👋 Welcome to Matchstick - a unit testing framework for The Graph protocol. Try out your mapping logic in a sandboxed environment and ensure your handlers run correctly when deploying your awesome subgraph!

Quick Start 🚀

Matchstick relies on a helper library - matchstick-as, written in AssemblyScript and used as an import in the unit tests.

Configuration ⚙️

Matchstick can be configured to use a custom tests and libs folder via matchstick.yaml config file:

• To change the default tests location (./tests), add testsFolder: path/to/tests_folder

• To change the default libs location (./node_modules), add libsFolder: path/to/node_modules

• To change the default manifest location (./subgraph.yaml), add manifestPath: path/to/subgraph.yaml

Docker 🐳

The quickest way to use Matchstick "out of the box" is to build and run an ubuntu-based Docker container with a Matchstick image. Steps:

• Install Docker if you don't have it already.

• Create a file named Dockerfile in the root folder of your subgraph project, and paste the contents of this file there. Replace <MATCHSTICK_VERSION> placeholder with the desired matchstick version. You can find all available versions here

• Build a Matchstick image using the following command:

docker build -t matchstick .

• The build step might take a while, but once that's done we can quickly run our tests like this:

docker run -it --rm --mount type=bind,source=<absolute/path/to/project>,target=/matchstick matchstick

❗ If you want to pass arguments to Matchstick (for instance to test only a specific datasource or to generate a test coverage report) you can do so like this:

docker run -e ARGS="gravity" -it --rm --mount type=bind,source=<absolute/path/to/project>,target=/matchstick matchstick

❗ Note: The command will mount the project folder in the container, so you don't need to rebuild the image after every change to your code. Also any changes that happen to files during the run will persist on the host machine as well. More info about docker bind mounts

After that you can go straight to the final setup step and you'll be all set to start writing your first unit test.

❗ If you have previously ran graph test you may encounter the following error during docker build: error from sender: failed to xattr node_modules/binary-install-raw/bin/binary-<platform>: permission denied. In this case create a file named .dockerignore in the root folder and add node_modules/binary-install-raw/bin

❗ Although using the Docker approach is easy, we highly recommend using Matchstick via OS-specific binary (which is downloaded automatically when you run graph test). The Docker approach should only be considered if for some reason you cannot get graph test to work, or if you just want to quickly try something out.

OS-specific release binaries ⚙️

The release binary comes in two flavours - for МacOS and Linux. To add Matchstick to your subgraph project just open up a terminal, navigate to the root folder of your project and simply run graph test - it downloads the latest Matchstick binary and runs the specified test or all tests in a test folder (or all existing tests if no datasource flag is specified). Example usage: graph test gravity.

❗ If you don't have Postgres installed, you will need to install it. Instructions for that below: ❗❗❗ Since graph-node depends on diesel (and diesel requires a local postgres installation) we highly advise using the commands below as adding it in any other way may cause unexpected errors!

MacOS 

❗ Postgres installation command:

brew install postgresql@14

Then create new symlink to the lib:

ln -sf /usr/local/opt/postgresql@14/lib/postgresql@14/libpq.5.dylib /usr/local/opt/postgresql/lib/libpq.5.dylib

Linux 🐧

❗ Postgres installation command (depends on your distro):

sudo apt install postgresql

WSL (Windows Subsystem for Linux) 🤖

You can use Matchstick on WSL both using the Docker approach and the binary approach. As WSL can be a bit tricky, here's a few tips in case you encounter issues like static BYTES = Symbol("Bytes") SyntaxError: Unexpected token = or <PROJECT_PATH>/node_modules/gluegun/build/index.js:13 throw up;, or anything else that looks off:

Please make sure you're on a newer version of Node.js (graph-cli doesn't support v10.19.0 anymore, and that is still the default version for new Ubuntu images on WSL. For instance Matchstick is confirmed to be working on WSL with v18.1.0, you can switch to it either via nvm or if you update your global Node.js). Don't forget to delete node_modules and to run npm install again after updating you nodejs! Then, make sure you have libpq installed, you can do that by running sudo apt-get install libpq-dev. And finally, do not use graph test (which uses your global installation of graph-cli and for some reason that looks like it's broken on WSL currently), instead use yarn test or npm run test (that will use the local, project-level instance of graph-cli, which works like a charm. For that you would of course need to have a "test" script in your package.json file which can be something as simple as "test": "graph test").

Install dependencies

In order to use the test helper methods and run the tests, you will need to install the following dependencies:

yarn add --dev matchstick-as

Now you can jump straight to the examples in our demo-subgraph and start your journey in Subgraph unit testing!

Building from source

Prerequisites

To build and run Matchstick you need to have the following installed on your system:

• Rust - How to install Rust
• PostgreSQL – PostgreSQL Downloads

Setup

Clone this repository and run cargo build. If that executes successfully congratulations 🎉 you're all set.

NOTE: You may encounter an error, related to missing libpq dependencies on your system. In that case - install the missing dependencies (listed in the error log) with your package manager.

Next steps 🎯

There is a lot of room for improvements to Matchstick. We're trying to gather as much feedback from subgraph developers as we can, to understand how we can solve the problems they face when building subgraphs, as well as how we can make the overall testing process as smooth and streamlined as possible.

There's a GitHub project board where we keep track of day to day work which you can check out here.

You can check out the full list of tasks here.

Technologies used 💻

The Matchstick framework is built in Rust and acts as a wrapper for the generated WebAssembly module that contains the mappings and the unit tests. It passes the host function implementations down to the module, to be used in the tests (and in the mappings if needed). The framework also acts as a proxy for structs defined in the graph-node repo, because it needs to pass down all the usual imports, as well as a few bonus/mocked ones glued on top.