fix(jest-jasmine2): fix Error message

packages/jest-jasmine2/src/__tests__/expectationResultFactory.test.ts

@@ -55,6 +55,18 @@ describe('expectationResultFactory', () => {
     expect(result.message).toEqual('Error: Expected `Pass`, received `Fail`.');
   });
 
+  it('returns the error name if the error message is empty', () => {
+    const options = {
+      actual: 'Fail',
+      error: new Error(),
+      expected: 'Pass',
+      matcherName: 'testMatcher',
+      passed: false,
+    };
+    const result = expectationResultFactory(options);
+    expect(result.message).toEqual('Error');
+  });
+
   it('returns the result if failed (with `error` as a string).', () => {
     const options = {
       actual: 'Fail',

packages/jest-jasmine2/src/expectationResultFactory.ts

@@ -25,6 +25,9 @@ function messageFormatter({error, message, passed}: Options) {
     typeof error.message === 'string' &&
     typeof error.name === 'string'
   ) {
+    if (error.message === '') {
+      return error.name;
+    }
     return `${error.name}: ${error.message}`;
   }
   return `thrown: ${prettyFormat(error, {maxDepth: 3})}`;