GOCBC-1149: Do not try parse response on error in GetAllScopes

Motivation
----------
If the management request fails to send for GetAllScopes then we
attempt to parse the response body which causes a panic because
the response object is nil. On error we should not be doing this.

Changes
-------
Move the call to tryParseErrorMessage out of the error handling
block and into the resp.Status != 200 handling block.

Change-Id: I856c026689967fef34207d3c2f99d68d5921000b
Reviewed-on: http://review.couchbase.org/c/gocb/+/159007
Reviewed-by: Brett Lawson <brett19@gmail.com>
Tested-by: Charles Dixon <chvckd@gmail.com>

bucket_collectionsmgr.go

@@ -116,15 +116,15 @@ func (cm *CollectionManager) GetAllScopes(opts *GetAllScopesOptions) ([]ScopeSpe
 
 	resp, err := cm.mgmtProvider.executeMgmtRequest(opts.Context, req)
 	if err != nil {
-		colErr := cm.tryParseErrorMessage(&req, resp)
-		if colErr != nil {
-			return nil, colErr
-		}
 		return nil, makeMgmtBadStatusError("failed to get all scopes", &req, resp)
 	}
 	defer ensureBodyClosed(resp.Body)
 
 	if resp.StatusCode != 200 {
+		colErr := cm.tryParseErrorMessage(&req, resp)
+		if colErr != nil {
+			return nil, colErr
+		}
 		return nil, makeMgmtBadStatusError("failed to get all scopes", &req, resp)
 	}
 
@@ -378,7 +378,7 @@ func (cm *CollectionManager) CreateScope(scopeName string, opts *CreateScopeOpti
 
 	resp, err := cm.mgmtProvider.executeMgmtRequest(opts.Context, req)
 	if err != nil {
-		return err
+		return makeGenericMgmtError(err, &req, resp)
 	}
 	defer ensureBodyClosed(resp.Body)
 

bucket_collectionsmgr_test.go

@@ -3,6 +3,7 @@ package gocb
 import (
 	"errors"
 	"fmt"
+	"github.com/stretchr/testify/mock"
 	"strconv"
 	"time"
 )
@@ -576,3 +577,18 @@ func (suite *IntegrationTestSuite) TestMaxNumberOfCollectionInScope() {
 
 	suite.Require().True(success)
 }
+
+func (suite *UnitTestSuite) TestGetAllScopesMgmtRequestFails() {
+	provider := new(mockMgmtProvider)
+	provider.On("executeMgmtRequest", nil, mock.AnythingOfType("gocb.mgmtRequest")).Return(nil, errors.New("http send failure"))
+
+	mgr := CollectionManager{
+		mgmtProvider: provider,
+		tracer:       &NoopTracer{},
+		meter:        &meterWrapper{meter: &NoopMeter{}, isNoopMeter: true},
+	}
+
+	scopes, err := mgr.GetAllScopes(nil)
+	suite.Require().NotNil(err)
+	suite.Require().Nil(scopes)
+}