Fix trimming and add better auto-detection

main.go

@@ -8,6 +8,7 @@ import (
 	"rare/cmd"
 	"rare/pkg/color"
 	"rare/pkg/humanize"
+	"rare/pkg/multiterm"
 
 	"github.com/urfave/cli"
 )
@@ -42,6 +43,10 @@ func main() {
 			Name:  "color",
 			Usage: "Force-enable color output",
 		},
+		cli.BoolFlag{
+			Name:  "notrim",
+			Usage: "By default, rare will trim output text for in-place updates. Setting this flag will disable that",
+		},
 	}
 
 	app.Commands = []cli.Command{
@@ -61,6 +66,9 @@ func main() {
 		if c.Bool("noformat") {
 			humanize.Enabled = false
 		}
+		if c.Bool("notrim") {
+			multiterm.AutoTrim = false
+		}
 		return nil
 	})
 

pkg/multiterm/linetrim.go

@@ -8,6 +8,8 @@ import (
 	"strings"
 )
 
+var AutoTrim = true
+
 const defaultRows, defaultCols = 24, 80
 
 func getTermRowsCols() (int, int) {
@@ -36,16 +38,33 @@ func getTermRowsCols() (int, int) {
 var computedRows, computedCols = 0, 0
 
 func init() {
-	computedRows, computedCols = getTermRowsCols()
+	if _, ok := os.LookupEnv("TERM"); ok {
+		computedRows, computedCols = getTermRowsCols()
+	} else {
+		AutoTrim = false
+	}
+}
+
+func TermRows() int {
+	return computedRows
+}
+
+func TermCols() int {
+	return computedCols
 }
 
 func WriteLineNoWrap(out io.Writer, s string) {
+	if !AutoTrim {
+		out.Write([]byte(s))
+		return
+	}
 	runes := []rune(s)
 
 	visibleRunes := 0
 	i := 0
-	for i < len(runes) && visibleRunes < computedCols-2 {
-		if i == '\x1b' {
+	for i < len(runes) && visibleRunes < computedCols {
+		if runes[i] == '\x1b' {
+			// parse colors
 			for runes[i] != 'm' && i < len(runes)-1 {
 				i++
 			}