package-tests

package-tests

This crate tests the packages found in the ./packages directory. Each package in there is its own crate, but they are not part of the larger workspace. This means that commands such as cargo build doesn't build them directly (rather, core builds them). Since we want a custom build flow for those packages, this is how we have to do it, but it is problematic with tests. Testing a packages isn't as simple as cargo test, in that case we would have to go into every package directory and run cargo test within each of them. This isn't really optimal.

This crate is aimed at solving that shortcoming. The packages themselves are focused on being small to compile to wasi, and all interfacing with them occurs with stdin/stdout. This means that we can do simple integration testing of the package itself by providing an input and output file. During development, creating a sample json file is useful since it can be piped into the program to see if it does what it expects, and this crate gives a simple path from that to a full-fledged test case.

Convert example.json to a test case

Let's say you are developing the html module, and you have an input file example.json with this content:

{
    "name": "__bold",
    "arguments": {},
    "children": [
        {
            "name": "__text",
            "data": "Hello, world",
            "arguments": {},
            "inline": true
        }
    ]
}

The file is simple enough and useful to find bugs in the code during development. You can run your application using cat example.json | cargo run -- transform __bold html When development is finished, it would be nice to have this as a test case, and the only things you have to do to convert this to an actual test case which is checked by cargo test is the following:

1. Move the file to the tests directory.
   • If you don't have a tests directory, make one as a sibling to src.
   • Optionally, give the file a more descriptive name of what is being tested
2. Add a key __test_transform_to with the value of what you use as the third argument to your package, which in this case is html. The first argument is retrieved from the node name.
3. Add a key __test_expected_result with the value of the resulting json you expect.

That's it! This crate will find all tests/*.json files one level deep within the packages folder and run them all on cargo test. Feel free to add multiple tests confirming that everything works as expected.