change mock return values to pointers

This allows up to detect an unset value from the zero value so that
defaults can be implemented, while still allowing tests to return
specific values of their choosing.

terraform/context_apply_test.go

@@ -1418,7 +1418,7 @@ func TestContext2Apply_dataBasic(t *testing.T) {
 	p := testProvider("null")
 	p.ApplyResourceChangeFn = testApplyFn
 	p.PlanResourceChangeFn = testDiffFn
-	p.ReadDataSourceResponse = providers.ReadDataSourceResponse{
+	p.ReadDataSourceResponse = &providers.ReadDataSourceResponse{
 		State: cty.ObjectVal(map[string]cty.Value{
 			"id":  cty.StringVal("yo"),
 			"foo": cty.NullVal(cty.String),
@@ -10402,13 +10402,12 @@ func TestContext2Apply_ProviderMeta_refresh_set(t *testing.T) {
 		},
 	}
 	rrcPMs := map[string]cty.Value{}
-	p.ReadResourceFn = func(req providers.ReadResourceRequest) providers.ReadResourceResponse {
+	p.ReadResourceFn = func(req providers.ReadResourceRequest) (resp providers.ReadResourceResponse) {
 		rrcPMs[req.TypeName] = req.ProviderMeta
-		newState, err := p.GetSchemaReturn.ResourceTypes[req.TypeName].CoerceValue(p.ReadResourceResponse.NewState)
+		newState, err := p.GetSchemaReturn.ResourceTypes[req.TypeName].CoerceValue(req.PriorState)
 		if err != nil {
 			panic(err)
 		}
-		resp := p.ReadResourceResponse
 		resp.NewState = newState
 		return resp
 	}
@@ -10792,7 +10791,7 @@ func TestContext2Apply_ProviderMeta_refreshdata_setNoSchema(t *testing.T) {
 			addrs.NewDefaultProvider("test"): testProviderFuncFixed(p),
 		},
 	})
-	p.ReadDataSourceResponse = providers.ReadDataSourceResponse{
+	p.ReadDataSourceResponse = &providers.ReadDataSourceResponse{
 		State: cty.ObjectVal(map[string]cty.Value{
 			"id":  cty.StringVal("yo"),
 			"foo": cty.StringVal("bar"),
@@ -10848,7 +10847,7 @@ func TestContext2Apply_ProviderMeta_refreshdata_setInvalid(t *testing.T) {
 			addrs.NewDefaultProvider("test"): testProviderFuncFixed(p),
 		},
 	})
-	p.ReadDataSourceResponse = providers.ReadDataSourceResponse{
+	p.ReadDataSourceResponse = &providers.ReadDataSourceResponse{
 		State: cty.ObjectVal(map[string]cty.Value{
 			"id":  cty.StringVal("yo"),
 			"foo": cty.StringVal("bar"),
@@ -11497,7 +11496,7 @@ output "output" {
 	nullP.ApplyResourceChangeFn = testApplyFn
 	nullP.PlanResourceChangeFn = testDiffFn
 
-	nullP.ReadDataSourceResponse = providers.ReadDataSourceResponse{
+	nullP.ReadDataSourceResponse = &providers.ReadDataSourceResponse{
 		State: cty.ObjectVal(map[string]cty.Value{
 			"id":     cty.StringVal("ID"),
 			"output": cty.StringVal("valid"),

terraform/context_import_test.go

@@ -22,7 +22,7 @@ func TestContextImport_basic(t *testing.T) {
 		},
 	})
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",
@@ -63,7 +63,7 @@ func TestContextImport_countIndex(t *testing.T) {
 		},
 	})
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",
@@ -125,7 +125,7 @@ func TestContextImport_collision(t *testing.T) {
 		}),
 	})
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",
@@ -164,7 +164,7 @@ func TestContextImport_missingType(t *testing.T) {
 	p := testProvider("aws")
 	m := testModule(t, "import-provider")
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				State: cty.ObjectVal(map[string]cty.Value{
@@ -205,7 +205,7 @@ func TestContextImport_missingType(t *testing.T) {
 func TestContextImport_moduleProvider(t *testing.T) {
 	p := testProvider("aws")
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",
@@ -269,7 +269,7 @@ func TestContextImport_providerModule(t *testing.T) {
 		},
 	})
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",
@@ -341,7 +341,7 @@ func TestContextImport_providerConfig(t *testing.T) {
 				},
 			})
 
-			p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+			p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 				ImportedResources: []providers.ImportedResource{
 					{
 						TypeName: "aws_instance",
@@ -396,7 +396,7 @@ func TestContextImport_providerConfigResources(t *testing.T) {
 		},
 	})
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",
@@ -435,7 +435,7 @@ func TestContextImport_refresh(t *testing.T) {
 		},
 	})
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",
@@ -448,7 +448,7 @@ func TestContextImport_refresh(t *testing.T) {
 
 	p.ReadResourceFn = nil
 
-	p.ReadResourceResponse = providers.ReadResourceResponse{
+	p.ReadResourceResponse = &providers.ReadResourceResponse{
 		NewState: cty.ObjectVal(map[string]cty.Value{
 			"id":  cty.StringVal("foo"),
 			"foo": cty.StringVal("bar"),
@@ -486,7 +486,7 @@ func TestContextImport_refreshNil(t *testing.T) {
 		},
 	})
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",
@@ -534,7 +534,7 @@ func TestContextImport_module(t *testing.T) {
 		},
 	})
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",
@@ -576,7 +576,7 @@ func TestContextImport_moduleDepth2(t *testing.T) {
 		},
 	})
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",
@@ -618,7 +618,7 @@ func TestContextImport_moduleDiff(t *testing.T) {
 		},
 	})
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",
@@ -674,7 +674,7 @@ func TestContextImport_multiState(t *testing.T) {
 		},
 	}
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",
@@ -743,7 +743,7 @@ func TestContextImport_multiStateSame(t *testing.T) {
 		},
 	}
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",
@@ -844,7 +844,7 @@ resource "test_resource" "unused" {
 		},
 	}
 
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "test_resource",
@@ -854,7 +854,7 @@ resource "test_resource" "unused" {
 			},
 		},
 	}
-	p.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	p.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "test_resource",

terraform/context_plan_test.go

@@ -1873,7 +1873,7 @@ func TestContext2Plan_computedInFunction(t *testing.T) {
 		},
 	}
 	p.PlanResourceChangeFn = testDiffFn
-	p.ReadDataSourceResponse = providers.ReadDataSourceResponse{
+	p.ReadDataSourceResponse = &providers.ReadDataSourceResponse{
 		State: cty.ObjectVal(map[string]cty.Value{
 			"computed": cty.ListVal([]cty.Value{
 				cty.StringVal("foo"),
@@ -2015,7 +2015,7 @@ func TestContext2Plan_dataResourceBecomesComputed(t *testing.T) {
 	schema := p.GetSchemaReturn.DataSources["aws_data_source"]
 	ty := schema.ImpliedType()
 
-	p.ReadDataSourceResponse = providers.ReadDataSourceResponse{
+	p.ReadDataSourceResponse = &providers.ReadDataSourceResponse{
 		// This should not be called, because the configuration for the
 		// data resource contains an unknown value for "foo".
 		Diagnostics: tfdiags.Diagnostics(nil).Append(fmt.Errorf("ReadDataSource called, but should not have been")),
@@ -5412,7 +5412,7 @@ output "out" {
 	})
 
 	p := testProvider("aws")
-	p.ReadDataSourceResponse = providers.ReadDataSourceResponse{
+	p.ReadDataSourceResponse = &providers.ReadDataSourceResponse{
 		State: cty.ObjectVal(map[string]cty.Value{
 			"id":  cty.StringVal("data_id"),
 			"foo": cty.StringVal("foo"),
@@ -5459,7 +5459,7 @@ resource "aws_instance" "foo" {
 	})
 
 	p := testProvider("aws")
-	p.ReadDataSourceResponse = providers.ReadDataSourceResponse{
+	p.ReadDataSourceResponse = &providers.ReadDataSourceResponse{
 		State: cty.ObjectVal(map[string]cty.Value{
 			"id":  cty.StringVal("data_id"),
 			"foo": cty.StringVal("foo"),
@@ -6114,7 +6114,7 @@ data "test_data_source" "foo" {}
 		},
 	}
 
-	p.ReadDataSourceResponse = providers.ReadDataSourceResponse{
+	p.ReadDataSourceResponse = &providers.ReadDataSourceResponse{
 		State: cty.ObjectVal(map[string]cty.Value{
 			"id":  cty.StringVal("data_id"),
 			"foo": cty.StringVal("foo"),
@@ -6261,7 +6261,7 @@ data "test_data_source" "d" {
 `})
 
 	p := testProvider("test")
-	p.ReadDataSourceResponse = providers.ReadDataSourceResponse{
+	p.ReadDataSourceResponse = &providers.ReadDataSourceResponse{
 		State: cty.ObjectVal(map[string]cty.Value{
 			"id":  cty.StringVal("this"),
 			"foo": cty.NullVal(cty.String),

terraform/context_refresh_test.go

@@ -49,7 +49,7 @@ func TestContext2Refresh(t *testing.T) {
 	}
 
 	p.ReadResourceFn = nil
-	p.ReadResourceResponse = providers.ReadResourceResponse{
+	p.ReadResourceResponse = &providers.ReadResourceResponse{
 		NewState: readState,
 	}
 	p.PlanResourceChangeFn = testDiffFn
@@ -514,7 +514,7 @@ func TestContext2Refresh_delete(t *testing.T) {
 	})
 
 	p.ReadResourceFn = nil
-	p.ReadResourceResponse = providers.ReadResourceResponse{
+	p.ReadResourceResponse = &providers.ReadResourceResponse{
 		NewState: cty.NullVal(p.GetSchemaReturn.ResourceTypes["aws_instance"].ImpliedType()),
 	}
 	p.PlanResourceChangeFn = testDiffFn
@@ -542,7 +542,7 @@ func TestContext2Refresh_ignoreUncreated(t *testing.T) {
 	})
 
 	p.ReadResourceFn = nil
-	p.ReadResourceResponse = providers.ReadResourceResponse{
+	p.ReadResourceResponse = &providers.ReadResourceResponse{
 		NewState: cty.ObjectVal(map[string]cty.Value{
 			"id": cty.StringVal("foo"),
 		}),
@@ -700,7 +700,7 @@ func TestContext2Refresh_noState(t *testing.T) {
 	})
 
 	p.ReadResourceFn = nil
-	p.ReadResourceResponse = providers.ReadResourceResponse{
+	p.ReadResourceResponse = &providers.ReadResourceResponse{
 		NewState: cty.ObjectVal(map[string]cty.Value{
 			"id": cty.StringVal("foo"),
 		}),
@@ -785,7 +785,7 @@ func TestContext2Refresh_outputPartial(t *testing.T) {
 	}
 
 	p.ReadResourceFn = nil
-	p.ReadResourceResponse = providers.ReadResourceResponse{
+	p.ReadResourceResponse = &providers.ReadResourceResponse{
 		NewState: cty.NullVal(p.GetSchemaReturn.ResourceTypes["aws_instance"].ImpliedType()),
 	}
 
@@ -841,7 +841,7 @@ func TestContext2Refresh_stateBasic(t *testing.T) {
 
 	p.ReadResourceFn = nil
 	p.PlanResourceChangeFn = testDiffFn
-	p.ReadResourceResponse = providers.ReadResourceResponse{
+	p.ReadResourceResponse = &providers.ReadResourceResponse{
 		NewState: readStateVal,
 	}
 
@@ -1142,7 +1142,7 @@ func TestContext2Refresh_vars(t *testing.T) {
 
 	p.ReadResourceFn = nil
 	p.PlanResourceChangeFn = testDiffFn
-	p.ReadResourceResponse = providers.ReadResourceResponse{
+	p.ReadResourceResponse = &providers.ReadResourceResponse{
 		NewState: readStateVal,
 	}
 
@@ -1333,7 +1333,7 @@ func TestContext2Refresh_schemaUpgradeFlatmap(t *testing.T) {
 			"test_thing": 5,
 		},
 	}
-	p.UpgradeResourceStateResponse = providers.UpgradeResourceStateResponse{
+	p.UpgradeResourceStateResponse = &providers.UpgradeResourceStateResponse{
 		UpgradedState: cty.ObjectVal(map[string]cty.Value{
 			"name": cty.StringVal("foo"),
 		}),
@@ -1420,7 +1420,7 @@ func TestContext2Refresh_schemaUpgradeJSON(t *testing.T) {
 			"test_thing": 5,
 		},
 	}
-	p.UpgradeResourceStateResponse = providers.UpgradeResourceStateResponse{
+	p.UpgradeResourceStateResponse = &providers.UpgradeResourceStateResponse{
 		UpgradedState: cty.ObjectVal(map[string]cty.Value{
 			"name": cty.StringVal("foo"),
 		}),
@@ -1545,7 +1545,7 @@ func TestContext2Refresh_dataResourceDependsOn(t *testing.T) {
 		},
 	}
 	p.PlanResourceChangeFn = testDiffFn
-	p.ReadDataSourceResponse = providers.ReadDataSourceResponse{
+	p.ReadDataSourceResponse = &providers.ReadDataSourceResponse{
 		State: cty.ObjectVal(map[string]cty.Value{
 			"compute": cty.StringVal("value"),
 		}),

terraform/context_validate_test.go

@@ -398,7 +398,7 @@ func TestContext2Validate_moduleBadResource(t *testing.T) {
 		},
 	})
 
-	p.ValidateResourceTypeConfigResponse = providers.ValidateResourceTypeConfigResponse{
+	p.ValidateResourceTypeConfigResponse = &providers.ValidateResourceTypeConfigResponse{
 		Diagnostics: tfdiags.Diagnostics{}.Append(fmt.Errorf("bad")),
 	}
 
@@ -582,7 +582,7 @@ func TestContext2Validate_providerConfig_bad(t *testing.T) {
 		},
 	})
 
-	p.PrepareProviderConfigResponse = providers.PrepareProviderConfigResponse{
+	p.PrepareProviderConfigResponse = &providers.PrepareProviderConfigResponse{
 		Diagnostics: tfdiags.Diagnostics{}.Append(fmt.Errorf("bad")),
 	}
 
@@ -618,7 +618,7 @@ func TestContext2Validate_providerConfig_skippedEmpty(t *testing.T) {
 		},
 	})
 
-	p.PrepareProviderConfigResponse = providers.PrepareProviderConfigResponse{
+	p.PrepareProviderConfigResponse = &providers.PrepareProviderConfigResponse{
 		Diagnostics: tfdiags.Diagnostics{}.Append(fmt.Errorf("should not be called")),
 	}
 
@@ -714,7 +714,7 @@ func TestContext2Validate_provisionerConfig_bad(t *testing.T) {
 		},
 	})
 
-	p.PrepareProviderConfigResponse = providers.PrepareProviderConfigResponse{
+	p.PrepareProviderConfigResponse = &providers.PrepareProviderConfigResponse{
 		Diagnostics: tfdiags.Diagnostics{}.Append(fmt.Errorf("bad")),
 	}
 
@@ -878,7 +878,7 @@ func TestContext2Validate_resourceConfig_bad(t *testing.T) {
 		},
 	})
 
-	p.ValidateResourceTypeConfigResponse = providers.ValidateResourceTypeConfigResponse{
+	p.ValidateResourceTypeConfigResponse = &providers.ValidateResourceTypeConfigResponse{
 		Diagnostics: tfdiags.Diagnostics{}.Append(fmt.Errorf("bad")),
 	}
 
@@ -1877,7 +1877,7 @@ resource "test_instance" "a" {
 		},
 	}
 
-	p.ValidateResourceTypeConfigResponse = providers.ValidateResourceTypeConfigResponse{
+	p.ValidateResourceTypeConfigResponse = &providers.ValidateResourceTypeConfigResponse{
 		Diagnostics: tfdiags.Diagnostics(nil).Append(tfdiags.SimpleWarning("don't frobble")),
 	}
 

terraform/node_resource_destroy_deposed_test.go

@@ -26,7 +26,7 @@ func TestNodePlanDeposedResourceInstanceObject_Execute(t *testing.T) {
 	)
 
 	p := testProvider("test")
-	p.UpgradeResourceStateResponse = providers.UpgradeResourceStateResponse{
+	p.UpgradeResourceStateResponse = &providers.UpgradeResourceStateResponse{
 		UpgradedState: cty.ObjectVal(map[string]cty.Value{
 			"id": cty.StringVal("bar"),
 		}),
@@ -86,7 +86,7 @@ func TestNodeDestroyDeposedResourceInstanceObject_Execute(t *testing.T) {
 	)
 
 	p := testProvider("test")
-	p.UpgradeResourceStateResponse = providers.UpgradeResourceStateResponse{
+	p.UpgradeResourceStateResponse = &providers.UpgradeResourceStateResponse{
 		UpgradedState: cty.ObjectVal(map[string]cty.Value{
 			"id": cty.StringVal("bar"),
 		}),

terraform/provider_mock.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"sync"
 
-	"github.com/zclconf/go-cty/cty"
 	ctyjson "github.com/zclconf/go-cty/cty/json"
 	"github.com/zclconf/go-cty/cty/msgpack"
 
@@ -26,30 +25,30 @@ type MockProvider struct {
 	GetSchemaReturn *ProviderSchema // This is using ProviderSchema directly rather than providers.GetSchemaResponse for compatibility with old tests
 
 	PrepareProviderConfigCalled   bool
-	PrepareProviderConfigResponse providers.PrepareProviderConfigResponse
+	PrepareProviderConfigResponse *providers.PrepareProviderConfigResponse
 	PrepareProviderConfigRequest  providers.PrepareProviderConfigRequest
 	PrepareProviderConfigFn       func(providers.PrepareProviderConfigRequest) providers.PrepareProviderConfigResponse
 
 	ValidateResourceTypeConfigCalled   bool
 	ValidateResourceTypeConfigTypeName string
-	ValidateResourceTypeConfigResponse providers.ValidateResourceTypeConfigResponse
+	ValidateResourceTypeConfigResponse *providers.ValidateResourceTypeConfigResponse
 	ValidateResourceTypeConfigRequest  providers.ValidateResourceTypeConfigRequest
 	ValidateResourceTypeConfigFn       func(providers.ValidateResourceTypeConfigRequest) providers.ValidateResourceTypeConfigResponse
 
 	ValidateDataSourceConfigCalled   bool
 	ValidateDataSourceConfigTypeName string
-	ValidateDataSourceConfigResponse providers.ValidateDataSourceConfigResponse
+	ValidateDataSourceConfigResponse *providers.ValidateDataSourceConfigResponse
 	ValidateDataSourceConfigRequest  providers.ValidateDataSourceConfigRequest
 	ValidateDataSourceConfigFn       func(providers.ValidateDataSourceConfigRequest) providers.ValidateDataSourceConfigResponse
 
 	UpgradeResourceStateCalled   bool
 	UpgradeResourceStateTypeName string
-	UpgradeResourceStateResponse providers.UpgradeResourceStateResponse
+	UpgradeResourceStateResponse *providers.UpgradeResourceStateResponse
 	UpgradeResourceStateRequest  providers.UpgradeResourceStateRequest
 	UpgradeResourceStateFn       func(providers.UpgradeResourceStateRequest) providers.UpgradeResourceStateResponse
 
 	ConfigureCalled   bool
-	ConfigureResponse providers.ConfigureResponse
+	ConfigureResponse *providers.ConfigureResponse
 	ConfigureRequest  providers.ConfigureRequest
 	ConfigureFn       func(providers.ConfigureRequest) providers.ConfigureResponse
 
@@ -58,27 +57,27 @@ type MockProvider struct {
 	StopResponse error
 
 	ReadResourceCalled   bool
-	ReadResourceResponse providers.ReadResourceResponse
+	ReadResourceResponse *providers.ReadResourceResponse
 	ReadResourceRequest  providers.ReadResourceRequest
 	ReadResourceFn       func(providers.ReadResourceRequest) providers.ReadResourceResponse
 
 	PlanResourceChangeCalled   bool
-	PlanResourceChangeResponse providers.PlanResourceChangeResponse
+	PlanResourceChangeResponse *providers.PlanResourceChangeResponse
 	PlanResourceChangeRequest  providers.PlanResourceChangeRequest
 	PlanResourceChangeFn       func(providers.PlanResourceChangeRequest) providers.PlanResourceChangeResponse
 
 	ApplyResourceChangeCalled   bool
-	ApplyResourceChangeResponse providers.ApplyResourceChangeResponse
+	ApplyResourceChangeResponse *providers.ApplyResourceChangeResponse
 	ApplyResourceChangeRequest  providers.ApplyResourceChangeRequest
 	ApplyResourceChangeFn       func(providers.ApplyResourceChangeRequest) providers.ApplyResourceChangeResponse
 
 	ImportResourceStateCalled   bool
-	ImportResourceStateResponse providers.ImportResourceStateResponse
+	ImportResourceStateResponse *providers.ImportResourceStateResponse
 	ImportResourceStateRequest  providers.ImportResourceStateRequest
 	ImportResourceStateFn       func(providers.ImportResourceStateRequest) providers.ImportResourceStateResponse
 
 	ReadDataSourceCalled   bool
-	ReadDataSourceResponse providers.ReadDataSourceResponse
+	ReadDataSourceResponse *providers.ReadDataSourceResponse
 	ReadDataSourceRequest  providers.ReadDataSourceRequest
 	ReadDataSourceFn       func(providers.ReadDataSourceRequest) providers.ReadDataSourceResponse
 
@@ -140,7 +139,7 @@ func (p *MockProvider) getDatasourceSchema(name string) providers.Schema {
 	return dataSchema
 }
 
-func (p *MockProvider) PrepareProviderConfig(r providers.PrepareProviderConfigRequest) providers.PrepareProviderConfigResponse {
+func (p *MockProvider) PrepareProviderConfig(r providers.PrepareProviderConfigRequest) (resp providers.PrepareProviderConfigResponse) {
 	p.Lock()
 	defer p.Unlock()
 
@@ -149,8 +148,13 @@ func (p *MockProvider) PrepareProviderConfig(r providers.PrepareProviderConfigRe
 	if p.PrepareProviderConfigFn != nil {
 		return p.PrepareProviderConfigFn(r)
 	}
-	p.PrepareProviderConfigResponse.PreparedConfig = r.Config
+
-	return p.PrepareProviderConfigResponse
+	if p.PrepareProviderConfigResponse != nil {
+		return *p.PrepareProviderConfigResponse
+	}
+
+	resp.PreparedConfig = r.Config
+	return resp
 }
 
 func (p *MockProvider) ValidateResourceTypeConfig(r providers.ValidateResourceTypeConfigRequest) (resp providers.ValidateResourceTypeConfigResponse) {
@@ -173,7 +177,11 @@ func (p *MockProvider) ValidateResourceTypeConfig(r providers.ValidateResourceTy
 		return p.ValidateResourceTypeConfigFn(r)
 	}
 
-	return p.ValidateResourceTypeConfigResponse
+	if p.ValidateResourceTypeConfigResponse != nil {
+		return *p.ValidateResourceTypeConfigResponse
+	}
+
+	return resp
 }
 
 func (p *MockProvider) ValidateDataSourceConfig(r providers.ValidateDataSourceConfigRequest) (resp providers.ValidateDataSourceConfigResponse) {
@@ -195,10 +203,14 @@ func (p *MockProvider) ValidateDataSourceConfig(r providers.ValidateDataSourceCo
 		return p.ValidateDataSourceConfigFn(r)
 	}
 
-	return p.ValidateDataSourceConfigResponse
+	if p.ValidateDataSourceConfigResponse != nil {
+		return *p.ValidateDataSourceConfigResponse
 	}
 
-func (p *MockProvider) UpgradeResourceState(r providers.UpgradeResourceStateRequest) providers.UpgradeResourceStateResponse {
+	return resp
+}
+
+func (p *MockProvider) UpgradeResourceState(r providers.UpgradeResourceStateRequest) (resp providers.UpgradeResourceStateResponse) {
 	p.Lock()
 	defer p.Unlock()
 
@@ -213,9 +225,10 @@ func (p *MockProvider) UpgradeResourceState(r providers.UpgradeResourceStateRequ
 		return p.UpgradeResourceStateFn(r)
 	}
 
-	resp := p.UpgradeResourceStateResponse
+	if p.UpgradeResourceStateResponse != nil {
+		return *p.UpgradeResourceStateResponse
+	}
 
-	if resp.UpgradedState == cty.NilVal {
 	switch {
 	case r.RawStateFlatmap != nil:
 		v, err := hcl2shim.HCL2ValueFromFlatmap(r.RawStateFlatmap, schemaType)
@@ -233,11 +246,11 @@ func (p *MockProvider) UpgradeResourceState(r providers.UpgradeResourceStateRequ
 		}
 		resp.UpgradedState = v
 	}
-	}
+
 	return resp
 }
 
-func (p *MockProvider) Configure(r providers.ConfigureRequest) providers.ConfigureResponse {
+func (p *MockProvider) Configure(r providers.ConfigureRequest) (resp providers.ConfigureResponse) {
 	p.Lock()
 	defer p.Unlock()
 
@@ -248,7 +261,11 @@ func (p *MockProvider) Configure(r providers.ConfigureRequest) providers.Configu
 		return p.ConfigureFn(r)
 	}
 
-	return p.ConfigureResponse
+	if p.ConfigureResponse != nil {
+		return *p.ConfigureResponse
+	}
+
+	return resp
 }
 
 func (p *MockProvider) Stop() error {
@@ -265,7 +282,7 @@ func (p *MockProvider) Stop() error {
 	return p.StopResponse
 }
 
-func (p *MockProvider) ReadResource(r providers.ReadResourceRequest) providers.ReadResourceResponse {
+func (p *MockProvider) ReadResource(r providers.ReadResourceRequest) (resp providers.ReadResourceResponse) {
 	p.Lock()
 	defer p.Unlock()
 
@@ -276,24 +293,25 @@ func (p *MockProvider) ReadResource(r providers.ReadResourceRequest) providers.R
 		return p.ReadResourceFn(r)
 	}
 
-	resp := p.ReadResourceResponse
+	if p.ReadResourceResponse != nil {
-	if resp.NewState != cty.NilVal {
+		resp = *p.ReadResourceResponse
-		// make sure the NewState fits the schema
+
-		// This isn't always the case for the existing tests
+		// Make sure the NewState conforms to the schema.
+		// This isn't always the case for the existing tests.
 		newState, err := p.GetSchemaReturn.ResourceTypes[r.TypeName].CoerceValue(resp.NewState)
 		if err != nil {
-			panic(err)
+			resp.Diagnostics = resp.Diagnostics.Append(err)
 		}
 		resp.NewState = newState
 		return resp
 	}
 
-	// just return the same state we received
+	// otherwise just return the same state we received
 	resp.NewState = r.PriorState
 	return resp
 }
 
-func (p *MockProvider) PlanResourceChange(r providers.PlanResourceChangeRequest) providers.PlanResourceChangeResponse {
+func (p *MockProvider) PlanResourceChange(r providers.PlanResourceChangeRequest) (resp providers.PlanResourceChangeResponse) {
 	p.Lock()
 	defer p.Unlock()
 
@@ -304,10 +322,14 @@ func (p *MockProvider) PlanResourceChange(r providers.PlanResourceChangeRequest)
 		return p.PlanResourceChangeFn(r)
 	}
 
-	return p.PlanResourceChangeResponse
+	if p.PlanResourceChangeResponse != nil {
+		return *p.PlanResourceChangeResponse
 	}
 
-func (p *MockProvider) ApplyResourceChange(r providers.ApplyResourceChangeRequest) providers.ApplyResourceChangeResponse {
+	return resp
+}
+
+func (p *MockProvider) ApplyResourceChange(r providers.ApplyResourceChangeRequest) (resp providers.ApplyResourceChangeResponse) {
 	p.Lock()
 	p.ApplyResourceChangeCalled = true
 	p.ApplyResourceChangeRequest = r
@@ -317,7 +339,10 @@ func (p *MockProvider) ApplyResourceChange(r providers.ApplyResourceChangeReques
 		return p.ApplyResourceChangeFn(r)
 	}
 
-	return p.ApplyResourceChangeResponse
+	if p.ApplyResourceChangeResponse != nil {
+		return *p.ApplyResourceChangeResponse
+	}
+	return resp
 }
 
 func (p *MockProvider) ImportResourceState(r providers.ImportResourceStateRequest) (resp providers.ImportResourceStateResponse) {
@@ -330,8 +355,10 @@ func (p *MockProvider) ImportResourceState(r providers.ImportResourceStateReques
 		return p.ImportResourceStateFn(r)
 	}
 
+	if p.ImportResourceStateResponse != nil {
+		resp = *p.ImportResourceStateResponse
 		// fixup the cty value to match the schema
-	for i, res := range p.ImportResourceStateResponse.ImportedResources {
+		for i, res := range resp.ImportedResources {
 			schema := p.GetSchemaReturn.ResourceTypes[res.TypeName]
 			if schema == nil {
 				resp.Diagnostics = resp.Diagnostics.Append(errors.New("no schema found for " + res.TypeName))
@@ -345,13 +372,14 @@ func (p *MockProvider) ImportResourceState(r providers.ImportResourceStateReques
 				return resp
 			}
 
-		p.ImportResourceStateResponse.ImportedResources[i] = res
+			resp.ImportedResources[i] = res
+		}
 	}
 
-	return p.ImportResourceStateResponse
+	return resp
 }
 
-func (p *MockProvider) ReadDataSource(r providers.ReadDataSourceRequest) providers.ReadDataSourceResponse {
+func (p *MockProvider) ReadDataSource(r providers.ReadDataSourceRequest) (resp providers.ReadDataSourceResponse) {
 	p.Lock()
 	defer p.Unlock()
 
@@ -362,7 +390,10 @@ func (p *MockProvider) ReadDataSource(r providers.ReadDataSourceRequest) provide
 		return p.ReadDataSourceFn(r)
 	}
 
-	return p.ReadDataSourceResponse
+	if p.ReadDataSourceResponse != nil {
+		resp = *p.ReadDataSourceResponse
+	}
+	return resp
 }
 
 func (p *MockProvider) Close() error {

terraform/transform_import_state_test.go

@@ -14,7 +14,7 @@ import (
 func TestGraphNodeImportStateExecute(t *testing.T) {
 	state := states.NewState()
 	provider := testProvider("aws")
-	provider.ImportResourceStateResponse = providers.ImportResourceStateResponse{
+	provider.ImportResourceStateResponse = &providers.ImportResourceStateResponse{
 		ImportedResources: []providers.ImportedResource{
 			{
 				TypeName: "aws_instance",