Simplify checkIfTerminal for Windows

Instead of relying on EnableVirtualTerminalProcessing from
github.com/konsorten/go-windows-terminal-sequences which just calls
GetConsoleMode, sets ENABLE_VIRTUAL_TERMINAL_PROCESSING and calls
SetConsoleMode with the new modified mode, implement it directly inside
checkIfTerminal. This also avoids the duplicate call to GetConsoleMode.

go.mod

@@ -2,7 +2,6 @@ module github.com/sirupsen/logrus
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/konsorten/go-windows-terminal-sequences v1.0.1
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/stretchr/testify v1.2.2
 	golang.org/x/sys v0.0.0-20190422165155-953cdadca894

go.sum

@@ -1,7 +1,5 @@
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
-github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=

terminal_check_windows.go

@@ -5,30 +5,23 @@ package logrus
 import (
 	"io"
 	"os"
-	"syscall"
 
-	sequences "github.com/konsorten/go-windows-terminal-sequences"
+	"golang.org/x/sys/windows"
 )
 
-func initTerminal(w io.Writer) {
-	switch v := w.(type) {
-	case *os.File:
-		sequences.EnableVirtualTerminalProcessing(syscall.Handle(v.Fd()), true)
-	}
-}
-
 func checkIfTerminal(w io.Writer) bool {
-	var ret bool
 	switch v := w.(type) {
 	case *os.File:
+		handle := windows.Handle(v.Fd())
 		var mode uint32
-		err := syscall.GetConsoleMode(syscall.Handle(v.Fd()), &mode)
-		ret = (err == nil)
-	default:
-		ret = false
-	}
-	if ret {
-		initTerminal(w)
+		if err := windows.GetConsoleMode(handle, &mode); err != nil {
+			return false
+		}
+		mode |= windows.ENABLE_VIRTUAL_TERMINAL_PROCESSING
+		if err := windows.SetConsoleMode(handle, mode); err != nil {
+			return false
+		}
+		return true
 	}
-	return ret
+	return false
 }

travis/install.sh

@@ -18,5 +18,5 @@ fi
 
 if [[ "$GO111MODULE" == "off" ]]; then
     # Should contain all regular (not indirect) modules from go.mod
-    go get github.com/stretchr/testify golang.org/x/sys/unix github.com/konsorten/go-windows-terminal-sequences
+    go get github.com/stretchr/testify golang.org/x/sys/unix golang.org/x/sys/windows
 fi