automaker/apps/server/tests/unit/lib/logger.test.ts

import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
import {
  LogLevel,
  createLogger,
  getLogLevel,
  setLogLevel,
} from "@/lib/logger.js";

describe("logger.ts", () => {
  let consoleSpy: {
    log: ReturnType<typeof vi.spyOn>;
    warn: ReturnType<typeof vi.spyOn>;
    error: ReturnType<typeof vi.spyOn>;
  };
  let originalLogLevel: LogLevel;

  beforeEach(() => {
    originalLogLevel = getLogLevel();
    consoleSpy = {
      log: vi.spyOn(console, "log").mockImplementation(() => {}),
      warn: vi.spyOn(console, "warn").mockImplementation(() => {}),
      error: vi.spyOn(console, "error").mockImplementation(() => {}),
    };
  });

  afterEach(() => {
    setLogLevel(originalLogLevel);
    consoleSpy.log.mockRestore();
    consoleSpy.warn.mockRestore();
    consoleSpy.error.mockRestore();
  });

  describe("LogLevel enum", () => {
    it("should have correct numeric values", () => {
      expect(LogLevel.ERROR).toBe(0);
      expect(LogLevel.WARN).toBe(1);
      expect(LogLevel.INFO).toBe(2);
      expect(LogLevel.DEBUG).toBe(3);
    });
  });

  describe("setLogLevel and getLogLevel", () => {
    it("should set and get log level", () => {
      setLogLevel(LogLevel.DEBUG);
      expect(getLogLevel()).toBe(LogLevel.DEBUG);

      setLogLevel(LogLevel.ERROR);
      expect(getLogLevel()).toBe(LogLevel.ERROR);
    });
  });

  describe("createLogger", () => {
    it("should create a logger with context prefix", () => {
      setLogLevel(LogLevel.INFO);
      const logger = createLogger("TestContext");

      logger.info("test message");

      expect(consoleSpy.log).toHaveBeenCalledWith("[TestContext]", "test message");
    });

    it("should log error at all log levels", () => {
      const logger = createLogger("Test");

      setLogLevel(LogLevel.ERROR);
      logger.error("error message");
      expect(consoleSpy.error).toHaveBeenCalledWith("[Test]", "error message");
    });

    it("should log warn when level is WARN or higher", () => {
      const logger = createLogger("Test");

      setLogLevel(LogLevel.ERROR);
      logger.warn("warn message 1");
      expect(consoleSpy.warn).not.toHaveBeenCalled();

      setLogLevel(LogLevel.WARN);
      logger.warn("warn message 2");
      expect(consoleSpy.warn).toHaveBeenCalledWith("[Test]", "warn message 2");
    });

    it("should log info when level is INFO or higher", () => {
      const logger = createLogger("Test");

      setLogLevel(LogLevel.WARN);
      logger.info("info message 1");
      expect(consoleSpy.log).not.toHaveBeenCalled();

      setLogLevel(LogLevel.INFO);
      logger.info("info message 2");
      expect(consoleSpy.log).toHaveBeenCalledWith("[Test]", "info message 2");
    });

    it("should log debug only when level is DEBUG", () => {
      const logger = createLogger("Test");

      setLogLevel(LogLevel.INFO);
      logger.debug("debug message 1");
      expect(consoleSpy.log).not.toHaveBeenCalled();

      setLogLevel(LogLevel.DEBUG);
      logger.debug("debug message 2");
      expect(consoleSpy.log).toHaveBeenCalledWith("[Test]", "[DEBUG]", "debug message 2");
    });

    it("should pass multiple arguments to log functions", () => {
      setLogLevel(LogLevel.DEBUG);
      const logger = createLogger("Multi");

      logger.info("message", { data: "value" }, 123);
      expect(consoleSpy.log).toHaveBeenCalledWith(
        "[Multi]",
        "message",
        { data: "value" },
        123
      );
    });
  });
});