consul/ui/packages/consul-ui/docs/testing.mdx

# Testing

## Running Tests

Our Ember application uses QUnit and QUnit's HTML runner in order to run tests.
As a human both of these should always be used to run tests. Currently you can
start the tests running by typing:

```bash
make test-oss-view
```

...in your terminal. This command will be changed to be the default `make test`
command at some point in the future.

As a human please always run the tests in a browser. You will sometimes spot
tiny details that are wrong with the application if you do this. We have other
`make` targets for running tests as a machine. Please don't use these machine
oriented targets as a human.

To re-run tests, simply refresh your browser or click the [Go] button in QUnit's
HTML test runner. If you then want to filter which tests to run you can use the
filter field in QUnit's HTML test runner to run a subset of tests (see below).
If you have started the tests with a filter, you don't have to quit everything
and start again in order to filter by something different.

### Running a single or a range of tests

Please use the same `make test-oss-view` command to get the tests up and
running. Once you have opened your browser window to view the tests, click the
[Abort] button to stop the test running. Then use the QUnit filter input text
field to filter by the tests you want to run.

Alternatively you can also run a single test by bypassing `make` and using:

```bash
yarn test:oss:view --filter=<test name substring>
```

Please note: If filtering using the CLI, normally you would expect a filter to
accept filenames. This is not the case here. When using Ember, tests are
filtered by test name not file name. You can get these test names by opening the
test file itself and finding the test you want run. You may need to escape
characters when doing that so be aware of that if you are copypasting.

Please be aware this that in bypassing `make` you will not have the project
setup for you automatically, certain housekeeping duties will not be performed
and you may skip some tests that are important for the thing (or things) you are
working on.

We also run a quick lint check for you (plus a few other things) that you should
fix up before you run your test.

If you do use yarn --filter, please run these other checks before submitting a
PR. If you just use `make test-oss-view` you (and nobody else) needs to worry
about those things.

Additionally, there are ongoing discussions regarding moving to use npm and or
corepack) as a package manager, so if you are using yarn, we may break your
workflow. If you are using `make`, don't worry as it stands right now nothing
will change.

If you specify your filter using the CLI and you make a typo or type your filter
wrong, or want to run a different filter. Don't quit the executing CLI command
and restart. That takes comparatively long time. You may aswell wait and then
amend the typo in QUnit's HTML test runner's filter input field.

Ember folks can also just use [`ember test`](https://cli.emberjs.com/release/basic-use/cli-commands/#testingyourapp)
and bypass both `yarn` and `make` but all of the above regarding using `yarn`
instead of `make` applies there also.

Please note: Currently the QUnit runner we depend on has an unfortunate UX
issue which means the filter input field is obscured by the frame used to run
your tests in. Until this is fixed in a version of QUnit we use, you can use
the Toggle QUnit Display bookmarklet to easily toggle the visibility of this window (you
should drag the below link to your browser bookmark bar, then clicking it
whilst on the test runner will hide the display):

| Link/Bookmarklet | Description |
| ---- | ----------- |
| [Toggle QUnit Display](javascript:(function()%7B(function()%7Bconst%20s%20%3D%20document.getElementById(%22ember-testing-container%22).style%3Bs.display%20%3D%20s.display%20%3D%3D%3D%20%22none%22%20%3F%20%22block%22%20%3A%20%22none%22%3B%7D)()%3B%7D)()%3B) | Toggle the QUnit display on or off during browser testing |

This also obscures test errors, messaging and the buttons to help you to re-run
a single test if you want to. So if you are doing a lot of testing for your
feature you might want to consider adding this to your bookmarks bar.

### Multiple 'spawning' test runners

Ember's testing support also has an unfortunate UX issue in that it can
sometimes spawn multiple test runners and once you have a few of these opened
for you things can get very confusing. To disable Ember from automatically
opening test runner windows for you, there is non-Ember environment variable we
added to tell it to stop doing this:

```bash
export TESTEM_AUTOLAUNCH=0
```

Suggestion: You could add this to your bash profile if you find it useful.

The above will prevent Ember's 'testem' implementation from automatically
opening windows for you. This of course means you have to navigate to the test
runner yourself, but that's sometimes a small wrinkle compared to having lots
and lots _and lots_ of test runner windows open.

### Testing different scenarios

Most tests are written to automatically switch between different scenarios
during the test so you don't usually have to worry about this, just run the
tests and you are done.

The exception is our namespace testing. We run our entire acceptance test
suite 4 or 5 times for different namespace settings. If you want to run some
acceptance tests with namespace scenarios enabled, this _could_ be run by
using:

```bash
make test-view
```

...but please don't do that, it takes a long time.

In CI these tests are run by a machine by using:

```bash
make test
```

...but again as a human, please don't do that, it takes a long time. PRs are
blocked for merge until these tests pass CI, i.e. the machine will run it for
you.

Of course there are times where you want to run these tests as a human. If you
want to run a specfic test _and_ include testing those tests whilst namespaces
are enabled then run the test suite as you usually would:

```bash
make test-view-oss
```

If you only want to run a filtered set of tests use the QUnit filter input
field to filter for the test you want run (for example maybe `dc / acls`)

Then use our development bookmarklet for turning on namespace support in the
UI:

| Link/Bookmarklet | Description |
| ---- | ----------- |
| [Enable Nspaces](javascript:Scenario('CONSUL_NSPACES_ENABLE=1')) | Enable Namespace Support |

When you click that it will run the filtered tests against all 'types' of
namespace scenarios.

Finally, for integration testing where we need to check for namespace support,
these tests are always run in our integration tests (these run a lot faster
than acceptance tests). You probably only want to use the above approach when
needing to test specific acceptance tests with namespace scenarios.

## Writing tests

Speaking generally, currently Consul favours unit tests (in `./tests/unit`)
and acceptance tests (in `./tests/acceptance`). We also have a fair amount of
integration tests (in `./tests/integration`) for testing that systems of
combined units work well together. What ember traditionally calls integration
tests, are mostly 'component' tests. We have far less of these as the vast
majority of our components are just 'glorified partials' and mostly contain
very simple template logic that is mostly (but not always) not very worthwhile
testing.

Overall, please don't test things we don't own for example don't spend time
testing that Ember's handlebars templating is printing out variables
correctly. Don't spend time testing that `ember-composable-helpers` `not`
helper is working correctly. The great thing about a declarative template
(basically a configuration file) is that it probably won't need much testing
in isolation.

### Acceptance tests

Our acceptance tests use a BDD style of testing. This means tests are
relatively simple to write, the writer does not need to think about
asynchronicity, and best of all they are very easy to read and understand what
is being tested, and therefore anyone can roughly understand what is being
tested/passing (or failing) tests.

We have roughly 20-30 reusable BDD steps you can use to write tests. We
occasionally add a new step but not very often. You should be able to write
the majority of your tests using the steps we already have. The steps
themselves are in `./tests/steps/{assertions,debug,double,interactions}` and
they are just simple javascript optionally asynchronous functions that are
specifically built to be __highly reusable__.

If you come to write a new step, please take some time to think about how
reusable it will be and try to word the title of the step taking that into
account. Look at some of the existing steps for examples.

We use the `yadda` npm package for our BDD support, just as the ember addon we
originally used for this used `yadda`. In the future we'd like to re-consider
and potentially use `cucumber.js`.

In order to create a new acceptance test/feature please use the ember
generator to do so:

```bash
ember generate feature dc/model/thing
```

This creates some additional JS that unfortunately is required by the ember
addon, so until we move away from that addon, this is the easiest way to get
started with a brand new acceptance test.

If you are not familiar with the steps available to write tests the best way
to write a new test is to look at the tests already written/and or scan
through the steps folders to see what's available. As mentioned above, there
are only around 30 steps.

We make some use of `ember-page-objects` to encapsulate some DOM
selecting/functionality. To be fair we kind of dip in and out of using
`ember-page-objects` and there is ongoing work to remove it entirely and
replace it with something simpler to work with. We also have
`ember-test-selectors` installed. So please use either a page object or a
test-selector for selecting/asserting DOM elements when writing tests. Prefer
page objects, but if you find it complicated/difficult or just plain smelly,
feel free to use a test-selector and use that directly in the test instead. At
some point we will reassess this and bring it all into line with one single
approach.

__Most importantly__: Please try to only use either a page-object or a
test-selector for DOM assertions/selections. Please try to avoid using any
complex selectors.

### Integration testing

We use `sinon` for making mocks for testing that systems work well together,
other than that please see Ember's own documentation for writing tests.

__Remember__: Integration testing does not mean 'component tests' it means
checking to make sure the units of a system work well together.

If you want to test a component in isolation whilst working on it, please create
an `.mdx` file in the component folder and use that to work on the component. We
use these `.mdx` files to isolate the component, work on it, manually/visually
test it and document it for others. If somebody needs to change the component in
future this means they already have test scenarios enabled/arranged for them to
use. Components should generally be small things, or made up of further small
components that are individually testable in isolation. There shouldn't be much
logic required in a new component. And if there is, and it's important enough to
need testing, you should consider splitting the logic off and testing it outside
of the component via integration testing and/or unit testing. This more manual
kind of component testing should be thought of as 'unit testing for a
component'. You are very unlikely to break something unless you change the code
of the actual component itself, and if you are doing this you are working with
the `mdx` file.and likely to notice. Whilst not perfect, this is where we are
right now.

We have very few single components that are an integrated system of further
components (where automated testing would be more necessary/useful) and our
application aims to stay that way for the foreseeable future. But if you write
something that may require more complicated and/or integrated testing consider
splitting those pieces into smaller more testable chunks that can be
automatically tested.

### Unit testing

Unit testing should be just that, _testing a single unit_, and therefore should
be as vanilla JS as possible. Our application generally favours using vanilla
JS where possible and then plumbing that functionality/logic into the Ember
framework. Therefore there should be very little mention of Ember in our Unit
tests (apart from Ember's test harness).

We do have coverage enabled for most of our unit tests, but it's not something
we generally use/keep an eye on. Coverage shouldn't necessarily be used as a
yard stick. We have it enabled for folks that find it useful/beneficial and
whilst good coverage is a positive it's not always an essential.

Coverage is run in CI but you can also run it locally with:

```bash
make test-coverage-view
```

We also have a fair amount of node based unit tests to test things that can't
be tested using Ember's testing approach or are just quicker to run using
node. You'll see these executed using TAP reporting when you run the `make
test-view-oss` command. But they can be executed on their own with:

```bash
make test-node
```

These node based unit tests live in `./node-tests` and use the beautifully
simple `tape` test runner with TAP reporting.

Lastly, just to reiterate when testing, just use:

```bash
make test-oss-view
```

If you need to filter to only run specific tests, use the QUnit HTML runner's
filter input field.