From 24ead40f88a52ccea43e2faed3f230d04890ccab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=EA=B9=80=EC=84=A0=EC=9A=B0?= <seonwoo960000@toss.im>
Date: Sun, 19 Jan 2025 21:34:20 +0900
Subject: [PATCH] Change `LimboStatement.java` to throw exception when the
 result is null which is the error case

---
 .../tursodatabase/core/LimboResultSet.java    |  6 +++++-
 .../tursodatabase/core/LimboStatement.java    |  8 +++++--
 .../tursodatabase/core/LimboStepResult.java   | 21 ++++++++++++++++++-
 .../jdbc4/JDBC4ResultSetTest.java             |  7 ++-----
 4 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/bindings/java/src/main/java/org/github/tursodatabase/core/LimboResultSet.java b/bindings/java/src/main/java/org/github/tursodatabase/core/LimboResultSet.java
index ebcbb8860..854e161b7 100644
--- a/bindings/java/src/main/java/org/github/tursodatabase/core/LimboResultSet.java
+++ b/bindings/java/src/main/java/org/github/tursodatabase/core/LimboResultSet.java
@@ -55,7 +55,11 @@ public class LimboResultSet {
         }
 
         lastStepResult = this.statement.step();
-        pastLastRow = lastStepResult == null || lastStepResult.isDone();
+        if (lastStepResult.isRow()) {
+            row++;
+        }
+
+        pastLastRow = lastStepResult.isDone();
         return !pastLastRow;
     }
 
diff --git a/bindings/java/src/main/java/org/github/tursodatabase/core/LimboStatement.java b/bindings/java/src/main/java/org/github/tursodatabase/core/LimboStatement.java
index 1cad05d14..f8c380247 100644
--- a/bindings/java/src/main/java/org/github/tursodatabase/core/LimboStatement.java
+++ b/bindings/java/src/main/java/org/github/tursodatabase/core/LimboStatement.java
@@ -38,9 +38,13 @@ public class LimboStatement {
         return resultSet.hasLastStepReturnedRow();
     }
 
-    @Nullable
     LimboStepResult step() throws SQLException {
-        return step(this.statementPointer);
+        final LimboStepResult result = step(this.statementPointer);
+        if (result == null) {
+            throw new SQLException("step() returned null, which is only returned when an error occurs");
+        }
+
+        return result;
     }
 
     @Nullable
diff --git a/bindings/java/src/main/java/org/github/tursodatabase/core/LimboStepResult.java b/bindings/java/src/main/java/org/github/tursodatabase/core/LimboStepResult.java
index f6a2119fd..7870cbeab 100644
--- a/bindings/java/src/main/java/org/github/tursodatabase/core/LimboStepResult.java
+++ b/bindings/java/src/main/java/org/github/tursodatabase/core/LimboStepResult.java
@@ -44,8 +44,27 @@ public class LimboStepResult {
     @Override
     public String toString() {
         return "LimboStepResult{" +
-               "stepResultId=" + stepResultId +
+               "stepResultName=" + getStepResultName() +
                ", result=" + Arrays.toString(result) +
                '}';
     }
+
+    private String getStepResultName() {
+        switch (stepResultId) {
+            case STEP_RESULT_ID_ROW:
+                return "ROW";
+            case STEP_RESULT_ID_IO:
+                return "IO";
+            case STEP_RESULT_ID_DONE:
+                return "DONE";
+            case STEP_RESULT_ID_INTERRUPT:
+                return "INTERRUPT";
+            case STEP_RESULT_ID_BUSY:
+                return "BUSY";
+            case STEP_RESULT_ID_ERROR:
+                return "ERROR";
+            default:
+                return "UNKNOWN";
+        }
+    }
 }
diff --git a/bindings/java/src/test/java/org/github/tursodatabase/jdbc4/JDBC4ResultSetTest.java b/bindings/java/src/test/java/org/github/tursodatabase/jdbc4/JDBC4ResultSetTest.java
index 2d10fdb32..46cf7e216 100644
--- a/bindings/java/src/test/java/org/github/tursodatabase/jdbc4/JDBC4ResultSetTest.java
+++ b/bindings/java/src/test/java/org/github/tursodatabase/jdbc4/JDBC4ResultSetTest.java
@@ -40,7 +40,7 @@ class JDBC4ResultSetTest {
     }
 
     @Test
-    @Disabled("https://github.com/tursodatabase/limbo/pull/743#issuecomment-2600746904")
+    // @Disabled("https://github.com/tursodatabase/limbo/pull/743#issuecomment-2600746904")
     void invoking_next_after_the_last_row_should_return_false() throws Exception {
         stmt.execute("CREATE TABLE users (id INT PRIMARY KEY, username TEXT);");
         stmt.execute("INSERT INTO users VALUES (1, 'sinwoo');");
@@ -50,11 +50,8 @@ class JDBC4ResultSetTest {
         stmt.execute("SELECT * FROM users");
         ResultSet resultSet = stmt.getResultSet();
 
-        long startTime = System.currentTimeMillis();
         while (resultSet.next()) {
-            if (System.currentTimeMillis() - startTime > 1000) {
-                throw new Exception("Should have finished now");
-            }
+            // run until next() returns false
         }
 
         // if the previous call to next() returned false, consecutive call to next() should return false as well