log4js-node/test/tap/stderrAppender-test.js

const { test } = require("tap");
const sandbox = require("@log4js-node/sandboxed-module");
const layouts = require("../../lib/layouts");

test("stderr appender", t => {
  const output = [];

  const appender = sandbox
    .require("../../lib/appenders/stderr", {
      globals: {
        process: {
          stderr: {
            write(data) {
              output.push(data);
            }
          }
        }
      }
    })
    .configure(
      { type: "stderr", layout: { type: "messagePassThrough" } },
      layouts
    );

  appender({ data: ["biscuits"] });
  t.plan(2);
  t.equal(output.length, 1, "There should be one message.");
  t.equal(output[0], "biscuits\n", "The message should be biscuits.");
  t.end();
});

test("stderr appender with default layout", t => {
  const output = [];
  layouts.colouredLayout = () => "I used the colouredLayout";

  const appender = sandbox
    .require("../../lib/appenders/stderr", {
      globals: {
        process: {
          stderr: {
            write(data) {
              output.push(data);
            }
          }
        }
      }
    })
    .configure({ type: "stderr" }, layouts);

  appender({ data: ["biscuits"] });
  t.plan(2);
  t.equal(output.length, 1, "There should be one message.");
  t.equal(
    output[0],
    "I used the colouredLayout\n",
    "The message should have gone through the default layout."
  );
  t.end();
});