chore: add test-watch script to the wrangler workspace

Watch the files in the wrangler workspace, and run the tests when anything changes:

```sh
> npm run test-watch -w wrangler
```

This will also run all the tests in a single process (rather than in parallel shards) and will increase the test-timeout to 50 seconds, which is helpful when debugging.

Author: petebacondarwin

.changeset/young-horses-jam.md

@@ -0,0 +1,13 @@
+---
+"wrangler": patch
+---
+
+chore: add test-watch script to the wrangler workspace
+
+Watch the files in the wrangler workspace, and run the tests when anything changes:
+
+```sh
+> npm run test-watch -w wrangler
+```
+
+This will also run all the tests in a single process (rather than in parallel shards) and will increase the test-timeout to 50 seconds, which is helpful when debugging.

CONTRIBUTING.md

@@ -135,8 +135,9 @@ Tests in a workspace are executed, by [Jest](https://jestjs.io/), which is confi
   ```
 - Watch the files in a specific workspace (e.g. wrangler), and run the tests when anything changes
   ```sh
-  > npm run test -w wrangler -- --watch
+  > npm run test-watch -w wrangler
   ```
+  This will also run all the tests in a single process (rather than in parallel shards) and will increase the test-timeout to 50 seconds, which is helpful when debugging.
 
 ## Steps For Making Changes
 

packages/wrangler/package.json

@@ -97,7 +97,8 @@
     "bundle": "node -r esbuild-register scripts/bundle.ts",
     "build": "npm run clean && npm run bundle",
     "start": "npm run bundle && NODE_OPTIONS=--enable-source-maps ./bin/wrangler.js",
-    "test": "CF_API_TOKEN=some-api-token CF_ACCOUNT_ID=some-account-id jest --silent=false --verbose=true"
+    "test": "CF_API_TOKEN=some-api-token CF_ACCOUNT_ID=some-account-id jest --silent=false --verbose=true",
+    "test-watch": "npm run test -- --runInBand --testTimeout=50000 --watch"
   },
   "engines": {
     "node": ">=16.7.0"