From c433477752476d8de64bdf99a88b26d469f1c05e Mon Sep 17 00:00:00 2001
From: isaacs <i@izs.me>
Date: Sat, 30 Sep 2023 10:20:02 -0700
Subject: [PATCH] tcompare: include known non-enumerable Error properties

Fix: https://github.com/tapjs/tapjs/issues/933
---
 src/tcompare/src/format.ts                    | 14 ++++++--
 .../tap-snapshots/test/format.tsx.test.cjs    | 18 ++++++++++
 src/tcompare/test/format.tsx                  | 33 +++++++++++++++++--
 3 files changed, 59 insertions(+), 6 deletions(-)

diff --git a/src/tcompare/src/format.ts b/src/tcompare/src/format.ts
index 68cd26520..0d9c3cdb0 100644
--- a/src/tcompare/src/format.ts
+++ b/src/tcompare/src/format.ts
@@ -822,8 +822,16 @@ export class Format {
   }
 
   getPojoKeys(obj: any = this.object): PropertyKey[] {
+    const keys: PropertyKey[] = []
+    // always include known non-enumerable properties of Error objects
+    if (obj instanceof Error) {
+      const known = ['errors', 'cause']
+      for (const prop of known) {
+        const desc = Object.getOwnPropertyDescriptor(obj, prop)
+        if (desc && !desc.enumerable) keys.push(prop)
+      }
+    }
     if (this.options.includeEnumerable) {
-      const keys: PropertyKey[] = []
       // optimized fast path, for/in over enumerable string keys only
       for (const i in obj) {
         keys.push(i)
@@ -835,9 +843,9 @@ export class Format {
       return keys
     }
 
-    const keys: PropertyKey[] = this.#getPojoKeys(obj).concat(
+    keys.push(...this.#getPojoKeys(obj).concat(
       this.#getPojoKeys(obj, true)
-    )
+    ))
     if (!this.options.includeGetters) {
       return keys
     }
diff --git a/src/tcompare/tap-snapshots/test/format.tsx.test.cjs b/src/tcompare/tap-snapshots/test/format.tsx.test.cjs
index 451bde392..26c363023 100644
--- a/src/tcompare/tap-snapshots/test/format.tsx.test.cjs
+++ b/src/tcompare/tap-snapshots/test/format.tsx.test.cjs
@@ -33,6 +33,24 @@ exports[`test/format.tsx > TAP > error without name/message > {} > tight > must
 new Object(undefined)
 `
 
+exports[`test/format.tsx > TAP > format aggregate errors and causes > must match snapshot 1`] = `
+AggregateError: aggregated errors {
+  "errors": Array [
+    Error: xyz {
+      "cause": "something",
+      [Symbol.for(hsmusic.sugar.index)]: 1,
+    },
+    AggregateError: agg agg {
+      "errors": Array [
+        TypeError: blzhr {
+          [Symbol.for(hsmusic.sugar.index)]: "something",
+        },
+      ],
+    },
+  ],
+}
+`
+
 exports[`test/format.tsx > TAP > format iterable > must match snapshot 1`] = `
 And [
   And [
diff --git a/src/tcompare/test/format.tsx b/src/tcompare/test/format.tsx
index 0c1f5c6c4..c67a4db44 100644
--- a/src/tcompare/test/format.tsx
+++ b/src/tcompare/test/format.tsx
@@ -318,9 +318,12 @@ t.test('invalid iterator', t => {
   // looks like an array
   t.equal(f.isArray(), true)
   // until you try to format it
-  t.equal(f.print(), `Object {
+  t.equal(
+    f.print(),
+    `Object {
   [Symbol.iterator]: Function [Symbol.iterator](),
-}`)
+}`
+  )
   // then it realizes it's actually not
   t.equal(f.isArray(), false)
   t.end()
@@ -455,9 +458,33 @@ t.test('formatting jsx', t => {
     }
     t.matchSnapshot(
       format(lookAlike),
-      `children=${format(children).replace(/\n/g, ' ').replace(/ +/g, ' ').replace(/, ([}\]])/g, '$1').replace(/([\[{]) /g, '$1')}`
+      `children=${format(children)
+        .replace(/\n/g, ' ')
+        .replace(/ +/g, ' ')
+        .replace(/, ([}\]])/g, '$1')
+        .replace(/([\[{]) /g, '$1')}`
     )
   }
 
   t.end()
 })
+
+t.test('format aggregate errors and causes', t => {
+  const sym = Symbol.for('hsmusic.sugar.index')
+  const errors = [
+    Object.assign(new Error('xyz', { cause: 'something' }), {
+      [sym]: 1,
+    }),
+    new AggregateError(
+      [
+        Object.assign(new TypeError('blzhr'), {
+          [sym]: 'something',
+        }),
+      ],
+      'agg agg'
+    ),
+  ]
+  const er = new AggregateError(errors, 'aggregated errors')
+  t.matchSnapshot(format(er))
+  t.end()
+})