Fix duplicate error name in messages

Author: ehmicky

CHANGELOG.md

@@ -1,3 +1,10 @@
+# 7.1.2
+
+## Bug fixes
+
+- When wrapping an error with a different class but the same `error.name`, do
+  not repeat that name in the error message
+
 # 7.1.1
 
 ## Bug fixes

src/merge/prefix.js

@@ -12,6 +12,9 @@ import { isSubclass } from '../utils/subclass.js'
 //  - When the parent is a subclass of the child, since the new class becomes
 //    the subclass, which already contains the other class in its chain, i.e.
 //    not worth adding to the message
+//  - When the error classes are different but have the same name.
+//    This is common when a library wraps another one with identical classes.
+//    For example, a CLI wrapping a programmatic library.
 export const shouldPrefixCause = (error, ErrorClass) => {
   const { cause } = error
   return (
@@ -30,7 +33,8 @@ const hasUsefulName = (cause, ErrorClass) =>
   !(
     isSubclass(cause.constructor, ErrorClass) ||
     isSubclass(ErrorClass, cause.constructor) ||
-    cause.constructor.name in globalThis
+    cause.constructor.name in globalThis ||
+    cause.name === ErrorClass.name
   )
 
 // Prefix `cause.name` to its `message`

src/merge/prefix.test.js

@@ -95,6 +95,21 @@ each(ErrorClasses, ({ title }, ErrorClass) => {
     const cause = new ErrorClass('causeMessage')
     t.is(new TestError('', { cause }).message, cause.message)
   })
+
+  test(`Name of cause with same name is ignored | ${title}`, (t) => {
+    const TestError = ErrorClass.subclass('TestError')
+    const OtherError = ErrorClass.subclass('TestError')
+    const cause = new OtherError('causeMessage')
+    t.is(new TestError('', { cause }).message, cause.message)
+  })
+
+  test(`Handle invalid error message | ${title}`, (t) => {
+    const TestError = ErrorClass.subclass('TestError')
+    const OtherError = ErrorClass.subclass('OtherError')
+    const error = new OtherError('')
+    error.message = true
+    t.is(new TestError('', { cause: error }).message, error.name)
+  })
 })
 
 const getExpectedMessage = (cause) => {
@@ -132,13 +147,3 @@ each(
 )
 
 const GENERATED_STACK_HINT = 'normalize-exception'
-
-each(ErrorClasses, ({ title }, ErrorClass) => {
-  test(`Handle invalid error message | ${title}`, (t) => {
-    const TestError = ErrorClass.subclass('TestError')
-    const OtherError = ErrorClass.subclass('OtherError')
-    const error = new OtherError('')
-    error.message = true
-    t.is(new TestError('', { cause: error }).message, error.name)
-  })
-})