Adds support for audio captioning with Whisper (#267)

* Add speech to text example in docs

* Add caption formats for audio transcription

* Add caption example to README

* Address sanity check errors

* Add tests for decodeResponse

* Use typechecker for audio response format

* Decoding response refactors

client_test.go

@@ -1,6 +1,8 @@
 package openai //nolint:testpackage // testing private field
 
 import (
+	"bytes"
+	"io"
 	"testing"
 )
 
@@ -20,3 +22,38 @@ func TestClient(t *testing.T) {
 		t.Errorf("Client does not contain proper orgID")
 	}
 }
+
+func TestDecodeResponse(t *testing.T) {
+	stringInput := ""
+
+	testCases := []struct {
+		name  string
+		value interface{}
+		body  io.Reader
+	}{
+		{
+			name:  "nil input",
+			value: nil,
+			body:  bytes.NewReader([]byte("")),
+		},
+		{
+			name:  "string input",
+			value: &stringInput,
+			body:  bytes.NewReader([]byte("test")),
+		},
+		{
+			name:  "map input",
+			value: &map[string]interface{}{},
+			body:  bytes.NewReader([]byte(`{"test": "test"}`)),
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			err := decodeResponse(tc.body, tc.value)
+			if err != nil {
+				t.Errorf("Unexpected error: %v", err)
+			}
+		})
+	}
+}