next-js-ts-pnp-hack.js

const typescript = require("typescript");
const { resolveModuleName } = require("ts-pnp");

const origCreateProgram = typescript.createProgram;

function createCompilerHost(compilerOptions) {
  const compilerHost = {
    ...typescript.createCompilerHost(compilerOptions),
    resolveModuleNames,
    resolveTypeReferenceDirectives,
  };

  return compilerHost;

  function fileExists(fileName) {
    return typescript.sys.fileExists(fileName);
  }

  function readFile(fileName) {
    return typescript.sys.readFile(fileName);
  }

  function resolveModuleNames(moduleNames, containingFile) {
    return moduleNames.map((moduleName) => {
      // Needed to make the aliases work that are described here:
      // https://nextjs.org/docs/advanced-features/module-path-aliases
      if (moduleName.startsWith("@/")) {
        return typescript.resolveModuleName(
          moduleName,
          containingFile,
          compilerOptions,
          { fileExists, readFile }
        ).resolvedModule;
      }
      return resolveModuleName(
        moduleName,
        containingFile,
        compilerOptions,
        compilerHost,
        typescript.resolveModuleName
      ).resolvedModule;
    });
  }

  function resolveTypeReferenceDirectives(typeDirectiveNames, containingFile) {
    return typeDirectiveNames.map((typeDirectiveName) => {
      return resolveModuleName(
        typeDirectiveName,
        containingFile,
        compilerOptions,
        compilerHost,
        typescript.resolveTypeReferenceDirective
      ).resolvedTypeReferenceDirective;
    });
  }
}

// ugh
typescript.createProgram = (fileNames, options) => {
  return origCreateProgram(fileNames, options, createCompilerHost(options));
};