Keep error static properties

Author: ehmicky

package-lock.json

@@ -1,22 +1,26 @@
 import { inspect } from 'util'
 
 import { getMessage } from './message.js'
-import { getStack } from './stack.js'
 import { printError } from './print.js'
+import { getEventProps } from './props.js'
+import { getStack } from './stack.js'
 
 const { custom } = inspect
 
 // Retrieve `error` which sums up all information that can be gathered about
 // the event.
 export const getError = function({ name, event }) {
+  const { stack, ...staticProps } = getEventProps(event)
   const message = getMessage({ event, name })
-  const stack = getStack({ event })
-  const error = buildError({ name, message, stack })
-  return { error, stack }
+  const stackA = getStack(stack)
+  const error = buildError({ name, message, stack: stackA, staticProps })
+  return { error, stack: stackA }
 }
 
-const buildError = function({ name, message, stack }) {
+const buildError = function({ name, message, stack, staticProps }) {
   const error = new Error(message)
+  // eslint-disable-next-line fp/no-mutating-assign
+  Object.assign(error, staticProps)
   // `error.name` should not be enumerable, to ensure it is correctly printed.
   // eslint-disable-next-line fp/no-mutating-methods
   Object.defineProperty(error, 'name', {

src/error/main.js

@@ -0,0 +1,16 @@
+// If event is an error, retrieve static properties except `name` and `message`
+export const getEventProps = function({ nextValue, value }) {
+  if (nextValue instanceof Error) {
+    return getErrorProps(nextValue)
+  }
+
+  if (value instanceof Error) {
+    return getErrorProps(value)
+  }
+
+  return {}
+}
+
+const getErrorProps = function(error) {
+  return { stack: error.stack, ...error }
+}

src/error/props.js

@@ -1,26 +1,7 @@
 // Retrieve `error.stack` by re-using the original error's stack trace
-export const getStack = function({ event: { nextValue, value } }) {
-  const stack = getEventStack({ nextValue, value })
-  const stackA = removeStackHeader({ stack })
-  return stackA
-}
-
-// Find the original error's stack trace
-const getEventStack = function({ nextValue, value }) {
-  if (nextValue instanceof Error) {
-    return nextValue.stack
-  }
-
-  if (value instanceof Error) {
-    return value.stack
-  }
-
-  return ''
-}
-
 // Remove first line of `Error.stack` as it contains `Error.name|message`,
 // which is already present in the upper error's `message`
-const removeStackHeader = function({ stack }) {
+export const getStack = function(stack = '') {
   return stack.replace(FIRST_LINE_REGEXP, '')
 }
 

src/error/stack.js

@@ -16,6 +16,7 @@ const snapshotArgs = function([error, level]) {
   return [
     normalizeMessage(inspect(error), { colors: false }),
     String(error),
+    Object.keys(error),
     level,
   ]
 }

test/log.js

@@ -1267,6 +1267,7 @@ Generated by [AVA](https://ava.li).
           Uncaught exception: Warning: WarningType: message␊
           [500] Detail␊
         Stack:␊
+          error properties: Object({ code: '500', detail: 'Detail' })␊
               at STACK TRACE␊
       ␊
       1 spec, 1 failure␊
@@ -1328,6 +1329,8 @@ Generated by [AVA](https://ava.li).
               [500] Detail␊
                   STACK TRACE␊
             type: Warning␊
+            code: "500"␊
+            detail: Detail␊
             tapCaught: uncaughtException␊
             test: TAP␊
             ...␊
@@ -1384,8 +1387,8 @@ Generated by [AVA](https://ava.li).
           expected: |-␊
             undefined␊
           actual: |-␊
-            [Warning: WarningType: message␊
-      [500] Detail]␊
+            { [Warning: WarningType: message␊
+      [500] Detail] code: '500', detail: 'Detail' }␊
           stack: |-␊
             Warning: WarningType: message␊
             [500] Detail␊
@@ -2036,6 +2039,7 @@ Generated by [AVA](https://ava.li).
           Uncaught exception: Warning: WarningType: message␊
           [500] Detail␊
         Stack:␊
+          error properties: Object({ code: '500', detail: 'Detail' })␊
               at STACK TRACE␊
       ␊
       1 spec, 1 failure␊
@@ -2097,6 +2101,8 @@ Generated by [AVA](https://ava.li).
               [500] Detail␊
                   STACK TRACE␊
             type: Warning␊
+            code: "500"␊
+            detail: Detail␊
             tapCaught: uncaughtException␊
             test: TAP␊
             ...␊
@@ -2153,8 +2159,8 @@ Generated by [AVA](https://ava.li).
           expected: |-␊
             undefined␊
           actual: |-␊
-            [Warning: WarningType: message␊
-      [500] Detail]␊
+            { [Warning: WarningType: message␊
+      [500] Detail] code: '500', detail: 'Detail' }␊
           stack: |-␊
             Warning: WarningType: message␊
             [500] Detail␊

test/options/snapshots/testing.js.md

@@ -16,13 +16,15 @@ Generated by [AVA](https://ava.li).
       `MultipleResolves: a promise was resolved/rejected multiple times:␊
       Initially resolved with: { success: true }␊
       Then rejected with: Error: message`,
+      [],
       'info',
       `i  multipleResolves (a promise was resolved multiple times) ␊
       Initially resolved with: { success: true }␊
       Then resolved again with: { success: true }`,
       `MultipleResolves: a promise was resolved multiple times:␊
       Initially resolved with: { success: true }␊
       Then resolved again with: { success: true }`,
+      [],
       'info',
       `i  multipleResolves (a promise was  multiple times) ␊
       Initially rejected with: Error: message␊
@@ -31,6 +33,7 @@ Generated by [AVA](https://ava.li).
       `MultipleResolves: a promise was resolved/rejected multiple times:␊
       Initially rejected with: Error: message␊
       Then resolved with: { success: true }`,
+      [],
       'info',
       `i  multipleResolves (a promise was rejected multiple times) ␊
       Initially rejected with: Error: message␊
@@ -39,6 +42,7 @@ Generated by [AVA](https://ava.li).
       `MultipleResolves: a promise was rejected multiple times:␊
       Initially rejected with: Error: message␊
       Then rejected again with: Error: message`,
+      [],
       'info',
     ]
 
@@ -50,6 +54,7 @@ Generated by [AVA](https://ava.li).
       `×  rejectionHandled (a promise was rejected and handled too late)  Error: message␊
           at STACK TRACE`,
       'RejectionHandled: a promise was rejected and handled too late: Error: message',
+      [],
       'error',
     ]
 
@@ -61,6 +66,7 @@ Generated by [AVA](https://ava.li).
       `×  uncaughtException (an exception was thrown but not caught)  Error: message␊
           at STACK TRACE`,
       'UncaughtException: an exception was thrown but not caught: Error: message',
+      [],
       'error',
     ]
 
@@ -72,6 +78,7 @@ Generated by [AVA](https://ava.li).
       `×  unhandledRejection (a promise was rejected but not handled)  Error: message␊
           at STACK TRACE`,
       'UnhandledRejection: a promise was rejected but not handled: Error: message',
+      [],
       'error',
     ]
 
@@ -85,21 +92,32 @@ Generated by [AVA](https://ava.li).
           at STACK TRACE`,
       `Warning: WarningType: message␊
       [500] Detail`,
+      [
+        'code',
+        'detail',
+      ],
       'warn',
       `‼  warning (WarningType1)  message␊
       [500] ␊
           at STACK TRACE`,
       `Warning: WarningType1: message␊
       [500] `,
+      [
+        'code',
+      ],
       'warn',
       `‼  warning (WarningType2)  message␊
       Detail␊
           at STACK TRACE`,
       `Warning: WarningType2: message␊
       Detail`,
+      [
+        'detail',
+      ],
       'warn',
       `‼  warning (WarningType3)  message␊
           at STACK TRACE`,
       'Warning: WarningType3: message',
+      [],
       'warn',
     ]