add readme and LICENSE

Author: kenfdev

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2022 Ken Fukuyama
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -1,2 +1,106 @@
-# stepfunctions-testing
+# Step Functions Testing Library
 
+## Features
+
+- Create a [MockConfigFile](https://docs.aws.amazon.com/step-functions/latest/dg/sfn-local-test-sm-exec.html) with JavaScript
+
+
+### Install
+
+```sh
+npm i stepfunctions-testing
+```
+## Usage
+
+### Creating a mocked response
+
+#### `Return` a response
+
+```js
+const checkIdentityLambdaMockedSuccess = new MockedResponse(
+  'CheckIdentityLambdaMockedSuccess'
+).return<any>({
+  StatusCode: 200,
+  Payload: {
+    statusCode: 200,
+    body: JSON.stringify({
+      approved: true,
+      message: 'identity validation passed',
+    }),
+  },
+});
+```
+
+#### `Throw` a response
+
+```js
+const checkIdentityLambdaMockedThrowError = new MockedResponse(
+  'CheckIdentityLambdaMockedThrowError'
+).throw('CustomValidationError', 'Check Identity Validation Failed');
+```
+
+#### Repeating responses
+
+```js
+const checkIdentityLambdaMockedThrowError = new MockedResponse(
+  'CheckIdentityLambdaMockedThrowError'
+).throw('CustomValidationError', 'Check Identity Validation Failed', /* repeat the response 3 times. total becomes 4 */ 3);
+```
+
+### Full example
+
+```js
+// Create mocked responses
+const checkIdentityLambdaMockedSuccess = new MockedResponse(
+  'CheckIdentityLambdaMockedSuccess'
+).return<any>({
+  StatusCode: 200,
+  Payload: {
+    statusCode: 200,
+    body: JSON.stringify({
+      approved: true,
+      message: 'identity validation passed',
+    }),
+  },
+});
+
+const checkAddressLambdaMockedSuccess = new MockedResponse(
+  'CheckAddressLambdaMockedSuccess'
+).return<any>({
+  StatusCode: 200,
+  Payload: {
+    statusCode: 200,
+    body: JSON.stringify({
+      approved: true,
+      message: 'address validation passed',
+    }),
+  },
+});
+
+// Create a state machine test definition
+const stateMachineTestDefinition = new StateMachineTestDefinition('SomeStateMachineName')
+  .addTestCase(
+    new StateMachineTestCase('HappyPathTest')
+      .withInput(input)
+      .addMockedState(
+        'CheckIdentity',
+        checkIdentityLambdaMockedSuccess
+      )
+      .addMockedState(
+        'CheckAddress',
+        checkAddressLambdaMockedSuccess
+      )
+  );
+
+// Create a config
+const config = new StepFunctionsMockConfig()
+      .addTestDefinition(stateMachineTestDefinition);
+
+// Convert the config object to JSON
+// You can write this down to a file to be used by step functions local
+config.toJSON();
+```
+
+## License
+
+stepfunctions-testing is available under the terms of [MIT License](./LICENSE)