canary `deno install` - can't find npm modules

deno 2.0.0-rc.1+7bfcb4d I'm having a deno.json like this

{
  "tasks": {
    "test": "vitest"
  },
  "imports": {
    "vitest": "npm:vitest@^2.0.5"
  }
}

{
  "tasks": {
    "test": "vitest"
  },
  "imports": {
    "vitest": "npm:vitest@^2.0.5"
  }
}

I run deno install I have a test like this:

import { expect, test } from "vitest"; // <- "Cannot find module 'vitest' or its corresponding type declarations.ts(2307)
function sum(a, b) {
  return a + b
}
test('adds 1 + 2 to equal 3', () => {
  expect(sum(1, 2)).toBe(3)
})

import { expect, test } from "vitest"; // <- "Cannot find module 'vitest' or its corresponding type declarations.ts(2307)
function sum(a, b) {
  return a + b
}
test('adds 1 + 2 to equal 3', () => {
  expect(sum(1, 2)).toBe(3)
})

Why can the type declarations not be found? deno install doesn't seem to make a node_modules folder by default - is that necessary for this this type to be found, or can the import mapping work? I also have the vitest.config.ts like this:

import {defineConfig} from "vitest/config";

export default defineConfig({
  test: {
    include: ['sum.test.ts']
  }
})

import {defineConfig} from "vitest/config";

export default defineConfig({
  test: {
    include: ['sum.test.ts']
  }
})

and when I run the task deno task test I get an error that "vitest/config" also can't be found:

➜ deno task test
Task test vitest
✘ [ERROR] Unterminated string literal

    vitest.config.ts:1:366:
      1 │ ...e:///Users/admin/repos/deno-kitchensink/vitest-demo/vitest.config.ts";import {defineConfig} from "vitest/config';
        ╵                                                                                                                     ^

failed to load config from /Users/admin/repos/deno-kitchensink/vitest-demo/vitest.config.ts

➜ deno task test
Task test vitest
✘ [ERROR] Unterminated string literal

    vitest.config.ts:1:366:
      1 │ ...e:///Users/admin/repos/deno-kitchensink/vitest-demo/vitest.config.ts";import {defineConfig} from "vitest/config';
        ╵                                                                                                                     ^

failed to load config from /Users/admin/repos/deno-kitchensink/vitest-demo/vitest.config.ts

5 Replies

marvinh.•3mo ago

You're having a syntax error in your vitest.config.ts file. A string or import specifier needs to start and end with the same quotation style. If it starts with double quotes it needs to end with double quotes.

- import {defineConfig} from "vitest/config';
+ import {defineConfig} from "vitest/config";
  
  export default defineConfig({
    test: {
      include: ['sum.test.ts']
    }
  })

- import {defineConfig} from "vitest/config';
+ import {defineConfig} from "vitest/config";
  
  export default defineConfig({
    test: {
      include: ['sum.test.ts']
    }
  })

Birk SkyumOP•3mo ago

Oh, right! So now I get "Error: Cannot find module 'vitest/config'" Should I setup-up import mapping for that as well next to the one for "vitest"

Birk SkyumOP•3mo ago

the types aren't picked up

marvinh.•3mo ago

not sure about the other errors. Just saw the typo in your code before going to bed. Might be worth filing an issue on GitHub for this

Birk SkyumOP•3mo ago

And thank you for that - I'd totally missed that Aha! Turns out adding the ""nodeModulesDir": "auto"," in the deno.json, and running deno install does wonders here.