpenAIError>;
@@ -215,6 +214,9 @@ pub enum OpenAIError {
     /// An error the client discovers before talking to the API
     #[error("Bad arguments")]
     BadArguments(String),
+    /// Network / protocol related errors
+    #[error("Error at the protocol level")]
+    ProtocolError(surf::Error),
 }
 
 impl From<api::ErrorMessage> for OpenAIError {
@@ -229,49 +231,86 @@ impl From<String> for OpenAIError {
     }
 }
 
+impl From<surf::Error> for OpenAIError {
+    fn from(e: surf::Error) -> Self {
+        OpenAIError::ProtocolError(e)
+    }
+}
+
 /// Client object. Must be constructed to talk to the API.
 pub struct OpenAIClient {
-    client: reqwest::Client,
-    root: String,
+    client: surf::Client,
+}
+
+/// Authentication middleware
+struct BearerToken {
+    token: String,
+}
+
+impl std::fmt::Debug for BearerToken {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        // Get the first few characters to help debug, but not accidentally log key
+        write!(
+            f,
+            r#"Bearer {{ token: "{}" }}"#,
+            self.token.get(0..8).ok_or(std::fmt::Error)?
+        )
+    }
+}
+
+impl BearerToken {
+    fn new(token: &str) -> Self {
+        Self {
+            token: String::from(token),
+        }
+    }
+}
+
+#[surf::utils::async_trait]
+impl surf::middleware::Middleware for BearerToken {
+    async fn handle(
+        &self,
+        mut req: surf::Request,
+        client: surf::Client,
+        next: surf::middleware::Next<'_>,
+    ) -> surf::Result<surf::Response> {
+        log::debug!("Request: {:?}", req);
+        req.insert_header("Authorization", format!("Bearer {}", self.token));
+        let response = next.run(req, client).await?;
+        log::debug!("Response: {:?}", response);
+        Ok(response)
+    }
 }
 
 impl OpenAIClient {
     /// Creates a new `OpenAIClient` given an api token
+    #[must_use]
     pub fn new(token: &str) -> Self {
-        let mut headers = HeaderMap::new();
-        headers.insert(
-            reqwest::header::AUTHORIZATION,
-            reqwest::header::HeaderValue::from_str(&format!("Bearer {}", token))
-                .expect("Client library error. Header value badly formatted"),
+        let mut client = surf::client();
+        client.set_base_url(
+            surf::Url::parse("https://api.openai.com/v1/").expect("Static string should parse"),
         );
-        Self {
-            client: reqwest::Client::builder()
-                .default_headers(headers)
-                .build()
-                .expect("Client library error. Should have constructed a valid http client."),
-            root: "https://api.openai.com/v1".into(),
-        }
+        client = client.with(BearerToken::new(token));
+        Self { client }
+    }
+
+    /// Allow setting the api root in the tests
+    #[cfg(test)]
+    fn set_api_root(&mut self, url: surf::Url) {
+        self.client.set_base_url(url);
     }
 
     /// Private helper for making gets
     async fn get<T: serde::de::DeserializeOwned>(&self, endpoint: &str) -> Result<T> {
-        let url = &format!("{}/{}", self.root, endpoint);
-        let response = self
-            .client
-            .get(url)
-            .send()
-            .await
-            .expect("Client error. Should have passed a valid url");
-        if response.status() != 200 {
-            return Err(OpenAIError::APIError(
-                response
-                    .json::<api::ErrorWrapper>()
-                    .await
-                    .expect("The API has returned something funky")
-                    .error,
-            ));
+        let mut response = self.client.get(endpoint).await?;
+        if let surf::StatusCode::Ok = response.status() {
+            Ok(response.body_json::<T>().await?)
+        } else {
+            {
+                let err = response.body_json::<api::ErrorWrapper>().await?.error;
+                Err(OpenAIError::APIError(err))
+            }
         }
-        Ok(response.json::<T>().await.unwrap())
     }
 
     /// Lists the currently available engines.
@@ -295,29 +334,26 @@ impl OpenAIClient {
 
     // Private helper to generate post requests. Needs to be a bit more flexible than
     // get because it should support SSE eventually
-    async fn post<B: serde::ser::Serialize>(
-        &self,
-        endpoint: &str,
-        body: B,
-    ) -> Result<reqwest::Response> {
-        let url = &format!("{}/{}", self.root, endpoint);
-        let response = self
+    async fn post<B, R>(&self, endpoint: &str, body: B) -> Result<R>
+    where
+        B: serde::ser::Serialize,
+        R: serde::de::DeserializeOwned,
+    {
+        let mut response = self
             .client
-            .post(url)
-            .json(&body)
-            .send()
-            .await
-            .expect("Client library error, json failed to parse");
-        if response.status() != 200 {
-            return Err(OpenAIError::APIError(
+            .post(endpoint)
+            .body(surf::Body::from_json(&body)?)
+            .await?;
+        match response.status() {
+            surf::StatusCode::Ok => Ok(response.body_json::<R>().await?),
+            _ => Err(OpenAIError::APIError(
                 response
-                    .json::<api::ErrorWrapper>()
+                    .body_json::<api::ErrorWrapper>()
                     .await
                     .expect("The API has returned something funky")
                     .error,
-            ));
+            )),
         }
-        Ok(response)
     }
     /// Get predicted completion of the prompt
     ///
@@ -330,11 +366,7 @@ impl OpenAIClient {
         let args = prompt.into();
         Ok(self
             .post(&format!("engines/{}/completions", args.engine), args)
-            .await?
-            //.text()
-            .json()
-            .await
-            .expect("Client error. JSON didn't parse correctly."))
+            .await?)
     }
 }
 
@@ -344,8 +376,11 @@ mod unit {
     use crate::{api, OpenAIClient, OpenAIError};
 
     fn mocked_client() -> OpenAIClient {
+        let _ = env_logger::builder().is_test(true).try_init();
         let mut client = OpenAIClient::new("bogus");
-        client.root = mockito::server_url();
+        client.set_api_root(
+            surf::Url::parse(&mockito::server_url()).expect("mockito url didn't parse"),
+        );
         client
     }
 
@@ -493,9 +528,9 @@ mod integration {
     use api::ErrorMessage;
 
     use crate::{api, OpenAIClient, OpenAIError};
-
     /// Used by tests to get a client to the actual api
     fn get_client() -> OpenAIClient {
+        let _ = env_logger::builder().is_test(true).try_init();
         let sk = std::env::var("OPENAI_SK").expect(
             "To run integration tests, you must put set the OPENAI_SK env var to your api token",
         );