Add instructions for updating dependencies

Remove diff-expo as npx expo install --fix already
handles this

CONTRIBUTING.md

@@ -24,22 +24,20 @@ yarn dev
 
 ## Test changes locally
 
-In Belt project directory:
+You can run Belt locally with:
 
 ```bash
-yarn link
+node bin/belt.js MyApp
 ```
 
-In some other directory:
+Or, with Bun (faster):
 
 ```bash
-yarn add create-belt-app
-yarn link create-belt-app
-
-# or whatever command
-yarn belt NewApp
+bun bin/belt.js MyApp
 ```
 
+This generates a new Belt app in builds/MyApp, `cd`s to the directory, runs tests, and then `cd`s back. You can then run that app by `cd`ing to the directory and running `yarn ios` or the desired command.
+
 ## Creating a pull request
 
 Make sure the tests pass:
@@ -48,10 +46,16 @@ Make sure the tests pass:
 yarn test
 ```
 
-Make your change, with new passing tests. Before committing your changes, run the code formatter:
+Before committing your changes, make sure the linter, formatter, and vitest tests all pass:
+
+```bash
+yarn test:all
+```
+
+Additionally, CI runs a check that uses the CLI to build an app and then ensures that the test suite of the new app passes. You can run this locally with:
 
 ```bash
-yarn pretty
+node bin/checks/build-with-latest-expo.check.js
 ```
 
 Follow the [style guide][style].
@@ -65,3 +69,49 @@ Push to your fork. Write a [good commit message][commit]. Submit a pull request.
 Others will give constructive feedback. This is a time for discussion and
 improvements, and making the necessary changes will be required before we can
 merge the contribution.
+
+## Updating Belt dependencies
+
+It's imperative that we keep dependencies up-to-date. We should monitor Expo and other dependency releases and update Belt when they come available.
+
+### Updating Expo
+
+Updating Expo is straightforward. When a new Expo version is released, open the Belt codebase, then:
+
+```bash
+cd templates/boilerplate
+yarn install
+
+# install latest Expo
+yarn add expo@latest
+
+# update dependencies to match versions required by latest Expo
+npx expo install --fix
+```
+
+Now, run the test suite with `yarn test:all` and then generate a new app and verify that it works with:
+
+```bash
+node bin/belt.js MyApp
+```
+
+Manually verify other commands also work (eg. push notifications). Todo: get better tests around these (i.e. tests that build an app and run the new app's test suite).
+
+### Updating other dependencies
+
+We can periodically update all dependencies to the latest versions with:
+
+```bash
+cd templates/boilerplate
+
+yarn install
+
+# with yarn 1
+yarn upgrade-interactive --latest
+
+# or, with yarn 2+
+yarn up --interactive
+
+# audit and fix any packages that aren't compatible with the installed Expo
+npx expo install --fix
+```

package.json

@@ -32,8 +32,7 @@
     "test:run": "vitest run",
     "test:all": "yarn lint && yarn test:run",
     "pub:beta": "yarn build && npm publish --tag beta",
-    "pub:release": "yarn build && npm publish",
-    "diff-expo": "node bin/diff-expo.js"
+    "pub:release": "yarn build && npm publish"
   },
   "dependencies": {
     "@inquirer/prompts": "^3.2.0",

templates/boilerplate/package.json

@@ -21,7 +21,7 @@
     "@react-native-async-storage/async-storage": "1.21.0",
     "@react-navigation/native": "^6.1.10",
     "@react-navigation/native-stack": "^6.9.18",
-    "expo": "~50.0.7",
+    "expo": "^50.0.8",
     "expo-status-bar": "~1.11.1",
     "jest": "^29.3.1",
     "jest-expo": "~50.0.2",