conf_test.go

@@ -17,12 +17,15 @@ editor = vim
 distance=13.42
 floats=0.5,2.37,6
 floatswithstring = 0.5, hello, 0.9
-no missedme
+false
 color`)
 
 func TestPackage(t *testing.T) {
 	r := bytes.NewReader(testConf)
-	c := parseReader(r)
+	c, err := parseReader(r)
+	if err != nil {
+		t.Fatal(err)
+	}
 	if _, err := c.Get("floatswithstring").Float64Slice(); err == nil {
 		t.Log("Float64Slice accepting incorrect values")
 		t.Fail()
@@ -99,7 +102,7 @@ func TestPackage(t *testing.T) {
 		t.Log("empty string erroneously converts to float")
 		t.Fail()
 	}
-	if def := c.GetDefault("non-existant-key", "myvalue"); def.Value != "myvalue" {
+	if def := c.GetDefault("non-existant-key", "myvalue"); def.String() != "myvalue" {
 		t.Log("GetDefault fails to apply default value")
 		t.Fail()
 	}

config.go

@@ -56,54 +56,57 @@
 // quite self-explanatory.
 package conf
 
-// Config holds parsed keys and values. Settings and Options can be
+// Config holds parsed keys and values.
-// accessed with Config.Settings and Config.Options maps directly.
+type Conf struct {
-type Config struct {
 	// Settings store key value pairs ("key = value" in config file)
 	// all key value pairs found when parsing input are accumulated in this map.
-	Settings map[string]string
+	settings map[string]string
-	// Options map stores single word options ("option" in config file)
-	Options map[string]struct{}
 }
 
 // Find looks up a Setting and returns it. If returned error is not nil
 // the requested key was not found and returned Setting has empty string in Value
 // field.
-func (c *Config) Find(key string) (s Setting, err error) {
+func (c *Conf) Find(key string) (Setting, bool) {
-	v, ok := c.Settings[key]
+	return c.get(key, "")
-	if !ok {
-		err = ErrNotFound
-	}
-	s.Value = v
-	return
 }
 
 // Get returns a Setting. If key was not found the returned Setting Value
 // will be empty string.
-func (c *Config) Get(key string) (s Setting) {
+func (c *Conf) Get(key string) Setting {
-	s.Value = c.Settings[key]
+	s, _ := c.get(key, "")
-	return
+	return s
 }
 
 // GetDefault looks up a Setting with requested key.
 // If lookup fails it returns Setting with Value field set to def.
-func (c *Config) GetDefault(key, def string) (s Setting) {
+func (c *Conf) GetDefault(key, def string) Setting {
-	v, ok := c.Settings[key]
+	s, _ := c.get(key, def)
-	switch ok {
+	return s
-	case true:
-		s.Value = v
-	default:
-		s.Value = def
-	}
-	return
 }
 
-// HasOption returns true if line:
+func (c *Conf) Settings() []Setting {
-//
+	list := make([]Setting, 0, len(c.settings))
-//	"key"
+
-//
+	for k, v := range c.settings {
-// was found in the parsed file
+		s := Setting{
-func (c *Config) HasOption(option string) (exists bool) {
+			Name:  k,
-	_, exists = c.Options[option]
+			Value: v,
-	return
+		}
+
+		list = append(list, s)
+	}
+
+	return list
+}
+
+func (c *Conf) get(key string, def string) (Setting, bool) {
+	v, ok := c.settings[key]
+	if def != "" && !ok {
+		v = def
+	}
+
+	return Setting{
+		Name:  key,
+		Value: v,
+	}, ok
 }

parser.go

@@ -2,66 +2,107 @@ package conf
 
 import (
 	"bufio"
+	"errors"
+	"fmt"
 	"io"
 	"os"
-	"regexp"
 	"strings"
 )
 
-var (
+const (
-	configKeyValueRe   = regexp.MustCompile(`(\w+) *= *(.+)\b[\t| |\n]*`)
+	strComment = "#"
-	configOptionRe     = regexp.MustCompile(`(\w+)`)
+	strEqSign  = "="
-	configCommentedOut = "#"
 )
 
-// ParseFile reads values from file. It returns nil and error if os.Open(filename) fails.
+var (
+	ErrFormat       = errors.New("conf: line does not match \"key = value\" pattern")
+	ErrDuplicateKey = errors.New("conf: duplicate key found")
+)
+
+// Open reads values from file. It returns nil and error if os.Open(filename) fails.
 // It would be wise to always check returned error.
 // ParseFile captures two types of values: "key = value" and "option". Either key value pair or
 // option must be put in its own line in the file.
 // Key or option must be a single word. In example line:
-// 	"option1 option2"
+//
+//	"option1 option2"
+//
 // only option1 will be captured. option2 needs to be in a separate line in the file to take effect.
 // In line "key = value1,value2,value3" all of value1, value2, and value3 will be
 // captured. They can be later accesed separately with Setting's Split() method.
-func ParseFile(filename string) (*Config, error) {
+func Open(filename string) (*Conf, error) {
 	file, err := os.Open(filename)
 	if err != nil {
 		return nil, err
 	}
-	defer file.Close()
+
-	return parseReader(file), nil
+	c, err := parseReader(file)
+	if err != nil {
+		return nil, err
+	}
+
+	return c, file.Close()
 }
 
-// ParseReader reads from r and returns Config. See also ParseFile.
+// Read reads from r and returns Config.
-func ParseReader(r io.Reader) *Config {
+func Read(r io.Reader) (*Conf, error) {
 	return parseReader(r)
 }
 
-// ParseReadCloser reads from r, returns Config and calls r.Close().
+func parseReader(r io.Reader) (*Conf, error) {
-// See also ParseFile.
+	settings := make(map[string]string)
-func ParseReadCloser(r io.ReadCloser) *Config {
-	defer r.Close()
-	return parseReader(r)
-}
 
-func parseReader(r io.Reader) *Config {
-	var c Config
-	c.Settings = make(map[string]string)
-	c.Options = make(map[string]struct{})
 	scanner := bufio.NewScanner(r)
+
 	for scanner.Scan() {
 		line := scanner.Text()
-		if strings.HasPrefix(line, configCommentedOut) {
+
+		line = trim(stripComment(line))
+		if line == "" {
 			continue
 		}
-		switch {
+
-		case configKeyValueRe.MatchString(line):
+		key, value, ok := toKV(line)
-			kvpair := configKeyValueRe.FindStringSubmatch(line)
+		if !ok {
-			c.Settings[kvpair[1]] = kvpair[2]
+			return nil, ErrFormat
-		case configOptionRe.MatchString(line):
-			opt := configOptionRe.FindString(line)
-			c.Options[opt] = struct{}{}
 		}
+
+		if _, ok := settings[key]; ok {
+			return nil, fmt.Errorf("%w: %s", ErrDuplicateKey, key)
+		}
+
+		settings[key] = value
 	}
-	return &c
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return &Conf{
+		settings: settings,
+	}, nil
+}
+
+func toKV(s string) (string, string, bool) {
+	k, v, ok := strings.Cut(s, strEqSign)
+	if !ok || k == "" || v == "" {
+		return "", "", false
+	}
+
+	return trim(k), trim(v), true
+}
+
+func trim(s string) string {
+	s = strings.TrimSpace(s)
+
+	return s
+}
+
+func stripComment(s string) string {
+	idx := strings.Index(s, strComment)
+	if idx > -1 {
+		s = s[:idx]
+	}
+
+	return s
 }

parser_test.go

@@ -0,0 +1,159 @@
+package conf
+
+import (
+	"bytes"
+	"errors"
+	"reflect"
+	"testing"
+)
+
+func Test_trim(t *testing.T) {
+	tc := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{
+			name: "empty",
+			in:   "",
+			want: "",
+		},
+		{
+			name: "comment",
+			in:   "# some comment",
+			want: "",
+		},
+		{
+			name: "comment",
+			in:   "#some comment",
+			want: "",
+		},
+		{
+			name: "comment",
+			in:   " #some comment",
+			want: "",
+		},
+		{
+			name: "key value",
+			in:   "key = value",
+			want: "key = value",
+		},
+		{
+			name: "key value with whitespace",
+			in:   " key = value ",
+			want: "key = value",
+		},
+		{
+			name: "key value with whitespace",
+			in:   "\tkey = value  \t",
+			want: "key = value",
+		},
+		{
+			name: "key value with whitespace",
+			in:   "\tkey = value  \t\n",
+			want: "key = value",
+		},
+		{
+			name: "key value with comment",
+			in:   "key = value #comment",
+			want: "key = value",
+		},
+		{
+			name: "option",
+			in:   "option \n",
+			want: "option",
+		},
+		{
+			name: "option with comment",
+			in:   "option # comment \n",
+			want: "option",
+		},
+	}
+
+	for _, c := range tc {
+		t.Run(c.name, func(t *testing.T) {
+			have := trim(c.in)
+			if have != c.want {
+				t.Errorf("want: %s, have: %s", have, c.want)
+			}
+		})
+	}
+}
+
+func TestRead(t *testing.T) {
+	tc := []struct {
+		name string
+		in   []byte
+		res  *Conf
+		err  error
+	}{
+		{
+			name: "empty",
+			in:   []byte{},
+			res: &Conf{
+				settings: make(map[string]string),
+				options:  map[string]struct{}{},
+			},
+			err: nil, // if the reader is empty its not out fault
+		},
+		{
+			name: "single key with spaces",
+			in:   []byte("key = value"),
+			res: &Conf{
+				settings: map[string]string{
+					"key": "value",
+				},
+				options: make(map[string]struct{}),
+			},
+			err: nil,
+		},
+		{
+			name: "single key no spaces",
+			in:   []byte("key=value"),
+			res: &Conf{
+				settings: map[string]string{
+					"key": "value",
+				},
+				options: make(map[string]struct{}),
+			},
+			err: nil,
+		},
+		{
+			name: "single key with newline",
+			in:   []byte("key=value\n"),
+			res: &Conf{
+				settings: map[string]string{
+					"key": "value",
+				},
+				options: make(map[string]struct{}),
+			},
+			err: nil,
+		},
+		{
+			name: "single key with comment and newline",
+			in:   []byte("key =value # this is a comment\n"),
+			res: &Conf{
+				settings: map[string]string{
+					"key": "value",
+				},
+				options: make(map[string]struct{}),
+			},
+			err: nil,
+		},
+	}
+
+	for _, c := range tc {
+		t.Run(c.name, func(t *testing.T) {
+			r := bytes.NewReader(c.in)
+
+			conf, err := Read(r)
+			if !errors.Is(err, c.err) {
+				t.Fatalf("want error: %v have: %v", c.err, err)
+			}
+
+			if !reflect.DeepEqual(c.res, conf) {
+				t.Fatalf("want: %+v, have: %+v", c.res, conf)
+			}
+		})
+	}
+}

settings.go

@@ -7,38 +7,23 @@ import (
 )
 
 var (
-	ErrNotFound        = errors.New("key not found")
+	ErrNotFound        = errors.New("conf: key not found")
-	ErrParsingBool     = errors.New("value can not be interpreted as bool")
+	ErrCouldNotConvert = errors.New("conf: could not cast one or more values to required type")
-	ErrCouldNotConvert = errors.New("could not cast one or more values to required type")
 )
 
-var valuesSeparator = ","
+const valuesSeparator = ","
-
-var boolMap = map[string]bool{
-	// what evaluates to true
-	"true": true,
-	"t":    true,
-	"1":    true,
-	"yes":  true,
-	"on":   true,
-	// what evaluates to false
-	"false": false,
-	"f":     false,
-	"0":     false,
-	"no":    false,
-	"off":   false,
-}
 
 // Setting represents key-value pair read from config file.
 // It's Value field holds the value of key parsed from the configuration
 type Setting struct {
+	Name  string
 	Value string
 }
 
 // Int converts Setting Value to int. Returned error
 // will be non nil if convesion failed.
-func (st Setting) Int() (int, error) {
+func (s Setting) Int() (int, error) {
-	return parseInt(st.Value)
+	return parseValue(s.Value, strconv.Atoi)
 }
 
 // IntSlice splits Setting Value (separator is ",") and adds
@@ -46,19 +31,14 @@ func (st Setting) Int() (int, error) {
 // If one or more values can not be converted to float64 those will be dropped
 // and method will return conf.ErrCouldNotConvert.
 // Check error to be sure that all required values were parsed.
-func (st Setting) IntSlice() ([]int, error) {
+func (s Setting) IntSlice() ([]int, error) {
-	return parseIntSlice(st.Value, valuesSeparator)
+	return parseSlice(s.Value, strconv.Atoi)
 }
 
-/* func (st Setting) split(sep string) Setting {
-	st.sep = sep //Choose separator to split values ?
-	return st
-} */
-
 // Float64 converts Setting Value to float64. Returned error
 // will be non nil if convesion failed.
-func (st Setting) Float64() (float64, error) {
+func (s Setting) Float64() (float64, error) {
-	return parseFloat64(st.Value)
+	return parseValue(s.Value, parseFloat64)
 }
 
 // Float64Slice splits Setting Value (separator is ",") and adds
@@ -66,92 +46,64 @@ func (st Setting) Float64() (float64, error) {
 // If one or more values can not be converted to float64 those will be dropped
 // and method will return conf.ErrCouldNotConvert.
 // Check error to be sure that all required values were parsed.
-func (st Setting) Float64Slice() ([]float64, error) {
+func (s Setting) Float64Slice() ([]float64, error) {
-	return parseFloat64Slice(st.Value, valuesSeparator)
+	return parseSlice(s.Value, parseFloat64)
 }
 
 // String returns option Value as string
 // This method also implements Stringer interface from fmt module
-func (st Setting) String() string {
+func (s Setting) String() string {
-	return st.Value
+	return s.Value
 }
 
 // StringSlice splits Setting's Value (separator is ",") and adds
 // each of resulting values to []string trimming leading and trailing spaces
 // from each string.
-func (st Setting) StringSlice() []string {
+func (s Setting) StringSlice() []string {
-	return tidySplit(st.Value, valuesSeparator)
+	return tidySplit(s.Value)
 }
 
 // Bool tries to interpret Setting's Value as bool
-// "1", "true", "on", "yes" (case insensitive) yields true
+// "1", "t", "T", true", "True", "TRUE" yields true
-// "0", "false", "off", "no" (case insensitive) yields false
+// "0", "f", "F, "false", "False", "FALSE" yields false
-// If nothing matches will return false and conf.ErrParsingBool
+// If nothing matches will return false and conf.ErrCouldNotConvert.
-func (st Setting) Bool() (bool, error) {
+func (s Setting) Bool() (bool, error) {
-	return parseBool(st.Value)
+	return parseValue(s.Value, strconv.ParseBool)
 }
 
-func parseInt(s string) (n int, err error) {
+func parseSlice[T any](s string, f func(string) (T, error)) ([]T, error) {
-	n, err = strconv.Atoi(s)
+	split := tidySplit(s)
-	return
-}
 
-func parseIntSlice(s, sep string) ([]int, error) {
+	list := make([]T, 0, len(split))
-	var (
+	for _, str := range split {
-		n      int
+		v, err := parseValue(str, f)
-		err    error
-		slice  []int
-		digits []string
-	)
-	digits = tidySplit(s, sep)
-	for _, d := range digits {
-		n, err = strconv.Atoi(d)
 		if err != nil {
-			err = ErrCouldNotConvert
+			return list, err
-			break
 		}
-		slice = append(slice, n)
+
+		list = append(list, v)
 	}
-	return slice, err
+
+	return list, nil
 }
 
-func parseFloat64(s string) (n float64, err error) {
+func parseValue[T any](s string, f func(string) (T, error)) (T, error) {
-	n, err = strconv.ParseFloat(s, 64)
+	v, err := f(s)
-	return
+	if err != nil {
-}
+		return v, errors.Join(ErrCouldNotConvert, err)
-
-func parseFloat64Slice(s, sep string) ([]float64, error) {
-	var (
-		n      float64
-		err    error
-		slice  []float64
-		digits []string
-	)
-	digits = tidySplit(s, sep)
-	for _, d := range digits {
-		n, err = strconv.ParseFloat(d, 64)
-		if err != nil {
-			err = ErrCouldNotConvert
-			break
-		}
-		slice = append(slice, n)
 	}
-	return slice, err
+
+	return v, err
 }
 
-func parseBool(s string) (value bool, err error) {
+func tidySplit(s string) []string {
-	s = strings.ToLower(s)
+	splitted := strings.Split(s, valuesSeparator)
-	value, ok := boolMap[s]
-	if !ok {
-		err = ErrParsingBool
-	}
-	return
-}
-
-func tidySplit(s, sep string) []string {
-	splitted := strings.Split(s, sep)
 	for i, str := range splitted {
-		splitted[i] = strings.Trim(str, " ")
+		splitted[i] = strings.TrimSpace(str)
 	}
 	return splitted
 }
+
+func parseFloat64(s string) (float64, error) {
+	return strconv.ParseFloat(s, 64)
+}