refactor(sep31): optimize sep31 customer id owner claim

* update sep31 customer id owner store to avoid unnecessary database lookup on successful claim

* refactor `created_at` column type in sep31 customer id owner table to `timestamp without time zone`

* add test case for `illegalstateexception` when sep31 customer id owner row is missing after non-inserting claim

* update test cases to verify sep31 claim optimization and non-inserting scenarios

Author: amandagonsalves

platform/src/main/java/org/stellar/anchor/platform/data/JdbcSep31CustomerIdOwnerStore.java

@@ -12,13 +12,16 @@ public JdbcSep31CustomerIdOwnerStore(JdbcSep31CustomerIdOwnerRepo repo) {
 
   @Override
   public boolean verifyOrClaim(String customerId, String creatorAccount, String creatorMemo) {
-    repo.claimIfAbsent(customerId, creatorAccount, creatorMemo);
+    if (repo.claimIfAbsent(customerId, creatorAccount, creatorMemo) == 1) {
+      return true;
+    }
+
     JdbcSep31CustomerIdOwner owner =
         repo.findById(customerId)
             .orElseThrow(
                 () ->
                     new IllegalStateException(
-                        "sep31_customer_id_owner row missing immediately after claim for id="
+                        "sep31_customer_id_owner row missing after a non-inserting claim for id="
                             + customerId));
 
     return Objects.equals(owner.getCreatorAccount(), creatorAccount)

platform/src/main/resources/db/migration/V29__sep31_customer_id_owner.sql

@@ -2,5 +2,5 @@ CREATE TABLE sep31_customer_id_owner (
     customer_id     VARCHAR(255) NOT NULL PRIMARY KEY,
     creator_account VARCHAR(255) NOT NULL,
     creator_memo    VARCHAR(255),
-    created_at      TIMESTAMP NOT NULL DEFAULT now()
+    created_at      TIMESTAMP WITHOUT TIME ZONE NOT NULL DEFAULT now()
 );

platform/src/test/kotlin/org/stellar/anchor/platform/data/JdbcSep31CustomerIdOwnerStoreTest.kt

@@ -29,12 +29,12 @@ class JdbcSep31CustomerIdOwnerStoreTest {
     }
 
   @Test
-  fun `first claim of a customer id succeeds`() {
+  fun `first claim of a customer id succeeds without a follow-up lookup`() {
     every { repo.claimIfAbsent("cust-1", "GALICE", "111") } returns 1
-    every { repo.findById("cust-1") } returns Optional.of(ownerRow("cust-1", "GALICE", "111"))
 
     assertTrue(store.verifyOrClaim("cust-1", "GALICE", "111"))
     verify(exactly = 1) { repo.claimIfAbsent("cust-1", "GALICE", "111") }
+    verify(exactly = 0) { repo.findById(any()) }
   }
 
   @Test
@@ -43,6 +43,7 @@ class JdbcSep31CustomerIdOwnerStoreTest {
     every { repo.findById("cust-1") } returns Optional.of(ownerRow("cust-1", "GALICE", "111"))
 
     assertTrue(store.verifyOrClaim("cust-1", "GALICE", "111"))
+    verify(exactly = 1) { repo.findById("cust-1") }
   }
 
   @Test
@@ -54,10 +55,20 @@ class JdbcSep31CustomerIdOwnerStoreTest {
   }
 
   @Test
-  fun `null memo is compared correctly`() {
-    every { repo.claimIfAbsent("cust-1", "GALICE", null) } returns 1
+  fun `null memo is compared correctly on the conflict path`() {
+    every { repo.claimIfAbsent("cust-1", "GALICE", null) } returns 0
     every { repo.findById("cust-1") } returns Optional.of(ownerRow("cust-1", "GALICE", null))
 
     assertTrue(store.verifyOrClaim("cust-1", "GALICE", null))
   }
+
+  @Test
+  fun `throws if the row is missing after a non-inserting claim`() {
+    every { repo.claimIfAbsent("cust-1", "GALICE", "111") } returns 0
+    every { repo.findById("cust-1") } returns Optional.empty()
+
+    assertThrows(IllegalStateException::class.java) {
+      store.verifyOrClaim("cust-1", "GALICE", "111")
+    }
+  }
 }