Merge pull request #1 from fred-sch/main

ClickHouseVapor fail safely if row count is inconsistent

Author: patrick-zippenfenig

Sources/ClickHouseVapor/ClickHouseColumnConvertible.swift

@@ -40,7 +40,7 @@ extension ClickHouseColumnConvertibleTyped {
 
     public func setClickHouseArray(_ data: [ClickHouseDataType]) throws {
         guard let array = data as? [Value] else {
-            throw ClickHouseVaporError.missmatchingDataType(columnName: key)
+            throw ClickHouseVaporError.mismatchingDataType(columnName: key)
         }
         self.wrappedValue = array
     }

Sources/ClickHouseVapor/ClickHouseModel.swift

@@ -64,17 +64,22 @@ extension ClickHouseModel {
         }
     }
 
-    public func insert(on connection: ClickHouseConnectionProtocol, engine: ClickHouseEngine? = nil)  -> EventLoopFuture<Void> {
+    public func insert(on connection: ClickHouseConnectionProtocol, engine: ClickHouseEngine? = nil)  throws -> EventLoopFuture<Void> {
         let fields = properties
         let engine = engine ?? Self.engine
-        let data = fields.compactMap {
-            return $0.count == 0 ? nil : ClickHouseColumn($0.key, $0.getClickHouseArray())
-        }
-        guard data.count > 0 else {
-            // no values -> nothing to do
+        
+        guard let rowCount = fields.first?.count else {
+            // no columns -> nothing to do
             return connection.eventLoop.makeSucceededFuture(())
         }
 
+        let data = try fields.compactMap { field -> ClickHouseColumn? in
+            // check that all columns have the same amount of rows
+            guard field.count == rowCount else {
+                throw ClickHouseVaporError.mismatchingRowCount(count: field.count, expected: rowCount)
+            }
+            return rowCount == 0 ? nil : ClickHouseColumn(field.key, field.getClickHouseArray())
+        }
         return connection.insert(into: engine.tableWithDatabase, data: data)
     }
 

Sources/ClickHouseVapor/ClickHouseVaporError.swift

@@ -6,5 +6,6 @@
 //
 
 public enum ClickHouseVaporError: Error {
-    case missmatchingDataType(columnName: String)
+    case mismatchingDataType(columnName: String)
+    case mismatchingRowCount(count: Int, expected: Int)
 }

Tests/ClickHouseVaporTests/ClickHouseVaporTests.swift

@@ -48,6 +48,13 @@ public class TestModel : ClickHouseModel {
 
 
 final class ClickHouseVaporTests: XCTestCase {
+    
+    static var allTests = [
+        ("testPing", testPing),
+        ("testModel", testModel),
+        ("testModelMissesColumns", testModelMissesColumns)
+    ]
+    
     func testPing() {
         let app = Application(.testing)
         defer { app.shutdown() }
@@ -103,8 +110,26 @@ final class ClickHouseVaporTests: XCTestCase {
         XCTAssertEqual(model3.id, model2.id)
         XCTAssertEqual(model3.timestamp, model2.timestamp)
     }
+    
+    /// model should fail if insert with empty columns is tried
+    public func testModelMissesColumns() {
+        let app = Application(.testing)
+        defer { app.shutdown() }
+        try! app.configureClickHouseDatabases()
+        app.logger.logLevel = .trace
+        
+        let model = TestModel()
+        
+        // drop table to ensure unit test
+        try! TestModel.deleteTable(on: app.clickHouse).wait()
+
+        
+        model.id = [ "x010", "ax51", "cd22" ]
+        model.fixed = [ "", "123456", "12345678901234" ]
+        model.temperature = [ 11.1, 10.4, 8.9 ]
+
+        try! TestModel.createTable(on: app.clickHouse).wait()
+        XCTAssertThrowsError(try model.insert(on: app.clickHouse).wait(), "\(ClickHouseVaporError.mismatchingRowCount(count: 0, expected: 3))")
+    }
 
-    static var allTests = [
-        ("testPing", testPing),
-    ]
 }