How can I make tsup resolve my typescript absolute import paths?

[isomorpheric]

👋 Hi and thank you so much for your work ❤️ 🤟🏼

Description

tsup is not resolving typescript absolute imports. I have a tsconfig.json that defines multiple absolute imports (see below). tsup bundles it without resolving for those absolute imports, so it causes errors when consuming the lib in other projects.

In your docs, I can see NormalizedOptions - which uses tsconfigResolvePaths - but when I try to put it in my config (see below) typescript gets angry 😠:

'tsconfigResolvePaths' does not exist in type 'Options | Options[] | ((overrideOptions: Options) => MaybePromise<Options | Options[]>)'

tsconfig.json:

"compilerOptions": {
    "baseUrl": ".",
    "paths": {
      "@services/*": [
        "./services/*"
      ],
      "@vendors/*": [
        "./vendors/*"
      ],
// ....
    },

tsup.config.json:

import { defineConfig } from 'tsup';

export default defineConfig({
  entry: {
    index: 'index.ts',
    'services/marketing/index': 'services/marketing/index.ts',
    'vendors/index': 'vendors/index.ts',
  },
  tsconfig: './tsconfig.json',
  splitting: false,
  sourcemap: true,
  clean: true,
});

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[wojtekKrol]

have the same issue

[dheerajsinghnagdali]

I have the same issue as well.

[undermuz]

have the same issue

[PureSci]

this is still an issue

[mehrangta]

Any updates/workarounds on this ?

[PHILLIPS71]

I'm encountering the same problem and have been using https://github.com/benyap/resolve-tspaths as a workaround. However, it doesn't function when minify is enabled 😞. It would be great if this feature were natively supported and working properly.

[ThijsZijdel]

bump..

[Tomas2D]

bump

[Tomas2D]

Since I have emitDecoratorMetadata: true in my tsconfig, tsup uses @swc/core to process it. But the problem is that tsup does not propagate related TSConfig information to the swc (here is the SWC plugin that I am talking about). However, there is a way how to do this.

My updated tsup.config.ts (simplified)

import { defineConfig } from "tsup";
import packageJson from "./package.json";
import swc, { JscConfig } from "@swc/core";
import type { JscTarget } from "@swc/types"; // 
import path from "node:path";

import tsConfig from "./tsconfig.json"; // important

export default defineConfig({
  entry: ["src/**/*.{ts,js}", "!src/**/*.test.ts"],
  tsconfig: "./tsconfig.json",
  sourcemap: true,
  dts: true,
  format: ["esm", "cjs"],
  plugins: [
    {
      name: "override-swc",
      esbuildOptions: (options) => {
        const plugin = options.plugins?.find((p) => p.name === "swc");
        if (plugin) {
          // Original Source: https://github.com/egoist/tsup/blob/49c11c3073ce977a01c84e7848fc070d5de0a652/src/esbuild/swc.ts#L14-L67
          // Reason: tsup does not provide a way to modify 'jsc' config
          plugin.setup = (build) => {
            // Force esbuild to keep class names as well
            build.initialOptions.keepNames = true;

            build.onLoad({ filter: /\.[jt]sx?$/ }, async (args: any) => {
              const isTs = /\.tsx?$/.test(args.path);

              const jsc: JscConfig = {
                parser: {
                  syntax: isTs ? "typescript" : "ecmascript",
                  decorators: true,
                },
                transform: {
                  legacyDecorator: true,
                  decoratorMetadata: true,
                },
                baseUrl: path.resolve(__dirname, tsConfig.compilerOptions.baseUrl || "."),  // this was missing
                paths: tsConfig.compilerOptions.paths,  // this was missing
                keepClassNames: true,
                target: (tsConfig.compilerOptions.target || "es2022").toLowerCase() as JscTarget,
              };

              const result = await swc.transformFile(args.path, {
                jsc,
                sourceMaps: true,
                configFile: false,
                swcrc: false,
              });

              let code = result.code;
              if (result.map) {
                const map: { sources: string[] } = JSON.parse(result.map);
                // Make sure sources are relative path
                map.sources = map.sources.map((source) => {
                  return path.isAbsolute(source)
                    ? path.relative(path.dirname(args.path), source)
                    : source;
                });
                code += `//# sourceMappingURL=data:application/json;base64,${Buffer.from(
                  JSON.stringify(map),
                ).toString("base64")}`;
              }
              return {
                contents: code,
              };
            });
          };
        }
      },
    },
  ],
  treeshake: true,
  shims: true,
  skipNodeModulesBundle: true,
  legacyOutput: false,
  bundle: false,
  splitting: false,
  silent: false,
  clean: true
});