ES module access to global or process.env improvements

[aabfred]

• Version: v9.8.0

• Platform: Linux Host-002 4.14.6-300.fc27.x86_64 deps: update openssl to 1.0.1j #1 SMP Thu Dec 14 15:31:24 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

• Subsystem: esm

• test.msj:
  console.log( "global.TEST", global.TEST );
  console.log( "process.env.TEST", process.env.TEST );
  global.TEST2 = "yes";
  process.env.TEST2 = "yes";

• index.mjs:
  global.TEST = "ok";
  process.env.TEST = "ok";
  import "./test";
  console.log( "global.TEST2", global.TEST2 );
  console.log( "process.env.TEST2", process.env.TEST2 );

$ node --experimental-modules ./index.mjs
global.TEST undefined
process.env.TEST undefined
global.TEST2 yes
process.env.TEST2 yes

Problem:
Imported module cannot access to global / process.env improvements while caller accesses to improvements done by imported module

Note:
Replacing import "./test" with import "./test?test=ok" doesn't provides an access to query parameters

[targos]

If I'm not mistaken, this is expected behavior. In ES modules, imported modules are executed first (from bottom to top of the graph). The place of the import statements in the source code does not change that.
The relative order imports matters though. It means that you can have a third module that changes the global and import it before test.mjs, like so:

• config.mjs:

   global.TEST = "ok";
   process.env.TEST = "ok";

• test.mjs:

   console.log( "global.TEST", global.TEST );
   console.log( "process.env.TEST", process.env.TEST );
   global.TEST2 = "yes";
   process.env.TEST2 = "yes";

• index.mjs:

   import "./config";
   import "./test";
   console.log( "global.TEST2", global.TEST2 );
   console.log( "process.env.TEST2", process.env.TEST2 );

$ node --experimental-modules index.mjs

    global.TEST ok
    process.env.TEST ok
    global.TEST2 yes
    process.env.TEST2 yes

Replacing import "./test" with import "./test?test=ok" doesn't provides an access to query parameters

It is not possible in Node 9, because the necessary APIs are not there.
It will be possible in Node 10, using import.meta:

• test.mjs:

   const url = new URL(import.meta.url);
   console.log(url.searchParams.get('test'));

• index.mjs:

   import "./test?test=ok";

$ node --experimental-modules index.mjs

    ok

/cc @bmeck

[bmeck]

the current behavior looks correct to me.

index.mjs has a dependency on test.mjs which by ECMA262 requires loading and evaluating test.mjs prior to beginning any evaluation of index.mjs. In particular imports are essentially hoisted to the top of a file. import is not imperative but being imperative was looked at in tc39/ecma262#368 .

[aabfred]

Thanks for your explainations.
I didn't knew this subtlety of ECMAScript.
You can close this issue