tsconfig’s paths aren’t prioritized over node_modules when a custom tsconfig is used

[iamakulov]

Hey,

I stumbled upon an issue with a custom tsconfig.json.

When you use a custom tsconfig, ESBuild seems to prioritize node_modules over tsconfig.json’s paths (which means you can’t overwrite any installed dependencies). This is not an issue when the tsconfig.json file is automatically detected.

Repro

1. Create the test project:

yarn init -y
yarn add esbuild linaria

# tsconfig.json
echo '{
  "compilerOptions": {
    "baseUrl": ".",
    "paths": {
      "linaria": ["./linaria-mock.ts"]
    }
  }
}' > tsconfig.json

# index.ts
echo 'import { css } from "linaria";

const styles = css`
  color: red;
`;

console.log(styles);' > index.ts

# linaria-mock.ts
echo 'export function css() {
  return 5;
}' > linaria-mock.ts

2. Run ESBuild with the --tsconfig flag:

yarn esbuild --bundle index.ts --outfile=out.js --platform=node --tsconfig=tsconfig.json

3. Try to run the generated bundle:

node out.js

Expected result

The linaria package should’ve been replaced with ./linaria-mock.ts. So the generated bundle should print 5:

$ node out.js
5

Actual result

The linaria package is used as-is, despite the paths section in tsconfig. Therefore, the generated bundle throws a Linaria error:

$ node out.js
/tmp/esbuild-bug-test/out.js:32
    throw new Error('Using the "css" tag in runtime is not supported. Make sure you have set up the Babel plugin correctly.');
    ^

Error: Using the "css" tag in runtime is not supported. Make sure you have set up the Babel plugin correctly.
    at Object.css2 (/tmp/esbuild-bug-test/out.js:32:11)
    at Object.<anonymous> (/tmp/esbuild-bug-test/out.js:58:27)
    at Module._compile (internal/modules/cjs/loader.js:1138:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
    at Module.load (internal/modules/cjs/loader.js:986:32)
    at Function.Module._load (internal/modules/cjs/loader.js:879:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
    at internal/main/run_main_module.js:17:47

Further notes

• The issue disappears if you use an automatically inferred tsconfig.json file:

  # Note: no --tsconfig=tsconfig.json flag
  $ yarn esbuild --bundle index.ts --outfile=out.js --platform=node
  $ node out.js
  5

• The issue disappears if you remove the linaria dependency:

  $ yarn remove linaria
  $ yarn esbuild --bundle index.ts --outfile=out.js --platform=node --tsconfig=tsconfig.json
  $ node out.js
  5

  In this case, the overwrite happens as expected.

[evanw]

Thanks for the report. This should be fixed as of esbuild version 0.6.6.