# Advanced update process This is an advanced version of the [standard update process](/core-features/automate-updating-dependencies). ## Managing migration steps When you run into problems running the `nx migrate --run-migrations` command, here are some solutions to break the process down into manageable steps. ### Make changes easier to review by committing after each migration runs Depending on the size of the update (e.g. migrating between major versions is likely to require more significant changes than migrating between feature releases), and the size of the workspace, the overall `nx migrate` process may generate a lot of changes which then need to be reviewed. Particularly if there are then manual changes which need to be made in addition to those made by `nx migrate`, it can make the associated PR harder to review because of not being able to distinguish between what was changed automatically and what was changed manually. If you pass `--create-commits` to the `--run-migrations` command, Nx will automatically create a dedicated commit for each successfully completed migration, for example: ```shell nx migrate --run-migrations --create-commits ``` Your git history will then look something like the following: ```{% command="nx migrate --run-migrations --create-commits" %} git log commit 8c862c780106ab8736985c01de1477309a403548 Author: YOUR_GIT_USERNAME Date: Thu Apr 14 18:35:44 2022 +0400 chore: [nx migration] name-of-the-second-migration-which-ran commit eb83bca97927af26aae731a2cf51ad62cc75efa3 Author: YOUR_GIT_USERNAME Date: Thu Apr 14 18:35:44 2022 +0400 chore: [nx migration] name-of-the-first-migration-which-ran etc ``` By default, nx will apply the prefix of `chore: [nx migration] ` to each commit in order to clearly identify it, but you can also customize this prefix by passing `--commit-prefix` to the command: ```shell nx migrate --run-migrations --create-commits --commit-prefix="chore(core): AUTOMATED - " ``` ```{% command='git log' %} commit 8c862c780106ab8736985c01de1477309a403548 Author: YOUR_GIT_USERNAME Date: Thu Apr 14 18:35:44 2022 +0400 chore(core): AUTOMATED - name-of-the-second-migration-which-ran commit eb83bca97927af26aae731a2cf51ad62cc75efa3 Author: YOUR_GIT_USERNAME Date: Thu Apr 14 18:35:44 2022 +0400 chore(core): AUTOMATED - name-of-the-first-migration-which-ran etc ``` ### Customizing which migrations run by altering `migrations.json` For small projects, running all the migrations at once often succeeds without any issues. For large projects, more flexibility is sometimes needed, and this is where having the separation between generating the migrations to be run, and actually running them, really shines. All you need to do is amend the JSON file in whatever way makes sense based on your circumstances, for example: - You may have to skip a migration. - You may want to run one migration at a time to address minor issues. - You may want to reorder migrations. - You may want to run the same migration multiple time if the process takes a long time and you had to rebase. Because you can run `nx migrate --run-migrations` as many times as you want, you can achieve all of that by commenting out and reordering items in `migrations.json`. The migration process can take a long time, depending on the number of migrations, so it is useful to commit the migrations file with the partially-updated repo alongside any changes which were created by previously completed migrations. You can even provide a custom location for the migrations file if you wish, you simply pass it to the `--run-migrations` option: ```shell nx migrate --run-migrations=migrations.json ``` ## Choosing optional package updates to apply While in most cases you want to be up to date with Nx and the dependencies it manages, sometimes you might need to stay on an older version of such a dependency. For example, you might want to update Nx to the latest version but keep Jest on **v27.x.x** and not update it to **v28.x.x**. For such scenarios, `nx migrate` allows you to choose what to update using the `--interactive` flag. {% callout type="note" title="Optional package updates" %} You can't choose to skip any arbitrary package update. To ensure that a plugin works well with older versions of a given package, the plugin must support it. Therefore, Nx plugin authors define what package updates are optional. {% /callout %} {% callout type="warning" title="Taking control of package updates" %} While opting out of applying some package updates is supported by Nx, please keep in mind that you are effectively taking control of those package updates and opting out of Nx managing them. This means you'll need to keep up with the version requirements for those packages and those that depend on them. You'll also need to consider more things when updating them at some point [as explained later](#updating-dependencies-that-are-behind-the-versions-nx-manages). {% /callout %} ### Interactively opting out of package updates To opt out of package updates, you need to run the migration in interactive mode: ```shell nx migrate latest --interactive ``` As the migration runs and collects the package updates, you'll be prompted to apply optional package updates, and you can choose what to do based on your needs. The `package.json` will be updated and the `migrations.json` will be generated considering your responses to those prompts. ### Updating dependencies that are behind the versions Nx manages Once you have skipped some optional updates, there'll come a time when you'll want to update those packages. To do so, you'll need to generate the package updates and migrations from the Nx version that contained those skipped updates. Say you skipped updating Jest to **v28.x.x**. That package update was meant to happen as part of the `@nrwl/jest@14.6.0` update, but you decided to skip it at the time. The `nx migrate` command collects updates for a package from versions higher than the currently installed version of the said package in the workspace. Since you need to collect updates and migrations that were meant to happen for version **14.6.0** (a version older that what's currently installed), you need to run the command and "fake" the installed version of the `@nrwl/jest` package to a version lower than **14.6.0**: ```shell nx migrate @nrwl/jest@latest --from=@nrwl/jest@14.5.0 ``` The above command will effectively collect any package update and migration meant to run if your workspace had `@nrwl/jest@14.5.0` installed. While collecting package updates and migrations for a specific package works, it's not always the best way to proceed. In the specific example we have been using, since you manage the `jest` package (because you opted out of its automated migrations), you also need to be mindful of packages that depend on it and act accordingly. You could have different version requirements from different packages that depend on it. An example would be if you decide to stay on Jest v27 while updating your Angular version to v15. The `jest-preset-angular` package doesn't have a version that works with both. All versions of `jest-preset-angular` that support Angular v15 require Jest v28. In that case you have a couple of options: - Don't update to Angular v15 - Update Jest to v28 and Angular to v15 If you choose the latter, you'll need to make sure package updates and migrations from `@nrwl/jest` (manages `jest`) and `@nrwl/angular` (manages `jest-preset-angular`) are collected. You can do that by using the `nx` package that groups the rest of the first-party Nx plugins: ```shell nx migrate latest --from=nx@14.5.0 ``` {% callout type="check" title="Collect updates for all packages" %} As a general rule, prefer to run `nx migrate latest --from=nx@` so package updates and migrations are collected from all Nx first-party plugins. By doing so, you'll be closer to what a fully-automated Nx migration does and avoid some potential issues. While it might collect migrations previously run in the repo, those migrations should be idempotent and you could always remove them from the `migrations.json` file if you want. {% /callout %} ## Other advanced capabilities ### Overriding versions Sometimes, you may want to use a different version of a package than what Nx recommends. To do that, specify the package and version: ```shell nx migrate latest --to="jest@22.0.0,cypress@3.4.0" ``` By default, Nx uses currently installed packages to calculate what migrations need to run. To override them, override the version: ```shell nx migrate latest --to="@nrwl/jest@12.0.0" ``` {% callout type="warning" title="Overriding versions" %} By choosing a version different of what Nx recommend you might use a package version that might have not been tested for a given Nx version. This might lead to unexpected issues. {% /callout %} ### Reverting a failed update Updates are best done on a clean git history so that it can be easily reversed if something fails. We try our best to make sure migrations do not fail but if one does, **please report it** on [GitHub](https://www.github.com/nrwl/nx/issues/new/). If an update fails for any reason, you can revert it as you do any other set of changes: ```shell git reset --hard # Reset any changes git clean -fd # Delete newly added files and directories ``` {% callout type="warning" title="--create-commits" %} If using `--create-commits`, you will need to first retrieve the SHA of the commit before your first automated migration commit in order to jump back to the point before the migrations ran, e.g. `git reset --hard YOUR_APPROPRIATE_SHA_HERE`) {% /callout %} ## Recommendations ### One major version at a time, small steps Migrating Jest, Cypress, ESLint, React, Angular, Next, and more is a difficult task. All the tools change at different rates, they can conflict with each other. In addition, every workspace is different. Even though our goal is for you to update any version of Nx to a newer version of Nx in a single go, sometimes it doesn't work. The following process is better for large workspaces. Say you want to migrate from Nx 10.1.0 to Nx 11.0.1. The following steps are more likely to work comparing to `nx migrate 11.0.1`. - Run `nx migrate 10.4.5` to update the latest version in the 10.x branch. - Run `nx migrate --run-migrations`. - Next, run `nx migrate 11.0.1`. - Run `nx migrate --run-migrations`.