tests/resource/aws_dx_gateway_association: Ensure v0 state upgrade is…

… still covered by acceptance testing

Output from acceptance testing:

```
--- PASS: TestAccAwsDxGatewayAssociation_V0StateUpgrade (2605.48s)
```

aws/resource_aws_dx_gateway_association_test.go

@@ -182,6 +182,28 @@ func testSweepDirectConnectGatewayAssociations(region string) error {
  return nil
 }
 
+// V0 state upgrade testing must be done via acceptance testing due to API call
+func TestAccAwsDxGatewayAssociation_V0StateUpgrade(t *testing.T) {
+ resourceName := "aws_dx_gateway_association.test"
+ rName := fmt.Sprintf("terraform-testacc-dxgwassoc-%d", acctest.RandInt())
+ rBgpAsn := randIntRange(64512, 65534)
+
+ resource.ParallelTest(t, resource.TestCase{
+ PreCheck: func() { testAccPreCheck(t) },
+ Providers: testAccProviders,
+ CheckDestroy: testAccCheckAwsDxGatewayAssociationDestroy,
+ Steps: []resource.TestStep{
+ {
+ Config: testAccDxGatewayAssociationConfig_basicVpnGatewaySingleAccount(rName, rBgpAsn),
+ Check: resource.ComposeTestCheckFunc(
+ testAccCheckAwsDxGatewayAssociationExists(resourceName),
+ testAccCheckAwsDxGatewayAssociationStateUpgradeV0(resourceName),
+ ),
+ },
+ },
+ })
+}
+
 func TestAccAwsDxGatewayAssociation_basicVpnGatewaySingleAccount(t *testing.T) {
  resourceName := "aws_dx_gateway_association.test"
  resourceNameDxGw := "aws_dx_gateway.test"
@@ -501,7 +523,7 @@ func testAccCheckAwsDxGatewayAssociationStateUpgradeV0(name string) resource.Tes
 
  rawState := map[string]interface{}{
  "dx_gateway_id": rs.Primary.Attributes["dx_gateway_id"],
- "vpn_gateway_id": rs.Primary.Attributes["vpn_gateway_id"],
+ "vpn_gateway_id": rs.Primary.Attributes["associated_gateway_id"], // vpn_gateway_id was removed in 3.0, but older state still has it
  }
 
  updatedRawState, err := resourceAwsDxGatewayAssociationStateUpgradeV0(rawState, testAccProvider.Meta())