feat: add support for toml and .env file formats in ReadFile function

.gitignore

@@ -7,3 +7,4 @@ Thumbs.db
 .env
 coverage.out
 bin
+cmd

README.md

@@ -2,7 +2,7 @@
 This project is a Go library for reading configuration data from various sources such as environment variables, command-line flags, and configuration files. The library provides a unified interface for reading configuration data, making it easier to manage and maintain your application's configuration.  
 
 ## Attention
-The library uses the [env](github.com/caarlos0/env) and [flaggy](github.com/integrii/flaggy) codebase to work with environment variables and flags. This is a temporary solution, maybe I’ll write my own implementation later. Thanks to the authors of these libraries for the work done!
+The library uses the [env](github.com/caarlos0/env), [toml](github.com/BurntSushi/toml), [godotenv](github.com/joho/godotenv) and [flaggy](github.com/integrii/flaggy) codebase to work with environment variables and flags. This is a temporary solution, maybe I’ll write my own implementation later. Thanks to the authors of these libraries for the work done!
 
 ### Installation
 To install the library, use the go get command:
@@ -17,7 +17,7 @@ The library provides several functions for reading configuration data:
 - `MustReadEnv(cfg any)`: Similar to `ReadEnv` but panics if the reading process fails.  
 - `ReadFlag(cfg any) error`: Reads command-line flags into the provided `cfg` structure. Each field in the `cfg` structure represents a command-line flag.  
 - `MustReadFlag(cfg any)`: Similar to `ReadFlag` but panics if the reading process fails.  
-- `ReadFile(path string, cfg any) error`: Reads configuration from a file into the provided `cfg` structure. The path parameter is the path to the configuration file. Each field in the `cfg` structure represents a configuration option. Supported file formats include JSON and YAML.
+- `ReadFile(path string, cfg any) error`: Reads configuration from a file into the provided `cfg` structure. The path parameter is the path to the configuration file. Each field in the `cfg` structure represents a configuration option. Supported file formats include JSON, YAML, TOML and .env.
 - `MustReadFile(path string, cfg any)`: Similar to `ReadFile` but panics if the reading process fails.
 
 Here is an example of how to use the library:

go.mod

@@ -8,3 +8,8 @@ require (
 	github.com/caarlos0/env/v10 v10.0.0
 	github.com/integrii/flaggy v1.5.2
 )
+
+require (
+	github.com/BurntSushi/toml v1.3.2 // indirect
+	github.com/joho/godotenv v1.5.1 // indirect
+)

go.sum

@@ -1,9 +1,13 @@
+github.com/BurntSushi/toml v1.3.2 h1:o7IhLm0Msx3BaB+n3Ag7L8EVlByGnpq14C4YWiu/gL8=
+github.com/BurntSushi/toml v1.3.2/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
 github.com/caarlos0/env/v10 v10.0.0 h1:yIHUBZGsyqCnpTkbjk8asUlx6RFhhEs+h7TOBdgdzXA=
 github.com/caarlos0/env/v10 v10.0.0/go.mod h1:ZfulV76NvVPw3tm591U4SwL3Xx9ldzBP9aGxzeN7G18=
 github.com/google/go-cmp v0.5.6 h1:BKbKCqvP6I+rmFHt06ZmyQtvB8xAkWdhFyr0ZUNZcxQ=
 github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/integrii/flaggy v1.5.2 h1:bWV20MQEngo4hWhno3i5Z9ISPxLPKj9NOGNwTWb/8IQ=
 github.com/integrii/flaggy v1.5.2/go.mod h1:dO13u7SYuhk910nayCJ+s1DeAAGC1THCMj1uSFmwtQ8=
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

internal/file/read.go

@@ -8,6 +8,10 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/dsbasko/go-cfg/pkg/structs"
+
+	"github.com/BurntSushi/toml"
+	"github.com/joho/godotenv"
 	"gopkg.in/yaml.v3"
 )
 
@@ -31,6 +35,14 @@ func Read(path string, cfg any) error {
 		if err = parseYAML(file, cfg); err != nil {
 			return fmt.Errorf("failed to parse yaml: %w", err)
 		}
+	case ".toml":
+		if err = parseTOML(file, cfg); err != nil {
+			return fmt.Errorf("failed to parse toml: %w", err)
+		}
+	case ".env":
+		if err = parseENV(file, cfg); err != nil {
+			return fmt.Errorf("failed to parse env: %w", err)
+		}
 	}
 
 	return nil
@@ -49,3 +61,27 @@ func parseJSON(r io.Reader, cfg any) error {
 func parseYAML(r io.Reader, cfg any) error {
 	return yaml.NewDecoder(r).Decode(cfg)
 }
+
+// parseTOML is a helper function used by Read to parse the TOML content of the file.
+// It takes an io.Reader and a pointer to a struct where each field represents a configuration option.
+// The function returns an error if the parsing process fails.
+func parseTOML(r io.Reader, cfg any) error {
+	_, err := toml.NewDecoder(r).Decode(cfg)
+	return err
+}
+
+// parseENV parses the environment variables from the given io.Reader and populates the provided configuration struct.
+// It uses the godotenv package to parse the data.
+// If an error occurs during parsing or populating the struct, it returns the error.
+func parseENV(r io.Reader, cfg any) error {
+	data, err := godotenv.Parse(r)
+	if err != nil {
+		return err
+	}
+
+	if err := structs.FromMap(data, cfg); err != nil {
+		return err
+	}
+
+	return nil
+}

pkg/structs/from-map.go

@@ -0,0 +1,86 @@
+package structs
+
+import (
+	"fmt"
+	"reflect"
+	"strconv"
+)
+
+// FromMap maps the values from the given data map to the corresponding fields in the cfg struct.
+// The cfg parameter must be a pointer to a struct. The mapping is done based on the "env" tag of each field.
+// If a field has a non-empty "env" tag, its value will be set to the corresponding value from the data map.
+// Returns an error if the cfg parameter is not a pointer to a struct.
+func FromMap(inMap map[string]string, inStruct any) error { // nolint: funlen,gocyclo,nolintlint
+	valueOf := reflect.ValueOf(inStruct)
+
+	if valueOf.Kind() != reflect.Ptr || valueOf.IsNil() {
+		return fmt.Errorf("must be a non-nil pointer to a struct")
+	}
+
+	valueOf = valueOf.Elem()
+	if valueOf.Kind() != reflect.Struct {
+		return fmt.Errorf("must be a pointer to a struct")
+	}
+
+	for i := 0; i < valueOf.NumField(); i++ {
+		field := valueOf.Type().Field(i)
+
+		// If the field is a struct, call FromMap recursively
+		// to map the values from the data map to the fields of the struct.
+		if field.Type.Kind() == reflect.Struct {
+			if err := FromMap(inMap, valueOf.Field(i).Addr().Interface()); err != nil {
+				return err
+			}
+			continue
+		}
+
+		tag := field.Tag.Get("env")
+		if tag != "" {
+			switch field.Type.Kind() {
+			case reflect.String:
+				valueOf.Field(i).SetString(inMap[tag])
+			case reflect.Int:
+				valInt, _ := strconv.ParseInt(inMap[tag], 10, 0)
+				valueOf.Field(i).SetInt(valInt)
+			case reflect.Int8:
+				valInt, _ := strconv.ParseInt(inMap[tag], 10, 8)
+				valueOf.Field(i).SetInt(valInt)
+			case reflect.Int16:
+				valInt, _ := strconv.ParseInt(inMap[tag], 10, 16)
+				valueOf.Field(i).SetInt(valInt)
+			case reflect.Int32:
+				valInt, _ := strconv.ParseInt(inMap[tag], 10, 32)
+				valueOf.Field(i).SetInt(valInt)
+			case reflect.Int64:
+				valInt, _ := strconv.ParseInt(inMap[tag], 10, 64)
+				valueOf.Field(i).SetInt(valInt)
+			case reflect.Uint:
+				valUint, _ := strconv.ParseUint(inMap[tag], 10, 0)
+				valueOf.Field(i).SetUint(valUint)
+			case reflect.Uint8:
+				valUint, _ := strconv.ParseUint(inMap[tag], 10, 8)
+				valueOf.Field(i).SetUint(valUint)
+			case reflect.Uint16:
+				valUint, _ := strconv.ParseUint(inMap[tag], 10, 16)
+				valueOf.Field(i).SetUint(valUint)
+			case reflect.Uint32:
+				valUint, _ := strconv.ParseUint(inMap[tag], 10, 32)
+				valueOf.Field(i).SetUint(valUint)
+			case reflect.Uint64:
+				valUint, _ := strconv.ParseUint(inMap[tag], 10, 64)
+				valueOf.Field(i).SetUint(valUint)
+			case reflect.Float64:
+				valFloat, _ := strconv.ParseFloat(inMap[tag], 64)
+				valueOf.Field(i).SetFloat(valFloat)
+			case reflect.Float32:
+				valFloat, _ := strconv.ParseFloat(inMap[tag], 32)
+				valueOf.Field(i).SetFloat(valFloat)
+			case reflect.Bool:
+				valBool, _ := strconv.ParseBool(inMap[tag])
+				valueOf.Field(i).SetBool(valBool)
+			}
+		}
+	}
+
+	return nil
+}