mocument

README

Mocument

Mocument is a mock implementation of AWS DocumentDB for use in unit and integration testing. It allows developers to simulate DocumentDB operations locally, enabling offline testing without the need for a real DocumentDB instance.

Purpose

The purpose of mocument is to provide a robust, easy-to-use mock version of AWS DocumentDB. This allows developers to:

• Perform unit and integration tests without needing access to a real DocumentDB instance
• Simulate various scenarios including latency and errors
• Ensure code that interacts with DocumentDB can be tested thoroughly in a controlled environment

Features

• Mock implementation of DocumentDB operations
• Configurable to simulate latency and errors
• Supports CRUD operations for documents within collections
• Easy to integrate into existing projects for testing purposes

Installation

To install mocument, use the following command:

go get github.com/kylejryan/mocument

Usage

Basic Usage

Here's a basic example of how to use mocument in your project:

package main

import (
    "context"
    "fmt"

    "github.com/aws/aws-lambda-go/lambda"
    "github.com/kylejryan/mocument/mock"
)

type MyEvent struct {
    Name string `json:"name"`
}

var dbClient *mock.MockDocDB

func init() {
    mockConfig := &mock.MockConfig{SimulateLatency: false, ErrorMode: false}
    dbClient = mock.NewMockDocDB(mockConfig)
}

// Handler is our lambda handler invoked by the `lambda.Start` function call
func Handler(ctx context.Context, event MyEvent) (string, error) {
    // Insert a document
    doc := map[string]interface{}{"name": event.Name}
    err := dbClient.InsertDocument("collection", doc)
    if err != nil {
        return "", fmt.Errorf("failed to insert document: %w", err)
    }

    // Find the document
    filter := map[string]interface{}{"name": event.Name}
    results, err := dbClient.FindDocument("collection", filter)
    if err != nil {
        return "", fmt.Errorf("failed to find document: %w", err)
    }

    return fmt.Sprintf("Found documents: %+v", results), nil
}

func main() {
    lambda.Start(Handler)
}

Testing

You can use mocument to write unit tests for your code that interacts with DocumentDB. Here is an example of a test file:

package main

import (
	"context"
	"fmt"
	"testing"

	"github.com/kylejryan/mocument/mock"
	"github.com/stretchr/testify/assert"
)

var mockDBClient *mock.MockDocDB

func init() {
	mockConfig := &mock.MockConfig{SimulateLatency: false, ErrorMode: false}
	mockDBClient = mock.NewMockDocDB(mockConfig)
}

func mockHandler(ctx context.Context, event MyEvent) (string, error) {
	// Use the mock clients instead of the real AWS clients
	collection := mockDBClient

	// Insert a document
	doc := map[string]interface{}{"name": event.Name}
	err := collection.InsertDocument("collection", doc)
	if err != nil {
		return "", fmt.Errorf("failed to insert document: %w", err)
	}

	// Find the document
	filter := map[string]interface{}{"name": event.Name}
	results, err := collection.FindDocument("collection", filter)
	if err != nil {
		return "", fmt.Errorf("failed to find document: %w", err)
	}

	return fmt.Sprintf("Found documents: %+v", results), nil
}

func TestHandler(t *testing.T) {
	// Create a fake event
	event := MyEvent{Name: "test"}

	// Call the handler with the mock client
	result, err := mockHandler(context.Background(), event)
	assert.NoError(t, err)
	assert.Contains(t, result, "Found documents")
}

Contributing

We welcome contributions to mocument! If you'd like to contribute, please follow these steps:

1. Fork the repository on GitHub.
2. Clone your fork locally:

git clone https://github.com/your-username/mocument.git

1. Create a branch for your feature or bug fix:

git checkout -b feature-or-bugfix-branch

1. Commit your changes with a clear message:

git commit -am "Add new feature or fix bug"

1. Push to the branch:

git push origin feature-or-bugfix-branch

1. Create a pull request on GitHub, describing your changes.

Please make sure to write tests for your changes and ensure all existing tests pass.

License

mocument is licensed under the MIT License. See the LICENSE file for more information.

Acknowledgements

This project is inspired by the need to have reliable and efficient local testing environments for applications that interact with AWS DocumentDB.