Here we go again...

pkg/types/body.go

@@ -0,0 +1,23 @@
+package types
+
+type Body string
+
+func (body Body) String() string {
+	return string(body)
+}
+
+type Bodies []Body
+
+func (bodies *Bodies) Append(body Body) {
+	*bodies = append(*bodies, body)
+}
+
+func (bodies *Bodies) Parse(rawValues ...string) {
+	for _, rawValue := range rawValues {
+		bodies.Append(ParseBody(rawValue))
+	}
+}
+
+func ParseBody(rawValue string) Body {
+	return Body(rawValue)
+}

pkg/types/body_test.go

@@ -0,0 +1,160 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBody_String(t *testing.T) {
+	t.Run("Body String returns correct value", func(t *testing.T) {
+		body := Body("test body content")
+		assert.Equal(t, "test body content", body.String())
+	})
+
+	t.Run("Body String with empty body", func(t *testing.T) {
+		body := Body("")
+		assert.Empty(t, body.String())
+	})
+
+	t.Run("Body String with JSON", func(t *testing.T) {
+		body := Body(`{"key": "value", "number": 42}`)
+		assert.JSONEq(t, `{"key": "value", "number": 42}`, body.String())
+	})
+
+	t.Run("Body String with special characters", func(t *testing.T) {
+		body := Body("special: !@#$%^&*()\nnewline\ttab")
+		assert.Equal(t, "special: !@#$%^&*()\nnewline\ttab", body.String())
+	})
+}
+
+func TestBodies_Append(t *testing.T) {
+	t.Run("Append single body", func(t *testing.T) {
+		bodies := &Bodies{}
+		bodies.Append(Body("first body"))
+
+		assert.Len(t, *bodies, 1)
+		assert.Equal(t, Body("first body"), (*bodies)[0])
+	})
+
+	t.Run("Append multiple bodies", func(t *testing.T) {
+		bodies := &Bodies{}
+		bodies.Append(Body("first"))
+		bodies.Append(Body("second"))
+		bodies.Append(Body("third"))
+
+		assert.Len(t, *bodies, 3)
+		assert.Equal(t, Body("first"), (*bodies)[0])
+		assert.Equal(t, Body("second"), (*bodies)[1])
+		assert.Equal(t, Body("third"), (*bodies)[2])
+	})
+
+	t.Run("Append to existing bodies", func(t *testing.T) {
+		bodies := &Bodies{Body("existing")}
+		bodies.Append(Body("new"))
+
+		assert.Len(t, *bodies, 2)
+		assert.Equal(t, Body("existing"), (*bodies)[0])
+		assert.Equal(t, Body("new"), (*bodies)[1])
+	})
+
+	t.Run("Append empty body", func(t *testing.T) {
+		bodies := &Bodies{}
+		bodies.Append(Body(""))
+
+		assert.Len(t, *bodies, 1)
+		assert.Empty(t, (*bodies)[0].String())
+	})
+}
+
+func TestBodies_Parse(t *testing.T) {
+	t.Run("Parse single value", func(t *testing.T) {
+		bodies := &Bodies{}
+		bodies.Parse("test body")
+
+		assert.Len(t, *bodies, 1)
+		assert.Equal(t, Body("test body"), (*bodies)[0])
+	})
+
+	t.Run("Parse multiple values", func(t *testing.T) {
+		bodies := &Bodies{}
+		bodies.Parse("body1", "body2", "body3")
+
+		assert.Len(t, *bodies, 3)
+		assert.Equal(t, Body("body1"), (*bodies)[0])
+		assert.Equal(t, Body("body2"), (*bodies)[1])
+		assert.Equal(t, Body("body3"), (*bodies)[2])
+	})
+
+	t.Run("Parse with existing bodies", func(t *testing.T) {
+		bodies := &Bodies{Body("existing")}
+		bodies.Parse("new1", "new2")
+
+		assert.Len(t, *bodies, 3)
+		assert.Equal(t, Body("existing"), (*bodies)[0])
+		assert.Equal(t, Body("new1"), (*bodies)[1])
+		assert.Equal(t, Body("new2"), (*bodies)[2])
+	})
+
+	t.Run("Parse empty values", func(t *testing.T) {
+		bodies := &Bodies{}
+		bodies.Parse("", "", "")
+
+		assert.Len(t, *bodies, 3)
+		for _, body := range *bodies {
+			assert.Empty(t, body.String())
+		}
+	})
+
+	t.Run("Parse no arguments", func(t *testing.T) {
+		bodies := &Bodies{}
+		bodies.Parse()
+
+		assert.Empty(t, *bodies)
+	})
+
+	t.Run("Parse JSON strings", func(t *testing.T) {
+		bodies := &Bodies{}
+		bodies.Parse(`{"key": "value"}`, `{"array": [1, 2, 3]}`)
+
+		assert.Len(t, *bodies, 2)
+		assert.JSONEq(t, `{"key": "value"}`, (*bodies)[0].String())
+		assert.JSONEq(t, `{"array": [1, 2, 3]}`, (*bodies)[1].String())
+	})
+}
+
+func TestParseBody(t *testing.T) {
+	t.Run("ParseBody with regular string", func(t *testing.T) {
+		body := ParseBody("test content")
+		assert.Equal(t, Body("test content"), body)
+	})
+
+	t.Run("ParseBody with empty string", func(t *testing.T) {
+		body := ParseBody("")
+		assert.Equal(t, Body(""), body)
+	})
+
+	t.Run("ParseBody with multiline string", func(t *testing.T) {
+		input := "line1\nline2\nline3"
+		body := ParseBody(input)
+		assert.Equal(t, Body(input), body)
+	})
+
+	t.Run("ParseBody with special characters", func(t *testing.T) {
+		input := "!@#$%^&*()_+-=[]{}|;':\",./<>?"
+		body := ParseBody(input)
+		assert.Equal(t, Body(input), body)
+	})
+
+	t.Run("ParseBody with unicode", func(t *testing.T) {
+		input := "Hello World 🌍"
+		body := ParseBody(input)
+		assert.Equal(t, Body(input), body)
+	})
+
+	t.Run("ParseBody preserves whitespace", func(t *testing.T) {
+		input := "  leading and trailing spaces  "
+		body := ParseBody(input)
+		assert.Equal(t, Body(input), body)
+	})
+}

pkg/types/config_file.go

@@ -0,0 +1,92 @@
+package types
+
+import (
+	"net/url"
+	"path/filepath"
+	"strings"
+)
+
+type ConfigFileType int
+
+const (
+	ConfigFileTypeYAML ConfigFileType = iota
+)
+
+func (t ConfigFileType) String() string {
+	switch t {
+	case ConfigFileTypeYAML:
+		return "yaml"
+	default:
+		return "unknown"
+	}
+}
+
+type ConfigFileLocationType int
+
+const (
+	ConfigFileLocationLocal ConfigFileLocationType = iota
+	ConfigFileLocationRemote
+)
+
+func (l ConfigFileLocationType) String() string {
+	switch l {
+	case ConfigFileLocationLocal:
+		return "local"
+	case ConfigFileLocationRemote:
+		return "remote"
+	default:
+		return "unknown"
+	}
+}
+
+type ConfigFile struct {
+	path         string
+	_type        ConfigFileType
+	locationType ConfigFileLocationType
+}
+
+func (configFile ConfigFile) String() string {
+	return configFile.path
+}
+
+func (configFile ConfigFile) Type() ConfigFileType {
+	return configFile._type
+}
+
+func (configFile ConfigFile) LocationType() ConfigFileLocationType {
+	return configFile.locationType
+}
+
+func ParseConfigFile(configFileRaw string) (*ConfigFile, error) {
+	configFileParsed := &ConfigFile{
+		path:         configFileRaw,
+		locationType: ConfigFileLocationLocal,
+	}
+
+	if strings.HasPrefix(configFileRaw, "http://") || strings.HasPrefix(configFileRaw, "https://") {
+		configFileParsed.locationType = ConfigFileLocationRemote
+	}
+
+	configFilePath := configFileRaw
+	if configFileParsed.locationType == ConfigFileLocationRemote {
+		remoteConfigFileParsed, err := url.Parse(configFileRaw)
+		if err != nil {
+			return nil, NewRemoteConfigFileParseError(err)
+		}
+		configFilePath = remoteConfigFileParsed.Path
+	}
+
+	configFileExtension, _ := strings.CutPrefix(filepath.Ext(configFilePath), ".")
+	if configFileExtension == "" {
+		return nil, ErrConfigFileExtensionNotFound
+	}
+
+	switch strings.ToLower(configFileExtension) {
+	case "yml", "yaml":
+		configFileParsed._type = ConfigFileTypeYAML
+	default:
+		return nil, NewUnknownConfigFileTypeError(configFileExtension)
+	}
+
+	return configFileParsed, nil
+}

pkg/types/config_file_test.go

@@ -0,0 +1,216 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestConfigFileType_String(t *testing.T) {
+	t.Run("ConfigFileTypeYAML returns yaml", func(t *testing.T) {
+		configType := ConfigFileTypeYAML
+		assert.Equal(t, "yaml", configType.String())
+	})
+
+	t.Run("Unknown config file type returns unknown", func(t *testing.T) {
+		configType := ConfigFileType(999)
+		assert.Equal(t, "unknown", configType.String())
+	})
+}
+
+func TestConfigFileLocationType_String(t *testing.T) {
+	t.Run("ConfigFileLocationLocal returns local", func(t *testing.T) {
+		locationType := ConfigFileLocationLocal
+		assert.Equal(t, "local", locationType.String())
+	})
+
+	t.Run("ConfigFileLocationRemote returns remote", func(t *testing.T) {
+		locationType := ConfigFileLocationRemote
+		assert.Equal(t, "remote", locationType.String())
+	})
+
+	t.Run("Unknown location type returns unknown", func(t *testing.T) {
+		locationType := ConfigFileLocationType(999)
+		assert.Equal(t, "unknown", locationType.String())
+	})
+}
+
+func TestConfigFile_String(t *testing.T) {
+	t.Run("String returns the file path", func(t *testing.T) {
+		configFile := ConfigFile{path: "/path/to/config.yaml"}
+		assert.Equal(t, "/path/to/config.yaml", configFile.String())
+	})
+
+	t.Run("String returns empty path", func(t *testing.T) {
+		configFile := ConfigFile{path: ""}
+		assert.Empty(t, configFile.String())
+	})
+}
+
+func TestConfigFile_Type(t *testing.T) {
+	t.Run("Type returns the config file type", func(t *testing.T) {
+		configFile := ConfigFile{_type: ConfigFileTypeYAML}
+		assert.Equal(t, ConfigFileTypeYAML, configFile.Type())
+	})
+}
+
+func TestConfigFile_LocationType(t *testing.T) {
+	t.Run("LocationType returns local", func(t *testing.T) {
+		configFile := ConfigFile{locationType: ConfigFileLocationLocal}
+		assert.Equal(t, ConfigFileLocationLocal, configFile.LocationType())
+	})
+
+	t.Run("LocationType returns remote", func(t *testing.T) {
+		configFile := ConfigFile{locationType: ConfigFileLocationRemote}
+		assert.Equal(t, ConfigFileLocationRemote, configFile.LocationType())
+	})
+}
+
+func TestParseConfigFile(t *testing.T) {
+	t.Run("Parse local YAML file with yml extension", func(t *testing.T) {
+		configFile, err := ParseConfigFile("config.yml")
+
+		require.NoError(t, err)
+		require.NotNil(t, configFile)
+		assert.Equal(t, "config.yml", configFile.String())
+		assert.Equal(t, ConfigFileTypeYAML, configFile.Type())
+		assert.Equal(t, ConfigFileLocationLocal, configFile.LocationType())
+	})
+
+	t.Run("Parse local YAML file with yaml extension", func(t *testing.T) {
+		configFile, err := ParseConfigFile("config.yaml")
+
+		require.NoError(t, err)
+		require.NotNil(t, configFile)
+		assert.Equal(t, "config.yaml", configFile.String())
+		assert.Equal(t, ConfigFileTypeYAML, configFile.Type())
+		assert.Equal(t, ConfigFileLocationLocal, configFile.LocationType())
+	})
+
+	t.Run("Parse local YAML file with uppercase extensions", func(t *testing.T) {
+		testCases := []string{"config.YML", "config.YAML", "config.Yml", "config.Yaml"}
+
+		for _, testCase := range testCases {
+			t.Run("Extension: "+testCase, func(t *testing.T) {
+				configFile, err := ParseConfigFile(testCase)
+
+				require.NoError(t, err)
+				require.NotNil(t, configFile)
+				assert.Equal(t, testCase, configFile.String())
+				assert.Equal(t, ConfigFileTypeYAML, configFile.Type())
+				assert.Equal(t, ConfigFileLocationLocal, configFile.LocationType())
+			})
+		}
+	})
+
+	t.Run("Parse remote HTTP YAML file", func(t *testing.T) {
+		configFile, err := ParseConfigFile("http://example.com/config.yaml")
+
+		require.NoError(t, err)
+		require.NotNil(t, configFile)
+		assert.Equal(t, "http://example.com/config.yaml", configFile.String())
+		assert.Equal(t, ConfigFileTypeYAML, configFile.Type())
+		assert.Equal(t, ConfigFileLocationRemote, configFile.LocationType())
+	})
+
+	t.Run("Parse remote HTTPS YAML file", func(t *testing.T) {
+		configFile, err := ParseConfigFile("https://example.com/path/config.yml")
+
+		require.NoError(t, err)
+		require.NotNil(t, configFile)
+		assert.Equal(t, "https://example.com/path/config.yml", configFile.String())
+		assert.Equal(t, ConfigFileTypeYAML, configFile.Type())
+		assert.Equal(t, ConfigFileLocationRemote, configFile.LocationType())
+	})
+
+	t.Run("Parse file with path separators", func(t *testing.T) {
+		configFile, err := ParseConfigFile("/path/to/config.yaml")
+
+		require.NoError(t, err)
+		require.NotNil(t, configFile)
+		assert.Equal(t, "/path/to/config.yaml", configFile.String())
+		assert.Equal(t, ConfigFileTypeYAML, configFile.Type())
+		assert.Equal(t, ConfigFileLocationLocal, configFile.LocationType())
+	})
+
+	t.Run("Parse file without extension returns error", func(t *testing.T) {
+		configFile, err := ParseConfigFile("config")
+
+		require.Error(t, err)
+		assert.Equal(t, ErrConfigFileExtensionNotFound, err)
+		assert.Nil(t, configFile)
+	})
+
+	t.Run("Parse file with unsupported extension returns error", func(t *testing.T) {
+		configFile, err := ParseConfigFile("config.json")
+
+		require.Error(t, err)
+		assert.IsType(t, &UnknownConfigFileTypeError{}, err)
+		assert.Contains(t, err.Error(), "json")
+		assert.Nil(t, configFile)
+	})
+
+	t.Run("Parse remote file with invalid URL returns error", func(t *testing.T) {
+		configFile, err := ParseConfigFile("http://192.168.1.%30/config.yaml")
+
+		require.Error(t, err)
+		assert.IsType(t, &RemoteConfigFileParseError{}, err)
+		assert.Nil(t, configFile)
+	})
+
+	t.Run("Parse remote file without extension returns error", func(t *testing.T) {
+		configFile, err := ParseConfigFile("https://example.com/config")
+
+		require.Error(t, err)
+		assert.Equal(t, ErrConfigFileExtensionNotFound, err)
+		assert.Nil(t, configFile)
+	})
+
+	t.Run("Parse remote file with unsupported extension returns error", func(t *testing.T) {
+		configFile, err := ParseConfigFile("https://example.com/config.txt")
+
+		require.Error(t, err)
+		assert.IsType(t, &UnknownConfigFileTypeError{}, err)
+		assert.Contains(t, err.Error(), "txt")
+		assert.Nil(t, configFile)
+	})
+
+	t.Run("Parse empty string returns error", func(t *testing.T) {
+		configFile, err := ParseConfigFile("")
+
+		require.Error(t, err)
+		assert.Equal(t, ErrConfigFileExtensionNotFound, err)
+		assert.Nil(t, configFile)
+	})
+
+	t.Run("Parse file with multiple dots in name", func(t *testing.T) {
+		configFile, err := ParseConfigFile("config.test.yaml")
+
+		require.NoError(t, err)
+		require.NotNil(t, configFile)
+		assert.Equal(t, "config.test.yaml", configFile.String())
+		assert.Equal(t, ConfigFileTypeYAML, configFile.Type())
+		assert.Equal(t, ConfigFileLocationLocal, configFile.LocationType())
+	})
+
+	t.Run("Parse remote URL with query parameters and fragment", func(t *testing.T) {
+		configFile, err := ParseConfigFile("https://example.com/path/config.yaml?version=1&format=yaml#section")
+
+		require.NoError(t, err)
+		require.NotNil(t, configFile)
+		assert.Equal(t, "https://example.com/path/config.yaml?version=1&format=yaml#section", configFile.String())
+		assert.Equal(t, ConfigFileTypeYAML, configFile.Type())
+		assert.Equal(t, ConfigFileLocationRemote, configFile.LocationType())
+	})
+
+	t.Run("Parse remote URL with port", func(t *testing.T) {
+		configFile, err := ParseConfigFile("https://example.com:8080/config.yml")
+
+		require.NoError(t, err)
+		require.NotNil(t, configFile)
+		assert.Equal(t, "https://example.com:8080/config.yml", configFile.String())
+		assert.Equal(t, ConfigFileTypeYAML, configFile.Type())
+		assert.Equal(t, ConfigFileLocationRemote, configFile.LocationType())
+	})
+}

pkg/types/cookie.go

@@ -0,0 +1,42 @@
+package types
+
+import "strings"
+
+type Cookie KeyValue[string, []string]
+
+type Cookies []Cookie
+
+func (cookies Cookies) GetValue(key string) *[]string {
+	for i := range cookies {
+		if cookies[i].Key == key {
+			return &cookies[i].Value
+		}
+	}
+	return nil
+}
+
+func (cookies *Cookies) Append(cookie Cookie) {
+	if item := cookies.GetValue(cookie.Key); item != nil {
+		*item = append(*item, cookie.Value...)
+	} else {
+		*cookies = append(*cookies, cookie)
+	}
+}
+
+func (cookies *Cookies) Parse(rawValues ...string) {
+	for _, rawValue := range rawValues {
+		cookies.Append(*ParseCookie(rawValue))
+	}
+}
+
+func ParseCookie(rawValue string) *Cookie {
+	parts := strings.SplitN(rawValue, "=", 2)
+	switch len(parts) {
+	case 1:
+		return &Cookie{Key: parts[0], Value: []string{""}}
+	case 2:
+		return &Cookie{Key: parts[0], Value: []string{parts[1]}}
+	default:
+		return &Cookie{Key: "", Value: []string{""}}
+	}
+}

pkg/types/cookie_test.go

@@ -0,0 +1,240 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCookies_GetValue(t *testing.T) {
+	t.Run("GetValue returns existing cookie value", func(t *testing.T) {
+		cookies := Cookies{
+			{Key: "session", Value: []string{"abc123"}},
+			{Key: "user", Value: []string{"john"}},
+		}
+
+		value := cookies.GetValue("session")
+		require.NotNil(t, value)
+		assert.Equal(t, []string{"abc123"}, *value)
+	})
+
+	t.Run("GetValue returns nil for non-existent cookie", func(t *testing.T) {
+		cookies := Cookies{
+			{Key: "session", Value: []string{"abc123"}},
+		}
+
+		value := cookies.GetValue("nonexistent")
+		assert.Nil(t, value)
+	})
+
+	t.Run("GetValue with empty cookies", func(t *testing.T) {
+		cookies := Cookies{}
+
+		value := cookies.GetValue("any")
+		assert.Nil(t, value)
+	})
+
+	t.Run("GetValue with multiple values", func(t *testing.T) {
+		cookies := Cookies{
+			{Key: "multi", Value: []string{"val1", "val2", "val3"}},
+		}
+
+		value := cookies.GetValue("multi")
+		require.NotNil(t, value)
+		assert.Equal(t, []string{"val1", "val2", "val3"}, *value)
+	})
+
+	t.Run("GetValue case sensitive", func(t *testing.T) {
+		cookies := Cookies{
+			{Key: "Cookie", Value: []string{"value"}},
+		}
+
+		value1 := cookies.GetValue("Cookie")
+		require.NotNil(t, value1)
+		assert.Equal(t, []string{"value"}, *value1)
+
+		value2 := cookies.GetValue("cookie")
+		assert.Nil(t, value2)
+	})
+}
+
+func TestCookies_Append(t *testing.T) {
+	t.Run("Append new cookie", func(t *testing.T) {
+		cookies := &Cookies{}
+		cookies.Append(Cookie{Key: "session", Value: []string{"abc123"}})
+
+		assert.Len(t, *cookies, 1)
+		assert.Equal(t, "session", (*cookies)[0].Key)
+		assert.Equal(t, []string{"abc123"}, (*cookies)[0].Value)
+	})
+
+	t.Run("Append to existing cookie key", func(t *testing.T) {
+		cookies := &Cookies{
+			{Key: "session", Value: []string{"abc123"}},
+		}
+		cookies.Append(Cookie{Key: "session", Value: []string{"def456"}})
+
+		assert.Len(t, *cookies, 1)
+		assert.Equal(t, []string{"abc123", "def456"}, (*cookies)[0].Value)
+	})
+
+	t.Run("Append different cookies", func(t *testing.T) {
+		cookies := &Cookies{}
+		cookies.Append(Cookie{Key: "session", Value: []string{"abc"}})
+		cookies.Append(Cookie{Key: "user", Value: []string{"john"}})
+		cookies.Append(Cookie{Key: "token", Value: []string{"xyz"}})
+
+		assert.Len(t, *cookies, 3)
+	})
+
+	t.Run("Append multiple values at once", func(t *testing.T) {
+		cookies := &Cookies{
+			{Key: "tags", Value: []string{"tag1"}},
+		}
+		cookies.Append(Cookie{Key: "tags", Value: []string{"tag2", "tag3"}})
+
+		assert.Len(t, *cookies, 1)
+		assert.Equal(t, []string{"tag1", "tag2", "tag3"}, (*cookies)[0].Value)
+	})
+
+	t.Run("Append empty value", func(t *testing.T) {
+		cookies := &Cookies{}
+		cookies.Append(Cookie{Key: "empty", Value: []string{""}})
+
+		assert.Len(t, *cookies, 1)
+		assert.Equal(t, []string{""}, (*cookies)[0].Value)
+	})
+}
+
+func TestCookies_Parse(t *testing.T) {
+	t.Run("Parse single cookie", func(t *testing.T) {
+		cookies := &Cookies{}
+		cookies.Parse("session=abc123")
+
+		assert.Len(t, *cookies, 1)
+		assert.Equal(t, "session", (*cookies)[0].Key)
+		assert.Equal(t, []string{"abc123"}, (*cookies)[0].Value)
+	})
+
+	t.Run("Parse multiple cookies", func(t *testing.T) {
+		cookies := &Cookies{}
+		cookies.Parse("session=abc123", "user=john", "token=xyz789")
+
+		assert.Len(t, *cookies, 3)
+		assert.Equal(t, "session", (*cookies)[0].Key)
+		assert.Equal(t, "user", (*cookies)[1].Key)
+		assert.Equal(t, "token", (*cookies)[2].Key)
+	})
+
+	t.Run("Parse cookies with same key", func(t *testing.T) {
+		cookies := &Cookies{}
+		cookies.Parse("pref=dark", "pref=large", "pref=en")
+
+		assert.Len(t, *cookies, 1)
+		assert.Equal(t, []string{"dark", "large", "en"}, (*cookies)[0].Value)
+	})
+
+	t.Run("Parse cookie without value", func(t *testing.T) {
+		cookies := &Cookies{}
+		cookies.Parse("sessionid")
+
+		assert.Len(t, *cookies, 1)
+		assert.Equal(t, "sessionid", (*cookies)[0].Key)
+		assert.Equal(t, []string{""}, (*cookies)[0].Value)
+	})
+
+	t.Run("Parse cookie with empty value", func(t *testing.T) {
+		cookies := &Cookies{}
+		cookies.Parse("empty=")
+
+		assert.Len(t, *cookies, 1)
+		assert.Equal(t, "empty", (*cookies)[0].Key)
+		assert.Equal(t, []string{""}, (*cookies)[0].Value)
+	})
+
+	t.Run("Parse cookie with multiple equals", func(t *testing.T) {
+		cookies := &Cookies{}
+		cookies.Parse("data=key=value=test")
+
+		assert.Len(t, *cookies, 1)
+		assert.Equal(t, "data", (*cookies)[0].Key)
+		assert.Equal(t, []string{"key=value=test"}, (*cookies)[0].Value)
+	})
+
+	t.Run("Parse no arguments", func(t *testing.T) {
+		cookies := &Cookies{}
+		cookies.Parse()
+
+		assert.Empty(t, *cookies)
+	})
+
+	t.Run("Parse with existing cookies", func(t *testing.T) {
+		cookies := &Cookies{
+			{Key: "existing", Value: []string{"value"}},
+		}
+		cookies.Parse("new=cookie")
+
+		assert.Len(t, *cookies, 2)
+		assert.Equal(t, "existing", (*cookies)[0].Key)
+		assert.Equal(t, "new", (*cookies)[1].Key)
+	})
+}
+
+func TestParseCookie(t *testing.T) {
+	t.Run("ParseCookie with key and value", func(t *testing.T) {
+		cookie := ParseCookie("session=abc123")
+		require.NotNil(t, cookie)
+		assert.Equal(t, "session", cookie.Key)
+		assert.Equal(t, []string{"abc123"}, cookie.Value)
+	})
+
+	t.Run("ParseCookie with only key", func(t *testing.T) {
+		cookie := ParseCookie("sessionid")
+		require.NotNil(t, cookie)
+		assert.Equal(t, "sessionid", cookie.Key)
+		assert.Equal(t, []string{""}, cookie.Value)
+	})
+
+	t.Run("ParseCookie with empty value", func(t *testing.T) {
+		cookie := ParseCookie("key=")
+		require.NotNil(t, cookie)
+		assert.Equal(t, "key", cookie.Key)
+		assert.Equal(t, []string{""}, cookie.Value)
+	})
+
+	t.Run("ParseCookie with multiple equals", func(t *testing.T) {
+		cookie := ParseCookie("data=base64=encoded=value")
+		require.NotNil(t, cookie)
+		assert.Equal(t, "data", cookie.Key)
+		assert.Equal(t, []string{"base64=encoded=value"}, cookie.Value)
+	})
+
+	t.Run("ParseCookie with empty string", func(t *testing.T) {
+		cookie := ParseCookie("")
+		require.NotNil(t, cookie)
+		assert.Empty(t, cookie.Key)
+		assert.Equal(t, []string{""}, cookie.Value)
+	})
+
+	t.Run("ParseCookie with spaces", func(t *testing.T) {
+		cookie := ParseCookie("key with spaces=value with spaces")
+		require.NotNil(t, cookie)
+		assert.Equal(t, "key with spaces", cookie.Key)
+		assert.Equal(t, []string{"value with spaces"}, cookie.Value)
+	})
+
+	t.Run("ParseCookie with special characters", func(t *testing.T) {
+		cookie := ParseCookie("key-._~=val!@#$%^&*()")
+		require.NotNil(t, cookie)
+		assert.Equal(t, "key-._~", cookie.Key)
+		assert.Equal(t, []string{"val!@#$%^&*()"}, cookie.Value)
+	})
+
+	t.Run("ParseCookie with URL encoded value", func(t *testing.T) {
+		cookie := ParseCookie("data=hello%20world%3D%26")
+		require.NotNil(t, cookie)
+		assert.Equal(t, "data", cookie.Key)
+		assert.Equal(t, []string{"hello%20world%3D%26"}, cookie.Value)
+	})
+}

pkg/types/errors.go

@@ -0,0 +1,113 @@
+package types
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+var (
+	// General
+	ErrNoError = errors.New("no error (internal)")
+
+	// CLI
+	ErrCLINoArgs         = errors.New("CLI expects arguments but received none")
+	ErrCLIUnexpectedArgs = errors.New("CLI received unexpected arguments")
+
+	// Config File
+	ErrConfigFileExtensionNotFound = errors.New("config file extension not found")
+)
+
+// ======================================== General ========================================
+
+type FieldParseError struct {
+	Field string
+	Err   error
+}
+
+func NewFieldParseError(field string, err error) *FieldParseError {
+	if err == nil {
+		err = ErrNoError
+	}
+	return &FieldParseError{field, err}
+}
+
+func (e FieldParseError) Error() string {
+	return fmt.Sprintf("Field '%s' parse failed: %v", e.Field, e.Err)
+}
+
+func (e FieldParseError) Unwrap() error {
+	return e.Err
+}
+
+type FieldParseErrors struct {
+	Errors []FieldParseError
+}
+
+func NewFieldParseErrors(fieldParseErrors []FieldParseError) FieldParseErrors {
+	return FieldParseErrors{fieldParseErrors}
+}
+
+func (e FieldParseErrors) Error() string {
+	if len(e.Errors) == 0 {
+		return "No field parse errors"
+	}
+	if len(e.Errors) == 1 {
+		return e.Errors[0].Error()
+	}
+
+	errorString := ""
+	for _, err := range e.Errors {
+		errorString += err.Error() + "\n"
+	}
+	errorString, _ = strings.CutSuffix(errorString, "\n")
+
+	return errorString
+}
+
+// ======================================== CLI ========================================
+
+type CLIUnexpectedArgsError struct {
+	Args []string
+}
+
+func NewCLIUnexpectedArgsError(args []string) CLIUnexpectedArgsError {
+	return CLIUnexpectedArgsError{args}
+}
+
+func (e CLIUnexpectedArgsError) Error() string {
+	return fmt.Sprintf("CLI received unexpected arguments: %v", strings.Join(e.Args, ","))
+}
+
+// ======================================== Config File ========================================
+
+type RemoteConfigFileParseError struct {
+	error error
+}
+
+func NewRemoteConfigFileParseError(err error) *RemoteConfigFileParseError {
+	if err == nil {
+		err = ErrNoError
+	}
+	return &RemoteConfigFileParseError{err}
+}
+
+func (e RemoteConfigFileParseError) Error() string {
+	return "Remote config file parse error: " + e.error.Error()
+}
+
+func (e RemoteConfigFileParseError) Unwrap() error {
+	return e.error
+}
+
+type UnknownConfigFileTypeError struct {
+	Type string
+}
+
+func NewUnknownConfigFileTypeError(_type string) *UnknownConfigFileTypeError {
+	return &UnknownConfigFileTypeError{_type}
+}
+
+func (e UnknownConfigFileTypeError) Error() string {
+	return "Unknown config file type: " + e.Type
+}

pkg/types/errors_test.go

@@ -0,0 +1,284 @@
+package types
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFieldParseError_Error(t *testing.T) {
+	t.Run("Error returns formatted message", func(t *testing.T) {
+		originalErr := errors.New("invalid value")
+		fieldErr := NewFieldParseError("username", originalErr)
+
+		expected := "Field 'username' parse failed: invalid value"
+		assert.Equal(t, expected, fieldErr.Error())
+	})
+
+	t.Run("Error with empty field name", func(t *testing.T) {
+		originalErr := errors.New("test error")
+		fieldErr := NewFieldParseError("", originalErr)
+
+		expected := "Field '' parse failed: test error"
+		assert.Equal(t, expected, fieldErr.Error())
+	})
+
+	t.Run("Error with nil underlying error", func(t *testing.T) {
+		fieldErr := NewFieldParseError("field", nil)
+
+		expected := "Field 'field' parse failed: no error (internal)"
+		assert.Equal(t, expected, fieldErr.Error())
+	})
+}
+
+func TestFieldParseError_Unwrap(t *testing.T) {
+	t.Run("Unwrap returns original error", func(t *testing.T) {
+		originalErr := errors.New("original error")
+		fieldErr := NewFieldParseError("field", originalErr)
+
+		assert.Equal(t, originalErr, fieldErr.Unwrap())
+	})
+
+	t.Run("Unwrap with nil error", func(t *testing.T) {
+		fieldErr := NewFieldParseError("field", nil)
+
+		assert.Equal(t, ErrNoError, fieldErr.Unwrap())
+	})
+}
+
+func TestNewFieldParseError(t *testing.T) {
+	t.Run("Creates FieldParseError with correct values", func(t *testing.T) {
+		originalErr := errors.New("test error")
+		fieldErr := NewFieldParseError("testField", originalErr)
+
+		assert.Equal(t, "testField", fieldErr.Field)
+		assert.Equal(t, originalErr, fieldErr.Err)
+	})
+
+	t.Run("Creates FieldParseError with ErrNoError when nil passed", func(t *testing.T) {
+		fieldErr := NewFieldParseError("testField", nil)
+
+		assert.Equal(t, "testField", fieldErr.Field)
+		assert.Equal(t, ErrNoError, fieldErr.Err)
+	})
+}
+
+func TestFieldParseErrors_Error(t *testing.T) {
+	t.Run("Error with no errors returns default message", func(t *testing.T) {
+		fieldErrors := NewFieldParseErrors([]FieldParseError{})
+
+		assert.Equal(t, "No field parse errors", fieldErrors.Error())
+	})
+
+	t.Run("Error with single error returns single error message", func(t *testing.T) {
+		fieldErr := *NewFieldParseError("field1", errors.New("error1"))
+		fieldErrors := NewFieldParseErrors([]FieldParseError{fieldErr})
+
+		expected := "Field 'field1' parse failed: error1"
+		assert.Equal(t, expected, fieldErrors.Error())
+	})
+
+	t.Run("Error with multiple errors returns concatenated messages", func(t *testing.T) {
+		fieldErr1 := *NewFieldParseError("field1", errors.New("error1"))
+		fieldErr2 := *NewFieldParseError("field2", errors.New("error2"))
+		fieldErr3 := *NewFieldParseError("field3", errors.New("error3"))
+		fieldErrors := NewFieldParseErrors([]FieldParseError{fieldErr1, fieldErr2, fieldErr3})
+
+		expected := "Field 'field1' parse failed: error1\nField 'field2' parse failed: error2\nField 'field3' parse failed: error3"
+		assert.Equal(t, expected, fieldErrors.Error())
+	})
+
+	t.Run("Error with two errors", func(t *testing.T) {
+		fieldErr1 := *NewFieldParseError("username", errors.New("too short"))
+		fieldErr2 := *NewFieldParseError("email", errors.New("invalid format"))
+		fieldErrors := NewFieldParseErrors([]FieldParseError{fieldErr1, fieldErr2})
+
+		expected := "Field 'username' parse failed: too short\nField 'email' parse failed: invalid format"
+		assert.Equal(t, expected, fieldErrors.Error())
+	})
+}
+
+func TestNewFieldParseErrors(t *testing.T) {
+	t.Run("Creates FieldParseErrors with correct values", func(t *testing.T) {
+		fieldErr1 := *NewFieldParseError("field1", errors.New("error1"))
+		fieldErr2 := *NewFieldParseError("field2", errors.New("error2"))
+		fieldErrors := NewFieldParseErrors([]FieldParseError{fieldErr1, fieldErr2})
+
+		assert.Len(t, fieldErrors.Errors, 2)
+		assert.Equal(t, fieldErr1, fieldErrors.Errors[0])
+		assert.Equal(t, fieldErr2, fieldErrors.Errors[1])
+	})
+
+	t.Run("Creates FieldParseErrors with empty slice", func(t *testing.T) {
+		fieldErrors := NewFieldParseErrors([]FieldParseError{})
+
+		assert.Empty(t, fieldErrors.Errors)
+	})
+}
+
+func TestCLIUnexpectedArgsError_Error(t *testing.T) {
+	t.Run("Error with single argument", func(t *testing.T) {
+		err := NewCLIUnexpectedArgsError([]string{"arg1"})
+
+		expected := "CLI received unexpected arguments: arg1"
+		assert.Equal(t, expected, err.Error())
+	})
+
+	t.Run("Error with multiple arguments", func(t *testing.T) {
+		err := NewCLIUnexpectedArgsError([]string{"arg1", "arg2", "arg3"})
+
+		expected := "CLI received unexpected arguments: arg1,arg2,arg3"
+		assert.Equal(t, expected, err.Error())
+	})
+
+	t.Run("Error with empty arguments", func(t *testing.T) {
+		err := NewCLIUnexpectedArgsError([]string{})
+
+		expected := "CLI received unexpected arguments: "
+		assert.Equal(t, expected, err.Error())
+	})
+
+	t.Run("Error with arguments containing special characters", func(t *testing.T) {
+		err := NewCLIUnexpectedArgsError([]string{"--flag", "value with spaces", "-x"})
+
+		expected := "CLI received unexpected arguments: --flag,value with spaces,-x"
+		assert.Equal(t, expected, err.Error())
+	})
+}
+
+func TestNewCLIUnexpectedArgsError(t *testing.T) {
+	t.Run("Creates CLIUnexpectedArgsError with correct values", func(t *testing.T) {
+		args := []string{"arg1", "arg2"}
+		err := NewCLIUnexpectedArgsError(args)
+
+		assert.Equal(t, args, err.Args)
+	})
+}
+
+func TestRemoteConfigFileParseError_Error(t *testing.T) {
+	t.Run("Error returns formatted message", func(t *testing.T) {
+		originalErr := errors.New("invalid URL")
+		err := NewRemoteConfigFileParseError(originalErr)
+
+		expected := "Remote config file parse error: invalid URL"
+		assert.Equal(t, expected, err.Error())
+	})
+
+	t.Run("Error with nil underlying error", func(t *testing.T) {
+		err := NewRemoteConfigFileParseError(nil)
+
+		expected := "Remote config file parse error: no error (internal)"
+		assert.Equal(t, expected, err.Error())
+	})
+}
+
+func TestRemoteConfigFileParseError_Unwrap(t *testing.T) {
+	t.Run("Unwrap returns original error", func(t *testing.T) {
+		originalErr := errors.New("original error")
+		err := NewRemoteConfigFileParseError(originalErr)
+
+		assert.Equal(t, originalErr, err.Unwrap())
+	})
+
+	t.Run("Unwrap with nil error", func(t *testing.T) {
+		err := NewRemoteConfigFileParseError(nil)
+
+		assert.Equal(t, ErrNoError, err.Unwrap())
+	})
+}
+
+func TestNewRemoteConfigFileParseError(t *testing.T) {
+	t.Run("Creates RemoteConfigFileParseError with correct values", func(t *testing.T) {
+		originalErr := errors.New("test error")
+		err := NewRemoteConfigFileParseError(originalErr)
+
+		assert.Equal(t, originalErr, err.error)
+	})
+
+	t.Run("Creates RemoteConfigFileParseError with ErrNoError when nil passed", func(t *testing.T) {
+		err := NewRemoteConfigFileParseError(nil)
+
+		assert.Equal(t, ErrNoError, err.error)
+	})
+}
+
+func TestUnknownConfigFileTypeError_Error(t *testing.T) {
+	t.Run("Error returns formatted message", func(t *testing.T) {
+		err := NewUnknownConfigFileTypeError("json")
+
+		expected := "Unknown config file type: json"
+		assert.Equal(t, expected, err.Error())
+	})
+
+	t.Run("Error with empty type", func(t *testing.T) {
+		err := NewUnknownConfigFileTypeError("")
+
+		expected := "Unknown config file type: "
+		assert.Equal(t, expected, err.Error())
+	})
+
+	t.Run("Error with special characters in type", func(t *testing.T) {
+		err := NewUnknownConfigFileTypeError("type.with.dots")
+
+		expected := "Unknown config file type: type.with.dots"
+		assert.Equal(t, expected, err.Error())
+	})
+}
+
+func TestNewUnknownConfigFileTypeError(t *testing.T) {
+	t.Run("Creates UnknownConfigFileTypeError with correct values", func(t *testing.T) {
+		err := NewUnknownConfigFileTypeError("xml")
+
+		assert.Equal(t, "xml", err.Type)
+	})
+}
+
+func TestErrorConstants(t *testing.T) {
+	t.Run("ErrNoError has correct message", func(t *testing.T) {
+		expected := "no error (internal)"
+		assert.Equal(t, expected, ErrNoError.Error())
+	})
+
+	t.Run("ErrCLINoArgs has correct message", func(t *testing.T) {
+		expected := "CLI expects arguments but received none"
+		assert.Equal(t, expected, ErrCLINoArgs.Error())
+	})
+
+	t.Run("ErrCLIUnexpectedArgs has correct message", func(t *testing.T) {
+		expected := "CLI received unexpected arguments"
+		assert.Equal(t, expected, ErrCLIUnexpectedArgs.Error())
+	})
+
+	t.Run("ErrConfigFileExtensionNotFound has correct message", func(t *testing.T) {
+		expected := "config file extension not found"
+		assert.Equal(t, expected, ErrConfigFileExtensionNotFound.Error())
+	})
+}
+
+func TestErrorImplementsErrorInterface(t *testing.T) {
+	t.Run("FieldParseError implements error interface", func(t *testing.T) {
+		var err error = NewFieldParseError("field", errors.New("test"))
+		assert.Error(t, err)
+	})
+
+	t.Run("FieldParseErrors implements error interface", func(t *testing.T) {
+		var err error = NewFieldParseErrors([]FieldParseError{})
+		assert.Error(t, err)
+	})
+
+	t.Run("CLIUnexpectedArgsError implements error interface", func(t *testing.T) {
+		var err error = NewCLIUnexpectedArgsError([]string{})
+		assert.Error(t, err)
+	})
+
+	t.Run("RemoteConfigFileParseError implements error interface", func(t *testing.T) {
+		var err error = NewRemoteConfigFileParseError(errors.New("test"))
+		assert.Error(t, err)
+	})
+
+	t.Run("UnknownConfigFileTypeError implements error interface", func(t *testing.T) {
+		var err error = NewUnknownConfigFileTypeError("test")
+		assert.Error(t, err)
+	})
+}

pkg/types/header.go

@@ -0,0 +1,52 @@
+package types
+
+import "strings"
+
+type Header KeyValue[string, []string]
+
+type Headers []Header
+
+// Has checks if a header with the given key exists.
+func (headers Headers) Has(key string) bool {
+	for i := range headers {
+		if headers[i].Key == key {
+			return true
+		}
+	}
+	return false
+}
+
+func (headers Headers) GetValue(key string) *[]string {
+	for i := range headers {
+		if headers[i].Key == key {
+			return &headers[i].Value
+		}
+	}
+	return nil
+}
+
+func (headers *Headers) Append(header Header) {
+	if item := headers.GetValue(header.Key); item != nil {
+		*item = append(*item, header.Value...)
+	} else {
+		*headers = append(*headers, header)
+	}
+}
+
+func (headers *Headers) Parse(rawValues ...string) {
+	for _, rawValue := range rawValues {
+		headers.Append(*ParseHeader(rawValue))
+	}
+}
+
+func ParseHeader(rawValue string) *Header {
+	parts := strings.SplitN(rawValue, ": ", 2)
+	switch len(parts) {
+	case 1:
+		return &Header{Key: parts[0], Value: []string{""}}
+	case 2:
+		return &Header{Key: parts[0], Value: []string{parts[1]}}
+	default:
+		return &Header{Key: "", Value: []string{""}}
+	}
+}

pkg/types/header_test.go

@@ -0,0 +1,277 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestHeaders_Has(t *testing.T) {
+	t.Run("Has returns true for existing header", func(t *testing.T) {
+		headers := Headers{
+			{Key: "Content-Type", Value: []string{"application/json"}},
+			{Key: "Authorization", Value: []string{"Bearer token"}},
+		}
+
+		assert.True(t, headers.Has("Content-Type"))
+		assert.True(t, headers.Has("Authorization"))
+	})
+
+	t.Run("Has returns false for non-existent header", func(t *testing.T) {
+		headers := Headers{
+			{Key: "Content-Type", Value: []string{"application/json"}},
+		}
+
+		assert.False(t, headers.Has("Authorization"))
+		assert.False(t, headers.Has("X-Custom-Header"))
+	})
+
+	t.Run("Has with empty headers", func(t *testing.T) {
+		headers := Headers{}
+
+		assert.False(t, headers.Has("Any-Header"))
+	})
+
+	t.Run("Has is case sensitive", func(t *testing.T) {
+		headers := Headers{
+			{Key: "Content-Type", Value: []string{"text/html"}},
+		}
+
+		assert.True(t, headers.Has("Content-Type"))
+		assert.False(t, headers.Has("content-type"))
+		assert.False(t, headers.Has("CONTENT-TYPE"))
+	})
+}
+
+func TestHeaders_GetValue(t *testing.T) {
+	t.Run("GetValue returns existing header value", func(t *testing.T) {
+		headers := Headers{
+			{Key: "Content-Type", Value: []string{"application/json"}},
+			{Key: "Accept", Value: []string{"text/html"}},
+		}
+
+		value := headers.GetValue("Content-Type")
+		require.NotNil(t, value)
+		assert.Equal(t, []string{"application/json"}, *value)
+	})
+
+	t.Run("GetValue returns nil for non-existent header", func(t *testing.T) {
+		headers := Headers{
+			{Key: "Content-Type", Value: []string{"application/json"}},
+		}
+
+		value := headers.GetValue("Authorization")
+		assert.Nil(t, value)
+	})
+
+	t.Run("GetValue with empty headers", func(t *testing.T) {
+		headers := Headers{}
+
+		value := headers.GetValue("Any-Header")
+		assert.Nil(t, value)
+	})
+
+	t.Run("GetValue with multiple values", func(t *testing.T) {
+		headers := Headers{
+			{Key: "Accept", Value: []string{"text/html", "application/xml", "application/json"}},
+		}
+
+		value := headers.GetValue("Accept")
+		require.NotNil(t, value)
+		assert.Equal(t, []string{"text/html", "application/xml", "application/json"}, *value)
+	})
+
+	t.Run("GetValue is case sensitive", func(t *testing.T) {
+		headers := Headers{
+			{Key: "X-Custom-Header", Value: []string{"value"}},
+		}
+
+		value1 := headers.GetValue("X-Custom-Header")
+		require.NotNil(t, value1)
+		assert.Equal(t, []string{"value"}, *value1)
+
+		value2 := headers.GetValue("x-custom-header")
+		assert.Nil(t, value2)
+	})
+}
+
+func TestHeaders_Append(t *testing.T) {
+	t.Run("Append new header", func(t *testing.T) {
+		headers := &Headers{}
+		headers.Append(Header{Key: "Content-Type", Value: []string{"application/json"}})
+
+		assert.Len(t, *headers, 1)
+		assert.Equal(t, "Content-Type", (*headers)[0].Key)
+		assert.Equal(t, []string{"application/json"}, (*headers)[0].Value)
+	})
+
+	t.Run("Append to existing header key", func(t *testing.T) {
+		headers := &Headers{
+			{Key: "Accept", Value: []string{"text/html"}},
+		}
+		headers.Append(Header{Key: "Accept", Value: []string{"application/json"}})
+
+		assert.Len(t, *headers, 1)
+		assert.Equal(t, []string{"text/html", "application/json"}, (*headers)[0].Value)
+	})
+
+	t.Run("Append different headers", func(t *testing.T) {
+		headers := &Headers{}
+		headers.Append(Header{Key: "Content-Type", Value: []string{"application/json"}})
+		headers.Append(Header{Key: "Authorization", Value: []string{"Bearer token"}})
+		headers.Append(Header{Key: "Accept", Value: []string{"*/*"}})
+
+		assert.Len(t, *headers, 3)
+	})
+
+	t.Run("Append multiple values at once", func(t *testing.T) {
+		headers := &Headers{
+			{Key: "Accept-Language", Value: []string{"en"}},
+		}
+		headers.Append(Header{Key: "Accept-Language", Value: []string{"fr", "de"}})
+
+		assert.Len(t, *headers, 1)
+		assert.Equal(t, []string{"en", "fr", "de"}, (*headers)[0].Value)
+	})
+
+	t.Run("Append empty value", func(t *testing.T) {
+		headers := &Headers{}
+		headers.Append(Header{Key: "Empty-Header", Value: []string{""}})
+
+		assert.Len(t, *headers, 1)
+		assert.Equal(t, []string{""}, (*headers)[0].Value)
+	})
+}
+
+func TestHeaders_Parse(t *testing.T) {
+	t.Run("Parse single header", func(t *testing.T) {
+		headers := &Headers{}
+		headers.Parse("Content-Type: application/json")
+
+		assert.Len(t, *headers, 1)
+		assert.Equal(t, "Content-Type", (*headers)[0].Key)
+		assert.Equal(t, []string{"application/json"}, (*headers)[0].Value)
+	})
+
+	t.Run("Parse multiple headers", func(t *testing.T) {
+		headers := &Headers{}
+		headers.Parse("Content-Type: application/json", "Authorization: Bearer token", "Accept: */*")
+
+		assert.Len(t, *headers, 3)
+		assert.Equal(t, "Content-Type", (*headers)[0].Key)
+		assert.Equal(t, "Authorization", (*headers)[1].Key)
+		assert.Equal(t, "Accept", (*headers)[2].Key)
+	})
+
+	t.Run("Parse headers with same key", func(t *testing.T) {
+		headers := &Headers{}
+		headers.Parse("Accept: text/html", "Accept: application/json", "Accept: application/xml")
+
+		assert.Len(t, *headers, 1)
+		assert.Equal(t, []string{"text/html", "application/json", "application/xml"}, (*headers)[0].Value)
+	})
+
+	t.Run("Parse header without value", func(t *testing.T) {
+		headers := &Headers{}
+		headers.Parse("X-Empty-Header")
+
+		assert.Len(t, *headers, 1)
+		assert.Equal(t, "X-Empty-Header", (*headers)[0].Key)
+		assert.Equal(t, []string{""}, (*headers)[0].Value)
+	})
+
+	t.Run("Parse header with empty value", func(t *testing.T) {
+		headers := &Headers{}
+		headers.Parse("X-Empty: ")
+
+		assert.Len(t, *headers, 1)
+		assert.Equal(t, "X-Empty", (*headers)[0].Key)
+		assert.Equal(t, []string{""}, (*headers)[0].Value)
+	})
+
+	t.Run("Parse header with multiple colons", func(t *testing.T) {
+		headers := &Headers{}
+		headers.Parse("X-Time: 12:34:56")
+
+		assert.Len(t, *headers, 1)
+		assert.Equal(t, "X-Time", (*headers)[0].Key)
+		assert.Equal(t, []string{"12:34:56"}, (*headers)[0].Value)
+	})
+
+	t.Run("Parse no arguments", func(t *testing.T) {
+		headers := &Headers{}
+		headers.Parse()
+
+		assert.Empty(t, *headers)
+	})
+
+	t.Run("Parse with existing headers", func(t *testing.T) {
+		headers := &Headers{
+			{Key: "Existing", Value: []string{"value"}},
+		}
+		headers.Parse("New: header")
+
+		assert.Len(t, *headers, 2)
+		assert.Equal(t, "Existing", (*headers)[0].Key)
+		assert.Equal(t, "New", (*headers)[1].Key)
+	})
+}
+
+func TestParseHeader(t *testing.T) {
+	t.Run("ParseHeader with key and value", func(t *testing.T) {
+		header := ParseHeader("Content-Type: application/json")
+		require.NotNil(t, header)
+		assert.Equal(t, "Content-Type", header.Key)
+		assert.Equal(t, []string{"application/json"}, header.Value)
+	})
+
+	t.Run("ParseHeader with only key", func(t *testing.T) {
+		header := ParseHeader("X-Header")
+		require.NotNil(t, header)
+		assert.Equal(t, "X-Header", header.Key)
+		assert.Equal(t, []string{""}, header.Value)
+	})
+
+	t.Run("ParseHeader with empty value", func(t *testing.T) {
+		header := ParseHeader("Key: ")
+		require.NotNil(t, header)
+		assert.Equal(t, "Key", header.Key)
+		assert.Equal(t, []string{""}, header.Value)
+	})
+
+	t.Run("ParseHeader with multiple colons", func(t *testing.T) {
+		header := ParseHeader("X-URL: https://example.com:8080/path")
+		require.NotNil(t, header)
+		assert.Equal(t, "X-URL", header.Key)
+		assert.Equal(t, []string{"https://example.com:8080/path"}, header.Value)
+	})
+
+	t.Run("ParseHeader with empty string", func(t *testing.T) {
+		header := ParseHeader("")
+		require.NotNil(t, header)
+		assert.Empty(t, header.Key)
+		assert.Equal(t, []string{""}, header.Value)
+	})
+
+	t.Run("ParseHeader with spaces in value", func(t *testing.T) {
+		header := ParseHeader("User-Agent: Mozilla/5.0 (Windows NT 10.0)")
+		require.NotNil(t, header)
+		assert.Equal(t, "User-Agent", header.Key)
+		assert.Equal(t, []string{"Mozilla/5.0 (Windows NT 10.0)"}, header.Value)
+	})
+
+	t.Run("ParseHeader without colon-space separator", func(t *testing.T) {
+		header := ParseHeader("Content-Type:application/json")
+		require.NotNil(t, header)
+		assert.Equal(t, "Content-Type:application/json", header.Key)
+		assert.Equal(t, []string{""}, header.Value)
+	})
+
+	t.Run("ParseHeader with trailing spaces", func(t *testing.T) {
+		header := ParseHeader("Header: value with spaces   ")
+		require.NotNil(t, header)
+		assert.Equal(t, "Header", header.Key)
+		assert.Equal(t, []string{"value with spaces   "}, header.Value)
+	})
+}

pkg/types/key_value.go

@@ -0,0 +1,6 @@
+package types
+
+type KeyValue[K comparable, V any] struct {
+	Key   K
+	Value V
+}

pkg/types/param.go

@@ -0,0 +1,42 @@
+package types
+
+import "strings"
+
+type Param KeyValue[string, []string]
+
+type Params []Param
+
+func (params Params) GetValue(key string) *[]string {
+	for i := range params {
+		if params[i].Key == key {
+			return &params[i].Value
+		}
+	}
+	return nil
+}
+
+func (params *Params) Append(param Param) {
+	if item := params.GetValue(param.Key); item != nil {
+		*item = append(*item, param.Value...)
+	} else {
+		*params = append(*params, param)
+	}
+}
+
+func (params *Params) Parse(rawValues ...string) {
+	for _, rawValue := range rawValues {
+		params.Append(*ParseParam(rawValue))
+	}
+}
+
+func ParseParam(rawValue string) *Param {
+	parts := strings.SplitN(rawValue, "=", 2)
+	switch len(parts) {
+	case 1:
+		return &Param{Key: parts[0], Value: []string{""}}
+	case 2:
+		return &Param{Key: parts[0], Value: []string{parts[1]}}
+	default:
+		return &Param{Key: "", Value: []string{""}}
+	}
+}

pkg/types/param_test.go

@@ -0,0 +1,281 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParams_GetValue(t *testing.T) {
+	t.Run("GetValue returns existing parameter value", func(t *testing.T) {
+		params := Params{
+			{Key: "name", Value: []string{"john"}},
+			{Key: "age", Value: []string{"25"}},
+		}
+
+		value := params.GetValue("name")
+		require.NotNil(t, value)
+		assert.Equal(t, []string{"john"}, *value)
+	})
+
+	t.Run("GetValue returns nil for non-existent parameter", func(t *testing.T) {
+		params := Params{
+			{Key: "name", Value: []string{"john"}},
+		}
+
+		value := params.GetValue("nonexistent")
+		assert.Nil(t, value)
+	})
+
+	t.Run("GetValue with empty params", func(t *testing.T) {
+		params := Params{}
+
+		value := params.GetValue("any")
+		assert.Nil(t, value)
+	})
+
+	t.Run("GetValue with multiple values", func(t *testing.T) {
+		params := Params{
+			{Key: "tags", Value: []string{"go", "test", "api"}},
+		}
+
+		value := params.GetValue("tags")
+		require.NotNil(t, value)
+		assert.Equal(t, []string{"go", "test", "api"}, *value)
+	})
+
+	t.Run("GetValue case sensitive", func(t *testing.T) {
+		params := Params{
+			{Key: "Name", Value: []string{"value"}},
+		}
+
+		value1 := params.GetValue("Name")
+		require.NotNil(t, value1)
+		assert.Equal(t, []string{"value"}, *value1)
+
+		value2 := params.GetValue("name")
+		assert.Nil(t, value2)
+	})
+}
+
+func TestParams_Append(t *testing.T) {
+	t.Run("Append new parameter", func(t *testing.T) {
+		params := &Params{}
+		params.Append(Param{Key: "name", Value: []string{"john"}})
+
+		assert.Len(t, *params, 1)
+		assert.Equal(t, "name", (*params)[0].Key)
+		assert.Equal(t, []string{"john"}, (*params)[0].Value)
+	})
+
+	t.Run("Append to existing parameter key", func(t *testing.T) {
+		params := &Params{
+			{Key: "tags", Value: []string{"go"}},
+		}
+		params.Append(Param{Key: "tags", Value: []string{"test"}})
+
+		assert.Len(t, *params, 1)
+		assert.Equal(t, []string{"go", "test"}, (*params)[0].Value)
+	})
+
+	t.Run("Append different parameters", func(t *testing.T) {
+		params := &Params{}
+		params.Append(Param{Key: "name", Value: []string{"john"}})
+		params.Append(Param{Key: "age", Value: []string{"25"}})
+		params.Append(Param{Key: "city", Value: []string{"NYC"}})
+
+		assert.Len(t, *params, 3)
+	})
+
+	t.Run("Append multiple values at once", func(t *testing.T) {
+		params := &Params{
+			{Key: "colors", Value: []string{"red"}},
+		}
+		params.Append(Param{Key: "colors", Value: []string{"blue", "green"}})
+
+		assert.Len(t, *params, 1)
+		assert.Equal(t, []string{"red", "blue", "green"}, (*params)[0].Value)
+	})
+
+	t.Run("Append empty value", func(t *testing.T) {
+		params := &Params{}
+		params.Append(Param{Key: "empty", Value: []string{""}})
+
+		assert.Len(t, *params, 1)
+		assert.Equal(t, []string{""}, (*params)[0].Value)
+	})
+}
+
+func TestParams_Parse(t *testing.T) {
+	t.Run("Parse single parameter", func(t *testing.T) {
+		params := &Params{}
+		params.Parse("name=john")
+
+		assert.Len(t, *params, 1)
+		assert.Equal(t, "name", (*params)[0].Key)
+		assert.Equal(t, []string{"john"}, (*params)[0].Value)
+	})
+
+	t.Run("Parse multiple parameters", func(t *testing.T) {
+		params := &Params{}
+		params.Parse("name=john", "age=25", "city=NYC")
+
+		assert.Len(t, *params, 3)
+		assert.Equal(t, "name", (*params)[0].Key)
+		assert.Equal(t, "age", (*params)[1].Key)
+		assert.Equal(t, "city", (*params)[2].Key)
+	})
+
+	t.Run("Parse parameters with same key", func(t *testing.T) {
+		params := &Params{}
+		params.Parse("filter=name", "filter=age", "filter=city")
+
+		assert.Len(t, *params, 1)
+		assert.Equal(t, []string{"name", "age", "city"}, (*params)[0].Value)
+	})
+
+	t.Run("Parse parameter without value", func(t *testing.T) {
+		params := &Params{}
+		params.Parse("debug")
+
+		assert.Len(t, *params, 1)
+		assert.Equal(t, "debug", (*params)[0].Key)
+		assert.Equal(t, []string{""}, (*params)[0].Value)
+	})
+
+	t.Run("Parse parameter with empty value", func(t *testing.T) {
+		params := &Params{}
+		params.Parse("empty=")
+
+		assert.Len(t, *params, 1)
+		assert.Equal(t, "empty", (*params)[0].Key)
+		assert.Equal(t, []string{""}, (*params)[0].Value)
+	})
+
+	t.Run("Parse parameter with multiple equals", func(t *testing.T) {
+		params := &Params{}
+		params.Parse("equation=x=y+z")
+
+		assert.Len(t, *params, 1)
+		assert.Equal(t, "equation", (*params)[0].Key)
+		assert.Equal(t, []string{"x=y+z"}, (*params)[0].Value)
+	})
+
+	t.Run("Parse no arguments", func(t *testing.T) {
+		params := &Params{}
+		params.Parse()
+
+		assert.Empty(t, *params)
+	})
+
+	t.Run("Parse with existing parameters", func(t *testing.T) {
+		params := &Params{
+			{Key: "existing", Value: []string{"value"}},
+		}
+		params.Parse("new=param")
+
+		assert.Len(t, *params, 2)
+		assert.Equal(t, "existing", (*params)[0].Key)
+		assert.Equal(t, "new", (*params)[1].Key)
+	})
+
+	t.Run("Parse URL-encoded values", func(t *testing.T) {
+		params := &Params{}
+		params.Parse("query=hello%20world", "special=%21%40%23")
+
+		assert.Len(t, *params, 2)
+		assert.Equal(t, []string{"hello%20world"}, (*params)[0].Value)
+		assert.Equal(t, []string{"%21%40%23"}, (*params)[1].Value)
+	})
+}
+
+func TestParseParam(t *testing.T) {
+	t.Run("ParseParam with key and value", func(t *testing.T) {
+		param := ParseParam("name=john")
+		require.NotNil(t, param)
+		assert.Equal(t, "name", param.Key)
+		assert.Equal(t, []string{"john"}, param.Value)
+	})
+
+	t.Run("ParseParam with only key", func(t *testing.T) {
+		param := ParseParam("debug")
+		require.NotNil(t, param)
+		assert.Equal(t, "debug", param.Key)
+		assert.Equal(t, []string{""}, param.Value)
+	})
+
+	t.Run("ParseParam with empty value", func(t *testing.T) {
+		param := ParseParam("key=")
+		require.NotNil(t, param)
+		assert.Equal(t, "key", param.Key)
+		assert.Equal(t, []string{""}, param.Value)
+	})
+
+	t.Run("ParseParam with multiple equals", func(t *testing.T) {
+		param := ParseParam("data=key=value=test")
+		require.NotNil(t, param)
+		assert.Equal(t, "data", param.Key)
+		assert.Equal(t, []string{"key=value=test"}, param.Value)
+	})
+
+	t.Run("ParseParam with empty string", func(t *testing.T) {
+		param := ParseParam("")
+		require.NotNil(t, param)
+		assert.Empty(t, param.Key)
+		assert.Equal(t, []string{""}, param.Value)
+	})
+
+	t.Run("ParseParam with spaces", func(t *testing.T) {
+		param := ParseParam("key with spaces=value with spaces")
+		require.NotNil(t, param)
+		assert.Equal(t, "key with spaces", param.Key)
+		assert.Equal(t, []string{"value with spaces"}, param.Value)
+	})
+
+	t.Run("ParseParam with special characters", func(t *testing.T) {
+		param := ParseParam("key-._~=val!@#$%^&*()")
+		require.NotNil(t, param)
+		assert.Equal(t, "key-._~", param.Key)
+		assert.Equal(t, []string{"val!@#$%^&*()"}, param.Value)
+	})
+
+	t.Run("ParseParam with numeric values", func(t *testing.T) {
+		param := ParseParam("count=42")
+		require.NotNil(t, param)
+		assert.Equal(t, "count", param.Key)
+		assert.Equal(t, []string{"42"}, param.Value)
+	})
+
+	t.Run("ParseParam with boolean-like values", func(t *testing.T) {
+		testCases := []struct {
+			input    string
+			expected string
+		}{
+			{"active=true", "true"},
+			{"enabled=false", "false"},
+			{"visible=1", "1"},
+			{"hidden=0", "0"},
+		}
+
+		for _, testCase := range testCases {
+			param := ParseParam(testCase.input)
+			require.NotNil(t, param)
+			assert.Equal(t, []string{testCase.expected}, param.Value)
+		}
+	})
+
+	t.Run("ParseParam with URL-encoded value", func(t *testing.T) {
+		param := ParseParam("message=hello%20world")
+		require.NotNil(t, param)
+		assert.Equal(t, "message", param.Key)
+		assert.Equal(t, []string{"hello%20world"}, param.Value)
+	})
+
+	t.Run("ParseParam with JSON-like value", func(t *testing.T) {
+		param := ParseParam(`data={"key":"value"}`)
+		require.NotNil(t, param)
+		assert.Equal(t, "data", param.Key)
+		assert.Equal(t, []string{`{"key":"value"}`}, param.Value)
+	})
+}

pkg/types/proxy.go

@@ -0,0 +1,38 @@
+package types
+
+import (
+	"fmt"
+	"net/url"
+)
+
+type Proxy url.URL
+
+func (proxy Proxy) String() string {
+	return (*url.URL)(&proxy).String()
+}
+
+type Proxies []Proxy
+
+func (proxies *Proxies) Append(proxy Proxy) {
+	*proxies = append(*proxies, proxy)
+}
+
+func (proxies *Proxies) Parse(rawValue string) error {
+	parsedProxy, err := ParseProxy(rawValue)
+	if err != nil {
+		return err
+	}
+
+	proxies.Append(*parsedProxy)
+	return nil
+}
+
+func ParseProxy(rawValue string) (*Proxy, error) {
+	urlParsed, err := url.Parse(rawValue)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse proxy URL: %w", err)
+	}
+
+	proxyParsed := Proxy(*urlParsed)
+	return &proxyParsed, nil
+}

pkg/types/proxy_test.go

@@ -0,0 +1,285 @@
+package types
+
+import (
+	"net/url"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestProxy_String(t *testing.T) {
+	t.Run("Proxy String returns correct URL", func(t *testing.T) {
+		u, err := url.Parse("http://proxy.example.com:8080")
+		require.NoError(t, err)
+
+		proxy := Proxy(*u)
+		assert.Equal(t, "http://proxy.example.com:8080", proxy.String())
+	})
+
+	t.Run("Proxy String with HTTPS", func(t *testing.T) {
+		u, err := url.Parse("https://secure-proxy.example.com:443")
+		require.NoError(t, err)
+
+		proxy := Proxy(*u)
+		assert.Equal(t, "https://secure-proxy.example.com:443", proxy.String())
+	})
+
+	t.Run("Proxy String with authentication", func(t *testing.T) {
+		u, err := url.Parse("http://user:pass@proxy.example.com:8080")
+		require.NoError(t, err)
+
+		proxy := Proxy(*u)
+		assert.Equal(t, "http://user:pass@proxy.example.com:8080", proxy.String())
+	})
+
+	t.Run("Proxy String with path", func(t *testing.T) {
+		u, err := url.Parse("http://proxy.example.com:8080/proxy/path")
+		require.NoError(t, err)
+
+		proxy := Proxy(*u)
+		assert.Equal(t, "http://proxy.example.com:8080/proxy/path", proxy.String())
+	})
+
+	t.Run("Proxy String with query params", func(t *testing.T) {
+		u, err := url.Parse("http://proxy.example.com:8080/?timeout=30&retry=3")
+		require.NoError(t, err)
+
+		proxy := Proxy(*u)
+		assert.Equal(t, "http://proxy.example.com:8080/?timeout=30&retry=3", proxy.String())
+	})
+}
+
+func TestProxies_Append(t *testing.T) {
+	t.Run("Append single proxy", func(t *testing.T) {
+		proxies := &Proxies{}
+		u, err := url.Parse("http://proxy1.example.com:8080")
+		require.NoError(t, err)
+
+		proxy := Proxy(*u)
+		proxies.Append(proxy)
+
+		assert.Len(t, *proxies, 1)
+		assert.Equal(t, "http://proxy1.example.com:8080", (*proxies)[0].String())
+	})
+
+	t.Run("Append multiple proxies", func(t *testing.T) {
+		proxies := &Proxies{}
+
+		url1, err := url.Parse("http://proxy1.example.com:8080")
+		require.NoError(t, err)
+		url2, err := url.Parse("http://proxy2.example.com:8081")
+		require.NoError(t, err)
+		url3, err := url.Parse("https://proxy3.example.com:443")
+		require.NoError(t, err)
+
+		proxies.Append(Proxy(*url1))
+		proxies.Append(Proxy(*url2))
+		proxies.Append(Proxy(*url3))
+
+		assert.Len(t, *proxies, 3)
+		assert.Equal(t, "http://proxy1.example.com:8080", (*proxies)[0].String())
+		assert.Equal(t, "http://proxy2.example.com:8081", (*proxies)[1].String())
+		assert.Equal(t, "https://proxy3.example.com:443", (*proxies)[2].String())
+	})
+
+	t.Run("Append to existing proxies", func(t *testing.T) {
+		existingURL, err := url.Parse("http://existing.example.com:8080")
+		require.NoError(t, err)
+
+		proxies := &Proxies{Proxy(*existingURL)}
+
+		newURL, err := url.Parse("http://new.example.com:8081")
+		require.NoError(t, err)
+
+		proxies.Append(Proxy(*newURL))
+
+		assert.Len(t, *proxies, 2)
+		assert.Equal(t, "http://existing.example.com:8080", (*proxies)[0].String())
+		assert.Equal(t, "http://new.example.com:8081", (*proxies)[1].String())
+	})
+}
+
+func TestProxies_Parse(t *testing.T) {
+	t.Run("Parse valid proxy URL", func(t *testing.T) {
+		proxies := &Proxies{}
+		err := proxies.Parse("http://proxy.example.com:8080")
+
+		require.NoError(t, err)
+		assert.Len(t, *proxies, 1)
+		assert.Equal(t, "http://proxy.example.com:8080", (*proxies)[0].String())
+	})
+
+	t.Run("Parse HTTPS proxy URL", func(t *testing.T) {
+		proxies := &Proxies{}
+		err := proxies.Parse("https://secure-proxy.example.com:443")
+
+		require.NoError(t, err)
+		assert.Len(t, *proxies, 1)
+		assert.Equal(t, "https://secure-proxy.example.com:443", (*proxies)[0].String())
+	})
+
+	t.Run("Parse proxy URL with authentication", func(t *testing.T) {
+		proxies := &Proxies{}
+		err := proxies.Parse("http://user:pass@proxy.example.com:8080")
+
+		require.NoError(t, err)
+		assert.Len(t, *proxies, 1)
+		assert.Equal(t, "http://user:pass@proxy.example.com:8080", (*proxies)[0].String())
+	})
+
+	t.Run("Parse invalid proxy URL", func(t *testing.T) {
+		proxies := &Proxies{}
+		err := proxies.Parse("://invalid-url")
+
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "failed to parse proxy URL")
+		assert.Empty(t, *proxies)
+	})
+
+	t.Run("Parse empty string", func(t *testing.T) {
+		proxies := &Proxies{}
+		err := proxies.Parse("")
+
+		require.NoError(t, err)
+		assert.Len(t, *proxies, 1)
+		assert.Empty(t, (*proxies)[0].String())
+	})
+
+	t.Run("Parse to existing proxies", func(t *testing.T) {
+		existingURL, err := url.Parse("http://existing.example.com:8080")
+		require.NoError(t, err)
+
+		proxies := &Proxies{Proxy(*existingURL)}
+		err = proxies.Parse("http://new.example.com:8081")
+
+		require.NoError(t, err)
+		assert.Len(t, *proxies, 2)
+		assert.Equal(t, "http://existing.example.com:8080", (*proxies)[0].String())
+		assert.Equal(t, "http://new.example.com:8081", (*proxies)[1].String())
+	})
+
+	t.Run("Parse proxy with special characters", func(t *testing.T) {
+		proxies := &Proxies{}
+		err := proxies.Parse("http://proxy.example.com:8080/path?param=value&other=test")
+
+		require.NoError(t, err)
+		assert.Len(t, *proxies, 1)
+		assert.Equal(t, "http://proxy.example.com:8080/path?param=value&other=test", (*proxies)[0].String())
+	})
+}
+
+func TestParseProxy(t *testing.T) {
+	t.Run("ParseProxy with valid HTTP URL", func(t *testing.T) {
+		proxy, err := ParseProxy("http://proxy.example.com:8080")
+
+		require.NoError(t, err)
+		require.NotNil(t, proxy)
+		assert.Equal(t, "http://proxy.example.com:8080", proxy.String())
+	})
+
+	t.Run("ParseProxy with valid HTTPS URL", func(t *testing.T) {
+		proxy, err := ParseProxy("https://secure-proxy.example.com:443")
+
+		require.NoError(t, err)
+		require.NotNil(t, proxy)
+		assert.Equal(t, "https://secure-proxy.example.com:443", proxy.String())
+	})
+
+	t.Run("ParseProxy with authentication", func(t *testing.T) {
+		proxy, err := ParseProxy("http://user:password@proxy.example.com:8080")
+
+		require.NoError(t, err)
+		require.NotNil(t, proxy)
+		assert.Equal(t, "http://user:password@proxy.example.com:8080", proxy.String())
+	})
+
+	t.Run("ParseProxy with path", func(t *testing.T) {
+		proxy, err := ParseProxy("http://proxy.example.com:8080/proxy/endpoint")
+
+		require.NoError(t, err)
+		require.NotNil(t, proxy)
+		assert.Equal(t, "http://proxy.example.com:8080/proxy/endpoint", proxy.String())
+	})
+
+	t.Run("ParseProxy with query parameters", func(t *testing.T) {
+		proxy, err := ParseProxy("http://proxy.example.com:8080/?timeout=30&retry=3")
+
+		require.NoError(t, err)
+		require.NotNil(t, proxy)
+		assert.Equal(t, "http://proxy.example.com:8080/?timeout=30&retry=3", proxy.String())
+	})
+
+	t.Run("ParseProxy with malformed URL", func(t *testing.T) {
+		proxy, err := ParseProxy("://malformed-url")
+
+		require.Error(t, err)
+		assert.Nil(t, proxy)
+		assert.Contains(t, err.Error(), "failed to parse proxy URL")
+	})
+
+	t.Run("ParseProxy with empty string", func(t *testing.T) {
+		proxy, err := ParseProxy("")
+
+		require.NoError(t, err)
+		require.NotNil(t, proxy)
+		assert.Empty(t, proxy.String())
+	})
+
+	t.Run("ParseProxy with localhost", func(t *testing.T) {
+		proxy, err := ParseProxy("http://localhost:3128")
+
+		require.NoError(t, err)
+		require.NotNil(t, proxy)
+		assert.Equal(t, "http://localhost:3128", proxy.String())
+	})
+
+	t.Run("ParseProxy with IP address", func(t *testing.T) {
+		proxy, err := ParseProxy("http://192.168.1.100:8080")
+
+		require.NoError(t, err)
+		require.NotNil(t, proxy)
+		assert.Equal(t, "http://192.168.1.100:8080", proxy.String())
+	})
+
+	t.Run("ParseProxy without scheme", func(t *testing.T) {
+		proxy, err := ParseProxy("proxy.example.com:8080")
+
+		require.NoError(t, err)
+		require.NotNil(t, proxy)
+		assert.Equal(t, "proxy.example.com:8080", proxy.String())
+	})
+
+	t.Run("ParseProxy with SOCKS protocol", func(t *testing.T) {
+		proxy, err := ParseProxy("socks5://proxy.example.com:1080")
+
+		require.NoError(t, err)
+		require.NotNil(t, proxy)
+		assert.Equal(t, "socks5://proxy.example.com:1080", proxy.String())
+	})
+
+	t.Run("ParseProxy preserves URL components", func(t *testing.T) {
+		rawURL := "http://user:pass@proxy.example.com:8080/path?param=value#fragment"
+		proxy, err := ParseProxy(rawURL)
+
+		require.NoError(t, err)
+		require.NotNil(t, proxy)
+		assert.Equal(t, rawURL, proxy.String())
+	})
+
+	t.Run("ParseProxy with percent encoding", func(t *testing.T) {
+		proxy, err := ParseProxy("http://proxy.example.com:8080/path%20with%20spaces")
+
+		require.NoError(t, err)
+		require.NotNil(t, proxy)
+		assert.Equal(t, "http://proxy.example.com:8080/path%20with%20spaces", proxy.String())
+	})
+
+	t.Run("ParseProxy error message format", func(t *testing.T) {
+		_, err := ParseProxy("http://[invalid-ipv6")
+
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "failed to parse proxy URL:")
+		assert.Contains(t, err.Error(), "missing ']' in host")
+	})
+}