From 22d8a4b764281ecc686cd7c43558da612d608e12 Mon Sep 17 00:00:00 2001
From: "Nelo-T. Wallus" <nelo@wallus.de>
Date: Thu, 9 May 2019 13:34:57 +0200
Subject: [PATCH] Return values from both data and error channels at once

The error channel is always being written to and closed last, reading
all values like this and returning them at once removes the need for if
clauses.
---
 cgo/command.go     |  9 ++-------
 cgo/connector.go   |  6 +++---
 cgo/statement.go   | 27 ++++++---------------------
 cgo/transaction.go |  9 ++-------
 4 files changed, 13 insertions(+), 38 deletions(-)

diff --git a/cgo/command.go b/cgo/command.go
index b845f23d..1999a6fd 100644
--- a/cgo/command.go
+++ b/cgo/command.go
@@ -81,14 +81,9 @@ func (conn *connection) execContext(ctx context.Context, query string) (*csComma
 		select {
 		case <-ctx.Done():
 			return nil, ctx.Err()
-		case cmd := <-recvCmd:
-			if cmd != nil {
-				return cmd, nil
-			}
 		case err := <-recvErr:
-			if err != nil {
-				return nil, err
-			}
+			cmd := <-recvCmd
+			return cmd, err
 		}
 	}
 }
diff --git a/cgo/connector.go b/cgo/connector.go
index 78dd4c9a..4b18278d 100644
--- a/cgo/connector.go
+++ b/cgo/connector.go
@@ -33,6 +33,7 @@ func NewConnector(dsn libdsn.DsnInfo) (driver.Connector, error) {
 		driverCtx.drop()
 		return nil, fmt.Errorf("Failed to open connection: %v", err)
 	}
+
 	defer func() {
 		// In- and decrease connections count before and after closing
 		// connection to prevent the context being deallocated.
@@ -64,10 +65,9 @@ func (connector *connector) Connect(ctx context.Context) (driver.Conn, error) {
 			}
 		}()
 		return nil, ctx.Err()
-	case conn := <-connChan:
-		return conn, nil
 	case err := <-errChan:
-		return nil, err
+		conn := <-connChan
+		return conn, err
 	}
 }
 
diff --git a/cgo/statement.go b/cgo/statement.go
index 3e0d8633..f10e6665 100644
--- a/cgo/statement.go
+++ b/cgo/statement.go
@@ -60,14 +60,9 @@ func (conn *connection) PrepareContext(ctx context.Context, query string) (drive
 				}
 			}()
 			return nil, ctx.Err()
-		case stmt := <-recvStmt:
-			if stmt != nil {
-				return stmt, nil
-			}
 		case err := <-recvErr:
-			if err != nil {
-				return nil, err
-			}
+			stmt := <-recvStmt
+			return stmt, err
 		}
 	}
 }
@@ -291,14 +286,9 @@ func (stmt *statement) ExecContext(ctx context.Context, args []driver.NamedValue
 		select {
 		case <-ctx.Done():
 			return nil, ctx.Err()
-		case res := <-recvResult:
-			if res != nil {
-				return res, nil
-			}
 		case err := <-recvErr:
-			if err != nil {
-				return nil, err
-			}
+			res := <-recvResult
+			return res, err
 		}
 	}
 }
@@ -343,14 +333,9 @@ func (stmt *statement) QueryContext(ctx context.Context, args []driver.NamedValu
 				}
 			}()
 			return nil, ctx.Err()
-		case rows := <-recvRows:
-			if rows != nil {
-				return rows, nil
-			}
 		case err := <-recvErr:
-			if err != nil {
-				return nil, err
-			}
+			rows := <-recvRows
+			return rows, err
 		}
 	}
 }
diff --git a/cgo/transaction.go b/cgo/transaction.go
index cd361929..5239e9f6 100644
--- a/cgo/transaction.go
+++ b/cgo/transaction.go
@@ -55,14 +55,9 @@ func (conn *connection) BeginTx(ctx context.Context, opts driver.TxOptions) (dri
 				}
 			}()
 			return nil, ctx.Err()
-		case tx := <-recvTx:
-			if tx != nil {
-				return tx, nil
-			}
 		case err := <-recvErr:
-			if err != nil {
-				return nil, err
-			}
+			tx := <-recvTx
+			return tx, err
 		}
 	}
 }