Update README with Jest specific language. Update some spec files with new syntax

README.md

@@ -10,9 +10,11 @@ There will eventually be a suggested order of completion, but at this time since
 Before you start you should have a few things installed on your machine:
 1. NPM. To check if you have NPM installed, type `npm --version` in your terminal. If you get back `Command 'npm' not found, but can be installed with:`, do NOT follow the instructions in the terminal to install with `apt-get`. (This causes permission issues.) Instead, install Node with NVM by following the instructions [here](https://github.com/TheOdinProject/curriculum/blob/master/foundations/installations/installing_node.md).
 2. Jest. Jest is a testing framework for JavaScript. To install it, type `npm install --save-dev jest`. We use `--save-dev` here to specify this module is for development purposes only.
-3. A copy of this repository. Copies of repositories on your machine are called clones. If you need help cloning, you can learn how [here](https://docs.github.com/en/github/creating-cloning-and-archiving-repositories/cloning-a-repository)
+3. A copy of this repository. Copies of repositories on your machine are called clones. If you need help cloning, you can learn how [here](https://docs.github.com/en/github/creating-cloning-and-archiving-repositories/cloning-a-repository).
 
-Each exercise includes 3 files: a markdown file with a description of the task, an empty (or mostly empty) JavaScript file, and a set of tests. To complete an exercise, you'll need to go to the exercise directory with `cd exerciseName` in the terminal and run `npm test exerciseName.spec.js`. This should run the test file and show you the output. When you first run a test, it will fail. This is by design! You must open the exercise file and write the code needed to get the test to pass. Some of the exercises have test conditions defined in their spec file that are defined as 'xit' compared to 'it'. This is purposeful. After you pass your first 'it', you will change the next 'xit' to an 'it' and test your code again. You'll do this until all conditions are satisfied.
+Each exercise includes 3 files: a markdown file with a description of the task, an empty (or mostly empty) JavaScript file, and a set of tests. To complete an exercise, you'll need to go to the exercise directory with `cd exerciseName` in the terminal and run `npm test exerciseName.spec.js`. This should run the test file and show you the output. When you first run a test, it will fail. This is by design! You must open the exercise file and write the code needed to get the test to pass. Some of the exercises have test conditions defined in their spec file that are defined as 'test.skip' compared to 'test'. This is purposeful. After you pass your first 'test', you will change the next 'test.skip' to an 'test' and test your code again. You'll do this until all conditions are satisfied.
+
+**Note**: Due to the way Jest handles failed tests, it will return an exit code of 1 if any tests fail. NPM will interpret this as an error and you may see some `npm ERR!` messages after Jest runs. You can ignore these, or run your test with `npm test exerciseName.spec.js --silent` to supress the errors.
 
 The first exercise, `helloWorld`, will walk you through the process in-depth.
 

caesar/caesar.spec.js

@@ -1,25 +1,26 @@
-const expect = require('expect');const caesar = require('./caesar')
+const expect = require('expect');
+const caesar = require('./caesar')
 
 describe('caesar', function() {
-  it('works with single letters', function() {
-    expect(caesar('A', 1)).toEqual('B');
+  test('works with single letters', function() {
+    expect(caesar('A', 1)).toBe('B');
   });
-  xit('works with words', function() {
-    expect(caesar('Aaa', 1)).toEqual('Bbb');
+  test.skip('works with words', function() {
+    expect(caesar('Aaa', 1)).toBe('Bbb');
   });
-  xit('works with phrases', function() {
-    expect(caesar('Hello, World!', 5)).toEqual('Mjqqt, Btwqi!');
+  test.skip('works with phrases', function() {
+    expect(caesar('Hello, World!', 5)).toBe('Mjqqt, Btwqi!');
   });
-  xit('works with negative shift', function() {
-    expect(caesar('Mjqqt, Btwqi!', -5)).toEqual('Hello, World!');
+  test.skip('works with negative shift', function() {
+    expect(caesar('Mjqqt, Btwqi!', -5)).toBe('Hello, World!');
   });
-  xit('wraps', function() {
-    expect(caesar('Z', 1)).toEqual('A');
+  test.skip('wraps', function() {
+    expect(caesar('Z', 1)).toBe('A');
   });
-  xit('works with large shift factors', function() {
-    expect(caesar('Hello, World!', 75)).toEqual('Ebiil, Tloia!');
+  test.skip('works with large shift factors', function() {
+    expect(caesar('Hello, World!', 75)).toBe('Ebiil, Tloia!');
   });
-  xit('works with large negative shift factors', function() {
-    expect(caesar('Hello, World!', -29)).toEqual('Ebiil, Tloia!');
+  test.skip('works with large negative shift factors', function() {
+    expect(caesar('Hello, World!', -29)).toBe('Ebiil, Tloia!');
   });
 });

helloWorld/helloWorld.js

@@ -1,5 +1,5 @@
 const helloWorld = function() {
-  return ''
+  return 'Yello Wold!'
 }
 
 module.exports = helloWorld;

helloWorld/helloWorld.spec.js

@@ -1,4 +1,4 @@
-const expect = require('expect');const { expect } = require('@jest/globals');
+const expect = require('expect');
 const helloWorld = require('./helloWorld');
 
 // describe('Hello World', function() {
@@ -7,6 +7,8 @@ const helloWorld = require('./helloWorld');
 //   });
 // });
 
-test('says "Hello, World!"', () => {
+describe('helloWorld', function() {
+  test('says "Hello, World!"', function() {
     expect(helloWorld()).toBe("Hello, World!");
+  })
 });

leapYears/leapYears.spec.js

@@ -1,4 +1,5 @@
-const expect = require('expect');const leapYears = require('./leapYears')
+const expect = require('expect');
+const leapYears = require('./leapYears')
 
 describe('leapYears', function() {
   it('works with non century years', function() {