Fix asserting a throw in a catch block

__tests__/expectSaga/assertions/throws.test.js

@@ -1,9 +1,12 @@
 /* eslint-disable require-yield */
-import { put } from 'redux-saga/effects';
+import { call, put } from 'redux-saga/effects';
 import expectSaga from 'expectSaga';
+import { throwError } from 'expectSaga/providers';
 
 class CustomError {}
 
+function myFunction() {}
+
 function* noErrorSaga() {
   yield put({ type: 'TEST_1' });
   yield put({ type: 'TEST_2' });
@@ -13,6 +16,14 @@ function* errorSaga(errorToThrow) {
   throw errorToThrow;
 }
 
+function* throwInCatch() {
+  try {
+    yield call(myFunction);
+  } catch (e) {
+    throw e;
+  }
+}
+
 test('matches based on error type', () =>
   expectSaga(errorSaga, new CustomError('Error Message'))
     .throws(CustomError)
@@ -94,3 +105,39 @@ test('exception bubbles up when no error expected', done => {
       done();
     });
 });
+
+test('matches exception when thrown in catch', () => {
+  const error = { message: 'test error' };
+
+  return expectSaga(throwInCatch)
+    .provide([[call(myFunction), throwError(error)]])
+    .throws(error)
+    .run();
+});
+
+test('fails when non-matching exception is thrown in catch', done => {
+  const error = { message: 'test error' };
+  const differentError = { message: 'test error 2' };
+
+  return expectSaga(throwInCatch)
+    .provide([[call(myFunction), throwError(differentError)]])
+    .throws(error)
+    .run()
+    .catch(e => {
+      expect(e.message).toMatch(/but instead threw/i);
+      done();
+    });
+});
+
+test('negative assertion fails when matching exception is thrown in catch', done => {
+  const error = { message: 'test error' };
+
+  return expectSaga(throwInCatch)
+    .provide([[call(myFunction), throwError(error)]])
+    .not.throws(error)
+    .run()
+    .catch(e => {
+      expect(e.message).toMatch(/expected not to throw/i);
+      done();
+    });
+});

src/expectSaga/sagaWrapper.js

@@ -115,7 +115,14 @@ export default function createSagaWrapper(
       },
 
       throw(e, fsm) {
-        result = wrappedIterator.throw(e);
+        try {
+          result = wrappedIterator.throw(e);
+        } catch (innerError) {
+          if (typeof onError === 'function') {
+            onError(innerError);
+          }
+          throw innerError;
+        }
         return fsm[LOOP](undefined, fsm);
       },
     });