addressing the comments

add copy methods to the Tx struct

conn_pool.go

@@ -542,26 +542,26 @@ func (p *ConnPool) CopyFrom(tableName Identifier, columnNames []string, rowSrc C
 	return c.CopyFrom(tableName, columnNames, rowSrc)
 }
 
-// CopyFromTextual acquires a connection, delegates the call to that connection, and releases the connection
+// CopyFromReader acquires a connection, delegates the call to that connection, and releases the connection
-func (p *ConnPool) CopyFromTextual(r io.Reader, sql string, args ...interface{}) error {
+func (p *ConnPool) CopyFromReader(r io.Reader, sql string) error {
 	c, err := p.Acquire()
 	if err != nil {
 		return err
 	}
 	defer p.Release(c)
 
-	return c.CopyFromTextual(r, sql, args...)
+	return c.CopyFromReader(r, sql)
 }
 
-// CopyToTextual acquires a connection, delegates the call to that connection, and releases the connection
+// CopyToWriter acquires a connection, delegates the call to that connection, and releases the connection
-func (p *ConnPool) CopyToTextual(w io.Writer, sql string, args ...interface{}) error {
+func (p *ConnPool) CopyToWriter(w io.Writer, sql string, args ...interface{}) error {
 	c, err := p.Acquire()
 	if err != nil {
 		return err
 	}
 	defer p.Release(c)
 
-	return c.CopyToTextual(w, sql, args...)
+	return c.CopyToWriter(w, sql, args...)
 }
 
 // BeginBatch acquires a connection and begins a batch on that connection. When

copy_from.go

@@ -283,9 +283,9 @@ func (c *Conn) CopyFrom(tableName Identifier, columnNames []string, rowSrc CopyF
 	return ct.run()
 }
 
-// CopyFromTextual uses the PostgreSQL textual format of the copy protocol
+// CopyFromReader uses the PostgreSQL textual format of the copy protocol
-func (c *Conn) CopyFromTextual(r io.Reader, sql string, args ...interface{}) error {
+func (c *Conn) CopyFromReader(r io.Reader, sql string) error {
-	if err := c.sendSimpleQuery(sql, args...); err != nil {
+	if err := c.sendSimpleQuery(sql); err != nil {
 		return err
 	}
 

copy_from_test.go

@@ -67,8 +67,8 @@ func TestConnCopyFromSmall(t *testing.T) {
 
 	mustExec(t, conn, "truncate foo")
 
-	if err := conn.CopyFromTextual(inputReader, "copy foo from stdin"); err != nil {
+	if err := conn.CopyFromReader(inputReader, "copy foo from stdin"); err != nil {
-		t.Errorf("Unexpected error for CopyFromTextual: %v", err)
+		t.Errorf("Unexpected error for CopyFromReader: %v", err)
 	}
 
 	rows, err = conn.Query("select * from foo")
@@ -155,8 +155,8 @@ func TestConnCopyFromLarge(t *testing.T) {
 
 	mustExec(t, conn, "truncate foo")
 
-	if err := conn.CopyFromTextual(strings.NewReader(inputStringRows), "copy foo from stdin"); err != nil {
+	if err := conn.CopyFromReader(strings.NewReader(inputStringRows), "copy foo from stdin"); err != nil {
-		t.Errorf("Unexpected error for CopyFromTextual: %v", err)
+		t.Errorf("Unexpected error for CopyFromReader: %v", err)
 	}
 
 	rows, err = conn.Query("select * from foo")
@@ -239,7 +239,7 @@ func TestConnCopyFromJSON(t *testing.T) {
 
 	mustExec(t, conn, "truncate foo")
 
-	if err := conn.CopyFromTextual(inputReader, "copy foo from stdin"); err != nil {
+	if err := conn.CopyFromReader(inputReader, "copy foo from stdin"); err != nil {
 		t.Errorf("Unexpected error for CopyFrom: %v", err)
 	}
 
@@ -343,12 +343,12 @@ func TestConnCopyFromFailServerSideMidway(t *testing.T) {
 
 	mustExec(t, conn, "truncate foo")
 
-	err = conn.CopyFromTextual(inputReader, "copy foo from stdin")
+	err = conn.CopyFromReader(inputReader, "copy foo from stdin")
 	if err == nil {
-		t.Errorf("Expected CopyFromTextual return error, but it did not")
+		t.Errorf("Expected CopyFromReader return error, but it did not")
 	}
 	if _, ok := err.(pgx.PgError); !ok {
-		t.Errorf("Expected CopyFromTextual return pgx.PgError, but instead it returned: %v", err)
+		t.Errorf("Expected CopyFromReader return pgx.PgError, but instead it returned: %v", err)
 	}
 
 	rows, err = conn.Query("select * from foo")
@@ -600,7 +600,7 @@ func TestConnCopyFromCopyFromSourceNextPanic(t *testing.T) {
 	}
 }
 
-func TestConnCopyFromTextualQueryError(t *testing.T) {
+func TestConnCopyFromReaderQueryError(t *testing.T) {
 	t.Parallel()
 
 	conn := mustConnect(t, *defaultConnConfig)
@@ -608,19 +608,19 @@ func TestConnCopyFromTextualQueryError(t *testing.T) {
 
 	inputReader := strings.NewReader("")
 
-	err := conn.CopyFromTextual(inputReader, "cropy foo from stdin")
+	err := conn.CopyFromReader(inputReader, "cropy foo from stdin")
 	if err == nil {
-		t.Errorf("Expected CopyFromTextual return error, but it did not")
+		t.Errorf("Expected CopyFromReader return error, but it did not")
 	}
 
 	if _, ok := err.(pgx.PgError); !ok {
-		t.Errorf("Expected CopyFromTextual return pgx.PgError, but instead it returned: %v", err)
+		t.Errorf("Expected CopyFromReader return pgx.PgError, but instead it returned: %v", err)
 	}
 
 	ensureConnValid(t, conn)
 }
 
-func TestConnCopyFromTextualNoTableError(t *testing.T) {
+func TestConnCopyFromReaderNoTableError(t *testing.T) {
 	t.Parallel()
 
 	conn := mustConnect(t, *defaultConnConfig)
@@ -628,13 +628,13 @@ func TestConnCopyFromTextualNoTableError(t *testing.T) {
 
 	inputReader := strings.NewReader("")
 
-	err := conn.CopyFromTextual(inputReader, "copy foo from stdin")
+	err := conn.CopyFromReader(inputReader, "copy foo from stdin")
 	if err == nil {
-		t.Errorf("Expected CopyFromTextual return error, but it did not")
+		t.Errorf("Expected CopyFromReader return error, but it did not")
 	}
 
 	if _, ok := err.(pgx.PgError); !ok {
-		t.Errorf("Expected CopyFromTextual return pgx.PgError, but instead it returned: %v", err)
+		t.Errorf("Expected CopyFromReader return pgx.PgError, but instead it returned: %v", err)
 	}
 
 	ensureConnValid(t, conn)

copy_to.go

@@ -25,7 +25,7 @@ func (c *Conn) readUntilCopyOutResponse() error {
 	}
 }
 
-func (c *Conn) CopyToTextual(w io.Writer, sql string, args ...interface{}) error {
+func (c *Conn) CopyToWriter(w io.Writer, sql string, args ...interface{}) error {
 	if err := c.sendSimpleQuery(sql, args...); err != nil {
 		return err
 	}

copy_to_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/jackc/pgx"
 )
 
-func TestConnCopyToTextualSmall(t *testing.T) {
+func TestConnCopyToWriterSmall(t *testing.T) {
 	t.Parallel()
 
 	conn := mustConnect(t, *defaultConnConfig)
@@ -30,8 +30,8 @@ func TestConnCopyToTextualSmall(t *testing.T) {
 
 	outputWriter := bytes.NewBuffer(make([]byte, 0, len(inputBytes)))
 
-	if err := conn.CopyToTextual(outputWriter, "copy foo to stdout"); err != nil {
+	if err := conn.CopyToWriter(outputWriter, "copy foo to stdout"); err != nil {
-		t.Errorf("Unexpected error for CopyToTextual: %v", err)
+		t.Errorf("Unexpected error for CopyToWriter: %v", err)
 	}
 
 	if i := bytes.Compare(inputBytes, outputWriter.Bytes()); i != 0 {
@@ -41,7 +41,7 @@ func TestConnCopyToTextualSmall(t *testing.T) {
 	ensureConnValid(t, conn)
 }
 
-func TestConnCopyToTextualLarge(t *testing.T) {
+func TestConnCopyToWriterLarge(t *testing.T) {
 	t.Parallel()
 
 	conn := mustConnect(t, *defaultConnConfig)
@@ -66,7 +66,7 @@ func TestConnCopyToTextualLarge(t *testing.T) {
 
 	outputWriter := bytes.NewBuffer(make([]byte, 0, len(inputBytes)))
 
-	if err := conn.CopyToTextual(outputWriter, "copy foo to stdout"); err != nil {
+	if err := conn.CopyToWriter(outputWriter, "copy foo to stdout"); err != nil {
 		t.Errorf("Unexpected error for CopyFrom: %v", err)
 	}
 
@@ -77,7 +77,7 @@ func TestConnCopyToTextualLarge(t *testing.T) {
 	ensureConnValid(t, conn)
 }
 
-func TestConnCopyToTextualQueryError(t *testing.T) {
+func TestConnCopyToWriterQueryError(t *testing.T) {
 	t.Parallel()
 
 	conn := mustConnect(t, *defaultConnConfig)
@@ -85,13 +85,13 @@ func TestConnCopyToTextualQueryError(t *testing.T) {
 
 	outputWriter := bytes.NewBuffer(make([]byte, 0))
 
-	err := conn.CopyToTextual(outputWriter, "cropy foo to stdout")
+	err := conn.CopyToWriter(outputWriter, "cropy foo to stdout")
 	if err == nil {
-		t.Errorf("Expected CopyFromTextual return error, but it did not")
+		t.Errorf("Expected CopyFromReader return error, but it did not")
 	}
 
 	if _, ok := err.(pgx.PgError); !ok {
-		t.Errorf("Expected CopyFromTextual return pgx.PgError, but instead it returned: %v", err)
+		t.Errorf("Expected CopyFromReader return pgx.PgError, but instead it returned: %v", err)
 	}
 
 	ensureConnValid(t, conn)

tx.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"io"
 	"time"
 
 	"github.com/pkg/errors"
@@ -237,6 +238,24 @@ func (tx *Tx) CopyFrom(tableName Identifier, columnNames []string, rowSrc CopyFr
 	return tx.conn.CopyFrom(tableName, columnNames, rowSrc)
 }
 
+// CopyFromReader delegates to the underlying *Conn
+func (tx *Tx) CopyFromReader(r io.Reader, sql string) error {
+	if tx.status != TxStatusInProgress {
+		return ErrTxClosed
+	}
+
+	return tx.conn.CopyFromReader(r, sql)
+}
+
+// CopyToWriter delegates to the underlying *Conn
+func (tx *Tx) CopyToWriter(w io.Writer, sql string, args ...interface{}) error {
+	if tx.status != TxStatusInProgress {
+		return ErrTxClosed
+	}
+
+	return tx.conn.CopyToWriter(w, sql, args...)
+}
+
 // Status returns the status of the transaction from the set of
 // pgx.TxStatus* constants.
 func (tx *Tx) Status() int8 {