genai: add test and example for JSON schema

genai/client_test.go

@@ -454,11 +454,50 @@ func TestLive(t *testing.T) {
 		}
 		got := responseString(res)
 		t.Logf("got %s", got)
+		// Accept any valid JSON
 		var a any
 		if err := json.Unmarshal([]byte(got), &a); err != nil {
 			t.Fatal(err)
 		}
 	})
+	t.Run("JSON schema", func(t *testing.T) {
+		model := client.GenerativeModel("gemini-1.5-pro-latest")
+		model.SetTemperature(0)
+		model.ResponseMIMEType = "application/json"
+		model.ResponseSchema = &Schema{
+			Type: TypeArray,
+			Items: &Schema{
+				Type: TypeObject,
+				Properties: map[string]*Schema{
+					"name": {
+						Type:        TypeString,
+						Description: "The name of the color",
+					},
+					"RGB": {
+						Type:        TypeString,
+						Description: "The RGB value of the color, in hex",
+					},
+				},
+				Required: []string{"name", "RGB"},
+			},
+		}
+		res, err := model.GenerateContent(ctx, Text("List the primary colors."))
+		if err != nil {
+			t.Fatal(err)
+		}
+		got := responseString(res)
+		t.Logf("got %s", got)
+		// Check that the format of the result matches the schema. The actual content
+		// doesn't matter here.
+
+		type color struct {
+			Name, RGB string
+		}
+		var v []color
+		if err := json.Unmarshal([]byte(got), &v); err != nil {
+			t.Fatal(err)
+		}
+	})
 }
 
 func TestJoinResponses(t *testing.T) {

genai/example_test.go

@@ -16,12 +16,14 @@
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"log"
 	"net/http"
 	"net/url"
 	"os"
+	"slices"
 
 	"github.com/google/generative-ai-go/genai"
 	"google.golang.org/api/googleapi"
@@ -141,6 +143,34 @@
 	fmt.Println("Num tokens:", resp.TotalTokens)
 }
 
+func ExampleGenerativeModel_JSONSchema() {
+	ctx := context.Background()
+	client, err := genai.NewClient(ctx, option.WithAPIKey(os.Getenv("GEMINI_API_KEY")))
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer client.Close()
+
+	model := client.GenerativeModel("gemini-1.5-pro")
+	model.ResponseMIMEType = "application/json"
+	model.ResponseSchema = &genai.Schema{
+		Type:  genai.TypeArray,
+		Items: &genai.Schema{Type: genai.TypeString},
+	}
+	res, err := model.GenerateContent(ctx, genai.Text("List the primary colors."))
+	if err != nil {
+		log.Fatal(err)
+	}
+	for _, part := range res.Candidates[0].Content.Parts {
+		if txt, ok := part.(genai.Text); ok {
+			var colors []string
+			if err := json.Unmarshal([]byte(txt), &colors); err != nil {
+				log.Fatal(err)
+			}
+			fmt.Println(colors)
+		}
+	}
+}
 func ExampleChatSession() {
 	ctx := context.Background()
 	client, err := genai.NewClient(ctx, option.WithAPIKey(os.Getenv("GEMINI_API_KEY")))
@@ -399,7 +429,7 @@
 	printResponse(res)
 }
 
-func ExampleToolConifg() {
+func ExampleToolConfig() {
 	// This example shows how to affect how the model uses the tools provided to it.
 	// By setting the ToolConfig, you can disable function calling.