logger.test.ts•4.51 kB
import {
afterEach,
beforeEach,
describe,
expect,
type Mock,
mock,
spyOn,
test,
} from "bun:test";
import { Logger, LogLevel } from "../../logger";
// Mock fs/promises
mock.module("fs/promises", () => ({
writeFile: mock(() => Promise.resolve()),
appendFile: mock(() => Promise.resolve()),
}));
describe("Logger", () => {
let logger: Logger;
let consoleSpy: Mock<typeof console.info>;
beforeEach(() => {
// Reset environment variables
process.env.MCP_SERVER_LOG_FILE = undefined;
// Create fresh spies for console methods
consoleSpy = spyOn(console, "info").mockImplementation(() => {});
spyOn(console, "debug").mockImplementation(() => {});
spyOn(console, "warn").mockImplementation(() => {});
spyOn(console, "error").mockImplementation(() => {});
// Create a fresh logger instance with known level
logger = new Logger(LogLevel.INFO);
});
afterEach(() => {
// Restore all mocks
mock.restore();
});
describe("constructor", () => {
test("should create logger with default INFO level", () => {
const defaultLogger = new Logger();
expect(defaultLogger).toBeInstanceOf(Logger);
});
test("should create logger with specified level", () => {
const debugLogger = new Logger(LogLevel.DEBUG);
expect(debugLogger).toBeInstanceOf(Logger);
});
test("should not initialize file logging when MCP_SERVER_LOG_FILE is not set", () => {
expect(process.env.MCP_SERVER_LOG_FILE).toBeUndefined();
// Logger should still be created successfully
expect(logger).toBeInstanceOf(Logger);
});
});
describe("setLevel", () => {
test("should update log level", () => {
const debugSpy = spyOn(console, "debug");
// Initially at INFO level, debug should not log
logger.debug("test debug message");
expect(debugSpy).not.toHaveBeenCalled();
// Change to DEBUG level, now debug should log
logger.setLevel(LogLevel.DEBUG);
logger.debug("test debug message after level change");
expect(debugSpy).toHaveBeenCalledWith(
expect.stringContaining("[DEBUG]"),
"test debug message after level change",
);
});
});
describe("logging methods", () => {
test("should log info messages when level is INFO", () => {
logger.info("test info message");
expect(consoleSpy).toHaveBeenCalledWith(
expect.stringContaining("[INFO]"),
"test info message",
);
});
test("should not log debug messages when level is INFO", () => {
const debugSpy = spyOn(console, "debug");
logger.debug("test debug message");
expect(debugSpy).not.toHaveBeenCalled();
});
test("should log warn messages", () => {
const warnSpy = spyOn(console, "warn");
logger.warn("test warning");
expect(warnSpy).toHaveBeenCalledWith(
expect.stringContaining("[WARN]"),
"test warning",
);
});
test("should log error messages", () => {
const errorSpy = spyOn(console, "error");
logger.error("test error");
expect(errorSpy).toHaveBeenCalledWith(
expect.stringContaining("[ERROR]"),
"test error",
);
});
test("should format messages with additional arguments", () => {
logger.info("test message", "arg1", { key: "value" });
expect(consoleSpy).toHaveBeenCalledWith(
expect.stringContaining("[INFO]"),
"test message",
"arg1",
{ key: "value" },
);
});
});
describe("logObject", () => {
test("should log objects with proper formatting", () => {
const testObj = { name: "test", value: 123 };
logger.logObject(LogLevel.INFO, "Test object:", testObj);
expect(consoleSpy).toHaveBeenCalledWith(
expect.stringContaining("[INFO]"),
expect.stringContaining("Test object:"),
expect.stringContaining(JSON.stringify(testObj, null, 2)),
);
});
});
describe("LogLevel enum", () => {
test("should have correct numeric values", () => {
expect(LogLevel.DEBUG).toBe(0);
expect(LogLevel.INFO).toBe(1);
expect(LogLevel.WARN).toBe(2);
expect(LogLevel.ERROR).toBe(3);
});
test("should have correct string representations", () => {
expect(LogLevel[LogLevel.DEBUG]).toBe("DEBUG");
expect(LogLevel[LogLevel.INFO]).toBe("INFO");
expect(LogLevel[LogLevel.WARN]).toBe("WARN");
expect(LogLevel[LogLevel.ERROR]).toBe("ERROR");
});
});
});