Import followed by a comments should be moved to the top of the generated file

[goswinr]

I did not know that 'emitJsStatement' will extract imports:

but if it has a comment, it won't:

see REPL
where is this implemented? I only found this

Fable/src/Fable.Core/Fable.Core.JsInterop.fs

Line 48 in c287b15

let emitJsStatement<'T> (args: obj) (jsCode: string) : 'T = nativeOnly

[MangelMaxime]

Hello,

Fable always try to put import statement at the top of the file.

The line that you liked is the exposed API, you will need to look into Fable.Transforms to find where that API is handled by Fable compilation/transformation.

For example, this API is probably handled here:

Fable/src/Fable.Transforms/Replacements.fs

Lines 1027 to 1032 in c287b15

	| Naming.StartsWith "emitJs" rest, [ args; macro ] ->
	match macro with
	| RequireStringConstOrTemplate com ctx r template ->
	let args = destructureTupleArgs [ args ]
	let isStatement = rest = "Statement"
	emitTemplate r t args isStatement template |> Some

But I am not sure yet where Fable does the re-ordering.

Could you please explain what is your request with this issue? Because I don't understand your request with the current title and description.

Is the request that import statement with a trailing comment should also be moved up too?

[goswinr]

Yes, sorry, @MangelMaxime my question was not clear.
The real question is how to emit

import JSZip from "jszip";

not

import {JSZip} from "jszip";

I tried all attributes form the docs :

REPL [<ImportMember("..")>]

REPL [<ImportMember(".." , "...")>] ( this should compile but doesn't ! Are the docs wrong? )

REPL [<Import(".." , "...")>]

REPL [<ImportDefault("..")>]

Is including it in a emitJsStatement (without a comment) the only way ?

[MangelMaxime]

There is indeed a typo in the documentation regarding ImportMember it only takes 1 argument.

Fable/src/Fable.Core/Fable.Core.Types.fs

Lines 60 to 62 in c287b15

	/// Takes the member name from the value it decorates
	type ImportMemberAttribute(from: string) =
	inherit Attribute()

But it would still not generate what you want as it would generate import {JSZip} from "jszip".

---

In JavaScript import JSZip from 'jszip'; is importing the default export from jszip.

To proves that you can try to run:

import JSZip from 'jszip';
import { default as bar } from 'jszip';

console.log(JSZip);
console.log(bar);

and you will see the same output for both console.log:

[Function: JSZip] {
  support: {
	...
  },
  defaults: {
	...
  },
  version: '3.10.1',
  loadAsync: [Function (anonymous)],
  external: { Promise: [Function: Promise] }
}
[Function: JSZip] {
  support: {
	...
  },
  defaults: {
	...
  },
  version: '3.10.1',
  loadAsync: [Function (anonymous)],
  external: { Promise: [Function: Promise] }
}

So using:

[<ImportDefault("jszip")>]
type JSZip() = class end

//or 

let jsZip1 = import "default" "jszip"
let jsZip2 = importDefault "jszip"

are equivalent. You don't need JSZip to respect the casing this is just an alias.

[goswinr]

Thanks, I found that only

open Fable.Core.JsInterop
do 
    import "default as JSZip" "jszip"

yields

import JSZip from "jszip";

REPL

[goswinr]

I still leave this issue open because I think import statement with a trailing comment should not behave differently.
(see initial issue)