refactor: Add config validation, defaults, and unit tests

config/config_test.go

@@ -0,0 +1,63 @@
+package config
+
+import (
+	"os"
+	"testing"
+
+	"github.com/rs/zerolog"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetConfig(t *testing.T) {
+	// Set up test environment variables
+	envVars := map[string]string{
+		EnvLogLevel:        "debug",
+		EnvRootPath:        ".",
+		EnvNumWorkers:      "5",
+		EnvWorkerBatchSize: "100",
+		EnvMaxResponseSize: "1048576",
+		EnvResponseTimeout: "30",
+	}
+
+	for k, v := range envVars {
+		os.Setenv(k, v)
+		defer os.Unsetenv(k)
+	}
+
+	// Get configuration
+	config := GetConfig()
+
+	// Assert configuration values
+	assert.Equal(t, zerolog.DebugLevel, config.LogLevel)
+	assert.Equal(t, ".", config.RootPath)
+	assert.Equal(t, 5, config.NumOfWorkers)
+	assert.Equal(t, 100, config.WorkerBatchSize)
+	assert.Equal(t, 1048576, config.MaxResponseSize)
+	assert.Equal(t, 30, config.ResponseTimeout)
+}
+
+func TestParsePositiveInt(t *testing.T) {
+	tests := []struct {
+		name    string
+		input   string
+		want    int
+		wantErr bool
+	}{
+		{"valid positive", "42", 42, false},
+		{"zero", "0", 0, true},
+		{"negative", "-1", 0, true},
+		{"invalid", "abc", 0, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := parsePositiveInt(tt.input)
+			if tt.wantErr {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.want, got)
+			}
+		})
+	}
+}