alepha/src/logger/__tests__/$logger.spec.ts

Easy-to-use modern TypeScript framework for building many kind of applications.

import { Alepha } from "alepha";
import { DateTimeProvider } from "alepha/datetime";
import { describe, it } from "vitest";
import {
  $logger,
  LogDestinationProvider,
  MemoryDestinationProvider,
} from "../index.ts";

describe("$logger", () => {
  class App {
    log = $logger();
  }

  it("should log in-memory", ({ expect }) => {
    const alepha = Alepha.create({
      env: {
        LOG_LEVEL: "trace",
      },
    }).with({
      provide: LogDestinationProvider,
      use: MemoryDestinationProvider,
    });
    const output = alepha.inject(MemoryDestinationProvider);
    const app = alepha.inject(App);

    app.log.info("Test log message");

    expect(output.logs[0].message).toBe("Test log message");
    expect(output.logs[0].level).toBe("INFO");
    expect(output.logs[0].service).toBe("App");
    expect(output.logs[0].module).toBe("app");
    expect(output.logs[0].app).toBeUndefined();
    expect(output.logs[0].context).toBeUndefined();
    expect(output.logs[0].timestamp).toBeDefined();

    app.log.trace("Trace log message");
    expect(output.logs[1].message).toBe("Trace log message");
    app.log.warn("Warning log message");
    expect(output.logs[2].message).toBe("Warning log message");
    app.log.error("Error log message");
    expect(output.logs[3].message).toBe("Error log message");
    app.log.debug("Debug log message");
    expect(output.logs[4].message).toBe("Debug log message");
  });

  it("should log with Alepha", async ({ expect }) => {
    const alepha = Alepha.create({
      env: {
        LOG_LEVEL: "info",
      },
    }).with({
      provide: LogDestinationProvider,
      use: MemoryDestinationProvider,
    });
    const output = alepha.inject(MemoryDestinationProvider);
    const app = alepha.inject(App);
    await alepha.start();
    app.log.info("Test log message");
    expect(output.logs.length).toBe(3);
  });

  it("should skip alepha logs", async ({ expect }) => {
    const alepha = Alepha.create({
      env: {
        LOG_LEVEL: "alepha.core:error,info",
      },
    }).with({
      provide: LogDestinationProvider,
      use: MemoryDestinationProvider,
    });
    const output = alepha.inject(MemoryDestinationProvider);
    const app = alepha.inject(App);
    await alepha.start();
    app.log.info("Test log message");
    expect(output.logs.length).toBe(1);
  });

  it("should emit log events for external listeners", async ({ expect }) => {
    const alepha = Alepha.create({
      env: {
        LOG_LEVEL: "info",
      },
    }).with({
      provide: LogDestinationProvider,
      use: MemoryDestinationProvider,
    });

    const now = alepha.inject(DateTimeProvider).pause();
    const app = alepha.inject(App);
    const logEvents: any[] = [];

    alepha.events.on("log", (event) => {
      logEvents.push(event);
    });

    app.log.info("Test event emission", { testData: "value" });

    expect(logEvents).toHaveLength(1);
    expect(logEvents[0].message).toMatch(/Test event emission/);
    expect(logEvents[0].entry.message).toBe("Test event emission");
    expect(logEvents[0].entry.level).toBe("INFO");
    expect(logEvents[0].entry.service).toBe("App");
    expect(logEvents[0].entry.module).toBe("app");
    expect(logEvents[0].entry.data).toEqual({ testData: "value" });
    expect(logEvents[0].entry.timestamp).toBe(now.valueOf());
  });
});