Ember 6.0 Released

– By Jared Galanis, Katie Gengler

Ember 6.0 continues the commitment to stability and reliability that developers have come to expect from the Ember ecosystem and further moves us towards the Polaris Edition of Ember. Get up-to-date with the latest in Ember and enjoy!

This post will cover our release strategy, how to upgrade, what to expect, and deprecated APIs that were removed.

This release follows the release strategy and goals proposed in RFC 830, Evolving Ember's Major Version Process. To summarize, every 12 minor releases, Ember will ship a new major release, which removes any deprecated code targeted for that major version.

When it comes to introducing new features, Ember generally aims to ship new features in minor releases, offering backwards compatibility for existing code at the same time as giving developers the chance to try out new capabilities. This approach reduces the challenges that teams face for major upgrades, compared to producing big, breaking, splashy major versions with lots of new features.

In Ember 5.x minor releases, we landed a bunch of features (along with various bug fixes, of course):

  • In Ember 5.1, we published stable types from Ember's own TypeScript source code. We also shipped official support for pnpm in ember-cli.

  • In Ember 5.2, we added a public import for the uniqueId helper so it can be used in <template>.

  • In Ember 5.3, we deprecated implicit record loading in Ember Routes.

  • In Ember 5.5, we made several changes to ember-cli to smooth the way to embroider and <template>. We also deprecated built-in support for using Travis CI as a CI provider.

  • In Ember 5.6, ember-cli gained a small but helpful feature to automatically choose a port when 4200 is already in use.

  • In Ember 5.7, we added an optional feature to opt in to the new behavior of deprecated implicit record loading in Ember Routes ahead of 6.0.

  • In Ember 5.8, we improved the parsing of .gts files in blueprints in ember-cli.

  • In Ember 5.9, we made a major improvement to our major version release process. When the until of a deprecation for ember-source or ember-cli is less than or equal to the version of the package being used, deprecations will throw. In this way, deprecations automatically "break" when they were intended to break and do not need to be manually cleaned up. If we leave the deprecations in place for at least the x.0 release, this has a nice side effect for users in that any missed deprecations will now throw once you upgrade, rather than vanish. This was part of RFC #0830.

    We also deprecated (action) and {{action}} in favor of on.

  • In Ember 5.10, we made internal changes to ember-source to build with Vite, with no AMD loader present. This ensures that Ember.js is strictly following the ES module spec.

    We also deprecated non-colocated component template resolution (component templates living in app/templates/components instead of app/components).

    Another deprecation of note is the Array Prototype extensions.

  • In Ember 5.12, there was an update to glimmer-vm that brought with it performance improvements.

We also made significant strides in key parts of the ecosystem outside the core framework itself over the past 18 months:

In November 2023, we updated the Lockstep Versioning strategy for Ember Data. EmberData continues to support all Ember LTS releases with an LTS of their own, but the exact versions no longer match. See the blog post for more details.

The Embroider Initiative brought a large amount of energy into our build tooling and has made it possible to build Ember apps with Vite. The RFC to make this the default for new apps is currently in Final Comment Period.

Ember 6.0 has no new features over Ember 5.12, because we did all that work in minor releases instead.

You can read more about our general release process here:

Beta cycle

This release kicks off the 6.1 beta cycle for all subprojects. We encourage our community (especially addon authors) to help test these beta builds and report any bugs before they are published as a final release in six weeks' time. The ember-try addon is a great way to continuously test your projects against the latest Ember releases.

Version 5.12 of Ember.js is now promoted to LTS (Long Term Support). The current LTS version of EmberData remains at version 5.3. An LTS version of Ember continues to receive security updates for 9 release cycles (54 weeks) and bugfixes for 6 cycles (36 weeks). LTS releases typically occur every four minor versions. The previous LTS version of Ember.js was 5.8.

How to upgrade to Ember 6

The most common approach for upgrading to 6.0 is to upgrade your app to the last version of Ember 5, which is 5.12, resolve all deprecation warnings, and then upgrade to 6.0. If your app or addon runs with no deprecations in the latest release of 5.12, you should be able to upgrade to Ember 6 with no additional changes. Step-by-step directions are below.

If your app is at a much earlier version in the 5.x series, we recommend upgrading in steps across the LTS versions: 5.4, 5.8, and then 5.12.

Follow these steps in order:

  1. Consider upgrading addons used in your app to the latest version that you can. This will reduce the uses of deprecated APIs in your dependencies.
  2. Upgrade your project to the latest patch version of Ember 5.12. Many developers can do this by running npx ember-cli-update --to 5.12. The general Ember upgrade guide has more details about how to upgrade your Ember app/addon.
  3. Make sure your app builds successfully.
  4. Resolve all deprecation warnings. These Deprecated APIs are removed in Ember 6.0. You may need to upgrade some of your addon dependencies if they are using deprecated APIs. See the Ember Deprecation Guide for more details about specific deprecations and how to resolve them. Applications that need to upgrade through several versions may want to consider isolating individual deprecations by using ember-cli-deprecation-workflow.
  5. Make sure your app builds successfully and your test suite passes with no deprecations.
  6. Upgrade your app to Ember 6.0. Again, many developers can do this by running npx ember-cli-update --to 6.0. Refer to the general Ember upgrade guide for more details about how to upgrade your Ember app/addon.

For help or advice along the way, visit Ember's forums or chat groups.

The journey towards Ember Polaris

Polaris is the name of an upcoming edition of Ember, first announced at EmberConf 2021. Over the course of 6.x, new features will be added to Ember that will eventually make up the new edition.

Since our major versions tend to be uneventful, Editions are the moment where the Ember community comes together to learn and build in new ways. An edition is a set of features, corresponding documentation, and tools that create a cohesive programming model. An edition marks a shift and step forward in the framework, beyond what individual features would accomplish. Ember Octane was the first new edition that was added to Ember.

Stay tuned for future blog posts with more details and calls for contributors!

Ember.js

Ember.js is the core framework for building ambitious web applications.

Changes in Ember.js 6.0

Ember.js 6.0 introduces no new public API. Instead, it comprises bug fixes and the breakage of previously deprecated public API from the 5.x cycle.

Bug Fixes

  • #20731 - Bump barrel file deprecations until 7.0.0

Features

Ember.js 6.0 introduced no new features.

Deprecations

Ember.js 6.0 introduced 0 deprecations. It removed all deprecations that were introduced before 5.10 and slated for removal in 6.0.

Ember 6.0 removes the following features deprecated during 5.x:

  • Removing the implicit route model hook behavior where if no Route#model hook was specified and a _id parameter was present, Ember would attempt to figure out how to load that model for you. There is an optional feature that lets you opt-in to the new behavior in 5.x.
  • Removing the (action) template helper and {{action}} modifier now that we have native classes and the {{on}} modifier.
  • Removing the runtime resolution of component templates, so if there is an import involved, there is no runtime resolution.
  • Removing the extension of the prototypes of native Javascript arrays to implement Ember.Enumerable, Ember.MutableEnumerable, Ember.MutableArray, Ember.Array. For convenient functions like filterBy or compact, you can directly convert to use native array methods.

For more details on how to resolve these deprecations in your app, see the deprecations guide.

Deprecations are added to Ember.js when an API will be removed at a later date. Each deprecation has an entry in the deprecation guide describing the migration path to a more stable API. Deprecated public APIs are not removed until a major release of the framework.

Consider using the ember-cli-deprecation-workflow addon if you would like to upgrade your application without immediately addressing deprecations.

For more details on changes in Ember.js 6.0, please review the Ember.js 6.0.0 release page.

EmberData

EmberData is the official data persistence library for Ember.js applications.

EmberData broke from Lockstep versioning in November 2023. Under the new policy, EmberData 5.3 is an LTS that supports ember-source 5.12 and ember-source 6.0. More compatibility info is available in the README.

EmberData is also in the process of rebranding to WarpDrive. Stay tuned for more info!

This support extends beyond bug-fixes. If minor enhancements can be made to better support new presentation class implementations that support the 5.x series we will willingly accept them. Our goal is that we want no one left behind.

To learn about the motivation and goals for upcoming changes to EmberData in 5.x, read the blog post, EmberData 5.X Update.

This will help you form the mental model of what to expect across the 5.x series, and understand deprecation removals in the context of the upcoming goals.

Ember CLI

Ember CLI is the command line interface for managing and packaging Ember.js applications.

Upgrading Ember CLI

You may upgrade Ember CLI using the ember-cli-update project:

npx ember-cli-update

This utility will help you to update your app or addon to the latest Ember CLI version. You will probably encounter merge conflicts, in which the default behavior is to let you resolve conflicts on your own. For more information on the ember-cli-update project, see the GitHub README.

While it is recommended to keep Ember CLI versions in sync with Ember and EmberData, this is not required. After updating ember-cli, you can keep your current version(s) of Ember or EmberData by editing package.json to revert the changes to the lines containing ember-source and ember-data.

Changes in Ember CLI 6.0

Features

Ember CLI 6.0 introduced 0 features.

Deprecations

Ember CLI 6.0 introduced 0 deprecations. Ember CLI 6.0 removed features and APIs that were deprecated in 5.x or earlier, please see the Deprecation guide for more information:

  • outputPaths build option was deprecated in 5.3 and is now removed.
  • Travis CI built-in support was deprecated in 5.5 and is now removed, including the --ci-provider=travis command-line flag.

For more details on the changes in Ember CLI 6.0 and detailed upgrade instructions, please review the Ember CLI 6.0.0 release page.

Thank You!

As a community-driven open-source project with an ambitious scope, each of these releases serves as a reminder that the Ember project would not have been possible without your continued support. We are extremely grateful to our contributors for their efforts.