# TypeScript ESLint Documentation
# Source: https://raw.githubusercontent.com/typescript-eslint/typescript-eslint/main/docs/maintenance/pull-requests/Dependency_Version_Upgrades.mdx
# Path: docs/maintenance/pull-requests/Dependency_Version_Upgrades.mdx

---
id: dependency-version-upgrades
title: Dependency Version Upgrades
---

## Renovate

We rely on [renovate bot](https://github.com/renovatebot/renovate/) to automatically raise PRs to update our dependencies using [this configuration](https://github.com/typescript-eslint/typescript-eslint/blob/main/.github/renovate.json5).

### Dependency Dashboard

Renovate is configured to manage a [dependency dashboard issue](https://github.com/typescript-eslint/typescript-eslint/issues/6687) which can be used to understand the tool's state:

- What dependency bumps require approval for renovate to action (eg because they are major bumps)
- What dependency bumps it is working on (i.e. pending)
- What dependency bumps are currently open and awaiting review + merge
  - Note that renovate is an asynchronous tools so this list will lag behind a bit after you merge PRs
- What dependency bumps have been ignored

Ticking a checkbox in this issue will cause renovate to action the dependency:

- If you tick one in the "Pending Approval" list it will approve it and renovate will raise a PR.
- If you tick one in the "Pending Status Checks" list it will cause renovate to create the PR before its internal status checks are complete.
- If you tick one in the "Open" list it will cause renovate to rebase the PR (if there are no manual changes) or recreate the PR (if there are manual changes).
- If you tick one in the "Ignored or Blocked" list it will cause renovate to recreate the PR.

### Merging Renovate PRs

Renovate will not automatically merge its dependency PRs because we have branch protection turned on. Renovate PRs must go through the same workflow as human PRs: i.e. all PRs must be approved with passing status checks before they can be merged.

Renovate will automatically update a PR if there is a conflict with `main`. You can also force it to rebase a PR by ticking the box in the PR's description, or ticking the relevant box on the dependency dashboard.

You should generally avoid clicking the "Update branch" button in the Github UI as this will create a human commit - which cause renovate to treat the branch as "dirty" and it will no longer automatically. Only click it if you are planning on merging the PR manually ASAP.

## Manual Dependency Updates

Occasionally it will be desirable to manually bump the dependencies in one commit rather than relying on renovate's many PRs. Doing so is just a matter of:

1. `git checkout main && git pull`
1. `yarn install`
1. `yarn update-interactive` - this will start yarn's prompt to update the deps.
   1. Ignore the lines with `*` deps as these are intentionally set as such.
   1. Avoid changing the dep ranges like the complex range we have for TypeScript (eg `>=4.7.4 <5.5.0`).
   1. Once you're ready, hit `enter` and yarn will make the changes and rerun the install.
1. Run all of the relevant checks locally so you can action any failures before raising a PR:
   1. `yarn build`
   1. `yarn typecheck`
   1. `yarn lint`
   1. `yarn test`
   1. `yarn integration-test`
1. Create a new branch (a name like `update-deps-20231201` is good just to keep it unique), create, and land a PR.

### Babel

Our published packages only depend on `@babel/*` packages as devDependencies.
You can generally upgrade those dependencies with:

1. `yarn add -D @babel/code-frame @babel/core @babel/eslint-parser @babel/parser @babel/types`
2. `npx nx run ast-spec:test -u`

The fixtures under `packages/ast-spec/` describe how the files are parsed under both Babel and our (TSESTree) parser.

### ESLint

The typescript-eslint repository contains four kinds of version ranges for the `eslint` package:

- Integration tests: Pinned to our lowest supported ESLint version
- Packages with a `*` `peerDependency` version: These fall back to the explicit `peerDependency` versions
- Packages with explicit `peerDependency` versions: The full range of supported ESLint major versions
- [Root `package.json`](https://github.com/typescript-eslint/typescript-eslint/blob/main/package.json)'s' `devDependency`: A relatively recent release, used only for repository development

:::tip
Whenever you discover any new areas of work that are blocked by dropping an old ESLint version, such as new ESLint API deprecations, add a _TODO_ comment that will be caught by the regular expressions under [Removing Support for an Old ESLint Version](#removing-support-for-an-old-eslint-version).
:::

#### Adding Support for a New ESLint Version

1. Upgrade the root `package.json` `devDependency` to the latest ESLint
1. Add the new major version to the explicit `peerDependency` versions
1. Check [`eslint-visitor-keys`](https://www.npmjs.com/package/eslint-visitor-keys) for a new version to be upgraded to as well.
1. Update [Users > Dependency Versions > ESLint](../../users/Dependency_Versions.mdx#eslint)

#### Removing Support for an Old ESLint Version

1. Increase the integration tests to the next lowest supported major version (`*.0.0`)
1. Remove the old major versions from packages with explicit `peerDependency` versions
1. Search for source code comments (excluding `CHANGELOG.md` files) that mention a now-unsupported version of ESLint.
   - For example, to remove support for v5, searches might include:
     - `/eslint.*5/i`
     - `/todo.*eslint.*5/i`
     - `/todo.*eslint/i`
1. Update [Users > Dependency Versions > ESLint](../../users/Dependency_Versions.mdx#eslint)

See [chore: drop support for ESLint v6](https://github.com/typescript-eslint/typescript-eslint/pull/5972) for reference.

### Node

The typescript-eslint repository contains three kinds of version ranges for Node:

- [`.github/workflows/ci.yml`](https://github.com/typescript-eslint/typescript-eslint/blob/main/.github/workflows/ci.yml)'s `PRIMARY_NODE_VERSION`: Set to the highest Node version we support
- `node-version`: Set to a tuple of our `[lowest, highest]` supported versions for our unit tests in CI
- `engines` field in all `package.json`s: explicitly lists all supported Node ranges

Change those numbers accordingly when adding support for a new Node version or removing support for an old Node version.

See [feat: drop support for node v12](https://github.com/typescript-eslint/typescript-eslint/pull/5918) + [chore: test node v14 on ci.yml](https://github.com/typescript-eslint/typescript-eslint/pull/5512) for reference.

### TypeScript

#### Adding Support for a New TypeScript Version

We generally start the process of supporting a new TypeScript version just after the first beta release for that version is made available.

1. Create and pin an issue with a title like _TypeScript X.Y Support_, `accepting prs`, `AST`, `dependencies`, and `New TypeScript Version` labels, and the following contents:
   1. A link to the _TypeScript X.Y Iteration Plan_ issue from the Microsoft issue tracker
   2. The following text:

      ```md
      This issue is just to track all of the new features and their implementation state in this project.
      As with all releases, we will not necessarily support all features until closer to the full release when everything the features are stabilised.

      _Please be patient._ ❤️
      ```

   3. A heading starting with `🔲 ` for each new TypeScript feature called out in the iteration plan that will impact us
   4. A heading titled _🔲 `lib.d.ts` Updates_ and the content _We will need to regenerate our types within `scope-manager`_
   5. A heading titled _Other changes with no impact to us_ containing a list of other changes that we don't believe will impact us

1. At this stage, it's fine to send and/or review PRs that implement necessary features, but wait to merge them until the new TypeScript version's RC is released
   - Whenever a PR is created, add ` (#1234)` to its respective heading, and change the heading's emoji from 🔲 to 🏗
   - Search for `expectBabelToNotSupport` to see how to support syntaxes not yet supported by Babel
1. Once the TypeScript RC version is released, start merging PRs
   - Whenever a PR is merged, change the respective heading's emoji from 🏗 to ✅
1. Create a PR with a title like `feat: update TypeScript to X.Y-rc` and the following changes:
   - In the root `package.json`, add `|| X.Y.1-rc2` to the `devDependency` on `typescript`
   - In the parser's `getLib`, update the `switch (target)` and its preceding comment as needed (see [#6782](https://github.com/typescript-eslint/typescript-eslint/pull/6782))
   - Change the `SUPPORTED_TYPESCRIPT_VERSIONS` constant's `<` version to the next version of TypeScript
   - Change the `SUPPORTED_PRERELEASE_RANGES` constant to equal `['X.Y.1-rc']`
   - Run `yarn generate-lib` to update `scope-manager`
1. Once all PRs needed for the RC update PR are merged, merge the RC update PR
1. Once TypeScript releases the stable X.Y version, create and merge a PR with a title like `chore: bump TypeScript from X.YRC to X.Y` and the following changes:
   - In the root `package.json`, remove `|| X.Y.1-rc2` from the `dependency` on `typescript`, and bump its `<` version to the next version of TypeScript
   - In the root `package.json`, change the `resolutions` on `typescript` to `X.Y.3`
   - Any other changes made necessary due to changes in TypeScript between the RC version and stable version
1. Send a PR that updates this documentation page to point to your newer issues and PRs
   - Also update any of these steps if you go with a different process

See for reference (caveat: these don't follow the exact process described here):

- [TypeScript 4.7 Support](https://github.com/typescript-eslint/typescript-eslint/issues/4800)
- [TypeScript 4.8 Support](https://github.com/typescript-eslint/typescript-eslint/issues/5227)
- [feat: support TypeScript 4.8](https://github.com/typescript-eslint/typescript-eslint/pull/5551)
- [feat: support TypeScript 4.9](https://github.com/typescript-eslint/typescript-eslint/pull/5716)
- [chore: bump TS from 4.9RC to 4.9](https://github.com/typescript-eslint/typescript-eslint/commit/a40a311bb52a2b1cfac43851b201f8cfc96c8d5d)

### Removing Support for an Old TypeScript Version

A single PR can remove support for old TypeScript versions as a breaking change:

1. Update the root `package.json` `devDependency`
1. Update the `SUPPORTED_TYPESCRIPT_VERSIONS` constant in `warnAboutTSVersion.ts`
1. Update the `versions` constant in `version-check.ts`
1. Update [Users > Dependency Versions > TypeScript](../../users/Dependency_Versions.mdx#typescript)
1. Update `MIN_TS_VERSION_SEMVER` in `packages/website/src/components/OptionsSelector.tsx`
1. Search for source code comments (excluding `CHANGELOG.md` files) that mention a now-unsupported version of TypeScript.
   - For example, to remove support for v4.3, searches might include:
     - `4.3`
     - `/is.*4.*3/i`
     - `/semver.*4.*3/i`
     - `/semver.satisfies/`
     - `/todo.*ts/i`
     - `/todo.*typescript/i`

See [feat: bump minimum supported TS version to 4.2.4](https://github.com/typescript-eslint/typescript-eslint/pull/5915).