terraform: provider mock should close itself to find bugs

terraform/resource_provider_mock.go

@@ -10,6 +10,8 @@ type MockResourceProvider struct {
 	// Anything you want, in case you need to store extra data with the mock.
 	Meta interface{}
 
+	CloseCalled                  bool
+	CloseError                   error
 	InputCalled                  bool
 	InputInput                   UIInput
 	InputConfig                  *ResourceConfig
@@ -55,6 +57,11 @@ type MockResourceProvider struct {
 	ValidateResourceReturnErrors []error
 }
 
+func (p *MockResourceProvider) Close() error {
+	p.CloseCalled = true
+	return p.CloseError
+}
+
 func (p *MockResourceProvider) Input(
 	input UIInput, c *ResourceConfig) (*ResourceConfig, error) {
 	p.InputCalled = true

terraform/resource_provider_mock_test.go

@@ -6,4 +6,5 @@ import (
 
 func TestMockResourceProvider_impl(t *testing.T) {
 	var _ ResourceProvider = new(MockResourceProvider)
+	var _ ResourceProviderCloser = new(MockResourceProvider)
 }