docs(readme): update example and readme

README.md

@@ -1,5 +1,78 @@
 # jest-helpers
-TypeScript helper functions for Jest which make your tests resilient to refactoring.
+TypeScript helper functions for Jest to help make your tests resilient to refactoring.
+
+## Install
+```sh
+npm install jest-helpers --save-dev
+```
+
+## Usage
+`./greeter.ts`
+```typescript
+export class Greeter {
+  getGreeting(name: string) {
+    return `Hello ${name}`;
+  }
+}
+
+export function showGreeting(greeter: Greeter, name: string) {
+  const greeting = greeter.getGreeting(name)
+  console.log(greeting)
+}
+```
+
+`./greeter.test.ts`
+```typescript
+import {
+  describeClass, describeFunction, describeMethod, describeModule, partialOf
+} from 'jest-helpers';
+import { Greeter, showGreeting } from './greeter';
+
+describeModule(() => {
+  describeClass(Greeter, () => {
+    describeMethod(Greeter, 'getGreeting', () => {
+      it('should return a personalised greeting', () => {
+        const greeter = new Greeter();
+        expect(greeter.getGreeting('Joe')).toEqual('Hello Joe');
+      });
+    });
+  });
+
+  describeFunction(showGreeting, () => {
+    it('should log greeting to the console', () => {
+      const greeterMock = partialOf<Greeter>({
+        getGreeting: jest.fn().mockReturnValue('yo!')
+      });
+
+      jest.spyOn(console, 'log');
+
+      showGreeting(greeterMock, 'Joe');
+
+      expect(greeterMock.getGreeting).toHaveBeenCalledWith('Joe');
+      expect(console.log).toHaveBeenCalledWith('yo!');
+    });
+  });
+});
+```
+
+Running `jest --verbose` will output something like
+```
+  example/greeter.ts
+    Greeter
+      getGreeting
+        ✓ should return a personalised greeting (4ms)
+    showGreeting
+      ✓ should log greeting to the console (2ms)
+```
+
+## Benefits
+- ✅ If you rename your `greeter.test.ts` module, it will automatically update the test description.
+
+- ✅ If you rename your `Greeter` class, it will automatically update the test description
+
+- ✅ If you rename your `Greeter.getGreeting` method, it will automatically update the test description
+
+- ✅ If you rename your `showGreeting` method, it will automatically update the test description
 
 ## Contributing
 Got an issue or a feature request? [Log it](https://github.com/codeandcats/jest-helpers/issues).

example/greeter.test.ts

@@ -1,5 +1,5 @@
-import { describeClass, describeMethod, describeModule } from '../src/index';
-import { Greeter } from './greeter';
+import { describeClass, describeFunction, describeMethod, describeModule, partialOf } from '../src';
+import { Greeter, showGreeting } from './greeter';
 
 describeModule(() => {
   describeClass(Greeter, () => {
@@ -10,4 +10,22 @@ describeModule(() => {
       });
     });
   });
+
+  describeFunction(showGreeting, () => {
+    it('should log greeting to the console', () => {
+      const greeterMock = partialOf<Greeter>({
+        getGreeting: jest.fn().mockReturnValue('yo!')
+      });
+
+      jest.spyOn(console, 'log').mockImplementation(() => {
+        //
+      });
+
+      showGreeting(greeterMock, 'Joe');
+
+      expect(greeterMock.getGreeting).toHaveBeenCalledWith('Joe');
+      // tslint:disable-next-line:no-console
+      expect(console.log).toHaveBeenCalledWith('yo!');
+    });
+  });
 });

example/greeter.ts

@@ -3,3 +3,9 @@ export class Greeter {
     return `Hello ${name}`;
   }
 }
+
+export function showGreeting(greeter: Greeter, name: string) {
+  const greeting = greeter.getGreeting(name);
+  // tslint:disable-next-line:no-console
+  console.log(greeting);
+}

src/index.ts

@@ -34,7 +34,7 @@ export interface NamedFunction {
   (...args: any[]): any;
 }
 
-export function innerDescribeClass(
+function innerDescribeClass(
   describe: DescribeFunction,
   classToDescribe: Class<{}>,
   describer: () => void
@@ -69,7 +69,7 @@ export function xdescribeClass(classToDescribe: Class<{}>, describer: () => void
   innerDescribeClass(xdescribe, classToDescribe, describer);
 }
 
-export function innerDescribeFunction(
+function innerDescribeFunction(
   describe: DescribeFunction,
   func: NamedFunction,
   describer: () => void
@@ -113,7 +113,7 @@ type FunctionPropertyNames<T> = {
   [K in keyof T]: T[K] extends Function ? K : never
 }[keyof T];
 
-export function innerDescribeMethod<TInstance>(
+function innerDescribeMethod<TInstance>(
   describe: DescribeFunction,
   methodName: FunctionPropertyNames<TInstance>,
   describer: () => void