Add isError typeguard

package.json

@@ -35,23 +35,23 @@
     "prepublishOnly": "npm run build"
   },
   "dependencies": {
-    "pino": "^8.16.1",
-    "undici": "5.27.2",
+    "pino": "^8.16.2",
+    "undici": "^5.28.2",
     "undici-retry": "^3.2.0"
   },
   "devDependencies": {
-    "@types/node": "^20.8.10",
-    "@typescript-eslint/eslint-plugin": "^6.9.1",
-    "@typescript-eslint/parser": "^6.9.1",
+    "@types/node": "^20.10.3",
+    "@typescript-eslint/eslint-plugin": "^6.13.1",
+    "@typescript-eslint/parser": "^6.13.1",
     "@vitest/coverage-v8": "^0.34.6",
     "auto-changelog": "^2.4.0",
-    "eslint": "^8.53.0",
+    "eslint": "^8.55.0",
     "eslint-config-prettier": "^9.0.0",
     "eslint-plugin-import": "^2.29.0",
     "eslint-plugin-prettier": "^5.0.1",
     "eslint-plugin-vitest": "^0.3.9",
     "prettier": "^3.0.3",
-    "typescript": "^5.2.2",
+    "typescript": "^5.3.2",
     "vitest": "^0.34.6",
     "zod": "^3.22.4",
     "vite": "4.5.0"

src/utils/typeUtils.spec.ts

@@ -3,13 +3,58 @@ import { PublicNonRecoverableError } from '../errors/PublicNonRecoverableError'
 
 import {
   hasMessage,
+  isError,
   isInternalError,
   isObject,
   isPublicNonRecoverableError,
   isStandardizedError,
 } from './typeUtils'
 
 describe('typeUtils', () => {
+  describe('isError', () => {
+    it('true for InternalError', () => {
+      const error = new InternalError({
+        message: 'dummy',
+        errorCode: 'code',
+      })
+
+      expect(isError(error)).toBe(true)
+    })
+
+    it('true for PublicNonRecoverableError', () => {
+      const error = new PublicNonRecoverableError({
+        message: 'dummy',
+        errorCode: 'code',
+      })
+
+      expect(isError(error)).toBe(true)
+    })
+
+    it('true for Error', () => {
+      const error = new Error('bam')
+
+      expect(isError(error)).toBe(true)
+    })
+
+    it('false for string', () => {
+      const error = 'bam'
+
+      expect(isError(error)).toBe(false)
+    })
+
+    it('false for a number', () => {
+      const error = 43
+
+      expect(isError(error)).toBe(false)
+    })
+
+    it('false for a plain object', () => {
+      const error = {}
+
+      expect(isError(error)).toBe(false)
+    })
+  })
+
   describe('isInternalError', () => {
     it('true for InternalError', () => {
       const error = new InternalError({

src/utils/typeUtils.ts

@@ -23,6 +23,12 @@ export function isInternalError(error: unknown): error is InternalError {
   return isObject(error) && error.name === 'InternalError'
 }
 
+export function isError(maybeError: unknown): maybeError is Error {
+  return (
+    maybeError instanceof Error || Object.prototype.toString.call(maybeError) === '[object Error]'
+  )
+}
+
 export function isPublicNonRecoverableError(error: unknown): error is PublicNonRecoverableError {
   return isObject(error) && error.name === 'PublicNonRecoverableError'
 }