fix(adapter,executor,tests): harden nimforum adapter and fix transaction/aggregate bugs

Adapter (baradb_sqlite.nim):
- getRow now returns @[] for missing rows (db_sqlite compat)
- insertID/nextId handle NULL (\N) values correctly
- preprocessQuery replaces SQLite-specific syntax:
  TIMESTAMP->DATETIME, DATETIME('now')->current timestamp, INET->STRING
- add dbBegin/dbCommit/dbRollback for transaction support

Executor:
- fix COMMIT treating empty values as DELETE (rows with only PK were lost)
- fix MIN/MAX aggregates including NULL (\N) which skewed results
- add numeric comparison for irNeq

Tests:
- stress_test: shared DB, 16 workers, correctness scan after run
- nimforum_smoke_test: 10 tests including schema, transactions, iterators

tests/nimforum_smoke_test.nim

@@ -1,8 +1,7 @@
-## NimForum Adapter Smoke Test
+## NimForum Adapter Smoke Test — comprehensive validation
 import std/unittest
 import std/osproc
 import std/os
-import std/strutils
 import std/strtabs
 import std/times
 
@@ -24,7 +23,23 @@ suite "NimForum Adapter Smoke Test":
     env["BARADB_DATA_DIR"] = dataDir
     env["BARADB_LOG_LEVEL"] = "error"
     serverProcess = startProcess("./build/baradadb", env=env, options={poStdErrToStdOut, poDaemon})
-    sleep(800)
+    # Wait for server to be ready (with timeout)
+    var pingDb: DbConn
+    var connected = false
+    for i in 0 ..< 50:
+      sleep(100)
+      try:
+        pingDb = open("127.0.0.1:" & $port, "", "", "default")
+        connected = true
+        break
+      except:
+        discard
+    if not connected:
+      serverProcess.terminate()
+      discard serverProcess.waitForExit()
+      removeDir(dataDir)
+      raise newException(IOError, "Server failed to start")
+    pingDb.close()
 
   teardown:
     if serverProcess != nil:
@@ -67,3 +82,170 @@ suite "NimForum Adapter Smoke Test":
     check row[row.len - 1] == "ten"
 
     db.close()
+
+  test "getRow returns @[] for missing rows":
+    var db = open("127.0.0.1:" & $port, "", "", "default")
+    db.exec(sql"CREATE TABLE nf_missing (id INT PRIMARY KEY)")
+    let row = db.getRow(sql"SELECT * FROM nf_missing WHERE id = 999")
+    check row.len == 0
+    db.close()
+
+  test "insertID and nextId":
+    var db = open("127.0.0.1:" & $port, "", "", "default")
+    db.exec(sql"CREATE TABLE nf_ids (id INT PRIMARY KEY, name STRING)")
+
+    let id1 = db.insertID(sql"INSERT INTO nf_ids (id, name) VALUES (5, 'five')")
+    check id1 == 5
+
+    let next = db.nextId("nf_ids")
+    check next == 6
+
+    db.close()
+
+  test "Transactions (BEGIN/COMMIT/ROLLBACK)":
+    var db = open("127.0.0.1:" & $port, "", "", "default")
+    db.exec(sql"CREATE TABLE nf_txn (id INT PRIMARY KEY)")
+
+    db.dbBegin()
+    db.exec(sql"INSERT INTO nf_txn (id) VALUES (1)")
+    db.dbCommit()
+    check db.getValue(sql"SELECT count(*) FROM nf_txn") == "1"
+
+    db.dbBegin()
+    db.exec(sql"INSERT INTO nf_txn (id) VALUES (2)")
+    db.dbRollback()
+    check db.getValue(sql"SELECT count(*) FROM nf_txn") == "1"
+
+    db.close()
+
+  test "fastRows iterator":
+    var db = open("127.0.0.1:" & $port, "", "", "default")
+    db.exec(sql"CREATE TABLE nf_iter (id INT PRIMARY KEY)")
+    db.exec(sql"INSERT INTO nf_iter (id) VALUES (1)")
+    db.exec(sql"INSERT INTO nf_iter (id) VALUES (2)")
+    db.exec(sql"INSERT INTO nf_iter (id) VALUES (3)")
+
+    var count = 0
+    for r in db.fastRows(sql"SELECT id FROM nf_iter ORDER BY id"):
+      count.inc
+    check count == 3
+
+    db.close()
+
+  test "execAffectedRows":
+    var db = open("127.0.0.1:" & $port, "", "", "default")
+    db.exec(sql"CREATE TABLE nf_aff (id INT PRIMARY KEY, name STRING)")
+    db.exec(sql"INSERT INTO nf_aff (id, name) VALUES (1, 'a')")
+    db.exec(sql"INSERT INTO nf_aff (id, name) VALUES (2, 'b')")
+
+    let affected = db.execAffectedRows(sql"DELETE FROM nf_aff WHERE id = 1")
+    check affected == 1
+
+    db.close()
+
+  test "tryExec success and failure":
+    var db = open("127.0.0.1:" & $port, "", "", "default")
+    db.exec(sql"CREATE TABLE nf_try (id INT PRIMARY KEY)")
+
+    check db.tryExec(sql"INSERT INTO nf_try (id) VALUES (1)") == true
+    check db.tryExec(sql"INSERT INTO nf_try (id) VALUES (1)") == false
+
+    db.close()
+
+  test "NimForum schema creation":
+    var db = open("127.0.0.1:" & $port, "", "", "default")
+
+    # Create nimforum-like schema (adapter preprocesses DATETIME/TIMESTAMP/INET)
+    db.exec(sql"""
+      CREATE TABLE thread (
+        id INT PRIMARY KEY,
+        name STRING NOT NULL,
+        views INT NOT NULL,
+        modified DATETIME NOT NULL DEFAULT DATETIME('now')
+      )
+    """)
+    db.exec(sql"CREATE UNIQUE INDEX ThreadNameIx ON thread (name)")
+
+    db.exec(sql"""
+      CREATE TABLE person (
+        id INT PRIMARY KEY,
+        name STRING NOT NULL,
+        password STRING NOT NULL,
+        email STRING NOT NULL,
+        creation DATETIME NOT NULL DEFAULT DATETIME('now'),
+        salt STRING NOT NULL,
+        user_status STRING NOT NULL,
+        lastOnline DATETIME NOT NULL DEFAULT DATETIME('now'),
+        ban STRING NOT NULL DEFAULT ''
+      )
+    """)
+    db.exec(sql"CREATE UNIQUE INDEX UserNameIx ON person (name)")
+
+    db.exec(sql"""
+      CREATE TABLE post (
+        id INT PRIMARY KEY,
+        author INT NOT NULL,
+        ip STRING NOT NULL,
+        header STRING NOT NULL,
+        content STRING NOT NULL,
+        thread INT NOT NULL,
+        creation DATETIME NOT NULL DEFAULT DATETIME('now')
+      )
+    """)
+
+    db.exec(sql"""
+      CREATE TABLE session (
+        id INT PRIMARY KEY,
+        ip STRING NOT NULL,
+        password STRING NOT NULL,
+        userid INT NOT NULL,
+        lastModified DATETIME NOT NULL DEFAULT DATETIME('now')
+      )
+    """)
+
+    db.exec(sql"""
+      CREATE TABLE antibot (
+        id INT PRIMARY KEY,
+        ip STRING NOT NULL,
+        answer STRING NOT NULL,
+        created DATETIME NOT NULL DEFAULT DATETIME('now')
+      )
+    """)
+
+    db.exec(sql"CREATE INDEX PersonStatusIdx ON person(user_status)")
+    db.exec(sql"CREATE INDEX PostByAuthorIdx ON post(thread, author)")
+
+    # Insert and query forum data
+    db.exec(sql"INSERT INTO thread (id, name, views) VALUES (1, 'First Thread', 0)")
+    db.exec(sql"INSERT INTO person (id, name, password, email, salt, user_status, ban) VALUES (1, 'admin', 'pw', 'a@b.c', 'salt', 'active', '')")
+    db.exec(sql"INSERT INTO post (id, author, ip, header, content, thread) VALUES (1, 1, '127.0.0.1', 'Hello', 'World', 1)")
+
+    let threads = db.getAllRows(sql"SELECT * FROM thread")
+    check threads.len == 1
+
+    let posts = db.getAllRows(sql"SELECT * FROM post WHERE thread = 1")
+    check posts.len == 1
+
+    db.close()
+
+  test "NimForum-like operations":
+    var db = open("127.0.0.1:" & $port, "", "", "default")
+
+    db.exec(sql"CREATE TABLE nf_ops (id INT PRIMARY KEY, views INT NOT NULL)")
+    db.exec(sql"INSERT INTO nf_ops (id, views) VALUES (1, 0)")
+
+    # Update views (like nimforum does)
+    let affected = db.execAffectedRows(sql"UPDATE nf_ops SET views = views + 1 WHERE id = 1")
+    check affected == 1
+
+    let views = db.getValue(sql"SELECT views FROM nf_ops WHERE id = 1")
+    check views == "1"
+
+    # Try update with DATETIME('now') (preprocessed by adapter)
+    db.exec(sql"CREATE TABLE nf_dt (id INT PRIMARY KEY, modified DATETIME)")
+    db.exec(sql"INSERT INTO nf_dt (id, modified) VALUES (1, DATETIME('now'))")
+    let dtRow = db.getRow(sql"SELECT modified FROM nf_dt WHERE id = 1")
+    check dtRow.len == 1
+    check dtRow[0].len > 0
+
+    db.close()

tests/stress_test.nim

@@ -1,73 +1,104 @@
-## Stress Test — parallel workloads against LSM-Tree
-## Each worker gets its own LSMTree instance (thread-safe via internal locks).
+## Stress Test — parallel workloads against shared LSM-Tree
+## Validates correctness under concurrent access.
 import std/os
 import std/random
+import std/strutils
 import std/times
 import std/monotimes
+import std/locks
 import barabadb/storage/lsm
 
 const
-  NumWorkers = 10
-  OpsPerWorker = 1000
-  KeySpace = 500
+  NumWorkers = 16
+  OpsPerWorker = 2000
+  KeySpace = 1000
 
 type
   WorkerArgs = tuple
     workerId: int
-    dataDir: string
+    db: ptr LSMTree
     errors: ptr int
+    lock: ptr Lock
 
 randomize()
 
 proc runWorker(args: WorkerArgs) {.thread.} =
-  var db: LSMTree
   var localErrors = 0
-  {.cast(gcsafe).}:
-    db = newLSMTree(args.dataDir)
+  var rng = initRand(args.workerId)
 
   for i in 0 ..< OpsPerWorker:
-    let op = rand(0 .. 2)
-    let key = "key_" & $args.workerId & "_" & $(rand(0 ..< KeySpace))
+    let op = rng.rand(0 .. 3)
+    let key = "key_" & $(rng.rand(0 ..< KeySpace))
     let value = cast[seq[byte]]("val_" & $i & "_" & $args.workerId)
 
     case op
     of 0:
-      db.put(key, value)
+      # Put
+      acquire(args.lock[])
+      try:
+        args.db[].put(key, value)
+      except:
+        localErrors.inc
+      finally:
+        release(args.lock[])
     of 1:
-      let (found, val) = db.get(key)
+      # Get and verify (if found, value should be from some worker)
+      acquire(args.lock[])
+      var found = false
+      var val: seq[byte]
+      try:
+        (found, val) = args.db[].get(key)
+      except:
+        localErrors.inc
+      finally:
+        release(args.lock[])
       if found:
-        if val != value and val.len > 0:
-          discard
+        let valStr = cast[string](val)
+        if not valStr.startsWith("val_"):
+          localErrors.inc
     of 2:
-      db.delete(key)
+      # Delete
+      acquire(args.lock[])
+      try:
+        args.db[].delete(key)
+      except:
+        localErrors.inc
+      finally:
+        release(args.lock[])
+    of 3:
+      # Overwrite
+      acquire(args.lock[])
+      try:
+        args.db[].put(key, value)
+      except:
+        localErrors.inc
+      finally:
+        release(args.lock[])
     else:
       discard
 
-  for k in 0 ..< KeySpace:
-    let key = "key_" & $args.workerId & "_" & $k
-    let (found, _) = db.get(key)
-    discard found
-
-  db.close()
   args.errors[] = localErrors
 
 proc main() =
-  let baseDir = "/tmp/baradb_stress_test"
+  let baseDir = "/tmp/baradb_stress_test_shared"
   removeDir(baseDir)
   createDir(baseDir)
 
   let start = getMonoTime()
 
-  var workerDirs: seq[string] = @[]
-  for i in 0 ..< NumWorkers:
-    workerDirs.add(baseDir / "worker_" & $i)
+  # Single shared database
+  var db = newLSMTree(baseDir)
+  var dbPtr = addr db
+  var dbLock: Lock
+  initLock(dbLock)
+  var lockPtr = addr dbLock
 
   # Run workers in parallel using std/threads
   var threadArr: array[NumWorkers, Thread[WorkerArgs]]
   var errorCounts: array[NumWorkers, int]
 
   for i in 0 ..< NumWorkers:
-    let args: WorkerArgs = (workerId: i, dataDir: workerDirs[i], errors: addr errorCounts[i])
+    let args: WorkerArgs = (workerId: i, db: dbPtr, errors: addr errorCounts[i], lock: lockPtr)
     createThread(threadArr[i], runWorker, args)
 
   var totalErrors = 0
@@ -75,15 +106,28 @@ proc main() =
     joinThread(threadArr[i])
     totalErrors += errorCounts[i]
 
+  # Verify: scan all keys and ensure no corruption
+  var scanErrors = 0
+  for k in 0 ..< KeySpace:
+    let key = "key_" & $k
+    let (found, val) = db.get(key)
+    if found:
+      let valStr = cast[string](val)
+      if not valStr.startsWith("val_"):
+        scanErrors.inc
+
+  db.close()
+
   let elapsed = (getMonoTime() - start).inMilliseconds
   let totalOps = NumWorkers * OpsPerWorker
 
   echo "Stress test completed: ", totalOps, " ops across ", NumWorkers, " workers"
   echo "Time: ", elapsed, " ms"
   echo "Throughput: ", float(totalOps) / (float(elapsed) / 1000.0), " ops/sec"
-  echo "Errors: ", totalErrors
+  echo "Runtime errors: ", totalErrors
+  echo "Scan errors: ", scanErrors
 
-  if totalErrors > 0:
+  if totalErrors > 0 or scanErrors > 0:
     quit(1)
 
   removeDir(baseDir)