smartconfig/typed_interpolation_test.go

package smartconfig

import (
	"fmt"
	"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)
				}
			}
		})
	}
}

func TestNumericConversionSafety(t *testing.T) {
	tests := []struct {
		name     string
		input    string
		expected interface{}
		desc     string
	}{
		{
			name:     "integer with leading zeros stays string",
			input:    "0123",
			expected: "0123",
			desc:     "Leading zeros should prevent integer conversion",
		},
		{
			name:     "float with trailing zeros",
			input:    "1.50",
			expected: "1.50",
			desc:     "Trailing zeros should prevent float conversion",
		},
		{
			name:     "scientific notation stays string",
			input:    "1e10",
			expected: "1e10",
			desc:     "Scientific notation should stay as string",
		},
		{
			name:     "integer within range converts",
			input:    "12345",
			expected: 12345,
			desc:     "Normal integers should convert",
		},
		{
			name:     "float with no trailing zeros converts",
			input:    "123.45",
			expected: 123.45,
			desc:     "Normal floats should convert",
		},
		{
			name:     "negative integer converts",
			input:    "-123",
			expected: -123,
			desc:     "Negative integers should convert",
		},
		{
			name:     "negative float converts",
			input:    "-123.45",
			expected: -123.45,
			desc:     "Negative floats should convert",
		},
		{
			name:     "very large number stays string",
			input:    "999999999999999999999999999999",
			expected: "999999999999999999999999999999",
			desc:     "Numbers beyond int range should stay as strings",
		},
		{
			name:     "float that looks like int converts to int",
			input:    "123.0",
			expected: "123.0",
			desc:     "Float notation should be preserved even for whole numbers",
		},
		{
			name:     "plus sign prevents conversion",
			input:    "+123",
			expected: "+123",
			desc:     "Plus sign should prevent conversion",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Set up environment variable
			varName := "TEST_NUMERIC_" + strings.ToUpper(strings.ReplaceAll(tt.name, " ", "_"))
			_ = os.Setenv(varName, tt.input)
			defer func() { _ = os.Unsetenv(varName) }()

			yaml := fmt.Sprintf("value: ${ENV:%s}", varName)
			config, err := NewFromReader(strings.NewReader(yaml))
			if err != nil {
				t.Fatalf("Failed to parse YAML: %v", err)
			}

			val, exists := config.Get("value")
			if !exists {
				t.Fatal("Expected value to exist")
			}

			// Check type and value
			switch expected := tt.expected.(type) {
			case int:
				if i, ok := val.(int); !ok {
					t.Errorf("%s: Expected int, got %T: %v", tt.desc, val, val)
				} else if i != expected {
					t.Errorf("%s: Expected %d, got %d", tt.desc, expected, i)
				}
			case float64:
				if f, ok := val.(float64); !ok {
					t.Errorf("%s: Expected float64, got %T: %v", tt.desc, val, val)
				} else if f != expected {
					t.Errorf("%s: Expected %f, got %f", tt.desc, expected, f)
				}
			case string:
				if s, ok := val.(string); !ok {
					t.Errorf("%s: Expected string, got %T: %v", tt.desc, val, val)
				} else if s != expected {
					t.Errorf("%s: Expected %q, got %q", tt.desc, expected, s)
				}
			}
		})
	}
}