Add test for collector config command

cmd/collector/main_test.go

@@ -0,0 +1,21 @@
+package main_test
+
+import (
+	"os/exec"
+	"testing"
+
+	"github.com/Azure/adx-mon/cmd/collector/config"
+	"github.com/pelletier/go-toml/v2"
+	"github.com/stretchr/testify/require"
+)
+
+func TestMainFunction_Config(t *testing.T) {
+	cmd := exec.Command("go", "run", ".", "config")
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("Failed to run main function: %v\nOutput: %s", err, string(output))
+	}
+
+	var fileConfig config.Config
+	require.NoError(t, toml.Unmarshal(output, &fileConfig))
+}