TESTING.md

Coverage report for integration testing.

We use nyc for getting the coverage results for the integration tests. We have the following conditions and aims for getting the coverage results:

• we spawn a separate process for the server on the integration tests.
• We would like to have a single coverage report for the entire test.

Approach

Server start mode

There are two ways by which we can spawn the server: ipc and stdio. WE are using stdio for spawning the server right now because of a (probable) timing issue setting up the ipc channel across the process lineage test -> spawned nyc process -> ELS server. This had manifest in two ways as below:

1. When running `jest` in `inspect-brk` mode, and when we 'spend' some time
   on a relevant breakpoint  (around connection setup in
   integration-test.js), then the `ipc` channel is setup correctly. But when
   we don't run it in debug mode, the ipc channel is _not_ setup right.

2.  If all the integration tests are run together (no -t on jest), the first
    test Initialize request alone fails for want of a response from the
    server, but further tests are getting a valid response (with empty
    array) as the project had not been inited.

So because of the above shortcomings, we choose to run the server in stdio mode. See package.json :: test:coverage task for the command to run the tests with coverage (single coverage for all unit and integration tests).

Caveat

Since we use the stdio for communication, we cannot use the same for logging. This prevents use of 'RemoteConsole' in the server code while testing is enabled. Hence, the remote console is set to null by using the flag isELSTesting.

Instrumentation

The nyc process which we spawn for running the server did not seem to collect coverage metrics for the server code, unless instrumented using an additional step before the actual tests are run.

Errors

Error: Header must provide a Content-Length property

• remove "console.log" from code base.