Cannot import local ES6 modules

[ppcano]

Using an example from samples/REST_API_testsuite/

cd samples/REST_API_testsuite/
k6 -v run v3_account_login.js

DEBU[0001] Babel: Transformed                            t=357.927232ms
DEBU[0001] Fetching source...                            url="https://common?_k6=1"
DEBU[0001] Fetching source...                            url="https://common"
ERRO[0001] GoError: Get https://common?_k6=1: dial tcp: lookup common: no such host
	at native
	at v3_account_login.js:40:122(62)

[ppcano]

@liclac

1. importing local modules doesn't look to be fully working.

import { myTrend, options, urlbase, thinktime1, thinktime2 } from "./common.js";

Works!

import { myTrend, options, urlbase, thinktime1, thinktime2 } from "./common";

ERRO[0000] GoError: open /Users/ppcano/dev/go/src/github.com/loadimpact/k6/samples/REST_API_testsuite/common: no such file or directory

You can easily test the k6 example:

cd samples/REST_API_testsuite/
k6 -v run v3_account_login.js

2. I think, a doc article should be written to detail how modules works. Thoughts?

[ragnarlonn]

A description of how the new load-file-system works (for both import statements and when specifying scripts to execute on the command line) would be very useful, yeah. If @liclac could write some short bullet points, or pseudo code that describes how it works, I can flesh it out into a proper docs page (and test it, so it works as expected).

[liclac]

Omitting .js is not supposed to work; we can check if a version with .js exists if we're loading locally, but not from a remote host, so we'd end up with code that works differently depending on where it's loaded from.

Pseudocode:

1. Resolve relative imports into an absolute path, relative to the calling file.
   • If this is a remote resource trying to load a local one as an absolute path (eg. /etc/passwd), block that. This is allowed from local scripts though.
2. Does the resolved path start with '/'?
   • Load it as a local file.
3. Does the path match any known services? (CDNJS, GitHub)
   • Check the corresponding adapter for the real URL and fetch that.
4. If not:
   • Treat the path as a schemaless https:// URL and fetch it.