e3.0.0 Added env variable support, improved cli arg, added tests, updated documentation.

This commit is contained in:
2025-07-01 13:06:07 -04:00
parent b1e241149e
commit 4053c463d6
17 changed files with 2290 additions and 615 deletions

239
config.go
View File

@ -1,40 +1,149 @@
// File: lixenwraith/config/config.go
// Package config provides thread-safe configuration management for Go applications
// with support for TOML files, command-line overrides, and default values.
// with support for multiple sources: TOML files, environment variables, command-line
// arguments, and default values with configurable precedence.
package config
import (
"errors" // Import errors package
"errors"
"fmt"
"sync"
)
// ErrConfigNotFound indicates the specified configuration file was not found.
var ErrConfigNotFound = errors.New("configuration file not found")
// Errors
var (
// ErrConfigNotFound indicates the specified configuration file was not found.
ErrConfigNotFound = errors.New("configuration file not found")
// ErrCLIParse indicates that parsing command-line arguments failed.
var ErrCLIParse = errors.New("failed to parse command-line arguments")
// ErrCLIParse indicates that parsing command-line arguments failed.
ErrCLIParse = errors.New("failed to parse command-line arguments")
// configItem holds both the default and current value for a configuration path
type configItem struct {
defaultValue any
currentValue any
// ErrEnvParse indicates that parsing environment variables failed.
ErrEnvParse = errors.New("failed to parse environment variables")
)
// Source represents a configuration source
type Source string
const (
SourceDefault Source = "default"
SourceFile Source = "file"
SourceEnv Source = "env"
SourceCLI Source = "cli"
)
// LoadMode defines how configuration sources are processed
type LoadMode int
const (
// LoadModeReplace completely replaces values (default behavior)
LoadModeReplace LoadMode = iota
// LoadModeMerge merges maps/structs instead of replacing
LoadModeMerge
)
// EnvTransformFunc converts a configuration path to an environment variable name
type EnvTransformFunc func(path string) string
// LoadOptions configures how configuration is loaded from multiple sources
type LoadOptions struct {
// Sources defines the precedence order (first = highest priority)
// Default: [SourceCLI, SourceEnv, SourceFile, SourceDefault]
Sources []Source
// EnvPrefix is prepended to environment variable names
// Example: "MYAPP_" transforms "server.port" to "MYAPP_SERVER_PORT"
EnvPrefix string
// EnvTransform customizes how paths map to environment variables
// If nil, uses default transformation (dots to underscores, uppercase)
EnvTransform EnvTransformFunc
// LoadMode determines how values are merged
LoadMode LoadMode
// EnvWhitelist limits which paths are checked for env vars (nil = all)
EnvWhitelist map[string]bool
// SkipValidation skips path validation during load
SkipValidation bool
}
// Config manages application configuration loaded from files and CLI arguments.
// DefaultLoadOptions returns the standard load options
func DefaultLoadOptions() LoadOptions {
return LoadOptions{
Sources: []Source{SourceCLI, SourceEnv, SourceFile, SourceDefault},
LoadMode: LoadModeReplace,
}
}
// configItem holds configuration values from different sources
type configItem struct {
defaultValue any
values map[Source]any // Values from each source
currentValue any // Computed value based on precedence
}
// Config manages application configuration loaded from multiple sources.
type Config struct {
items map[string]configItem
mutex sync.RWMutex
items map[string]configItem
mutex sync.RWMutex
options LoadOptions // Current load options
fileData map[string]any // Cached file data
envData map[string]any // Cached env data
cliData map[string]any // Cached CLI data
}
// New creates and initializes a new Config instance.
func New() *Config {
return &Config{
items: make(map[string]configItem),
items: make(map[string]configItem),
options: DefaultLoadOptions(),
fileData: make(map[string]any),
envData: make(map[string]any),
cliData: make(map[string]any),
}
}
// NewWithOptions creates a new Config instance with custom load options
func NewWithOptions(opts LoadOptions) *Config {
c := New()
c.options = opts
return c
}
// SetLoadOptions updates the load options and recomputes current values
func (c *Config) SetLoadOptions(opts LoadOptions) error {
c.mutex.Lock()
defer c.mutex.Unlock()
c.options = opts
// Recompute all current values based on new precedence
for path, item := range c.items {
item.currentValue = c.computeValue(path, item)
c.items[path] = item
}
return nil
}
// computeValue determines the current value based on precedence
func (c *Config) computeValue(path string, item configItem) any {
// Check sources in precedence order
for _, source := range c.options.Sources {
if val, exists := item.values[source]; exists && val != nil {
return val
}
}
// No source had a value, use default
return item.defaultValue
}
// Get retrieves a configuration value using the path.
// It returns the current value (or default if not explicitly set).
// It returns the current value based on configured precedence.
// The second return value indicates if the path was registered.
func (c *Config) Get(path string) (any, bool) {
c.mutex.RLock()
@ -48,11 +157,29 @@ func (c *Config) Get(path string) (any, bool) {
return item.currentValue, true
}
// GetSource retrieves a value from a specific source
func (c *Config) GetSource(path string, source Source) (any, bool) {
c.mutex.RLock()
defer c.mutex.RUnlock()
item, registered := c.items[path]
if !registered {
return nil, false
}
val, exists := item.values[source]
return val, exists
}
// Set updates a configuration value for the given path.
// It returns an error if the path is not registered.
// Note: This allows setting a value of a different type than the default.
// Type-specific getters will handle conversion attempts.
// It sets the value in the highest priority source (typically CLI).
// Returns an error if the path is not registered.
func (c *Config) Set(path string, value any) error {
return c.SetSource(path, c.options.Sources[0], value)
}
// SetSource sets a value for a specific source
func (c *Config) SetSource(path string, source Source, value any) error {
c.mutex.Lock()
defer c.mutex.Unlock()
@ -61,7 +188,81 @@ func (c *Config) Set(path string, value any) error {
return fmt.Errorf("path %s is not registered", path)
}
item.currentValue = value
if item.values == nil {
item.values = make(map[Source]any)
}
item.values[source] = value
item.currentValue = c.computeValue(path, item)
c.items[path] = item
// Update source cache
switch source {
case SourceFile:
c.fileData[path] = value
case SourceEnv:
c.envData[path] = value
case SourceCLI:
c.cliData[path] = value
}
return nil
}
// GetSources returns all sources that have a value for the given path
func (c *Config) GetSources(path string) map[Source]any {
c.mutex.RLock()
defer c.mutex.RUnlock()
item, registered := c.items[path]
if !registered {
return nil
}
result := make(map[Source]any)
for source, value := range item.values {
result[source] = value
}
return result
}
// Reset clears all non-default values and resets to defaults
func (c *Config) Reset() {
c.mutex.Lock()
defer c.mutex.Unlock()
// Clear source caches
c.fileData = make(map[string]any)
c.envData = make(map[string]any)
c.cliData = make(map[string]any)
// Reset all items to default values
for path, item := range c.items {
item.values = make(map[Source]any)
item.currentValue = item.defaultValue
c.items[path] = item
}
}
// ResetSource clears all values from a specific source
func (c *Config) ResetSource(source Source) {
c.mutex.Lock()
defer c.mutex.Unlock()
// Clear source cache
switch source {
case SourceFile:
c.fileData = make(map[string]any)
case SourceEnv:
c.envData = make(map[string]any)
case SourceCLI:
c.cliData = make(map[string]any)
}
// Remove source values from all items
for path, item := range c.items {
delete(item.values, source)
item.currentValue = c.computeValue(path, item)
c.items[path] = item
}
}