Meteor 1.5 with dynamic imports is officially released!

announce
21

Great work @benjamn and everyone involved. I just upgraded and successfully built my project to web/android and iOS.

1 Like
22

This is awesome. Now I donā€™t need to switch to other framework for performance reasons.

One question - Do we still need the ā€œimportsā€ folder to make it work or will it work with any folder set-up we may have.

23

I think that for now, you still need to use the imports folder :robot:

1 Like
24

Iā€™m likely going to just write a script to run immediately before pushing a new version that makes sure itā€™s been removed. Our workflow already includes a couple of steps just before pushing a new version that should be automated anyway (update README, bump version number in config).

Introducing another build state might be the way to go, although my gut says that should be carefully thought about. In the meantime, a pre-production-build script seems fairly simple, and something a lot of people are already doing.

25

A blog post with some step-by-steps for upgrading from 1.4 to 1.5 would be awesome!

like expo does: https://blog.expo.io/expo-sdk-v17-0-0-is-now-available-2c4f13362816

Albeit I have not upgraded yet, so maybe itā€™s too straightforward to justify a blogpostā€¦ but just a thought

26

There are zero steps! :]

8 Likes
27

Iā€™d just like to see a 1.5 app with plenty of examples of dynamic imports with sync & acync calls. Maybe importing Packages and symlinks for code sharing. Basically a enterprise level setup.

28

Iā€™ve been working on a post about dynamic imports and how to optimize clientside bundlesā€¦ not sure if my article is any better than the meteor blog and this thread, but at least itā€™s a new take and perhaps covers a slightly different angle:

Hope this helps, and let me know if I need to correct anything. I plan on making a few more posts from different angles.

@viejo can you try importing the component which uses asser and not asset itself?

@a.com that post isnā€™t about the upgrade, but about how to benefit from it.

@aadams we have a large codebase which we have profiled and implemented several dynamic imports already, but entirely derivatives of the above pattern.

  1. find big packages which can be easily sectioned off and dynamically import components until they disappear.
  2. split all non-primary routes into dynamic imports (heavy handed, temp step)
  3. refactor step #2 to instead prefer importing components themselves, not routes + pages + components
11 Likes
29

Thanks for sharing @zeroasterisk, very helpful.

1 Like
30

I can confirm that I just tested the upgrade on my version of Meteor Mantra Kickstarter (from 1.4.4.2). Flawless!! Instant green on all Mocha unit tests and Chimp Cucumber end to end tests.

Congratulations guys. Fabulous job!

2 Likes
31

@viejo Iā€™m guessing your app was created a while back. For new Meteor apps, the assert built-in package is provided by the meteor-node-stubs npm package. So if you run

meteor npm install --save meteor-node-stubs

then youā€™ll have access to assert and all the other Node built-ins, though they will be bundled only if you actually use them (so you donā€™t need to worry about the size of unused packages).

1 Like
32

Just wanted to say thank you, and share some of our experience. Weā€™ve been using Meteor since ~0.5-0.6. Our current app is a mix of React and Blaze. When 1.5 was announced we decided it was time to take a fresh look at the app and build it again with the new best practices. Hereā€™s the exact same page, with the exact same data, both running in locally development modeā€™s performance summary within Chrome devtools (hint: the faster one is 1.5 using dynamic imports).

7 Likes
34

For me dynamic imports have been working great with exception of safari on mac.
Things work great in development however the production build (even with minifiers off) introduces some bugs that are definitely triggered during dynamic imports. No error is thrown by the promise returned so its hard to pin point what goes wrong.

2 Likes
35

Please file an issue on GitHub!

36

Thanks. I just want to be sure its not an issue on my end before reporting it.

37

The best way to confirm that is to create a small reproduction and see if it works!

38

For anyone who doesnā€™t keep tabs on the Meteor pull requests every once in awhileā€¦

There has been some good work merged recently in this PR to allow a much nicer way to use the bundle-visualizer package that came with Meteor 1.5. See the bundle-visualizer README. So now you can do this:

meteor --extra-packages bundle-visualizer --production

which is cleaner than the previous usage

meteor add bundle-visualzer
meteor --production
meteor remove bundle-visualizer

looks much better to me!

3 Likes