minidyn

Amazon DynamoDB testing library written in Go.

Goals

• Make local testing for DynamoDB as accurate as possible.
• Run DynamoDB tests in a CI without external dependencies.
• Identify errors caused by DynamoDB restrictions.

Usage

Create the dynamodb client:

client := minidyn.NewClient()

Define the tables and indexes schemas,you can use the SDKs methods to create tables.

client.CreateTable(&dynamodb.CreateTableInput{
  TableName: aws.String("pokemons"),
  AttributeDefinitions: []*dynamodb.AttributeDefinition{
    {
      AttributeName: aws.String("id"),
      AttributeType: aws.String("S"),
    },
  },
  BillingMode: aws.String("PAY_PER_REQUEST"),
  KeySchema: []*dynamodb.KeySchemaElement{
    {
      AttributeName: aws.String("id"),
      KeyType:       aws.String("HASH"),
    },
  },
})

Or you can use the AddTable and AddIndex method helper.

err := client.AddTable("pokemons", "id", "primary_type")
if err != nil {
  return err
}

err = client.AddIndex("pokemons", "type_index", "primary_type", "")
if err != nil {
  return err
}

NOTE these methods only support string attributes.

Language interpreter

This library has an interpreter implementation for the DynamoDB Expressions.

Conditional Expressions

Types

Name	Type	Short	Supported?
Number	scalar	N	y
String	scalar	S	y
Binary	scalar	B	y
Bool	scalar	BOOL	y
Null	scalar	NULL	y
List	document	L	y
Map	document	M	y
StringSet	set	SS	y
NumberSet	set	NS	y
BinarySet	set	BS	y

Expressions

	Syntax	Supported?
operand comparator operand	= <> < <= > and >=	y
operand BETWEEN operand AND operand	N,S,B	y
operand IN ( operand (',' operand (, ...) ))		y
function	attribute_exists, attribute_not_exists, attribute_type, begins_with, contains, size	y
condition AND condition		y
condition OR condition		y
NOT condition		y

Update Expressions

Expressions

	Syntax	Supported?
SET	SET action [, action] ...	y
REMOVE	REMOVE action [, action] ...	y
ADD	ADD action [, action] ...	y
DELETE	DELETE action [, action] ...	y
function	list_append, if_not_exists	y

What to do when the interpreter does not work properly?

When it happens you can override the intepretation using like this:

client.ActivateNativeInterpreter()

client.GetNativeInterpreter().AddUpdater(table, "SET secondary_type = :secondary_type", func(item map[string]*dynamodb.AttributeValue, updates map[string]*dynamodb.AttributeValue) {
   item["secondary_type"] = updates[":secondary_type"]
})

Note: Please, report us the issue with the interpreter through https://github.com/truora/minidyn/issues

License

The MIT License