Turf: v7 alpha release

[rowanwins]

Inline with the suggestions contained within #1428 I've been working on getting a v7 release ready (see #1432)

API Changes

• There haven't been any changes to module API's

Higher level changes

• Modules are now ES6 modules, written in plain ol' js, and built into a single package using rollup
• Lerna is now no longer used for publishing as only a single package is published

Module enhancements

• JSTS has been replaced in union, difference, intersect by polygon-clipping
  -dissolve has been overhauled
• a number of other minor enhancements and fixes to modules...

Testing

• My initial testing of the alpha bundle has been going ok
• @shongololo has raised an issue around ReferenceError: m is not defined when buffering linestrings.
  
  
  
  • need to do a bit of digging here, may be a minification issue or something else... although see note below, ideally I'm hoping to do away with the jsts dependency in the buffer module
  
  

Outstanding issues

• The only module where jsts remains in use is buffer. I'm currently working on a replacement here
  
  
  
  • In the buffer replacement above I'm trying to build my library pulling in a couple of turf modules (eg coordEach). For some reason the build is pulling in all of turf rather than just the couple of modules I want (aka tree-shaking doesn't appear to be working...)
  
  
• In my case I'm again using rollup as my build tool. I could perhaps investigate using webpack although it would be nice to have turf 'just working' irrespective of build tool choice.

Where to find it

• v7.0.0-alpha.1 has been published to npm
• Or it can be found in the v7 branch

What next

• Try to resolve tree-shaking issue noted above
• Publicise changes more widely

cc @stebogit @tmcw

[songololo]

@rowanwins this is a huge step forward, thank you.

Regarding tree shaking, I'm going by memory, but I believe that it didn't work with webpack either. I'll update this with further comments if I figure anything out.

Update: Looked again and it seems webpack production mode is bundling what I assume to be the entire packaged turf.min.js file instead of extracting the relevant es modules from js. Might be a rollup configuration issue?

[rowanwins]

Yep confirmed webpack also isn't succesful in tree-shaking, need to do some more digging on the turf config end...

[rowanwins]

Hmm so I've done some more digging and it found a few things

• it looks like when there are multiple exports from a single file (eg helpers or meta) it struggles to shake things properly
  
  
  
  • Problematic because pretty much every turf modules calls one or multiple of them
  
  
• 3rd party module dependencies which get used in turf modules (eg concaveman) aren't being shaken

So a few options I can think of

1. Accept that it won't shake as well as I'd like and move on
2. Split those files with multiple exports out into single files (eg could still have a helpers directory, but put the featurecollection module in one file, and the feature in another)
   
   
   
   • I suspect this would help with some of the shaking but wouldn't fix those 3rd party imports...
   
   

Have tried hunting around for similar libraries but the ones I can think of (namely simple-statistics and lodash) don't have any dependencies.

Any brilliant ideas @tmcw ?

PS This is where the lerna mono-repo stuff was helpful :)

[songololo]

In case it helps, browsing through rollup's docs they have a suggestion regarding false-positives - to import using import map from 'lodash-es/map style vs. import { map } from 'lodash-es')

You can often mitigate those false positives by importing submodules (e.g. import map from 'lodash-es/map' rather than import { map } from 'lodash-es').

PS - More listed under danger zone on fine-tuning tree-shaking using treeshake.propertyReadSideEffects property.

[andrewharvey]

1. Split those files with multiple exports out into single files (eg could still have a helpers directory, but put the featurecollection module in one file, and the feature in another)
   I suspect this would help with some of the shaking but wouldn't fix those 3rd party imports...

As I mentioned at https://github.com/Turfjs/turf/issues/1428#issuecomment-401651415 anything to de-group helpers/meta etc. is :+1 in my opinion.

Looking forward to being able to just use:

import { feature, featureEach } from `@turf/turf`

[Morgul]

@rowanwins If you're still having problems, you might reach out to the OpenLayers devs, they made their v5 work correctly with treeshaking in webpack, rollup and parcel. (v4 had the same problems you seem to be running into).

I'll bet they'd be more than willing to share their experiences.

As a side note, right now Turf is a full 40% of my current webpack bundle for my application. (I found this issue looking for issues about tree shaking in turf.) I'm extremely excited about the v7 changes.

[rowanwins]

Hi @Morgul

Thanks for the suggestion. We have actually made a bit of progress on the treeshaking front thanks to some advice from @tmcw so I think we're back on track. Basically the issues primarily relate to some of our 3rd part dependencies so I've been doing some work on upstream libs and inlining others to make them more friendly for us.

So stay tuned :)

[sheerun]

Our application size is suffering from jsts. Maybe some help rewriting buffer? Could you point to something?

[tmcw]

@sheerun Take a look at #88, which is the master issue for removing JSTS. It's kind of like the 'sword in the stone' for this project.

[dpmcmlxxvi]

@rowanwins Just wondering, what is the status on v7?

[zakjan]

I tried all ways of importing from turf ([email protected], @turf/turf, @turf/boolean-contains), but tree-shaking doesn't work for any of them with Rollup, not even with Rollup dangerous switches. Visualized with rollup-plugin-visualizer, full @turf/meta and @turf/helpers are included, which are probably unnecessary.

I'm sorry, but this is a blocker for me for building a lightweight browser library https://github.com/zakjan/leaflet-lasso Until turf supports tree-shaking properly, for browser use I need to look for another library.

[tmcw]

Folks, if you can help out please do, but please don't threadsit on these issues. The status of v7 is readable in the original post of this issue, in the PR linked in the main thread, along with the commits therein. Per those issues, getting everything tree-shakeable is still something that's being worked on, so you shouldn't expect it to work yet: it won't.

@zakjan It looks like your library just needs a point in polygon method. You'll find many standalone modules for that by googling or searching npm: for example, point-in-polygon.

[rowanwins]

Hi @zakjan & @dpmcmlxxvi

There are a few more unresolved issues around the polygon-clipping library that are preventing it from shaking properly, for example I think this use of the singleton pattern, as well as these variables and functions. I have a version locally which shakes however it breaks a lot of tests which would need to be refactored accordingly.

With tree-shaking I think the meta and helper modules these will be relatively low priority as minified they come out very small.

I've also released point-in-polygon-hao recently which works with polygons containing holes out of the box as well as degenerate polygons (compared to point-in-polygon).