add example for EJS setup and Jest

it doesn't cover jest dom

Author: SallyMcGrath

debugging/exampleEJS/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "book-library",
+  "version": "1.0.0",
+  "description": "## topics: debugging, DOM",
+  "main": "script.mjs",
+  "type": "module",
+  "scripts": {
+    "test": "node --experimental-vm-modules node_modules/jest/bin/jest.js"
+  },
+  "dependencies": {
+    "jest": "^29.7.0"
+  },
+  "jest": {
+    "testEnvironment": "node",
+    "transform": {}
+  }
+}

debugging/exampleEJS/readme.md

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+# Example setup using Jest and EJS
+
+It can be a bit tricky to see how to use EJS modules with Jest. The error message you get is not very helpful. This is a simple example of how to set up Jest to work with EJS.
+
+1. Look in `package.json`
+1. Under `scripts` you will see `"test": "node --experimental-vm-modules node_modules/jest/bin/jest.js"` instead of just `"test": "jest"`
+1. The next necessary condition is to define this set of properties and values
+  ```
+  "jest": {
+    "testEnvironment": "node",
+    "transform": {}
+  }
+  ```
+1. This is what the documentation is trying to explain https://jestjs.io/docs/ecmascript-modules but it is not very clear.
+
+
+### Example error
+
+```
+npm test book.test.js 
+
+> [email protected] test
+> jest book.test.js
+
+ FAIL  ./book.test.js
+  ● Test suite failed to run
+
+    Jest encountered an unexpected token
+
+    Jest failed to parse a file. This happens e.g. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is not configured to support such syntax.
+
+    Out of the box Jest supports Babel, which will be used to transform your files into valid JS based on your Babel configuration.
+
+    By default "node_modules" folder is ignored by transformers.
+
+    Here's what you can do:
+     • If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/ecmascript-modules for how to enable it.
+     • If you are trying to use TypeScript, see https://jestjs.io/docs/getting-started#using-typescript
+     • To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
+     • If you need a custom transformation specify a "transform" option in your config.
+     • If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.
+    You'll find more details and examples of these config options in the docs:
+    https://jestjs.io/docs/configuration
+    For information about custom transformations, see:
+    https://jestjs.io/docs/code-transformation
+
+    Details:
+
+    /home/USER/Desktop/CYF/Module-Data-Flows/debugging/book-library/book.test.js:1
+    ({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){import createBook from "./book";
+                                                                                      ^^^^^^
+
+    SyntaxError: Cannot use import statement outside a module
+
+      at Runtime.createScriptFromCode (node_modules/jest-runtime/build/index.js:1505:14)
+
+Test Suites: 1 failed, 1 total
+Tests:       0 total
+Snapshots:   0 total
+Time:        0.194 s
+Ran all test suites matching /book.test.js/i.
+```

debugging/exampleEJS/script.js

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+
+function exampleFunction() {
+return true
+}
+
+export default exampleFunction;
+

debugging/exampleEJS/script.test.js

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+//check import works
+import exampleFunction from './script';
+// check these functions exist
+describe('Basic test', () => {
+  test('exampleFunction exists', () => {
+    expect(exampleFunction).toBeDefined();
+  });
+});
+
+