Apollo Federation Subgraph Compatibility Testing

@apollo/federation-subgraph-compatibility script is an NPM package that allows you to test given subgraph's implementation for compatibility against the Apollo Federation Subgraph Specification. This testing suite verifies various Federation features against subgraph implementation. See compatibility testing docs for details on the expected schema and the data sets as well as information about the executed tests.

Apollo Federation Subgraph Compatibility Testing
- Installation
- Usage
- Contact
- Security
- License

Installation

Apollo Federation subgraph compatibility test script is published to NPM.

npm install --dev @apollo/federation-subgraph-compatibility

You can execute the script using NPX

# remote package
npx @apollo/federation-subgraph-compatibility --help

# package installed locally
npx fedtest --help

# package installed globally
fedtest --help

Usage

@apollo/federation-subgraph-compatibility test script starts a supergraph that consists of your subgraph implementation, two reference subgraphs and Apollo Router. Since script needs to manage multiple processes, you need to specify which process management technology should be used to run the tests. Currently script supports PM2 and Docker Compose.

npx fedtest --help
Usage: fedtest [options] [command]

Run Apollo Federation subgraph compatibility tests

Options:
  -V, --version             output the version number
  -h, --help                display help for command

Commands:
  pm2 [options]             Start supergraph using PM2
  docker [options]          Start supergraph using Docker Compose
  help [options] [command]  display help for command

PM2

PM2 is a Node based process manager. When tests are run using pm2 command, script will start the supergraph using Apollo Rover dev command.

npx fedtest pm2 --help
Usage: fedtest pm2 [options]

Start supergraph using PM2

Options:
  --config <subgraph.config.js>  optional PM2 configuration file
  --debug                        debug mode with extra log info
  --endpoint <url>               subgraph endpoint
  --failOnRequired               boolean flag to indicate whether any failing required test should fail the script.
  --failOnWarning                boolean flag to indicate whether any failing test should fail the script.
  --format <json|markdown>       optional output file format (choices: "json", "markdown", default: "markdown")
  -h, --help                     display help for command
  --quiet                        suppress logging to minimum
  --schema <schema.graphql>      optional path to schema file, if omitted composition will fallback to introspection

If your subgraph is already up and running, you can run compatibility tests using PM2 by specifying --endpoint <url> option. This will create supergraph that uses introspection to read subgraph schema.

npx fedtest pm2 --endpoint http://localhost:8080/graphql

If you have a subgraph schema available, you can also specify it on the command line. Schema path can be absolute or relative to the current directory.

npx fedtest pm2 --endpoint http://localhost:8080/graphql --schema /path/to/schema.graphql

PM2 can also be used to start your subgraph. You can specify an ecosystem config file that contains information how to start your subgraph.

// simple PM2 subgraph config that starts Node application
module.exports = {
    apps : [{
      name   : "subgraph product",
      script : "index.js",
      cwd: "/path/to/your/implementation"
    }]
}

npx fedtest pm2 --endpoint http://localhost:8080/graphql --config /path/to/subgraph.config.js

Docker Compose

Docker Compose is a tool for running multi-container Docker applications. When tests are run using docker command, script will compose supergraph using Apollo Rover supergraph compose command and run standalone router image.

npx fedtest docker --help
Usage: fedtest docker [options]

Start supergraph using Docker Compose

Options:
  --compose <docker-compose.yaml>  Path to docker compose file
  --debug                          debug mode with extra log info
  --failOnRequired                 boolean flag to indicate whether any failing required test should fail the script.
  --failOnWarning                  boolean flag to indicate whether any failing test should fail the script.
  --format <json|markdown>         optional output file format (choices: "json", "markdown", default: "markdown")
  -h, --help                       display help for command
  --path <path>                    GraphQL endpoint path (default: "")
  --port <port>                    HTTP server port (default: "4001")
  --quiet                          suppress logging to minimum
  --schema <schema.graphql>        Path to schema file

In order to run compatibility tests using docker command, you need to pass both compose file and subgraph schema file. Paths to files can be absolute or relative to the current working directory.

npx fedtest docker --compose /path/to/docker-compose.yaml --schema /path/to/schema.graphql

Docker Compose file is a YAML configuration file that defines all services, networks and volumes necessary for running your application. For Apollo Federation compatibility tests we require you to define a service called products which should expose your GraphQL endpoint at http://localhost:4001.

services:
  products:
    # must be a relative path to the directory that will be used to run the tests
    # if you are going to run the tests from the same directory as your docker file, then you can specify .
    build: path/to/my-implementation
    # expose ports
    ports:
      - 4001:4001

If your application exposes custom path (e.g. /graphql) or use different port, make sure to also specify those values as command line arguments.

# docker compose file starts subgraph exposing http://localhost:8080/graphql
npx fedtest docker --compose /path/to/docker-compose.yaml --schema /path/to/schema.graphql --path /graphql --port 8080

For compose file examples, see the example implementations in this repository. For additional details, please refer to the Docker compose documentation.

Test Results

Script logs the compatibility test results on the console and also generates corresponding results file. By default, script will generate results in a markdown format. You can change this behavior by specifying and --format json option.

# generate results.json file
npx fedtest pm2 --endpoint http://localhost:8080/graphql --format json

Debug Mode

In order to enable debug mode that provides more verbose logs, specify --debug option on the command line.

npx fedtest pm2 --endpoint http://localhost:8080/graphql --debug

Contact

If you have a specific question about the testing library or code, please start a discussion in the Apollo community forums.

Security

For more info on how to contact the team for security issues, see our Security Policy.

License

This library is licensed under The MIT License (MIT).