refactor GetEmptyPort into shared util

Author: angelamayxie

_example/main_test.go

@@ -17,9 +17,9 @@ package main
 import (
 	"database/sql"
 	"fmt"
-	"net"
 	"testing"
 
+	gms "github.com/dolthub/go-mysql-server/sql"
 	_ "github.com/go-sql-driver/mysql"
 	"github.com/gocraft/dbr/v2"
 	"github.com/stretchr/testify/assert"
@@ -35,7 +35,8 @@ var expectedResults = [][]string{
 
 func TestExampleUsersDisabled(t *testing.T) {
 	enableUsers = false
-	useUnusedPort(t)
+	_, err := gms.GetEmptyPort()
+	require.NoError(t, err)
 	go func() {
 		main()
 	}()
@@ -53,7 +54,8 @@ func TestExampleUsersDisabled(t *testing.T) {
 func TestExampleRootUserEnabled(t *testing.T) {
 	enableUsers = true
 	pretendThatFileExists = false
-	useUnusedPort(t)
+	_, err := gms.GetEmptyPort()
+	require.NoError(t, err)
 	go func() {
 		main()
 	}()
@@ -74,7 +76,8 @@ func TestExampleRootUserEnabled(t *testing.T) {
 func TestExampleLoadedUser(t *testing.T) {
 	enableUsers = true
 	pretendThatFileExists = true
-	useUnusedPort(t)
+	_, err := gms.GetEmptyPort()
+	require.NoError(t, err)
 	go func() {
 		main()
 	}()
@@ -99,7 +102,8 @@ func TestExampleLoadedUser(t *testing.T) {
 func TestIssue1621(t *testing.T) {
 	// This is an issue that is specific to using the example server, as this is not a logic issue but a setup issue
 	enableUsers = true
-	useUnusedPort(t)
+	_, err := gms.GetEmptyPort()
+	require.NoError(t, err)
 	go func() {
 		main()
 	}()
@@ -141,11 +145,3 @@ func checkRows(t *testing.T, expectedRows [][]string, actualRows *sql.Rows) {
 	}
 	assert.NoError(t, actualRows.Close())
 }
-
-func useUnusedPort(t *testing.T) {
-	// Tests should grab an open port, otherwise they'll fail if some hardcoded port is already in use
-	listener, err := net.Listen("tcp", ":0")
-	require.NoError(t, err)
-	port = listener.Addr().(*net.TCPAddr).Port
-	require.NoError(t, listener.Close())
-}

enginetest/engine_only_test.go

@@ -19,7 +19,6 @@ import (
 	sql2 "database/sql"
 	"fmt"
 	"io"
-	"net"
 	"runtime"
 	"strings"
 	"testing"
@@ -1051,7 +1050,7 @@ func TestAlterTableWithBadSchema(t *testing.T) {
 			ctx := harness.NewContext()
 			ctx.SetCurrentDatabase("mydb")
 			_, iter, _, err := engine.Query(ctx, tt.q)
-			// errors should be analyze time, not execution time
+			// errors should analyze time, not execution time
 			if tt.err {
 				require.Error(t, err)
 			} else {
@@ -1065,14 +1064,10 @@ func TestAlterTableWithBadSchema(t *testing.T) {
 
 func newDatabase() (*sql2.DB, func()) {
 	// Grab an empty port so that tests do not fail if a specific port is already in use
-	listener, err := net.Listen("tcp", ":0")
+	port, err := sql.GetEmptyPort()
 	if err != nil {
 		panic(err)
 	}
-	port := listener.Addr().(*net.TCPAddr).Port
-	if err = listener.Close(); err != nil {
-		panic(err)
-	}
 
 	harness := enginetest.NewDefaultMemoryHarness()
 	pro := harness.Provider()

enginetest/enginetests.go

@@ -20,7 +20,6 @@ import (
 	dsql "database/sql"
 	"fmt"
 	"io"
-	"net"
 	"os"
 	"reflect"
 	"strings"
@@ -2144,7 +2143,8 @@ func TestUserAuthentication(t *testing.T, h Harness) {
 	}
 	clientHarness.Setup(setup.MydbData, setup.MytableData)
 
-	port := getEmptyPort(t)
+	port, err := sql.GetEmptyPort()
+	require.NoError(t, err)
 	for _, script := range queries.ServerAuthTests {
 		t.Run(script.Name, func(t *testing.T) {
 			ctx := NewContextWithClient(clientHarness, sql.Client{
@@ -2240,14 +2240,6 @@ func TestUserAuthentication(t *testing.T, h Harness) {
 	}
 }
 
-func getEmptyPort(t *testing.T) int {
-	listener, err := net.Listen("tcp", ":0")
-	require.NoError(t, err)
-	port := listener.Addr().(*net.TCPAddr).Port
-	require.NoError(t, listener.Close())
-	return port
-}
-
 func TestComplexIndexQueries(t *testing.T, harness Harness) {
 	harness.Setup(setup.ComplexIndexSetup...)
 	e := mustNewEngine(t, harness)
@@ -5725,7 +5717,8 @@ func testCharsetCollationWire(t *testing.T, h Harness, sessionBuilder server.Ses
 		harness.Setup(setup.MydbData)
 	}
 
-	port := getEmptyPort(t)
+	port, err := sql.GetEmptyPort()
+	require.NoError(t, err)
 	for _, script := range tests {
 		t.Run(script.Name, func(t *testing.T) {
 			serverConfig := server.Config{
@@ -5829,7 +5822,8 @@ func extractCollationIdForField(r *dsql.Rows, i int) uint64 {
 func TestTypesOverWire(t *testing.T, harness ClientHarness, sessionBuilder server.SessionBuilder) {
 	harness.Setup(setup.MydbData)
 
-	port := getEmptyPort(t)
+	port, err := sql.GetEmptyPort()
+	require.NoError(t, err)
 	for _, script := range queries.TypeWireTests {
 		t.Run(script.Name, func(t *testing.T) {
 			e := mustNewEngine(t, harness)

enginetest/server_engine.go

@@ -20,7 +20,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"net"
 	"strconv"
 	"strings"
 	"testing"
@@ -61,7 +60,7 @@ func NewServerQueryEngine(t *testing.T, engine *sqle.Engine, builder server.Sess
 		panic(err)
 	}
 
-	p, err := findEmptyPort()
+	p, err := sql.GetEmptyPort()
 	if err != nil {
 		return nil, err
 	}
@@ -708,19 +707,6 @@ func prepareBindingArgs(ctx *sql.Context, bindings map[string]sqlparser.Expr) ([
 	return args, nil
 }
 
-func findEmptyPort() (int, error) {
-	listener, err := net.Listen("tcp", ":0")
-	if err != nil {
-		return -1, err
-	}
-	port := listener.Addr().(*net.TCPAddr).Port
-	if err = listener.Close(); err != nil {
-		return -1, err
-
-	}
-	return port, nil
-}
-
 func (s *ServerQueryEngine) CloseSession(connID uint32) {
 	// TODO
 }

enginetest/server_engine_test.go

@@ -5,7 +5,6 @@ import (
 	gosql "database/sql"
 	"fmt"
 	"math"
-	"net"
 	"os"
 	"testing"
 
@@ -25,19 +24,6 @@ var (
 	noUserFmt = "no_user:@tcp(%s:%d)/"
 )
 
-func findEmptyPort() (int, error) {
-	listener, err := net.Listen("tcp", ":0")
-	if err != nil {
-		return -1, err
-	}
-	port := listener.Addr().(*net.TCPAddr).Port
-	if err = listener.Close(); err != nil {
-		return -1, err
-
-	}
-	return port, nil
-}
-
 // initTestServer initializes an in-memory server with the given port, but does not start it.
 func initTestServer(port int) (*server.Server, error) {
 	pro := memory.NewDBProvider()
@@ -58,7 +44,7 @@ func initTestServer(port int) (*server.Server, error) {
 
 // TestSmoke checks that an in-memory server can be started and stopped without error.
 func TestSmoke(t *testing.T) {
-	port, err := findEmptyPort()
+	port, err := sql.GetEmptyPort()
 	require.NoError(t, err)
 
 	s, err := initTestServer(port)
@@ -315,7 +301,7 @@ func TestServerPreparedStatements(t *testing.T) {
 		},
 	}
 
-	port, perr := findEmptyPort()
+	port, perr := sql.GetEmptyPort()
 	require.NoError(t, perr)
 
 	s, serr := initTestServer(port)
@@ -381,7 +367,7 @@ func TestServerVariables(t *testing.T) {
 	hostname, herr := os.Hostname()
 	require.NoError(t, herr)
 
-	port, perr := findEmptyPort()
+	port, perr := sql.GetEmptyPort()
 	require.NoError(t, perr)
 
 	s, serr := initTestServer(port)

sql/testutils.go

@@ -14,9 +14,24 @@
 
 package sql
 
+import "net"
+
 func MustConvert(val interface{}, _ ConvertInRange, err error) interface{} {
 	if err != nil {
 		panic(err)
 	}
 	return val
 }
+
+func GetEmptyPort() (int, error) {
+	listener, err := net.Listen("tcp", ":0")
+	if err != nil {
+		return -1, err
+	}
+	port := listener.Addr().(*net.TCPAddr).Port
+	if err = listener.Close(); err != nil {
+		return -1, err
+
+	}
+	return port, nil
+}