command: Do not count data sources in plan totals

Fixes #7483

command/hook_count.go

@@ -1,6 +1,7 @@
 package command
 
 import (
+	"strings"
 	"sync"
 
 	"github.com/hashicorp/terraform/terraform"
@@ -90,6 +91,11 @@ func (h *CountHook) PostDiff(
 	h.Lock()
 	defer h.Unlock()
 
+	// We don't count anything for data sources
+	if strings.HasPrefix(n.Id, "data.") {
+		return terraform.HookActionContinue, nil
+	}
+
 	switch d.ChangeType() {
 	case terraform.DiffDestroyCreate:
 		h.ToRemoveAndAdd += 1

command/hook_count_test.go

@@ -182,3 +182,37 @@ func TestCountHookPostDiff_NoChange(t *testing.T) {
 			expected, h)
 	}
 }
+
+func TestCountHookPostDiff_DataSource(t *testing.T) {
+	h := new(CountHook)
+
+	resources := map[string]*terraform.InstanceDiff{
+		"data.foo": &terraform.InstanceDiff{
+			Destroy: true,
+		},
+		"data.bar": &terraform.InstanceDiff{},
+		"data.lorem": &terraform.InstanceDiff{
+			Destroy: false,
+			Attributes: map[string]*terraform.ResourceAttrDiff{
+				"foo": &terraform.ResourceAttrDiff{},
+			},
+		},
+		"data.ipsum": &terraform.InstanceDiff{Destroy: true},
+	}
+
+	for k, d := range resources {
+		n := &terraform.InstanceInfo{Id: k}
+		h.PostDiff(n, d)
+	}
+
+	expected := new(CountHook)
+	expected.ToAdd = 0
+	expected.ToChange = 0
+	expected.ToRemoveAndAdd = 0
+	expected.ToRemove = 0
+
+	if !reflect.DeepEqual(expected, h) {
+		t.Fatalf("Expected %#v, got %#v instead.",
+			expected, h)
+	}
+}