feat: add unit testing library as dependency (#26)

README.md

@@ -110,39 +110,51 @@ possible in your explanation and we'll address it as quick as we can.
 
 #### Quickstart Dev Instructions
 
-1.  **Install Dependecies.**
+1. **Install Dependecies.**
 
-    Using yarn, install all dependencies
+   Using yarn, install all dependencies
 
-    ```shell
-    yarn install
-    ```
+   ```shell
+   yarn install
+   ```
 
-2.  **Make changes to the source code**
+2. **Make changes to the source code**
 
-3.  **Compile your code**
+3. **Compile your code**
 
-    You need to bundle your code, let's run:
+   You need to bundle your code, let's run:
 
-    ```shell
-    yarn build
-    ```
+   ```shell
+   yarn build
+   ```
 
-    If yarn build fails try using:
+   If yarn build fails try using:
 
-    ```shell
-    bin/build
-    ```
+   ```shell
+   bin/build
+   ```
 
-4.  **Building your code automatically in the background**
+4. **Building your code automatically in the background**
 
-    Recommended: Webpack can detect changes and build automatically
+   Recommended: Webpack can detect changes and build automatically
 
-    ```shell
-    yarn watch
-    ```
+   ```shell
+   yarn watch
+   ```
 
-    Your compiled code can be found in this repo.
+   Your compiled code can be found in this repo.
+
+5. Running unit tests
+
+   ```shell
+   yarn test
+   ```
+
+   or
+
+   ```shell
+   bin/test
+   ```
 
 **`./report_table.js`**: This visualization's minified distribution file.
 

bin/test

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+GIT_ROOT_DIR=$(git rev-parse --show-toplevel)
+
+# Installs yarn if it is not already installed.
+function looker::install_yarn() {
+  if command -v yarn &> /dev/null; then
+    npm install -g yarn
+  fi
+}
+
+# Configures the project if the user has not already done so.
+function looker::configure() {
+  looker::install_yarn
+  pushd "$GIT_ROOT_DIR" &> /dev/null
+  if [[ ! -d "$GIT_ROOT_DIR/node_modules" ]]; then
+    yarn
+  fi
+  popd &> /dev/null
+}
+
+# Runs all the unit tests.
+function looker::test() {
+  pushd "$GIT_ROOT_DIR" &> /dev/null
+  env NODE_OPTIONS="--openssl-legacy-provider" yarn test
+  popd &> /dev/null
+}
+
+# Entry-point.
+function looker::main() {
+  looker::configure
+  looker::test
+}
+
+looker::main
+
+exit 0

package.json

@@ -10,6 +10,7 @@
     "css-loader": "^3.6.0",
     "eslint": "^8.40.0",
     "eslint-config-prettier": "^8.8.0",
+    "jest": "^29.6.1",
     "prettier": "^2.8.8",
     "style-loader": "^1.2.1",
     "url-loader": "^4.1.0",
@@ -23,6 +24,7 @@
   },
   "scripts": {
     "build": "webpack",
-    "watch": "webpack  --watch --progress"
+    "watch": "webpack  --watch --progress",
+    "test": "jest"
   }
 }

src/example.test.js

@@ -0,0 +1,9 @@
+function example() {
+  return 'hi';
+}
+
+describe('example', () => {
+  test('should say hi', () => {
+    expect(example()).toBe('hi');
+  });
+});