command: fix tests

command/apply_test.go

@@ -487,7 +487,7 @@ func TestApply_vars(t *testing.T) {
 			actual = v.(string)
 		}
 
-		return nil, nil
+		return &terraform.ResourceDiff{}, nil
 	}
 
 	args := []string{
@@ -530,7 +530,7 @@ func TestApply_varFile(t *testing.T) {
 			actual = v.(string)
 		}
 
-		return nil, nil
+		return &terraform.ResourceDiff{}, nil
 	}
 
 	args := []string{

command/command_test.go

@@ -85,6 +85,7 @@ func testStateFile(t *testing.T, s *terraform.State) string {
 
 func testProvider() *terraform.MockResourceProvider {
 	p := new(terraform.MockResourceProvider)
+	p.DiffReturn = &terraform.ResourceDiff{}
 	p.RefreshFn = func(
 		s *terraform.ResourceState) (*terraform.ResourceState, error) {
 		return s, nil

terraform/context.go

@@ -491,7 +491,8 @@ func (c *Context) applyWalkFn() depgraph.WalkFunc {
 			if diff == nil {
 				return fmt.Errorf(
 					"%s: diff became nil during Apply. This is a bug with "+
-						"the resource provider. Please report a bug.")
+						"the resource provider. Please report a bug.",
+					r.Id)
 			}
 
 			// Delete id from the diff because it is dependent on
@@ -507,7 +508,8 @@ func (c *Context) applyWalkFn() depgraph.WalkFunc {
 					r.Diff, diff)
 				return fmt.Errorf(
 					"%s: diffs didn't match during apply. This is a "+
-						"bug with the resource provider, please report a bug.")
+						"bug with the resource provider, please report a bug.",
+					r.Id)
 			}
 		}