--- id: versioning title: Versioning --- We follow [semantic versioning (semver)](https://semver.org). This page exists to help set guidelines around when what we consider to fall within each of the semver categories. All of the packages in this project are published with the same version number to make it easier to coordinate both releases and installations. We publish a canary release on every successful merge to `main`, so **you never need to wait for a new stable version to make use of any updates**. Additionally, we promote to the `latest` tag on NPM once per week, **on Mondays at 1 pm Eastern**. The latest version under the `latest` tag is: NPM Version The latest version under the `canary` tag **(latest commit to `main`)** is: NPM Version :::note The only exception to the automated publishes described above is when we are in the final phases of creating the next major version of the libraries - e.g. going from `1.x.x` to `2.x.x`. During these periods, we manually publish `canary` releases until we are happy with the release and promote it to `latest`. ::: ### ESLint > The version range of ESLint currently supported is `^6.0.0 || ^7.0.0 || ^8.0.0`. We generally support at least the latest two major versions of ESLint. ### Node This project makes an effort to support Active LTS and Maintenance LTS release statuses of Node according to [Node's release document](https://nodejs.org/en/about/releases). Support for specific Current status releases are considered periodically. ### TypeScript > The version range of TypeScript currently supported is `>=4.3.5 <5.1.0`. Note that we mirror [DefinitelyTyped's version support window](https://github.com/DefinitelyTyped/DefinitelyTyped/#support-window) - meaning we only support versions of TypeScript less than 2 years old. You may find that our tooling works on older TypeScript versions however we provide no guarantees and **_we will not accept issues against unsupported versions_**. #### Supporting New TypeScript Releases With each new TypeScript release we file an issue to track the changes in the new version. The issue should always be pinned, and you can also [find the issues by searching for issues tagged with "New TypeScript Version"](https://github.com/typescript-eslint/typescript-eslint/issues?q=is%3Aissue+label%3A%22New+TypeScript+Version%22+sort%3Acreated-desc). If the issue is open, we do not have official support yet - please be patient. In terms of what versions we support: - We do not support the `beta` releases. - We _generally_ do not officially support the `rc` releases. - We endeavor to support the latest stable TypeScript versions as soon as possible after the release. Generally we will begin working on supporting the next release when the `rc` version is released. #### Version Warning Logs Note that our packages have an open `peerDependency` requirement in order to allow for experimentation on newer/beta versions of TypeScript. However if you use a non-supported version of TypeScript, the parser will log a warning to the console. If you want to disable this warning, you can configure this in your `parserOptions`. See: [Parser > `warnOnUnsupportedTypeScriptVersion`](../packages/Parser.mdx#warnonunsupportedtypescriptversion). ## Breaking Changes When considering whether a change should be counted as "breaking" we first need to consider what package(s) it impacts. For example breaking changes for the parser packages have a different standard to those for the ESLint plugins. This is because not only do they have _very_ different API surfaces, they also are consumed in very different ways. Please note that the lists provided below are non-exhaustive and are intended to serve as examples to help guide maintainers when planning and reviewing changes. ### `ast-spec` and `visitor-keys` A change to the AST **_shall_** be considered breaking if it: - Removes or renames an existing AST Node. - Removes or renames an existing property on an AST Node. - Changes a type in a non-refining way (i.e. `string` to `number`). A change to the AST **_shall not_** be considered breaking if it: - Adds a new property to the AST. - Adds a new node type to the AST. - Adds a new node type to an existing union type. - Refines a type to be more specific (i.e. `string` to `'literal' | 'union'`). - Removes a type from a union that was erroneously added and did not match the runtime AST. ### `eslint-plugin` and `eslint-plugin-tslint` A change to the plugins **_shall_** be considered breaking if it will require the user to change their config. More specifically: - Removes or renames an option. - Changes the default option of a rule. - Changes a rule's schema to be stricter. - Consumes type information to a rule that did not previously consume it. - Removes or renames a rule. - Changes any of the recommended configurations. - Changes the default behavior of a rule in such a way that causes new reports in a large set of cases in an average codebase. A change to the plugins **_shall not_** be considered breaking if it: - Adds an option that by default does not remove existing functionality. - Adds a rule. - Deprecates a rule. - Adds additional checks to an existing rule that causes new reports in a small-to-medium set of cases in an average codebase. - Refactors a rule's code in a way that does not introduce additional reports. - Changes to a rule's description or other metadata. - Adds a fixer or suggestion fixer. - Removes a fixer or suggestion fixer. - Fixes incorrect behavior in a rule that may or may not introduce additional reports. #### `parser`, `typescript-estree`, `scope-manager`, `types`, `type-utils`, `utils` A change to these packages **_shall_** be considered breaking if it: - Changes the API surface in a backwards-incompatible way (remove or rename functions, types, etc). A change to these packages **_shall not_** be considered breaking if it: - Adds to the API surface (add functions, types, etc). - Deprecates parts of the API surface. - Adds **_optional_** arguments to functions or properties to input types. - Adds additional properties to output types. - Adds documentation in the form of JSDoc comments. ### Internal packages Any packages in this project that are not part of our public API surface (such as `eslint-plugin-internal` or `website`) shall not be considered when calculating new package versions.