deno test - Cannot resolve module

[LukeChannings]

λ deno --version
deno 1.7.0+ada43cc (canary, x86_64-apple-darwin)
v8 8.9.255.3
typescript 4.1.3

I have an import map:

{
  "imports": {
    "/": "./",
  }
}

My program runs correctly with:

deno run -A --unstable --import-map=./import_map.json ./cmd/moviematch/main.ts

I have a simple test file:

import { assertEquals } from "https://deno.land/std@0.84.0/testing/asserts.ts";

import { getDirectories } from "/internal/app/plex/api.ts";

Deno.test("getDirectories", async () => {
 // test getDirectories
});

When I run:

λ deno test --import-map ./import_map.json -A --unstable

I get:

Check file:///Users/luke/Developer/MovieMatch/$deno$test.ts
error: Cannot resolve module "file:///Users/luke/Developer/MovieMatch/Users/luke/Developer/MovieMatch/internal/app/plex/api_test.ts" from "file:///Users/luke/Developer/MovieMatch/$deno$test.ts".

Things I've tried:

• Moving the test into a standalone test folder and selecting it with deno test --import-map ./import_map.json -A --unstable tests
• Importing the source relatively (works, but absolute imports are used throughout so it fails further on)

Why is the behaviour of deno test different to deno run?

[kitsonk]

deno test creates a "synthetic" module which imports all the test modules it find, that is why the behaviour is different.

[nayeemrmn]

I was going to say we should reconsider a non-file URL for $deno$test.ts so it's not subject to this, but $deno$eval.ts and $deno$repl.ts etc. can't be helped because we want relative specifiers to work for them.

I think the fake module specifier we use should be put through the import map, and the result of that should be passed to insert_cached() instead.

[kitsonk]

I think the fake module specifier we use should be put through the import map, and the result of that should be passed to insert_cached() instead.

That sounds reasonable.

[caspervonb]

If #9662 ends up landing we'll be removing the synthetic test module as a side effect.

[LukeChannings]

As a side note, I've found that I can work around this issue by being more specific with aliases:

{
  "imports": {
    "/internal/": "../internal/",
    "/types/": "../types/"
  }
}

(paths are ../ because I keep my import_map.json in ./configs)

I'm not sure why this works, but it does.