testing.md

Creating Tests

Tests can be created using functions from the synapse:test module; Synapse does not require you to create a separate file for tests (but you can if you wish). The interfaces are similar to existing test frameworks e.g. Mocha, Jest, etc. in that you can create individual tests as well as suites of tests.

For example:

import { describe, it } from 'synapse:test'

describe('a test suite', () => {
    it('runs a test', () => {
        console.log('hi')
    })
})

Creates a test suite named "a test suite" and a test within that suite called "runs a test", following the BDD-style of naming.

You can also create tests outside of a suite:

import { test, it } from 'synapse:test'

test('console.log("hi")', () => {
    console.log("hi")
})

Note that it is an alias for test. Both can be used interchangeably.

Running tests

Use the command synapse test to run all tests. You can provide specific filenames to only run tests in those files as well.

Note that tests are considered a "resource" (albeit a local one). That means a "deploy" operation is required to create/update tests. This happens automatically when you run synapse test. Any resources that your tests depend on could be updated which might not be wanted. A future release may include ways to control this behavior.

Assertion functions

synapse:test exports a few basic functions for making comparisons (equivalents are from node:assert):

• expect - truthy check, equivalent to ok
• expectEqual - deep comparison, equivalent to assertDeepStrictEqual
• expectReferenceEqual - shallow comparison, equivalent to assertStrictEqual

One thing that should stand out is the swapping of deep equal and shallow equal. This was done because structural equality is far more useful and common for distributed systems.

Using other testing frameworks

Other frameworks have not been tested, however, it might be possible to use existing frameworks with varying degrees of functionality.

In general, mocking and assertion utilities should be compatible.