TypeScript "importsNotUsedAsValues" compiler option doesn't take effect while using path alias or baseUrl

[RageYL]

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

import type { MyType } from 'mymodule';

generates

const mymodule_1 = require('...')

This problem was already reported in this closed issue: #783.

Minimum reproduction code

import { TypeA } from 'src/type-a'
import type { TypeB } from 'src/type-b'
import { TypeC } from './type-c'
import type { TypeD } from './type-d'

npm run build generates:

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const type_a_1 = require("./type-a");
const type_b_1 = require("./type-b");

Steps to reproduce

https://github.com/RageYL/nest-cli-type-imports-bug

Expected behavior

No code should be emitted for type only imports.

Package version

8.1.2

NestJS version

8.1.2

Node.js version

14.17.6

In which operating systems have you tested?

• macOS
• Windows
• Linux

Other

From a quick google, we can skip the existing logic in https://github.com/nestjs/nest-cli/blob/master/lib/compiler/hooks/tsconfig-paths.hook.ts#L18 with the following edit:

-          tsBinary.isImportDeclaration(node) ||
+          (tsBinary.isImportDeclaration(node) && !node.importClause?.isTypeOnly) ||
```

[jmcdo29]

Can you make a git repo with the steps to reproduce, so we can just clone, install, and verify the issue?

[RageYL]

Created a repo from scratch using @nestjs/cli and edited the main file: https://github.com/RageYL/nest-cli-type-imports-bug

[liaoyinglong]

has anything news?

[jmcdo29]

This slipped my radar for a bit, sorry about that. The reproduction does indeed reproduce and shows tsc working as expected, and the proposed code change does fix up nest build so that it acts like tsc in this case. I'll get a PR made for fixing this done today

[kamilmysliwiec]

Let's track this here #1449