From c501353388eb7e0f6a30f6ee491b7ea73e688031 Mon Sep 17 00:00:00 2001
From: Darren Ethier <darren@roughsmootheng.in>
Date: Wed, 23 Jan 2019 08:52:47 -0500
Subject: [PATCH] Improve castError handling of non strings (#13315)

This pull removes castError from reduxRoutine and just passes along the value thrown instead of potentially coercing to an error.

- Exposes values to consuming code.
- Less opinionated about what happens with the error.
---
 packages/redux-routine/CHANGELOG.md           |  4 +++-
 packages/redux-routine/src/cast-error.js      | 14 --------------
 packages/redux-routine/src/runtime.js         |  6 +-----
 packages/redux-routine/src/test/cast-error.js | 18 ------------------
 packages/redux-routine/src/test/index.js      |  2 +-
 5 files changed, 5 insertions(+), 39 deletions(-)
 delete mode 100644 packages/redux-routine/src/cast-error.js
 delete mode 100644 packages/redux-routine/src/test/cast-error.js

diff --git a/packages/redux-routine/CHANGELOG.md b/packages/redux-routine/CHANGELOG.md
index b820720f392bc..dbddb8321016b 100644
--- a/packages/redux-routine/CHANGELOG.md
+++ b/packages/redux-routine/CHANGELOG.md
@@ -2,7 +2,9 @@
 
 ### Bug Fixes
 
-- Fix unhandled promise rejection error caused by returning null from registered generator ([#13314](https://github.com/WordPress/gutenberg/pull/13314)
+- Fix unhandled promise rejection error caused by returning null from registered generator ([#13314](https://github.com/WordPress/gutenberg/pull/13314))
+- The middleware will no longer attempt to coerce an error to an instance of `Error`, and instead passes through the thrown value directly. This resolves issues where an `Error` would be thrown when the underlying values were not of type `Error` or `string` (e.g. a thrown object) and the message would end up not being useful (e.g. `[Object object]`).
+([#13315](https://github.com/WordPress/gutenberg/pull/13315)) 
 
 ## 3.0.3 (2018-10-19)
 
diff --git a/packages/redux-routine/src/cast-error.js b/packages/redux-routine/src/cast-error.js
deleted file mode 100644
index 9bc2e22a46d40..0000000000000
--- a/packages/redux-routine/src/cast-error.js
+++ /dev/null
@@ -1,14 +0,0 @@
-/**
- * Casts value as an error if it's not one.
- *
- * @param {*} error The value to cast.
- *
- * @return {Error} The cast error.
- */
-export default function castError( error ) {
-	if ( ! ( error instanceof Error ) ) {
-		error = new Error( error );
-	}
-
-	return error;
-}
diff --git a/packages/redux-routine/src/runtime.js b/packages/redux-routine/src/runtime.js
index 484d65ac6c035..d3de265c3f2b1 100644
--- a/packages/redux-routine/src/runtime.js
+++ b/packages/redux-routine/src/runtime.js
@@ -8,7 +8,6 @@ import isPromise from 'is-promise';
 /**
  * Internal dependencies
  */
-import castError from './cast-error';
 import { isActionOfType, isAction } from './is-action';
 
 /**
@@ -27,10 +26,7 @@ export default function createRuntime( controls = {}, dispatch ) {
 		const routine = control( value );
 		if ( isPromise( routine ) ) {
 			// Async control routine awaits resolution.
-			routine.then(
-				yieldNext,
-				( error ) => yieldError( castError( error ) ),
-			);
+			routine.then( yieldNext, yieldError );
 		} else {
 			next( routine );
 		}
diff --git a/packages/redux-routine/src/test/cast-error.js b/packages/redux-routine/src/test/cast-error.js
deleted file mode 100644
index bdca1c7c202b9..0000000000000
--- a/packages/redux-routine/src/test/cast-error.js
+++ /dev/null
@@ -1,18 +0,0 @@
-/**
- * Internal dependencies
- */
-import castError from '../cast-error';
-
-describe( 'castError', () => {
-	it( 'should return error verbatim', () => {
-		const error = new Error( 'Foo' );
-
-		expect( castError( error ) ).toBe( error );
-	} );
-
-	it( 'should return string as message of error', () => {
-		const error = 'Foo';
-
-		expect( castError( error ) ).toEqual( new Error( 'Foo' ) );
-	} );
-} );
diff --git a/packages/redux-routine/src/test/index.js b/packages/redux-routine/src/test/index.js
index 98aedf7bbef47..79a35673f70a5 100644
--- a/packages/redux-routine/src/test/index.js
+++ b/packages/redux-routine/src/test/index.js
@@ -61,7 +61,7 @@ describe( 'createMiddleware', () => {
 			try {
 				yield { type: 'WAIT_FAIL' };
 			} catch ( error ) {
-				expect( error.message ).toBe( 'Message' );
+				expect( error ).toBe( 'Message' );
 			}
 		}