diff --git a/src/helpers.ts b/src/helpers.ts
index 4270ec2..e2285df 100644
--- a/src/helpers.ts
+++ b/src/helpers.ts
@@ -1,21 +1,24 @@
 /**
  * Check if is browser env
  */
-export const isBrowser: boolean = !!(typeof window != "undefined" && window.document)
+export const isBrowser: boolean = !!(
+  typeof window != "undefined" && window.document
+)
 
 /**
  * Transform string to RGB
  * @param str
  */
-export function stringToRgb(str: string):[number, number, number] {
+export function stringToRgb(str: string): [number, number, number] {
+  if (!str) return [128, 128, 128]
   let hash = 0
   for (let i = 0; i < str.length; i++) {
     let character = str.charCodeAt(i)
-    hash = ((hash << 5) - hash) + character
+    hash = (hash << 5) - hash + character
     hash = Math.abs(hash & hash)
   }
-  const r = (hash & 0xFF0000) >> 16
-  const g = (hash & 0x00FF00) >> 8
-  const b = hash & 0x0000FF
+  const r = (hash & 0xff0000) >> 16
+  const g = (hash & 0x00ff00) >> 8
+  const b = hash & 0x0000ff
   return [r, g, b]
 }
diff --git a/test/debug.test.ts b/test/debug.test.ts
index c0bfd2a..a13e81f 100644
--- a/test/debug.test.ts
+++ b/test/debug.test.ts
@@ -1,9 +1,97 @@
-import {describe, it, expect} from "vitest"
+import { describe, it, expect, beforeEach, afterEach } from "vitest"
+import debug from "../src"
 
-import debug from "../src";
+describe("debug", () => {
+  // Mock console.log
+  const originalConsoleLog = console.log
+  let consoleLogCalls: any[][] = []
 
-describe("Debug", () => {
-  it("should be defined", () => {
-    expect(debug).toBeDefined();
-  });
-});
+  beforeEach(() => {
+    // Reset mock calls before each test
+    consoleLogCalls = []
+    console.log = (...args: any[]) => {
+      consoleLogCalls.push(args)
+      return originalConsoleLog(...args)
+    }
+  })
+
+  afterEach(() => {
+    // Restore original console.log
+    console.log = originalConsoleLog
+    // Clear process.env.DEBUG
+    delete process.env.DEBUG
+  })
+
+  it("should log only if we add DEBUG={namespace} as env var", () => {
+    // Test when DEBUG equals the namespace
+    process.env.DEBUG = "test-namespace"
+    const testDebug = debug("test-namespace")
+    testDebug("Test message")
+    expect(consoleLogCalls.length).toBe(1)
+    expect(consoleLogCalls[0][1]).toBe("Test message")
+
+    // Test when DEBUG equals *
+    process.env.DEBUG = "*"
+    const testDebugWildcard = debug("any-namespace")
+    testDebugWildcard("Wildcard test")
+    expect(consoleLogCalls.length).toBe(2)
+    expect(consoleLogCalls[1][1]).toBe("Wildcard test")
+
+    // Test when DEBUG uses wildcard prefix (namespace:*)
+    process.env.DEBUG = "prefix:*"
+    const testDebugPrefix = debug("prefix:something")
+    testDebugPrefix("Prefix test")
+    expect(consoleLogCalls.length).toBe(3)
+    expect(consoleLogCalls[2][1]).toBe("Prefix test")
+
+    // Test when DEBUG doesn't match
+    process.env.DEBUG = "different-namespace"
+    const testNoDebug = debug("test-namespace")
+    testNoDebug("Should not log")
+    expect(consoleLogCalls.length).toBe(3) // Count shouldn't increase
+  })
+
+  it("should log only logs from a spectific namespace", () => {
+    // Create multiple debug loggers with different namespaces
+    const debug1 = debug("namespace1")
+    const debug2 = debug("namespace2")
+    const debug3 = debug("namespace3")
+
+    // Set DEBUG to only match one namespace
+    process.env.DEBUG = "namespace2"
+
+    // Call all loggers
+    debug1("Message from namespace1")
+    debug2("Message from namespace2")
+    debug3("Message from namespace3")
+
+    // Verify only namespace2 logged a message
+    expect(consoleLogCalls.length).toBe(1)
+    expect(consoleLogCalls[0][1]).toBe("Message from namespace2")
+  })
+
+  it("should not handle undefined namespace", () => {
+    process.env.DEBUG = "*"
+    const testDebug = debug(undefined)
+    testDebug("Test with undefined namespace")
+    expect(consoleLogCalls.length).toBe(1)
+  })
+
+  it("should log multiple arguments correctly", () => {
+    process.env.DEBUG = "test-namespace"
+    const testDebug = debug("test-namespace")
+    testDebug("First argument", "Second argument", { key: "value" }, 123)
+    expect(consoleLogCalls.length).toBe(1)
+    expect(consoleLogCalls[0][1]).toBe("First argument")
+    expect(consoleLogCalls[0][2]).toBe("Second argument")
+    expect(consoleLogCalls[0][3]).toEqual({ key: "value" })
+    expect(consoleLogCalls[0][4]).toBe(123)
+  })
+
+  it("should not log when DEBUG is not set", () => {
+    // DEBUG is already deleted in afterEach
+    const testDebug = debug("test-namespace")
+    testDebug("Should not log")
+    expect(consoleLogCalls.length).toBe(0)
+  })
+})