Move error_test.go to a separate test package (#5796)

What changed?
Moved error_test.go to a separate test package

Why?
The folder testdata is ignored when running tests, so moving this test to a test package that isn't ignored

How did you test it?
Made sure the test runs when doing go test and make test

Potential risks

Release notes

Documentation Changes

common/types/testdata/error_test.go → common/testing/allisset.go

@@ -20,7 +20,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
-package testdata
+package testing
 
 import (
 	"reflect"
@@ -29,28 +29,14 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func TestAllFieldsSetInTestErrors(t *testing.T) {
-	for _, err := range Errors {
-		name := reflect.TypeOf(err).Elem().Name()
-		t.Run(name, func(t *testing.T) {
-			// Test all fields are set in the error
-			assert.True(t, checkAllIsSet(err))
-		})
-	}
-}
-
-func checkAllIsSet(err error) bool {
+func allIsSet(t *testing.T, err error) {
 	// All the errors are pointers, so we get the value with .Elem
 	errValue := reflect.ValueOf(err).Elem()
 
 	for i := 0; i < errValue.NumField(); i++ {
 		field := errValue.Field(i)
 
 		// IsZero checks if the value is the default value (e.g. nil, "", 0 etc)
-		if field.IsZero() {
-			return false
-		}
+		assert.True(t, !field.IsZero(), "Field %s is not set", errValue.Type().Field(i).Name)
 	}
-
-	return true
 }

common/testing/allisset_test.go

@@ -0,0 +1,40 @@
+// The MIT License (MIT)
+
+// Copyright (c) 2017-2020 Uber Technologies Inc.
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package testing
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/uber/cadence/common/types/testdata"
+)
+
+func TestAllFieldsSetInTestErrors(t *testing.T) {
+	for _, err := range testdata.Errors {
+		name := reflect.TypeOf(err).Elem().Name()
+		t.Run(name, func(t *testing.T) {
+			// Test all fields are set in the error
+			allIsSet(t, err)
+		})
+	}
+}