add some examples

example_test.go

@@ -0,0 +1,67 @@
+package dynamo_test
+
+import (
+	"context"
+	"log"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/aws/retry"
+	"github.com/aws/aws-sdk-go-v2/config"
+	"github.com/aws/aws-sdk-go-v2/credentials"
+	"github.com/guregu/dynamo/v2"
+)
+
+func ExampleNew() {
+	// Basic setup example.
+	// See: https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/config for more on configuration options.
+	const region = "us-west-2"
+	cfg, err := config.LoadDefaultConfig(
+		context.Background(),
+		config.WithRegion(region),
+	)
+	if err != nil {
+		log.Fatal(err)
+	}
+	db := dynamo.New(cfg)
+	// use the db
+	_ = db
+}
+
+func ExampleNew_local_endpoint() {
+	// Example of connecting to a DynamoDB local instance.
+	// See: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/DynamoDBLocal.DownloadingAndRunning.html
+	const endpoint = "http://localhost:8000"
+	resolver := aws.EndpointResolverWithOptionsFunc(
+		func(service, region string, options ...interface{}) (aws.Endpoint, error) {
+			return aws.Endpoint{URL: endpoint}, nil
+		},
+	)
+	// credentials can be anything, but must be set
+	creds := credentials.NewStaticCredentialsProvider("dummy", "dummy", "")
+	cfg, err := config.LoadDefaultConfig(
+		context.Background(),
+		config.WithRegion("local"), // region can also be anything
+		config.WithEndpointResolverWithOptions(resolver),
+		config.WithCredentialsProvider(creds),
+	)
+	if err != nil {
+		log.Fatal(err)
+	}
+	db := dynamo.New(cfg)
+	// use the db
+	_ = db
+}
+
+func ExampleRetryTx() {
+	// `dynamo.RetryTx` is an option you can pass to retry.NewStandard.
+	// It will automatically retry canceled transactions.
+	cfg, err := config.LoadDefaultConfig(context.Background(), config.WithRetryer(func() aws.Retryer {
+		return retry.NewStandard(dynamo.RetryTx)
+	}))
+	if err != nil {
+		log.Fatal(err)
+	}
+	db := dynamo.New(cfg)
+	// use the db
+	_ = db
+}