create a SimpleDiff for the new provider shims

Terraform now handles any actual "diffing" of resource, and the existing
Diff functions are only used to shim the schema.Provider to the new
methods. Since terraform is handling what used to be the Diff, the
provider now should not modify the diff based on RequiresNew due to it
interfering with the ignore_changes handling.

helper/schema/backend.go

@@ -6,8 +6,8 @@ import (
 	"github.com/hashicorp/terraform/tfdiags"
 	"github.com/zclconf/go-cty/cty"
 
-	"github.com/hashicorp/terraform/configs/configschema"
 	"github.com/hashicorp/terraform/config/hcl2shim"
+	"github.com/hashicorp/terraform/configs/configschema"
 	"github.com/hashicorp/terraform/terraform"
 )
 
@@ -77,7 +77,7 @@ func (b *Backend) Configure(obj cty.Value) tfdiags.Diagnostics {
 
 	// Get a ResourceData for this configuration. To do this, we actually
 	// generate an intermediary "diff" although that is never exposed.
-	diff, err := sm.Diff(nil, shimRC, nil, nil)
+	diff, err := sm.Diff(nil, shimRC, nil, nil, true)
 	if err != nil {
 		diags = diags.Append(err)
 		return diags

helper/schema/provider.go

@@ -251,7 +251,7 @@ func (p *Provider) Configure(c *terraform.ResourceConfig) error {
 
 	// Get a ResourceData for this configuration. To do this, we actually
 	// generate an intermediary "diff" although that is never exposed.
-	diff, err := sm.Diff(nil, c, nil, p.meta)
+	diff, err := sm.Diff(nil, c, nil, p.meta, true)
 	if err != nil {
 		return err
 	}
@@ -296,6 +296,20 @@ func (p *Provider) Diff(
 	return r.Diff(s, c, p.meta)
 }
 
+// SimpleDiff is used by the new protocol wrappers to get a diff that doesn't
+// attempt to calculate ignore_changes.
+func (p *Provider) SimpleDiff(
+	info *terraform.InstanceInfo,
+	s *terraform.InstanceState,
+	c *terraform.ResourceConfig) (*terraform.InstanceDiff, error) {
+	r, ok := p.ResourcesMap[info.Type]
+	if !ok {
+		return nil, fmt.Errorf("unknown resource type: %s", info.Type)
+	}
+
+	return r.simpleDiff(s, c, p.meta)
+}
+
 // Refresh implementation of terraform.ResourceProvider interface.
 func (p *Provider) Refresh(
 	info *terraform.InstanceInfo,
@@ -311,7 +325,7 @@ func (p *Provider) Refresh(
 // Resources implementation of terraform.ResourceProvider interface.
 func (p *Provider) Resources() []terraform.ResourceType {
 	keys := make([]string, 0, len(p.ResourcesMap))
-	for k, _ := range p.ResourcesMap {
+	for k := range p.ResourcesMap {
 		keys = append(keys, k)
 	}
 	sort.Strings(keys)

helper/schema/provisioner.go

@@ -152,7 +152,7 @@ func (p *Provisioner) Apply(
 		}
 
 		sm := schemaMap(p.ConnSchema)
-		diff, err := sm.Diff(nil, terraform.NewResourceConfig(c), nil, nil)
+		diff, err := sm.Diff(nil, terraform.NewResourceConfig(c), nil, nil, true)
 		if err != nil {
 			return err
 		}
@@ -166,7 +166,7 @@ func (p *Provisioner) Apply(
 		// Build the configuration data. Doing this requires making a "diff"
 		// even though that's never used. We use that just to get the correct types.
 		configMap := schemaMap(p.Schema)
-		diff, err := configMap.Diff(nil, c, nil, nil)
+		diff, err := configMap.Diff(nil, c, nil, nil, true)
 		if err != nil {
 			return err
 		}

helper/schema/resource.go

@@ -287,7 +287,35 @@ func (r *Resource) Diff(
 		return nil, fmt.Errorf("[ERR] Error decoding timeout: %s", err)
 	}
 
-	instanceDiff, err := schemaMap(r.Schema).Diff(s, c, r.CustomizeDiff, meta)
+	instanceDiff, err := schemaMap(r.Schema).Diff(s, c, r.CustomizeDiff, meta, true)
+	if err != nil {
+		return instanceDiff, err
+	}
+
+	if instanceDiff != nil {
+		if err := t.DiffEncode(instanceDiff); err != nil {
+			log.Printf("[ERR] Error encoding timeout to instance diff: %s", err)
+		}
+	} else {
+		log.Printf("[DEBUG] Instance Diff is nil in Diff()")
+	}
+
+	return instanceDiff, err
+}
+
+func (r *Resource) simpleDiff(
+	s *terraform.InstanceState,
+	c *terraform.ResourceConfig,
+	meta interface{}) (*terraform.InstanceDiff, error) {
+
+	t := &ResourceTimeout{}
+	err := t.ConfigDecode(r, c)
+
+	if err != nil {
+		return nil, fmt.Errorf("[ERR] Error decoding timeout: %s", err)
+	}
+
+	instanceDiff, err := schemaMap(r.Schema).Diff(s, c, r.CustomizeDiff, meta, false)
 	if err != nil {
 		return instanceDiff, err
 	}

helper/schema/schema.go

@@ -410,7 +410,8 @@ func (m schemaMap) Diff(
 	s *terraform.InstanceState,
 	c *terraform.ResourceConfig,
 	customizeDiff CustomizeDiffFunc,
-	meta interface{}) (*terraform.InstanceDiff, error) {
+	meta interface{},
+	handleRequiresNew bool) (*terraform.InstanceDiff, error) {
 	result := new(terraform.InstanceDiff)
 	result.Attributes = make(map[string]*terraform.ResourceAttrDiff)
 
@@ -456,6 +457,7 @@ func (m schemaMap) Diff(
 		}
 	}
 
+	if handleRequiresNew {
 		// If the diff requires a new resource, then we recompute the diff
 		// so we have the complete new resource diff, and preserve the
 		// RequiresNew fields where necessary so the user knows exactly what
@@ -534,6 +536,8 @@ func (m schemaMap) Diff(
 			result = result2
 		}
 
+	}
+
 	// Go through and detect all of the ComputedWhens now that we've
 	// finished the diff.
 	// TODO

helper/schema/schema_test.go

@@ -3246,7 +3246,7 @@ func TestSchemaMap_Diff(t *testing.T) {
 				}
 			}
 
-			d, err := schemaMap(tc.Schema).Diff(tc.State, terraform.NewResourceConfig(c), tc.CustomizeDiff, nil)
+			d, err := schemaMap(tc.Schema).Diff(tc.State, terraform.NewResourceConfig(c), tc.CustomizeDiff, nil, true)
 			if err != nil != tc.Err {
 				t.Fatalf("err: %s", err)
 			}
@@ -4096,7 +4096,7 @@ func TestSchemaMap_DiffSuppress(t *testing.T) {
 				}
 			}
 
-			d, err := schemaMap(tc.Schema).Diff(tc.State, terraform.NewResourceConfig(c), nil, nil)
+			d, err := schemaMap(tc.Schema).Diff(tc.State, terraform.NewResourceConfig(c), nil, nil, true)
 			if err != nil != tc.Err {
 				t.Fatalf("#%q err: %s", tn, err)
 			}

helper/schema/shims.go

@@ -29,7 +29,7 @@ func diffFromValues(prior, planned cty.Value, res *Resource, cust CustomizeDiffF
 
 	cfg := terraform.NewResourceConfigShimmed(planned, configSchema)
 
-	diff, err := schemaMap(res.Schema).Diff(instanceState, cfg, cust, nil)
+	diff, err := schemaMap(res.Schema).Diff(instanceState, cfg, cust, nil, false)
 	if err != nil {
 		return nil, err
 	}
@@ -41,8 +41,8 @@ func diffFromValues(prior, planned cty.Value, res *Resource, cust CustomizeDiffF
 // get a new cty.Value state. This is used to convert the diff returned from
 // the legacy provider Diff method to the state required for the new
 // PlanResourceChange method.
-func ApplyDiff(state cty.Value, d *terraform.InstanceDiff, schemaBlock *configschema.Block) (cty.Value, error) {
+func ApplyDiff(base cty.Value, d *terraform.InstanceDiff, schema *configschema.Block) (cty.Value, error) {
-	return d.ApplyToValue(state, schemaBlock)
+	return d.ApplyToValue(base, schema)
 }
 
 // StateValueToJSONMap converts a cty.Value to generic JSON map via the cty JSON

helper/schema/shims_test.go

@@ -2024,11 +2024,11 @@ func TestShimSchemaMap_Diff(t *testing.T) {
 						RequiresNew: true,
 					},
 
-					"address": &terraform.ResourceAttrDiff{
+					// "address": &terraform.ResourceAttrDiff{
-						Old:         "foo",
+					// 	Old:         "foo",
-						New:         "",
+					// 	New:         "",
-						NewComputed: true,
+					// 	NewComputed: true,
-					},
+					// },
 				},
 			},
 
@@ -2075,11 +2075,11 @@ func TestShimSchemaMap_Diff(t *testing.T) {
 						RequiresNew: true,
 					},
 
-					"ports.#": &terraform.ResourceAttrDiff{
+					// "ports.#": &terraform.ResourceAttrDiff{
-						Old:         "1",
+					// 	Old:         "1",
-						New:         "",
+					// 	New:         "",
-						NewComputed: true,
+					// 	NewComputed: true,
-					},
+					// },
 				},
 			},
 
@@ -2849,10 +2849,6 @@ func TestShimSchemaMap_Diff(t *testing.T) {
 
 			Diff: &terraform.InstanceDiff{
 				Attributes: map[string]*terraform.ResourceAttrDiff{
-					"instances.#": &terraform.ResourceAttrDiff{
-						Old: "2",
-						New: "2",
-					},
 					"instances.2": &terraform.ResourceAttrDiff{
 						Old:         "22",
 						New:         "",
@@ -2973,10 +2969,6 @@ func TestShimSchemaMap_Diff(t *testing.T) {
 
 			Diff: &terraform.InstanceDiff{
 				Attributes: map[string]*terraform.ResourceAttrDiff{
-					"ports.#": &terraform.ResourceAttrDiff{
-						Old: "3",
-						New: "3",
-					},
 					"ports.1": &terraform.ResourceAttrDiff{
 						Old: "1",
 						New: "1",
@@ -3103,8 +3095,6 @@ func TestShimSchemaMap_Diff(t *testing.T) {
 			Diff: &terraform.InstanceDiff{
 				Attributes: map[string]*terraform.ResourceAttrDiff{
 					"ports.#": &terraform.ResourceAttrDiff{
-						Old:         "3",
-						New:         "",
 						NewComputed: true,
 						RequiresNew: true,
 					},
@@ -3357,10 +3347,6 @@ func TestShimSchemaMap_Diff(t *testing.T) {
 
 			Diff: &terraform.InstanceDiff{
 				Attributes: map[string]*terraform.ResourceAttrDiff{
-					"ports.#": &terraform.ResourceAttrDiff{
-						Old: "3",
-						New: "3",
-					},
 					"ports.1": &terraform.ResourceAttrDiff{
 						Old: "1",
 						New: "1",
@@ -3576,7 +3562,7 @@ func TestShimSchemaMap_Diff(t *testing.T) {
 			}
 
 			{
-				d, err := InternalMap(tc.Schema).Diff(tc.State, terraform.NewResourceConfig(c), tc.CustomizeDiff, nil)
+				d, err := InternalMap(tc.Schema).Diff(tc.State, terraform.NewResourceConfig(c), tc.CustomizeDiff, nil, false)
 				if err != nil != tc.Err {
 					t.Fatalf("err: %s", err)
 				}

helper/schema/testing.go

@@ -18,7 +18,7 @@ func TestResourceDataRaw(
 	}
 
 	sm := schemaMap(schema)
-	diff, err := sm.Diff(nil, terraform.NewResourceConfig(c), nil, nil)
+	diff, err := sm.Diff(nil, terraform.NewResourceConfig(c), nil, nil, true)
 	if err != nil {
 		t.Fatalf("err: %s", err)
 	}