getDependencyTreeWithEsbuild.js

// @ts-check

require('path');
const esbuild = require('esbuild');

async function main() {
  const {plugin, set} = createDependencyPlugin();

  await esbuild.build({
    bundle: true,
    format: 'esm',
    platform: "node",
    plugins: [plugin],
    logLevel: 'info',
    entryPoints: [
      __filename
    ]
  })

  console.log(set);
}

main();

/**
 * @typedef {string} Dependency
 */

/**
 * @returns {{ set: Map<string, Set<Dependency>>, plugin: import('esbuild').Plugin }}
 */
function createDependencyPlugin() {
  /** @type {Map<string, Set<Dependency>>} */
  const set = new Map();

  return {
    set, plugin: {
      name: 'dependency-tracker',
      setup(b) {
        b.onResolve({filter: /.?/}, args => {
          const key = args.importer ?? '__entry__'
          const deps = set.get(key) ?? new Set();
          deps.add(args.path);
          set.set(key, deps);
          return null;
        })
      }
    }
  };
}