bun.sh/test/js/bun/shell/epipe.test.ts

import { describe, expect, test } from "bun:test";
import { isPosix } from "harness";
import { createTestBuilder } from "./test_builder";
const TestBuilder = createTestBuilder(import.meta.path);

describe.if(isPosix)("IOWriter epipe", () => {
  TestBuilder.command`yes | head`
    .exitCode(0)
    .stdout("y\ny\ny\ny\ny\ny\ny\ny\ny\ny\n")
    .runAsTest("builtin pipe to command");

  test("concurrent", async () => {
    const promises = Array(100)
      .fill(0)
      .map(() => Bun.$`yes | head`.text());

    const results = await Promise.all(promises);
    for (const result of results) {
      expect(result).toBe("y\ny\ny\ny\ny\ny\ny\ny\ny\ny\n");
    }
  });
});