Add tests for root command

glow_test.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestGlowSources(t *testing.T) {
+	tt := []string{
+		"",
+		".",
+		"README.md",
+		"github.com/charmbracelet/glow",
+		"https://github.com/charmbracelet/glow",
+	}
+
+	for _, v := range tt {
+		buf := &bytes.Buffer{}
+		err := executeArg(rootCmd, v, buf)
+
+		if err != nil {
+			t.Errorf("Error during execution (args: %s): %v", v, err)
+		}
+		if buf.Len() == 0 {
+			t.Errorf("Output buffer should not be empty (args: %s)", v)
+		}
+	}
+}
+
+func TestGlowFlags(t *testing.T) {
+	tt := []struct {
+		args  []string
+		check func() bool
+	}{
+		{
+			args: []string{"-p"},
+			check: func() bool {
+				return pager
+			},
+		},
+		{
+			args: []string{"-s", "light"},
+			check: func() bool {
+				return style == "light"
+			},
+		},
+		{
+			args: []string{"-w", "40"},
+			check: func() bool {
+				return width == 40
+			},
+		},
+	}
+
+	for _, v := range tt {
+		err := rootCmd.ParseFlags(v.args)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !v.check() {
+			t.Errorf("Parsing flag failed: %s", v.args)
+		}
+	}
+}