smartconfig/typed_interpolation_test.go

package smartconfig

import (
	"os"
	"strings"
	"testing"
)

func TestTypedInterpolation(t *testing.T) {
	testCases := []struct {
		name   string
		yaml   string
		env    map[string]string
		checks []struct {
			key          string
			expectedVal  interface{}
			expectedType string
		}
	}{
		{
			name: "unquoted number interpolation",
			yaml: `port: ${ENV:PORT}`,
			env:  map[string]string{"PORT": "8080"},
			checks: []struct {
				key          string
				expectedVal  interface{}
				expectedType string
			}{
				{key: "port", expectedVal: 8080, expectedType: "int"},
			},
		},
		{
			name: "force string with prefix",
			yaml: `port: "port-${ENV:PORT}"`,
			env:  map[string]string{"PORT": "8080"},
			checks: []struct {
				key          string
				expectedVal  interface{}
				expectedType string
			}{
				{key: "port", expectedVal: "port-8080", expectedType: "string"},
			},
		},
		{
			name: "boolean interpolation",
			yaml: `enabled: ${ENV:ENABLED}`,
			env:  map[string]string{"ENABLED": "true"},
			checks: []struct {
				key          string
				expectedVal  interface{}
				expectedType string
			}{
				{key: "enabled", expectedVal: true, expectedType: "bool"},
			},
		},
		{
			name: "float interpolation",
			yaml: `timeout: ${ENV:TIMEOUT}`,
			env:  map[string]string{"TIMEOUT": "30.5"},
			checks: []struct {
				key          string
				expectedVal  interface{}
				expectedType string
			}{
				{key: "timeout", expectedVal: 30.5, expectedType: "float64"},
			},
		},
		{
			name: "mixed content stays string",
			yaml: `message: "Hello ${ENV:NAME}!"`,
			env:  map[string]string{"NAME": "World"},
			checks: []struct {
				key          string
				expectedVal  interface{}
				expectedType string
			}{
				{key: "message", expectedVal: "Hello World!", expectedType: "string"},
			},
		},
		{
			name: "nested interpolation with type",
			yaml: `value: ${ENV:PREFIX_${ENV:SUFFIX}}`,
			env:  map[string]string{"SUFFIX": "VAL", "PREFIX_VAL": "42"},
			checks: []struct {
				key          string
				expectedVal  interface{}
				expectedType string
			}{
				{key: "value", expectedVal: 42, expectedType: "int"},
			},
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			// Set environment variables
			for k, v := range tc.env {
				_ = os.Setenv(k, v)
				defer func(key string) { _ = os.Unsetenv(key) }(k)
			}

			// Load config
			config, err := NewFromReader(strings.NewReader(tc.yaml))
			if err != nil {
				t.Fatalf("Failed to load config: %v", err)
			}

			// Check values and types
			for _, check := range tc.checks {
				val, exists := config.Get(check.key)
				if !exists {
					t.Errorf("Key %s not found", check.key)
					continue
				}

				// Check type
				actualType := ""
				switch val.(type) {
				case string:
					actualType = "string"
				case int:
					actualType = "int"
				case float64:
					actualType = "float64"
				case bool:
					actualType = "bool"
				default:
					actualType = "unknown"
				}

				if actualType != check.expectedType {
					t.Errorf("Key %s: expected type %s, got %s (value: %v)",
						check.key, check.expectedType, actualType, val)
				}

				// Check value
				if val != check.expectedVal {
					t.Errorf("Key %s: expected value %v, got %v",
						check.key, check.expectedVal, val)
				}
			}
		})
	}
}