Personally, I would like to have us support TypeScript-type interfaces where plain objects that have the correct properties pass the check.[1]
I have no idea how difficult this would be for SWF-compatible code, but even if it’s supported for JS-only code, that would be a huge production booster. My $0.02, Harbs [1]https://www.typescriptlang.org/docs/handbook/interfaces.html <https://www.typescriptlang.org/docs/handbook/interfaces.html> > On Jan 7, 2019, at 6:03 AM, Alex Harui <aha...@adobe.com.INVALID> wrote: > > I just fixed a bug in the compiler, and now we are getting more of these > implicit coercion errors because the recent Google Closure Typedefs now > specify interfaces as parameters to certain contructors (or maybe they always > did and the compiler is now getting better at catching these errors). > > Code that looked like: > > var blob:Blob = new Blob([text], { type: 'text/plain' }); > > or > > customEvent = new window.Event(type, {bubbles: bubbles, cancelable: > cancelable}); > > now results in a compiler error because the plain objects don't implement > whatever interface of properties the constructor expects. I think Google > Closure did this so that the properties in the plain object don't get renamed > by the minifier. > > One solution, that Yishay tried in this commit was simply to lie to the > compiler and tell it that the plain object was a BlobPropertyBag. And while > that is the "least amount of code" solution, I didn’t like that solution > because it looks funny to have lots of places in our code where a plain > object is coerced to a type. > > So, I went and created classes that implement BlobPropertyBag and other > interfaces. I didn't like adding the weight of additional class definitions > but the classes I did were small, just a couple of properties. However, for > Event,there is a pretty big list of properties just to specify bubbles and > cancelable. The compiler was not catching that plain object before, but now > with the fix I just made it will. And I’m not sure it is worth adding a > large class with lots of properties. > > So, I thought of a third idea which is a hack between what Yishay tried and > the interface implementations I did, which is to have a factory that returns > an instance of the interface, but actually returns a plain object. As long > as no code actually tests that the instance implements the interface, it > should work. And that would localize the coercion of a plain object to an > interface in relatively few known places in our code. > > The pattern would be to create a top-level factory function() unless it makes > sense to add it to a class so for Blob it might look like: > > /** > * @royaleignorecoercion BlobPropertyBag > */ > public function createBlobPropertyBag():BlobPropertyBag > { > // return a plain object but fool the compiler into thinking it is an > implementation of the interface > return {} as BlobPropertyBag; > } > > IMO, this also future-proofs the code in case we ever run where there is > runtime type-checking and need to someday return a real concrete instance > that implements the interface. > > Thoughts? > -Alex > > > On 12/26/18, 11:02 PM, "Yishay Weiss" <yishayj...@hotmail.com> wrote: > > Sounds good, feel free to revert. > > > > ________________________________ > From: Alex Harui <aha...@adobe.com.INVALID> > Sent: Thursday, December 27, 2018 3:43:45 AM > To: dev@royale.apache.org; comm...@royale.apache.org > Subject: Re: [royale-asjs] branch develop updated: Fix implicit coercion > error > > I don't think we should hack it like this. Casting a plain object to a > type makes the code look strange, and it might not minify correctly. I have > a different fix I hope to put in shortly where we actually pass in an > instance of the BlogPropertyBag. > > -Alex > > On 12/26/18, 6:57 AM, "yish...@apache.org" <yish...@apache.org> wrote: > > This is an automated email from the ASF dual-hosted git repository. > > yishayw pushed a commit to branch develop > in repository > https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitbox.apache.org%2Frepos%2Fasf%2Froyale-asjs.git&data=02%7C01%7Caharui%40adobe.com%7C00f548a683d34a9c88b508d66bc93265%7Cfa7b1b5a7b34438794aed2c178decee1%7C0%7C0%7C636814909228765885&sdata=5DaM3aljpj1rk4FD0KBSzLWrfi9jzCOmbnAvfy2me8o%3D&reserved=0 > > > The following commit(s) were added to refs/heads/develop by this push: > new 2f127d4 Fix implicit coercion error > 2f127d4 is described below > > commit 2f127d459ee807f197950e11af947c623c270369 > Author: DESKTOP-RH4S838\Yishay <yishayj...@hotmail.com> > AuthorDate: Wed Dec 26 16:57:33 2018 +0200 > > Fix implicit coercion error > --- > > .../src/main/royale/org/apache/royale/storage/file/DataOutputStream.as | 2 +- > .../apache/royale/storage/providers/AndroidExternalStorageProvider.as > | 2 +- > .../royale/org/apache/royale/storage/providers/WebStorageProvider.as > | 2 +- > 3 files changed, 3 insertions(+), 3 deletions(-) > > diff --git > a/frameworks/projects/Storage/src/main/royale/org/apache/royale/storage/file/DataOutputStream.as > > b/frameworks/projects/Storage/src/main/royale/org/apache/royale/storage/file/DataOutputStream.as > index cff76eb..55eab71 100644 > --- > a/frameworks/projects/Storage/src/main/royale/org/apache/royale/storage/file/DataOutputStream.as > +++ > b/frameworks/projects/Storage/src/main/royale/org/apache/royale/storage/file/DataOutputStream.as > @@ -117,7 +117,7 @@ public class DataOutputStream extends > EventDispatcher implements IDataOutput > public function writeText(text:String):void > { > COMPILE::JS { > - var blob:Blob = new Blob([text], { type: > 'text/plain' }); > + var blob:Blob = new Blob([text], { type: > 'text/plain' } as BlobPropertyBag); > _fileWriter.write(blob); > } > COMPILE::SWF { > diff --git > a/frameworks/projects/Storage/src/main/royale/org/apache/royale/storage/providers/AndroidExternalStorageProvider.as > > b/frameworks/projects/Storage/src/main/royale/org/apache/royale/storage/providers/AndroidExternalStorageProvider.as > index ea79a5b..cf05a73 100644 > --- > a/frameworks/projects/Storage/src/main/royale/org/apache/royale/storage/providers/AndroidExternalStorageProvider.as > +++ > b/frameworks/projects/Storage/src/main/royale/org/apache/royale/storage/providers/AndroidExternalStorageProvider.as > @@ -199,7 +199,7 @@ package org.apache.royale.storage.providers > > _target.dispatchEvent(newEvent); > }; > > - var blob:Blob = > new Blob([text], { type: 'text/plain' }); > + var blob:Blob = > new Blob([text], { type: 'text/plain' } as BlobPropertyBag); > > fileWriter.write(blob); > }, function(e):void { > var > errEvent:FileErrorEvent = new FileErrorEvent("ERROR"); > diff --git > a/frameworks/projects/Storage/src/main/royale/org/apache/royale/storage/providers/WebStorageProvider.as > > b/frameworks/projects/Storage/src/main/royale/org/apache/royale/storage/providers/WebStorageProvider.as > index 1632bfa..dd9c84c 100644 > --- > a/frameworks/projects/Storage/src/main/royale/org/apache/royale/storage/providers/WebStorageProvider.as > +++ > b/frameworks/projects/Storage/src/main/royale/org/apache/royale/storage/providers/WebStorageProvider.as > @@ -199,7 +199,7 @@ package org.apache.royale.storage.providers > > _target.dispatchEvent(newEvent); > }; > > - var blob:Blob = > new Blob([text], { type: 'text/plain' }); > + var blob:Blob = > new Blob([text], { type: 'text/plain' } as BlobPropertyBag); > > fileWriter.write(blob); > }, function(e):void { > var > errEvent:FileErrorEvent = new FileErrorEvent("ERROR"); > > > > > >
