NOTE: I’m pushing this out before it is ready so you can be working on it over the weekend, etc. I will update with clarifications and perhaps requests for more code. But this gets you started.

The purpose: Getting ready for the midterm.

There are two pieces:

  • Run some sanity tests.
  • Convert GetGist from React Function to React Component so we can add state to it.
    • Use the state to allow the user to iterate over the list of Gists.


The goal of the Sanity Tests assignments is to make sure you have a specific set, and only that specific set, of methods in components/App.js from the week03-rest-basics assignment. At this stage, my tests should confirm that the methods I want to see are available, but it does not look for other methods that I feel are not needed. That would be an improvement but I’m not there yet.

NOTE: Some of you may be calling the project that uses all your micros and calls GitHub by some other name than week03-rest-basics. That is fine, just tell me clearly the name of the project and branch that contains the code you want me to view.

I’m trying to do two things:

  • Provide guidance on what I want to see. To write in way that cannot be misunderstood the names of the methods I want to see in a class.
  • Ensure that at least parts of each assignment are easy for me to grade and troubleshoot because we are all using the same strategy and naming scheme.

More specifically, it checks that you have two methods that call fetch:

  • queryServer
  • fetchGistList

It also checks that you have two methods processing the JSON retrieved by these fetch methods.

  • queryServer should call setData from its second then method.
  • fetchGistList should call setGistList from its second then method.

At this stage, you don’t need anything else in the App.js other than the constructor and render method.

Recall that I want you to write code that looks like this code from the Address Simple Assignment:

In that code, elfQuery is similar to queryServer in week03-rest-basics and setData is similar to setData in week03-rest-basics.

After checking for four methods, the Sanity tests then check if a specific set of files are found in the components folder. I think that part is entirely self-explanatory, so I have focused on the code that looks for four specific methods that I want to see.

But I don’t Have any Gists

I’ve noticed that not everyone has any gists or only have on gist. Think of gists as a place to store methods that you use a lot. Here are some candidates:

  • An example of how to call fetch
  • A simple default React Component.
  • The /foo route that we use in routes/index.js
  • Bash Scripts that you have written that you don’t want to forget
  • Your .my_bash_aliases file

Sanity Tests

Let’s build some tests that check whether or not we are all building more or less the same application.

  • Create a directory called client/src/sanity-tests.
  • Here are the steps to get the Sanity.App.test.js test Suite and put it in your new sanity folder.
    • First, you will need to install elf-utils: npm i elven-code
    • You should also pull the latest from JsObjects, and then type slb and run ./CreateSymbolicLinks
    • This will add a symbolic link to a new script to your bin folder: ~/bin/get-tests
    • Run get-tests from your sanity folder. Select React Props Sanity Tests. It will add Sanity.App.test.js to your project.
  • Add the following to the scripts property in your client/package.json file: “sanity-test”: “react-scripts test Sanity*“
  • Run the test: npm run sanity-tests and make sure everything passes.

Needless to say, you cannot change anything in the test. However, I may change the test at some point. I’ll try to set up something like the get-gist bash script so that you can easily get the latest version of my test. (I’m referring to ~/bin/get-gist. I’m not talking about the GetGist component or microservice in our assignment.)

At this time (May 3), a run on my system looks like this:

PASS  src/sanity/Sanity.App.test.js
App Tests
✓ renders without crashing (5ms)
✓ App.js includes the method setData (1ms)
✓ App.js includes the method setGistList (1ms)
✓ App.js includes the method fetchGistList
✓ App.js includes the method queryServer (1ms)
✓ checks if App.js exists
✓ checks if ElfHeader exists
✓ checks if GetGist exists
✓ checks if GetUser exists
✓ checks if Qux exists
✓ checks if TestRoutes exists (1ms)

Test Suites: 1 passed, 1 total
Tests:       11 passed, 11 total
Snapshots:   0 total
Time:        0.632s, estimated 1s
Ran all test suites matching /Sanity*/i.

Watch Usage: Press w to show more.


To get some of the tests to pass, you might have to refactor your code in App.js to follow the model laid out Jest Express Address Simple assignment. The point being that we want to factor the code for parsing the JSON sent by the server into a separate method with a name like setData. Ideally, I should have a more descriptive name.

Update GetGist

Our goal is to be able to iterate over the list of gists you retrieved from your repository. The user should press buttons and see the various items in your list.

Convert the src/components/GetGist.js React component from a Function Component to a React Class Component. I’ll leave that up to you.

If you are currently passing in only a single gist object, change your code so you pass in an array of gistList objects. For instance your app-init gistList could have something like this in, at least as a starting point:

gistList: [{id: 'unknown1'}, {id: 'unknown2'}]

Of course, your call in the git-gist microservice will return objects with more than just an id field. In the midterm we will probably starting working with more than one field.

NOTE: There should be no need to change the git-gist microservice from the previous assignment. It still does the same thing, and we still call it the same way. The difference will be in the way we display the data we get from the call to our microservice. Of course, the microservice gets its data from GitHub via our GitHub API call.

In GetGist declare state with at least one property called index. The ability to declare state is the reason we switch from a React Function to a React Class Component. (For now we will ignore the new React hooks technology.) Use this index property to iterate over your gistList. Add a next and prev buttons that increment and decrement our index state and update your component state. For instance, if the next button is pressed, index is incremented, and the next item in our gist list is displayed.

  • The next and prev buttons should be declared inside GetGist
  • GetGist should have an H1 element with this text: Get Gist Component
  • You should also have one or two paragraph elements for displaying the date from an individual gist and current value of appInit.result.

The point is that much of GetGist is self contained. At this point, we will continue to show it on our main page, but we can use HR controls or other techniques to separate it from the other code.

For now, it is okay if your component iterates out of bounds if you press next or previous one too many times or at the wrong time. I’ll probably ask you to fix that for the midterm, but you don’t have to fix it for this assignment.

We should gray out the FetchGistList button after we select it once, but again, that is probably for the midterm.

To better understand what I want, watch the 2 minute video.


I want to add tests like the ones in Address Simple. I’ve written a number of them myself, but have not gotten that written up yet. I’ll add this soon.

Here is one of the tests I’ll want you to include. We have not done anything exactly like this before:

it('renders setGistList call directly', () => {
    const wrapper = shallow(<App appInit={appInit}/>);
    debug('IN TEST BUT BEFORE', wrapper.state('gistList'));
    expect(wrapper.state('gistList')).toEqual([{id: 'unknown'}]);
    const gistListFromServer = [{id: 'found'}];
    wrapper.instance().setGistList({gistList: gistListFromServer});

The point is that our paragraph elements for displaying the data are now in GetGist so we need some other way to confirm that we can parse the mock data that could have been sent from the server.

Turn it in

Just push your most recent work. I’m assuming you are working in week03-rest-basics, but regardless, please specify folder and branch. Tag it too.


What my tests looked like on various dates. The point being that we build up test suites slowly over time.

April 23:

Test Suites: 1 failed, 1 total
Tests:       1 failed, 1 total

April 27:

PASS  src/tests/GetGist.test.js
PASS  src/tests/GetUser.test.js
PASS  src/tests/ElfHeader.test.js
PASS  src/tests/Qux.test.js
PASS  src/tests/App.test.js
 ● Console

   console.log src/components/App.js:10
     FOO test

Test Suites: 5 passed, 5 total
Tests:       5 passed, 5 total
Snapshots:   0 total
Time:        1.189s
Ran all test suites.

Watch Usage: Press w to show more.

April 30:

Test Suites: 6 passed, 6 total
Tests:       10 passed, 10 total

What my tests looked like on May 3:

PASS  src/tests/Qux.test.js
PASS  src/tests/TestRoutes.test.js
PASS  src/tests/ElfHeader.test.js
PASS  src/tests/App.test.js
PASS  src/tests/GetUser.test.js
PASS  src/tests/GetGist.test.js

Test Suites: 6 passed, 6 total
Tests:       12 passed, 12 total
Snapshots:   0 total
Time:        1.9s, estimated 2s
Ran all test suites.

Watch Usage: Press w to show more.