Add default message if none provided

README.md

@@ -68,7 +68,7 @@ constructor(status, message, properties)
 Where:
 
 - `status`: A HTTP status code as number or a identifier (like: `NotFound`). If the identifier is not valid or the number outside the validity range (`400 <= status <= 599`), it defaults to 500.
-- `message`: The error message. This is optional.
+- `message`: The error message. This is optional. If not provided, the default HTTP status code description will be used.
 - `properties`: A list of additional properties to attach to the error. With the exception of `code`, `message`, `stack`, `expose` and `headers`, all properties that already exist in the object are ignored. This is optional.
 
 The returned instance is a descendant class of `Error` with the following base properties, plus all the other properties specified in the constructor:

src/base.ts

@@ -18,9 +18,9 @@ export class HttpError extends Error {
 
   constructor(status: number | string, message?: string | GenericObject, properties?: GenericObject) {
     // Normalize arguments
-    if (typeof message === 'object') {
+    if (typeof message === 'object' && message !== null) {
       properties = message
-      message = properties.message || ''
+      message = properties.message
     }
 
     if (!properties) {
@@ -37,6 +37,11 @@ export class HttpError extends Error {
       status = 500
     }
 
+    // Add default message if none provided
+    if (typeof message !== 'string') {
+      message = messagesByCodes[status] || ''
+    }
+
     // Extract special properties for Error constructor
     const errorOptions: ErrorOptions = {}
     if (properties.cause) {

test/base.test.ts

@@ -19,6 +19,14 @@ test('HttpError', async () => {
     deepStrictEqual(otherError.code, 'HTTP_ERROR_570')
   })
 
+  await test('it should use a default message', () => {
+    const error = new HttpError(404)
+    const otherError = new HttpError(404, { key1: 'value1' })
+
+    deepStrictEqual(error.message, 'Not Found')
+    deepStrictEqual(otherError.message, 'Not Found')
+  })
+
   await test('it should support cause', () => {
     const cause = new Error('WHATEVER')
     const error = new HttpError(404, 'WHATEVER', { key1: 'value1', cause })