package main

import (
    "image/png"
    "os"
    "testing"
)

// go test -run TestDecodeQR -v
func TestDecodeQR(t *testing.T) {
    path := os.Getenv("QR_TEST_FILE")
    if path == "" {
        t.Skip("set QR_TEST_FILE to a PNG path to run")
        return
    }
    f, err := os.Open(path)
    if err != nil {
        t.Fatal(err)
    }
    defer f.Close()
    img, err := png.Decode(f)
    if err != nil {
        t.Fatal(err)
    }
    txt, err := DecodeQR(img)
    if err != nil {
        t.Fatalf("decode error: %v", err)
    }
    t.Logf("decoded: %d bytes", len(txt))
}