docs: document how to use transform with jodeshift

packages/codemods/README.md

@@ -2,6 +2,15 @@
 
 A tool for helping upgrade to fetch-mock@12.
 
+## Usage
+
+1. Install `npm i -D @fetch-mock/codemods jscodeshift`;
+2. Manually modify any code using `.sandbox()` according to the example above.
+3. Run `jscodeshift -t node_modules/@fetch-mock/codemods/wrc/index.jscodeshift .` to run over your entire project, or replace `.` with the directory/file paths you wish to modify. [The jscodeshift CLI has many options](https://jscodeshift.com/run/cli/) - adjust them to suit your project.
+4. For scenarios where the codemod is unable to detect which variable contains a fetch-mock instance (e.g. when it is required in a global set up file, or when using `jest.mock()`) you may pass in one or more variable names using the `FM_VARIABLES` environment variable e.g. `FM_VARIABLES=fm,fetch`
+5. After the codemods have executed, run your tests, correcting all the errors thrown. The notes on what is in/out of scope will help guide you.
+6. Once all your tests are fixed you should be able to uninstall the codemods: `npm uninstall @fetch-mock/codemods jscodeshift`
+
 ## Features
 
 - Identifies instances of fetch-mock imported using `require` or `import`
@@ -18,11 +27,12 @@ A tool for helping upgrade to fetch-mock@12.
 - Javascript is a language with multiple ways to do the same thing. While these codemods attempt to cover a few different patterns, it's likely that they don't cover all the ways fetch-mock is being used. Please raise an issue if you think they can be improved.
 - fetch-mock@12 no longer has the `.mock()` method which combines defining a route _and_ setting up global mocking. All calls to `.mock()` are replaced by `.route()`.
   If using global `fetch` you will also need to call `.mockGlobal()` at least once per test suite.
-- The `.sandbox()` method previously created a `fetch` function that also had all the fetch-mock methods attached. This is no longer the case, but pulling it apart is complex and deliberately left out of scope for thsi codemod.
-- Any uses of fetch-mock prior to assignig to a variable will not be modified e.g. `require('fetch-mock').mock('a', 'b')` will not be converted to `require('fetch-mock').route('a', 'b')`
+- The `.sandbox()` method previously created a `fetch` function that also had all the fetch-mock methods attached. This is no longer the case, but pulling it apart is complex and deliberately left out of scope for this codemod.
+- Any uses of fetch-mock prior to assigning to a variable will not be modified e.g. `require('fetch-mock').mock('a', 'b')` will not be converted to `require('fetch-mock').route('a', 'b')`
 - When using a pattern such as `jest.mock('node-fetch', () => require('fetch-mock').sandbox())`, the codemod is unable to identify that `require('node-fetch')` will be an instance of fetch-mock.
+- On the server side fetch-mock was previously built around node-fetch's classes, but now uses native `fetch`. In most cases, even if your application code still uses node-fetch, your mocks will still work. However, if you explicitly create instances of `Request` or `Headers` using node-fetch's classes, you may need to provide these to fetch-mock.
 
-Taking the last 3 points together, this example illustrates the kind of manual modifications required:
+Taking the last 4 points together, this example illustrates the kind of manual modifications required:
 
 ### Before
 
@@ -43,7 +53,18 @@ it('runs a test', () => {
 ```js
 const fetchMock = require('fetch-mock');
 
-jest.mock('node-fetch', () => fetchMock.fetchHandler);
+jest.mock('node-fetch', () => {
+	const nodeFetch = jest.requireActual('node-fetch');
+	// only needed if your application makes use of Response, Request
+	// or Headers classes directly
+	Object.assign(fetchMock.config, {
+		fetch: nodeFetch,
+		Response: nodeFetch.Response,
+		Request: nodeFetch.Request,
+		Headers: nodeFetch.Headers,
+	});
+	return fetchMock.fetchHandler;
+});
 const nodeFetch = require('node-fetch');
 
 it('runs a test', () => {
@@ -52,10 +73,3 @@ it('runs a test', () => {
 	expect(fetchMock.called()).toBe(true);
 });
 ```
-
-## Usage
-
-1. Do all your manual mods
-2. run
-3. correct all errors
-   If you use `.sandbox()` or other mocing libraries to assign fetch-mock to

packages/codemods/package.json

@@ -2,11 +2,7 @@
 	"name": "@fetch-mock/codemods",
 	"description": "Codemods for upgrading fetch-mock",
 	"version": "0.0.0",
-	"exports": {
-		"import": "./src/index.js"
-	},
 	"main": "./src/index.js",
-	"module": "./src/index.js",
 	"type": "module",
 	"engines": {
 		"node": ">=18.11.0"

tsconfig.json

@@ -7,6 +7,5 @@
 		"target": "es2021"
 	},
 	"include": ["./packages/**/src/*.ts"],
-	"exclude": ["node_modules", "packages/**/__tests__"],
-	"ts-node": {"esm": true}
+	"exclude": ["node_modules", "packages/**/__tests__"]
 }