Add package to generate QR codes

qr/encode.go

@@ -0,0 +1,60 @@
+package qr
+
+import (
+	"io"
+
+	"rsc.io/qr"
+)
+
+const blackSquare = "\033[40m  \033[0m"
+const whiteSquare = "\033[47m  \033[0m"
+
+type encodingParams struct {
+	Level     qr.Level
+	Writer    io.Writer
+	BlackChar string
+	WhiteChar string
+}
+
+//Creates a QR that can be displayed on a terminal
+func encode(text string, params encodingParams) error {
+	w := params.Writer
+	white := params.WhiteChar
+	black := params.BlackChar
+	code, err := qr.Encode(text, params.Level)
+
+	if err != nil {
+		return err
+	}
+
+	w.Write([]byte(white))
+	for i := 0; i <= code.Size; i++ {
+		w.Write([]byte(white))
+	}
+	w.Write([]byte("\n"))
+
+	for i := 0; i <= code.Size; i++ {
+		w.Write([]byte(white))
+		for j := 0; j <= code.Size; j++ {
+			if code.Black(i, j) {
+				w.Write([]byte(black))
+			} else {
+				w.Write([]byte(white))
+			}
+		}
+		w.Write([]byte("\n"))
+	}
+	return err
+}
+
+//Encode encodes the given text as a QR code, the QR is written
+//on the given writer
+func Encode(text string, w io.Writer) error {
+	params := encodingParams{
+		Level:     qr.L,
+		Writer:    w,
+		BlackChar: blackSquare,
+		WhiteChar: whiteSquare,
+	}
+	return encode(text, params)
+}

qr/encode_test.go

@@ -0,0 +1,32 @@
+package qr
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestQRWritingDoesNotFail(t *testing.T) {
+	type args struct {
+		text string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantErr bool
+	}{
+		{
+			"QR encoding",
+			args{"whatever"},
+			false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			w := &bytes.Buffer{}
+			if err := Encode(tt.args.text, w); (err != nil) != tt.wantErr {
+				t.Errorf("Encode() error = %v, wantErr %v", err, tt.wantErr)
+			}
+
+		})
+	}
+}