accept io.Reader instead of os.File to make it more flexible

README.md

@@ -1,7 +1,7 @@
 # MODO
 <img src="./images/modo.gif" alt="modo.gif"></img>
 
-> Modo is a simple cli app that lets you interact any text file that contains checkboxes in the markdown format.
+> Modo is a simple cross platform cli app that lets you interact any text file that contains checkboxes in the markdown format.
 
 ## Why
 

cmd/modo/main.go

@@ -15,7 +15,12 @@ func main() {
 		return
 	}
 	defer f.Close()
-	todos, err := parser.ParseTodos(f)
+	lineEndingLen, err := parser.GetLineEndingLen(f)
+	if err != nil {
+		slog.Error("something went wrong", "error", err)
+		return
+	}
+	todos, err := parser.ParseTodos(f, lineEndingLen)
 	if err != nil {
 		slog.Error("something went wrong", "error", err)
 	}

internal/parser/parser.go

@@ -2,6 +2,7 @@ package parser
 
 import (
 	"bufio"
+	"io"
 	"log/slog"
 	"os"
 	"strings"
@@ -33,28 +34,16 @@ func (t *Todo) ToggleChecked(f *os.File) {
 	}
 }
 
-func ParseTodos(f *os.File) ([]Todo, error) {
+func ParseTodos(f io.Reader, lineEndingLen int) ([]Todo, error) {
 	todos := make([]Todo, 0)
 	scanner := bufio.NewScanner(f)
 	offset := int64(0)
-	lineEnding := 1
-	crlf, err := isCRLF(f)
-	if err != nil {
-		return todos, err
-	}
-	if crlf {
-		lineEnding = 2
-	}
-	_, err = f.Seek(0, 0)
-	if err != nil {
-		return todos, err
-	}
 	for scanner.Scan() {
 		line := scanner.Text()
 		if todo, ok := ParseTodo(line, offset); ok {
 			todos = append(todos, todo)
 		}
-		offset += int64(len(line) + lineEnding)
+		offset += int64(len(line) + lineEndingLen)
 	}
 	return todos, nil
 }
@@ -68,6 +57,22 @@ func isCRLF(f *os.File) (bool, error) {
 	return len(line) > 1 && line[len(line)-2] == '\r' && line[len(line)-1] == '\n', nil
 }
 
+func GetLineEndingLen(f *os.File) (int, error) {
+	lineEndingLen := 1
+	crlf, err := isCRLF(f)
+	if err != nil {
+		return 0, err
+	}
+	if crlf {
+		lineEndingLen = 2
+	}
+	_, err = f.Seek(0, 0)
+	if err != nil {
+		return 0, err
+	}
+	return lineEndingLen, nil
+}
+
 func ParseTodo(line string, offset int64) (Todo, bool) {
 	ogLine := line
 	line = strings.Trim(line, " ")