feat(terminal): add terminal detection methods

go.mod

@@ -6,5 +6,5 @@ require (
 	github.com/briandowns/spinner v0.0.0-20190319032542-ac46072a5a91
 	github.com/fatih/color v1.7.0 // indirect
 	github.com/mattn/go-colorable v0.1.1 // indirect
-	github.com/mattn/go-isatty v0.0.8 // indirect
+	github.com/mattn/go-isatty v0.0.12
 )

go.sum

@@ -7,4 +7,8 @@ github.com/mattn/go-colorable v0.1.1/go.mod h1:FuOcm+DKB9mbwrcAfNl7/TZVBZ6rcncea
 github.com/mattn/go-isatty v0.0.5/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
 github.com/mattn/go-isatty v0.0.8 h1:HLtExJ+uU2HOZ+wI0Tt5DtUDrx8yhUqDcp7fYERX4CE=
 github.com/mattn/go-isatty v0.0.8/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
+github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
+github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20200116001909-b77594299b42 h1:vEOn+mP2zCOVzKckCZy6YsCtDblrpj/w7B9nxGNELpg=
+golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

streams.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/briandowns/spinner"
+	"github.com/mattn/go-isatty"
 )
 
 // IOStreams provides standard names for iostreams and common methods for managing
@@ -28,6 +29,26 @@ type IOStreams struct {
 	sp *spinner.Spinner
 }
 
+// IsTerminal returns true when IOStreams Out is a terminal file descriptor
+func (s IOStreams) IsTerminal() bool {
+	if osOutFile, ok := s.Out.(*os.File); ok {
+		if osOutFile == os.Stdout {
+			return isatty.IsTerminal(osOutFile.Fd())
+		}
+	}
+	return false
+}
+
+// IsCygwinTerminal returns true when IOStreams Out is a Cygwin file descriptor
+func (s IOStreams) IsCygwinTerminal() bool {
+	if osOutFile, ok := s.Out.(*os.File); ok {
+		if osOutFile == os.Stdout {
+			return isatty.IsCygwinTerminal(osOutFile.Fd())
+		}
+	}
+	return false
+}
+
 // StartSpinner begins the progress spinner
 func (s IOStreams) StartSpinner() {
 	s.sp.Start()

streams_test.go

@@ -28,3 +28,12 @@ func TestSpinnerPrint(t *testing.T) {
 	s.Print("hallo!")
 	s.StopSpinner()
 }
+
+func TestIsNotATerminal(t *testing.T) {
+	str, _, _, _ := NewTestIOStreams()
+	if str.IsTerminal() {
+		t.Fatal("expected buffer streams to not be a terminal")
+	} else if str.IsCygwinTerminal() {
+		t.Fatal("expected buffer streams to not be a cygwin terminal")
+	}
+}