Use yarn workspace info to create TS project references.

setup-ts-project-references-for-yarn-workspaces.js

const { execSync } = require('child_process');
const { readFileSync, writeFileSync } = require('fs');
const { relative } = require('path');
const utf8 = { encoding: 'utf8' };

function writeJson(path, content) {
  writeFileSync(path, JSON.stringify(content, null, 2) + '\n', utf8);
}

function readJson(path) {
  return JSON.parse(readFileSync(path, utf8));
}

function exec(cmd) {
  return execSync(cmd, utf8).trim();
}

function refsMatch(a, b) {
  if (a.length !== b.length) {
    return false;
  }
  a.sort();
  b.sort();
  return a.every((v, i) => {
    aa = v.path;
    bb = b[i].path;
    return aa && bb && aa === bb;
  });
}

function main() {
  const packages = JSON.parse(exec(`yarn --silent workspaces info`));

  const updated = [];

  Object.entries(packages).forEach(([pkg, data]) => {
    // all the "workspaceDependencies" should be
    // typescript references.
    if (data.workspaceDependencies.length > 0) {
      const refs = data.workspaceDependencies.map(dep => {
        return {
          path: relative(`/${data.location}`, `/${packages[dep].location}`)
        };
      });

      // now update our tsconfig.json
      const file = `./${data.location}/tsconfig.json`;
      const tsConfig = readJson(file);
      if (
        !Array.isArray(tsConfig.references) ||
        !refsMatch(tsConfig.references, refs)
      ) {
        updated.push(pkg);
        tsConfig.references = refs;
        writeJson(file, tsConfig);
      }
    }
  });

  if (updated.length) {
    console.log('Updated references in packages:\n');
    updated.map(p => console.log(' - ' + p));
  } else {
    console.log('All references correct');
  }
  console.log(
    '\nRemember to add `composite:true` and `incremental:true` to get ' +
      'the most out of the project references.'
  );
}

main();