fix!: fix failure when api key as param and not env

BREAKING CHANGE:

- Rename `ClientError.ApiKeyError` to `MissingApiKey`.
- Rename `ClientError.ReadResponseTextError` to `ClientError.UnreadableResponseText`.

tests/v1_client_new_test.rs

@@ -26,6 +26,37 @@ fn test_client_new_with_none_params() {
 fn test_client_new_with_all_params() {
     let maybe_original_mistral_api_key = std::env::var("MISTRAL_API_KEY").ok();
     std::env::remove_var("MISTRAL_API_KEY");
+
+    let api_key = Some("test_api_key_from_param".to_string());
+    let endpoint = Some("https://example.org".to_string());
+    let max_retries = Some(10);
+    let timeout = Some(20);
+
+    let client = Client::new(
+        api_key.clone(),
+        endpoint.clone(),
+        max_retries.clone(),
+        timeout.clone(),
+    )
+    .unwrap();
+
+    expect!(client.api_key).to_be(api_key.unwrap());
+    expect!(client.endpoint).to_be(endpoint.unwrap());
+    expect!(client.max_retries).to_be(max_retries.unwrap());
+    expect!(client.timeout).to_be(timeout.unwrap());
+
+    match maybe_original_mistral_api_key {
+        Some(original_mistral_api_key) => {
+            std::env::set_var("MISTRAL_API_KEY", original_mistral_api_key)
+        }
+        None => std::env::remove_var("MISTRAL_API_KEY"),
+    }
+}
+
+#[test]
+fn test_client_new_with_api_key_as_both_env_and_param() {
+    let maybe_original_mistral_api_key = std::env::var("MISTRAL_API_KEY").ok();
+    std::env::remove_var("MISTRAL_API_KEY");
     std::env::set_var("MISTRAL_API_KEY", "test_api_key_from_env");
 
     let api_key = Some("test_api_key_from_param".to_string());
@@ -62,8 +93,8 @@ fn test_client_new_with_missing_api_key() {
     let call = || Client::new(None, None, None, None);
 
     match call() {
-        Ok(_) => panic!("Expected `ClientError::ApiKeyError` but got Ok.`"),
-        Err(error) => assert_eq!(error, ClientError::ApiKeyError),
+        Ok(_) => panic!("Expected `ClientError::MissingApiKey` but got Ok.`"),
+        Err(error) => assert_eq!(error, ClientError::MissingApiKey),
     }
 
     match maybe_original_mistral_api_key {