fix: BaseError@walk to return null when predicate fn not matches (#…

…874) * fix: `BaseError@walk` to return `null` when predicate fn not matches * Update young-spiders-taste.md --------- Co-authored-by: jxom <[email protected]>
wevm · Jul 11, 2023 · a9bc9f6 · a9bc9f6 · vercel · Jul 11, 2023
1 parent 072daaa
commit a9bc9f6
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Showing 3 changed files with 18 additions and 2 deletions.
diff --git a/.changeset/young-spiders-taste.md b/.changeset/young-spiders-taste.md
@@ -0,0 +1,5 @@
+---
+"viem": patch
+---
+
+Fixed `BaseError.walk` to return `null` if the predicate callback is not satisfied.
diff --git a/src/errors/base.test.ts b/src/errors/base.test.ts
@@ -153,3 +153,13 @@ test('walk: predicate fn', () => {
     Version: [email protected]]
   `)
 })
+
+test('walk: predicate fn (no match)', () => {
+  class FooError extends BaseError {}
+  class BarError extends BaseError {}
+
+  const err = new BaseError('test1', {
+    cause: new Error('test2', { cause: new BarError('test3') }),
+  })
+  expect(err.walk((err) => err instanceof FooError)).toBeNull()
+})
diff --git a/src/errors/base.ts b/src/errors/base.ts
@@ -67,6 +67,7 @@ export class BaseError extends Error {
 
 function walk(err: unknown, fn?: (err: unknown) => boolean): unknown {
   if (fn?.(err)) return err
-  if ((err as Error).cause) return walk((err as Error).cause, fn)
-  return err
+  if (err && typeof err === 'object' && 'cause' in err)
+    return walk(err.cause, fn)
+  return fn ? null : err
 }