add test fetching computed set value by address

This is not a recommended method, but it does serve to verify that the
set values in the ResourceData internal state are correctly computed,
which indicates that the expected configuration was passed in.

builtin/providers/test/resource_state_func.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"math/rand"
 
+	"github.com/hashicorp/terraform/helper/hashcode"
 	"github.com/hashicorp/terraform/helper/schema"
 )
 
@@ -35,6 +36,26 @@ func testResourceStateFunc() *schema.Resource {
 				Type:     schema.TypeString,
 				Optional: true,
 			},
+
+			// set block with computed elements
+			"set_block": {
+				Type:     schema.TypeSet,
+				Optional: true,
+				Set:      setBlockHash,
+				Elem: &schema.Resource{
+					Schema: map[string]*schema.Schema{
+						"required": {
+							Type:     schema.TypeString,
+							Required: true,
+						},
+						"optional": {
+							Type:     schema.TypeString,
+							Optional: true,
+							Computed: true,
+						},
+					},
+				},
+			},
 		},
 	}
 }
@@ -44,6 +65,13 @@ func stateFuncHash(v interface{}) string {
 	return hex.EncodeToString(hash[:])
 }
 
+func setBlockHash(v interface{}) int {
+	m := v.(map[string]interface{})
+	required, _ := m["required"].(string)
+	optional, _ := m["optional"].(string)
+	return hashcode.String(fmt.Sprintf("%s|%s", required, optional))
+}
+
 func testResourceStateFuncCreate(d *schema.ResourceData, meta interface{}) error {
 	d.SetId(fmt.Sprintf("%x", rand.Int63()))
 
@@ -57,6 +85,22 @@ func testResourceStateFuncCreate(d *schema.ResourceData, meta interface{}) error
 		}
 	}
 
+	// Check that we can lookup set elements by our computed hash.
+	// This is not advised, but we can use this to make sure the final diff was
+	// prepared with the correct values.
+	setBlock, ok := d.GetOk("set_block")
+	if ok {
+		set := setBlock.(*schema.Set)
+		for _, obj := range set.List() {
+			idx := setBlockHash(obj)
+			requiredAddr := fmt.Sprintf("%s.%d.%s", "set_block", idx, "required")
+			_, ok := d.GetOkExists(requiredAddr)
+			if !ok {
+				return fmt.Errorf("failed to get attr %q from %#v", fmt.Sprintf(requiredAddr), d.State().Attributes)
+			}
+		}
+	}
+
 	return testResourceStateFuncRead(d, meta)
 }
 

builtin/providers/test/resource_state_func_test.go

@@ -58,3 +58,28 @@ resource "test_resource_state_func" "foo" {
 		},
 	})
 }
+
+func TestResourceStateFunc_getOkSetElem(t *testing.T) {
+	resource.UnitTest(t, resource.TestCase{
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckResourceDestroy,
+		Steps: []resource.TestStep{
+			resource.TestStep{
+				Config: strings.TrimSpace(`
+resource "test_resource_state_func" "foo" {
+}
+
+resource "test_resource_state_func" "bar" {
+	set_block {
+		required = "foo"
+		optional = test_resource_state_func.foo.id
+	}
+	set_block {
+		required = test_resource_state_func.foo.id
+	}
+}
+				`),
+			},
+		},
+	})
+}