Unexpected character '@' when using path aliases

[viT-1]

What happens and why it is wrong

Just try same way
index.ts:
import SomeComponent from '@common/SomeComponent';
and got error:

Error: Unexpected character '@' (Note that you need plugins to import files that are not JavaScript)
at error (C:\Projects\PACWorld\Branches\PacWorldWeb3-vuejs\PacWorld3\node_modules\rollup\dist\rollup.js:9408:30)
at Module.error (C:\Projects\PACWorld\Branches\PacWorldWeb3-vuejs\PacWorld3\node_modules\rollup\dist\rollup.js:13347:9)
at tryParse (C:\Projects\PACWorld\Branches\PacWorldWeb3-vuejs\PacWorld3\node_modules\rollup\dist\rollup.js:13262:16)
at Module.setSource (C:\Projects\PACWorld\Branches\PacWorldWeb3-vuejs\PacWorld3\node_modules\rollup\dist\rollup.js:13573:33)
at Promise.resolve.catch.then.then.then (C:\Projects\PACWorld\Branches\PacWorldWeb3-vuejs\PacWorld3\node_modules\rollup\dist\rollup.js:16398:20)

Environment

Win10, MS Visual Studio 2019

Versions

• typescript: 3.5.2
• rollup: 1.17.0
• rollup-plugin-typescript2: 0.22.1

rollup.config.js

const rolTts = require('ttypescript');
const rolTypescript = require('rollup-plugin-typescript2');
// ...
plugins: [
	rolTypescript({
		tsconfig: './src/tsconfig.json',
		clean: true,
		tsconfigOverride: {
			declaration: false,
			compileOnSave: false,
		},
		typescript: rolTts,
	}),
]

tsconfig.json

	"extends": "../tsproject.json",
	"compilerOptions": {
		"baseUrl": ".",
		"paths": {
			"@common/*": ["./common.blocks/*"]
		}
	}

[viT-1]

Initially tsconfig was without "compileOnSave" option,
but with adding this option to tsconfig file I have two funny errors:

rpt2: config error TS5023: Unknown compiler option 'compileOnSave'.
rpt2: config error TS5024: Compiler option 'compileOnSave' requires a value of type boolean.

Thats why I need to workaround through adding "tsconfigOverride" =(

[ezolenko]

You need a rollup-plugin-node-resolve plugin in front of typescript plugin

[viT-1]

Now I haven't TS5023 & TS5024 errors but still have problems with '@'

[viT-1]

Please reopen the issue.
I try your rollup plugin with @zerollup/ts-transform-paths transformer configured two ways:

1. through tsconfig.json >compilerOptions>plugins
2. through typescript & transformers options

and still haven't success!
but have success (npm run deploy.dev & npm run www.dev) with npm run ttsc (ttypescript) which use only tsconfig.json with same @zerollup/ts-transform-paths

[ezolenko]

You can probably use transformers option on rpt2 plugin itself if you want to avoid ttypescript wrapper. Might have to shim the interfaces a bit to make @zerollup/ts-transform-paths work (or maybe not, let me know either way if you go this route).

[ezolenko]

If ts-transform-paths works, is there anything to fix on this side though?

[viT-1]

I tried transformers (point 2), no success =(

[viT-1]

Migrate to rollup-plugin-typescript with rollup-plugin-import-resolver

[agilgur5]

I'm not sure what was going on in OP's codebase as no repro was provided and the issue they linked to (#159) was due to an invalid misconfiguration. The config posted here has a similar misconfiguration, compilerOptions is missing within tsconfigOverrides.

I also found the old commit from a repo they later linked (I modified their comment to point to the permalink as well), but didn't see a Rollup config there, so hard to tell what the issue was here.

It was likely a misconfiguration though, as lots of people have gotten path aliases, ttypescript, and ts-transform-paths working with this plugin; see #201 for one reference (can point to more in downstream TSDX as well).
OP also said in their last comment that they eventually used rollup-plugin-import-resolver, which is a plugin for resolving things like path aliases.