Improve error reporting for connection closure, invalid query syntax,…

… and unique constraint violations. (#68)
vapor · Dec 6, 2021 · f0e8ad7 · f0e8ad7
1 parent 03cc5d4
commit f0e8ad7
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Showing 5 changed files with 45 additions and 20 deletions.
diff --git a/Sources/MySQLNIO/MySQLConnection.swift b/Sources/MySQLNIO/MySQLConnection.swift
@@ -71,7 +71,12 @@ public final class MySQLConnection: MySQLDatabase {
     }
 
     public func send(_ command: MySQLCommand, logger: Logger) -> EventLoopFuture<Void> {
+        guard self.channel.isActive else {
+            return self.channel.eventLoop.makeFailedFuture(MySQLError.closed)
+        }
+
         let promise = self.eventLoop.makePromise(of: Void.self)
+
         let c = MySQLCommandContext(
             handler: command,
             promise: promise

diff --git a/Sources/MySQLNIO/MySQLError.swift b/Sources/MySQLNIO/MySQLError.swift
@@ -15,6 +15,9 @@ public enum MySQLError: Error, CustomStringConvertible, LocalizedError {
     /// A uniqueness constraint was violated. Associated value is message from server with details.
     case duplicateEntry(String)
 
+    /// A syntax error occurred in a query. Associated value is message from server with details.
+    case invalidSyntax(String)
+
     public var message: String {
         switch self {
         case .secureConnectionRequired:
@@ -39,6 +42,8 @@ public enum MySQLError: Error, CustomStringConvertible, LocalizedError {
             return "Connection closed."
         case .duplicateEntry(let message):
             return "Duplicate entry: \(message)"
+        case .invalidSyntax(let message):
+            return "Invalid syntax: \(message)"
         }
     }
 

diff --git a/Sources/MySQLNIO/MySQLQueryCommand.swift b/Sources/MySQLNIO/MySQLQueryCommand.swift
@@ -92,6 +92,8 @@ private final class MySQLQueryCommand: MySQLCommand {
             switch errorPacket.errorCode {
             case .DUP_ENTRY:
                 error = MySQLError.duplicateEntry(errorPacket.errorMessage)
+            case .PARSE_ERROR:
+                error = MySQLError.invalidSyntax(errorPacket.errorMessage)
             default:
                 error = MySQLError.server(errorPacket)
             }

diff --git a/Sources/MySQLNIO/MySQLSimpleQueryCommand.swift b/Sources/MySQLNIO/MySQLSimpleQueryCommand.swift
@@ -38,8 +38,17 @@ private final class MySQLSimpleQueryCommand: MySQLCommand {
         // print("QUERY \(state): \(packet.payload.debugDescription)")
         guard !packet.isError else {
             self.state = .done
-            let error = try packet.decode(MySQLProtocol.ERR_Packet.self, capabilities: capabilities)
-            throw MySQLError.server(error)
+            let errorPacket = try packet.decode(MySQLProtocol.ERR_Packet.self, capabilities: capabilities)
+            let error: Error
+            switch errorPacket.errorCode {
+            case .DUP_ENTRY:
+                error = MySQLError.duplicateEntry(errorPacket.errorMessage)
+            case .PARSE_ERROR:
+                error = MySQLError.invalidSyntax(errorPacket.errorMessage)
+            default:
+                error = MySQLError.server(errorPacket)
+            }
+            throw error
         }
         switch self.state {
         case .ready:

diff --git a/Tests/MySQLNIOTests/MySQLNIOTests.swift b/Tests/MySQLNIOTests/MySQLNIOTests.swift
@@ -108,35 +108,39 @@ final class MySQLNIOTests: XCTestCase {
     func testSimpleQuery_syntaxError() throws {
         let conn = try MySQLConnection.test(on: self.eventLoop).wait()
         defer { try! conn.close().wait() }
-        do {
-            _ = try conn.simpleQuery("SELECT &").wait()
-            XCTFail("should have thrown")
-        } catch let error as MySQLError {
-            switch error {
-            case .server(let packet):
-                XCTAssertEqual(packet.errorCode, .PARSE_ERROR)
-            default:
-                XCTFail("unexpected error type")
+        XCTAssertThrowsError(try conn.simpleQuery("SELECT &").wait()) { error in
+            guard case .invalidSyntax = error as? MySQLError else {
+                return XCTFail("Exected MySQLError.invalidSyntax, but found \(error)")
             }
         }
     }
 
     func testQuery_syntaxError() throws {
         let conn = try MySQLConnection.test(on: self.eventLoop).wait()
         defer { try! conn.close().wait() }
-        do {
-            _ = try conn.query("SELECT &").wait()
-            XCTFail("should have thrown")
-        } catch let error as MySQLError {
-            switch error {
-            case .server(let packet):
-                XCTAssertEqual(packet.errorCode, .PARSE_ERROR)
-            default:
-                XCTFail("unexpected error type")
+        XCTAssertThrowsError(try conn.query("SELECT &").wait()) { error in
+            guard case .invalidSyntax = error as? MySQLError else {
+                return XCTFail("Exected MySQLError.invalidSyntax, but found \(error)")
             }
         }
     }
 
+    func testSimpleQuery_duplicateEntry() throws {
+        let conn = try MySQLConnection.test(on: self.eventLoop).wait()
+        defer { try! conn.close().wait() }
+        let dropResults = try conn.simpleQuery("DROP TABLE IF EXISTS foos").wait()
+        XCTAssertEqual(dropResults.count, 0)
+        let createResults = try conn.simpleQuery("CREATE TABLE foos (id BIGINT SIGNED unique, name VARCHAR(64))").wait()
+        XCTAssertEqual(createResults.count, 0)
+        let insertResults = try conn.simpleQuery("INSERT INTO foos VALUES (1, 'one')").wait()
+        XCTAssertEqual(insertResults.count, 0)
+        XCTAssertThrowsError(try conn.query("INSERT INTO foos VALUES (1, 'two')").wait()) { error in
+            guard case .duplicateEntry = error as? MySQLError else {
+                return XCTFail("Expected MySQLError.duplicateEntry, but found \(error)")
+            }
+        }
+    }
+
     func testQuery_duplicateEntry() throws {
         let conn = try MySQLConnection.test(on: self.eventLoop).wait()
         defer { try! conn.close().wait() }