- Getting Started with Mocha and Chai 3:16
- General Structure of Test Files 4:10
- Setting Up Mocha 4 questions
- Installing Mocha 1 objective
- Installing Chai 1 objective
- Test Suites and Test Specs (describe and it) 3:34
- Mocha Chai Basics 4 questions
- Writing Our First Test Suite 14:49
- Writing Our First Test Suite - Part 2 8:15
- Challenge: Expanding Our Expectations 9:57
- Answer: Expanding Our Expectations 12:05
- A Testing Test! 1 objective
- Assert Your Knowledge 5 questions
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General Structure of Test Files
4:10In this video, we’ll go over the specific way Mocha expects us to organize our files in order to run properly.
Different frameworks require us to set
up our file structure differently.
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They want us to name our
test files differently.
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Or put them in different places.
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The main issue is that we don't want
to track down our test files manually
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every time we run them.
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The whole point of automated testing
is that our tests are easier and
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better to use than our
old manual testing style.
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If our tests are annoying to use then
we might go through all the trouble of
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writing them only to never actually
run them while we're developing.
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That would be a huge waste.
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So, we want our test to be easy to run and
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write that way we're more likely
to actually test our code.
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>> Mocha has a really convenient feature.
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Since we've already installed
Mocha as a dependency for
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our project, we can have NPM use it to
run all of our tests automatically.
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So first, in the console,
we'll run npm init.
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This sets up our project to be portable,
and
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it takes advantage of some
convenient npm features.
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Now, in the console, npm asks us a bunch
of questions about our project setup.
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But for now, I'm just going to
press Enter for all of these and
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accept the defaults, since I don't
plan to publish this project anywhere.
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The result is that we have
a package.json file for our project.
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Now it doesn't have much in it right now.
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But notice that the scripts field
has a test about that already.
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By default, the test method will normally
just give us a warning in our terminal or
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consul that says error no test specified.
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But in our package.json file npm has
already set the test command to use Mocha.
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And although we've been explicitly telling
Mocha which files to run, we can actually
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save even more time by keeping all of our
test files in a directory called test.
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It's important that the directory is
specifically named test, not tests.
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Or Test with a capital t,
and it has to be located
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at the same level of our project
structure as the package.JSON file.
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It makes sense to have all our tests in
one directory at the top of our project.
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It makes it easy to pull in code
from other files in our project
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because the follow path will
always be from the same directory.
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That also makes it easy
to organize our tests.
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And for ourselves to find the right
test file after we see it
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output in our console.
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Now if we forget to install
Mocha before running npm init,
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we can always just go change this part
of our package.json file by hand.
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And you can check the teacher's notes
to learn more about customizing your
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package.json file to run task for us,
like starting our automated test group.
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So if we follow these guidelines then
we just get to run npm test, and
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Mocha will automatically run every single
test in the test directory for us.
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So let's create a new directory called
test here at the root of our project.
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And I'll move the main test.js
file inside the new test folder.
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So now when I run npm test in a console,
I get the same output as running Mocha.
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Great.
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Earlier I mentioned that it's important
that the directory is specifically named
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test in all lowercase letters.
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Naming the test directory badly is
a common mistake developers make
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when setting up suites.
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So let's see what Mocha's output is when
we use a directory name other than test.
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For instance,
let's change the name to tests.
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Then run npm test in the console.
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So now Mocha can't find
what it's looking for, so
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we get this test failed
error in the console output.
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And the same would happen if
the name is test with a capital T.
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So I'll change the name back to test.
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Then run npm test in the console, and
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now Mocha once again automatically runs
every single test In the test directory.
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Okay, so in the next video we'll really
start building our first test suite.
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