diff --git a/all_test.go b/all_test.go
index c02adf1..2f09f0e 100644
--- a/all_test.go
+++ b/all_test.go
@@ -118,7 +118,7 @@ func TestInMemory(t *testing.T) {
 	}
 
 	// default section always exists
-	if c.AddSection(DEFAULT_SECTION) {
+	if c.AddSection(DefaultSection) {
 		t.Errorf("AddSection failure: true on default section insert")
 	}
 
@@ -187,13 +187,13 @@ func TestInMemory(t *testing.T) {
 
 	// == Test cycle
 
-	c.AddOption(DEFAULT_SECTION, "opt1", "%(opt2)s")
-	c.AddOption(DEFAULT_SECTION, "opt2", "%(opt1)s")
+	c.AddOption(DefaultSection, "opt1", "%(opt2)s")
+	c.AddOption(DefaultSection, "opt2", "%(opt1)s")
 
-	_, err = c.String(DEFAULT_SECTION, "opt1")
+	_, err = c.String(DefaultSection, "opt1")
 	if err == nil {
 		t.Errorf("String failure: no error for cycle")
-	} else if strings.Index(err.Error(), "cycle") < 0 {
+	} else if !strings.Contains(err.Error(), "cycle") {
 		t.Errorf("String failure: incorrect error for cycle")
 	}
 }
@@ -218,7 +218,7 @@ func TestReadFile(t *testing.T) {
 	buf.WriteString("  # Let me put another comment\n")
 	buf.WriteString("option3= line1\n line2: \n\tline3=v # Comment multiline with := in value\n")
 	buf.WriteString("; Another comment\n")
-	buf.WriteString("[" + DEFAULT_SECTION + "]\n")
+	buf.WriteString("[" + DefaultSection + "]\n")
 	buf.WriteString("variable1=small\n")
 	buf.WriteString("variable2=a_part_of_a_%(variable1)s_test\n")
 	buf.WriteString("[secTION-2]\n")
@@ -241,7 +241,7 @@ func TestReadFile(t *testing.T) {
 	}
 
 	// check number of options 6 of [section-1] plus 2 of [default]
-	opts, err := c.Options("section-1")
+	opts, _ := c.Options("section-1")
 	if len(opts) != 8 {
 		t.Errorf("Options failure: wrong number of options: %d", len(opts))
 	}
@@ -266,8 +266,8 @@ func TestWriteReadFile(t *testing.T) {
 	cw.AddOption("First-Section", "option2", "2")
 
 	cw.AddOption("", "host", "www.example.com")
-	cw.AddOption(DEFAULT_SECTION, "protocol", "https://")
-	cw.AddOption(DEFAULT_SECTION, "base-url", "%(protocol)s%(host)s")
+	cw.AddOption(DefaultSection, "protocol", "https://")
+	cw.AddOption(DefaultSection, "base-url", "%(protocol)s%(host)s")
 
 	cw.AddOption("Another-Section", "useHTTPS", "y")
 	cw.AddOption("Another-Section", "url", "%(base-url)s/some/path")
@@ -298,8 +298,8 @@ func TestSectionOptions(t *testing.T) {
 	cw.AddOption("First-Section", "option2", "2")
 
 	cw.AddOption("", "host", "www.example.com")
-	cw.AddOption(DEFAULT_SECTION, "protocol", "https://")
-	cw.AddOption(DEFAULT_SECTION, "base-url", "%(protocol)s%(host)s")
+	cw.AddOption(DefaultSection, "protocol", "https://")
+	cw.AddOption(DefaultSection, "base-url", "%(protocol)s%(host)s")
 
 	cw.AddOption("Another-Section", "useHTTPS", "y")
 	cw.AddOption("Another-Section", "url", "%(base-url)s/some/path")
@@ -336,7 +336,7 @@ func TestSectionOptions(t *testing.T) {
 		t.Fatalf("SectionOptions reads wrong data: %v", options)
 	}
 
-	options, err = cr.SectionOptions(DEFAULT_SECTION)
+	options, err = cr.SectionOptions(DefaultSection)
 
 	if err != nil {
 		t.Fatalf("SectionOptions failure: %s", err)
@@ -375,18 +375,18 @@ func TestMerge(t *testing.T) {
 	target.Merge(source)
 
 	// Assert whether a regular option was merged from source -> target
-	if result, _ := target.String(DEFAULT_SECTION, "one"); result != "source1" {
+	if result, _ := target.String(DefaultSection, "one"); result != "source1" {
 		t.Errorf("Expected 'one' to be '1' but instead it was '%s'", result)
 	}
 	// Assert that a non-existent option in source was not overwritten
-	if result, _ := target.String(DEFAULT_SECTION, "five"); result != "5" {
+	if result, _ := target.String(DefaultSection, "five"); result != "5" {
 		t.Errorf("Expected 'five' to be '5' but instead it was '%s'", result)
 	}
 	// Assert that a folded option was correctly unfolded
-	if result, _ := target.String(DEFAULT_SECTION, "two_+_three"); result != "source2 + source3" {
+	if result, _ := target.String(DefaultSection, "two_+_three"); result != "source2 + source3" {
 		t.Errorf("Expected 'two_+_three' to be 'source2 + source3' but instead it was '%s'", result)
 	}
-	if result, _ := target.String(DEFAULT_SECTION, "four"); result != "4" {
+	if result, _ := target.String(DefaultSection, "four"); result != "4" {
 		t.Errorf("Expected 'four' to be '4' but instead it was '%s'", result)
 	}
 
diff --git a/config.go b/config.go
index b7c17f4..c19518f 100644
--- a/config.go
+++ b/config.go
@@ -19,16 +19,17 @@ import (
 	"strings"
 )
 
+// config constants
 const (
 	// Default section name.
-	DEFAULT_SECTION = "DEFAULT"
+	DefaultSection = "DEFAULT"
 	// Maximum allowed depth when recursively substituing variable names.
-	_DEPTH_VALUES = 200
+	DepthValues = 200
 
-	DEFAULT_COMMENT       = "# "
-	ALTERNATIVE_COMMENT   = "; "
-	DEFAULT_SEPARATOR     = ":"
-	ALTERNATIVE_SEPARATOR = "="
+	DefaultComment       = "# "
+	AlternativeComment   = "; "
+	DefaultSeparator     = ":"
+	AlternativeSeparator = "="
 )
 
 var (
@@ -58,11 +59,11 @@ type Config struct {
 	separator string
 
 	// Sections order
-	lastIdSection int            // Last section identifier
+	lastIDSection int            // Last section identifier
 	idSection     map[string]int // Section : position
 
 	// The last option identifier used for each section.
-	lastIdOption map[string]int // Section : last identifier
+	lastIDOption map[string]int // Section : last identifier
 
 	// Section -> option : value
 	data map[string]map[string]*tValue
@@ -80,16 +81,16 @@ type tValue struct {
 //
 // == Arguments
 //
-// comment: has to be `DEFAULT_COMMENT` or `ALTERNATIVE_COMMENT`
-// separator: has to be `DEFAULT_SEPARATOR` or `ALTERNATIVE_SEPARATOR`
+// comment: has to be `DefaultComment` or `AlternativeComment`
+// separator: has to be `DefaultSeparator` or `AlternativeSeparator`
 // preSpace: indicate if is inserted a space before of the separator
 // postSpace: indicate if is added a space after of the separator
 func New(comment, separator string, preSpace, postSpace bool) *Config {
-	if comment != DEFAULT_COMMENT && comment != ALTERNATIVE_COMMENT {
+	if comment != DefaultComment && comment != AlternativeComment {
 		panic("comment character not valid")
 	}
 
-	if separator != DEFAULT_SEPARATOR && separator != ALTERNATIVE_SEPARATOR {
+	if separator != DefaultSeparator && separator != AlternativeSeparator {
 		panic("separator character not valid")
 	}
 
@@ -108,17 +109,17 @@ func New(comment, separator string, preSpace, postSpace bool) *Config {
 	c.comment = comment
 	c.separator = separator
 	c.idSection = make(map[string]int)
-	c.lastIdOption = make(map[string]int)
+	c.lastIDOption = make(map[string]int)
 	c.data = make(map[string]map[string]*tValue)
 
-	c.AddSection(DEFAULT_SECTION) // Default section always exists.
+	c.AddSection(DefaultSection) // Default section always exists.
 
 	return c
 }
 
 // NewDefault creates a configuration representation with values by default.
 func NewDefault() *Config {
-	return New(DEFAULT_COMMENT, DEFAULT_SEPARATOR, false, true)
+	return New(DefaultComment, DefaultSeparator, false, true)
 }
 
 // Merge merges the given configuration "source" with this one ("target").
diff --git a/context.go b/context.go
index 8d7f57b..340f900 100644
--- a/context.go
+++ b/context.go
@@ -30,10 +30,12 @@ type Context struct {
 	section string // Check this section first, then fall back to DEFAULT
 }
 
+// NewContext creates a default section and returns config context
 func NewContext() *Context {
 	return &Context{config: NewDefault()}
 }
 
+// LoadContext loads the ini config from gives multiple conf paths
 func LoadContext(confName string, confPaths []string) (*Context, error) {
 	ctx := NewContext()
 	for _, confPath := range confPaths {
@@ -51,18 +53,24 @@ func LoadContext(confName string, confPaths []string) (*Context, error) {
 	return ctx, nil
 }
 
+// Raw returns raw config instance
 func (c *Context) Raw() *Config {
 	return c.config
 }
 
+// SetSection the section scope of ini config
+// For e.g.: dev or prod
 func (c *Context) SetSection(section string) {
 	c.section = section
 }
 
+// SetOption sets the value for the given key
 func (c *Context) SetOption(name, value string) {
 	c.config.AddOption(c.section, name, value)
 }
 
+// Int returns `int` config value and if found returns true
+// otherwise false
 func (c *Context) Int(option string) (result int, found bool) {
 	result, err := c.config.Int(c.section, option)
 	if err == nil {
@@ -76,6 +84,8 @@ func (c *Context) Int(option string) (result int, found bool) {
 	return 0, false
 }
 
+// IntDefault returns `int` config value if found otherwise
+// returns given default int value
 func (c *Context) IntDefault(option string, dfault int) int {
 	if r, found := c.Int(option); found {
 		return r
@@ -83,6 +93,8 @@ func (c *Context) IntDefault(option string, dfault int) int {
 	return dfault
 }
 
+// Bool returns `bool` config value and if found returns true
+// otherwise false
 func (c *Context) Bool(option string) (result, found bool) {
 	result, err := c.config.Bool(c.section, option)
 	if err == nil {
@@ -96,6 +108,8 @@ func (c *Context) Bool(option string) (result, found bool) {
 	return false, false
 }
 
+// BoolDefault returns `bool` config value if found otherwise
+// returns given default bool value
 func (c *Context) BoolDefault(option string, dfault bool) bool {
 	if r, found := c.Bool(option); found {
 		return r
@@ -103,6 +117,8 @@ func (c *Context) BoolDefault(option string, dfault bool) bool {
 	return dfault
 }
 
+// String returns `string` config value and if found returns true
+// otherwise false
 func (c *Context) String(option string) (result string, found bool) {
 	if r, err := c.config.String(c.section, option); err == nil {
 		return stripQuotes(r), true
@@ -110,6 +126,8 @@ func (c *Context) String(option string) (result string, found bool) {
 	return "", false
 }
 
+// StringDefault returns `string` config value if found otherwise
+// returns given default string value
 func (c *Context) StringDefault(option, dfault string) string {
 	if r, found := c.String(option); found {
 		return r
@@ -117,6 +135,8 @@ func (c *Context) StringDefault(option, dfault string) string {
 	return dfault
 }
 
+// HasSection checks if the configuration has the given section.
+// (The default section always exists.)
 func (c *Context) HasSection(section string) bool {
 	return c.config.HasSection(section)
 }
diff --git a/error.go b/error.go
index 44296c0..ab8e386 100644
--- a/error.go
+++ b/error.go
@@ -14,12 +14,14 @@
 
 package config
 
+// SectionError type string
 type SectionError string
 
 func (e SectionError) Error() string {
 	return "section not found: " + string(e)
 }
 
+// OptionError type string
 type OptionError string
 
 func (e OptionError) Error() string {
diff --git a/option.go b/option.go
index c3184ed..0f98de3 100644
--- a/option.go
+++ b/option.go
@@ -27,13 +27,13 @@ func (c *Config) AddOption(section string, option string, value string) bool {
 	c.AddSection(section) // Make sure section exists
 
 	if section == "" {
-		section = DEFAULT_SECTION
+		section = DefaultSection
 	}
 
 	_, ok := c.data[section][option]
 
-	c.data[section][option] = &tValue{c.lastIdOption[section], value}
-	c.lastIdOption[section]++
+	c.data[section][option] = &tValue{c.lastIDOption[section], value}
+	c.lastIDOption[section]++
 
 	return !ok
 }
@@ -59,7 +59,7 @@ func (c *Config) HasOption(section string, option string) bool {
 		return false
 	}
 
-	_, okd := c.data[DEFAULT_SECTION][option]
+	_, okd := c.data[DefaultSection][option]
 	_, oknd := c.data[section][option]
 
 	return okd || oknd
@@ -75,18 +75,18 @@ func (c *Config) Options(section string) (options []string, err error) {
 
 	// Keep a map of option names we've seen to deduplicate.
 	optionMap := make(map[string]struct{},
-		len(c.data[DEFAULT_SECTION])+len(c.data[section]))
-	for s, _ := range c.data[DEFAULT_SECTION] {
+		len(c.data[DefaultSection])+len(c.data[section]))
+	for s := range c.data[DefaultSection] {
 		optionMap[s] = struct{}{}
 	}
-	for s, _ := range c.data[section] {
+	for s := range c.data[section] {
 		optionMap[s] = struct{}{}
 	}
 
 	// Get the keys.
 	i := 0
 	options = make([]string, len(optionMap))
-	for k, _ := range optionMap {
+	for k := range optionMap {
 		options[i] = k
 		i++
 	}
@@ -104,7 +104,7 @@ func (c *Config) SectionOptions(section string) (options []string, err error) {
 
 	options = make([]string, len(c.data[section]))
 	i := 0
-	for s, _ := range c.data[section] {
+	for s := range c.data[section] {
 		options[i] = s
 		i++
 	}
diff --git a/section.go b/section.go
index c8304c3..d982d43 100644
--- a/section.go
+++ b/section.go
@@ -22,7 +22,7 @@ package config
 // It returns true if the new section was inserted, and false if the section
 // already existed.
 func (c *Config) AddSection(section string) bool {
-	// DEFAULT_SECTION
+	// DefaultSection
 	if section == "" {
 		return false
 	}
@@ -34,8 +34,8 @@ func (c *Config) AddSection(section string) bool {
 	c.data[section] = make(map[string]*tValue)
 
 	// Section order
-	c.idSection[section] = c.lastIdSection
-	c.lastIdSection++
+	c.idSection[section] = c.lastIDSection
+	c.lastIDSection++
 
 	return true
 }
@@ -46,16 +46,16 @@ func (c *Config) RemoveSection(section string) bool {
 	_, ok := c.data[section]
 
 	// Default section cannot be removed.
-	if !ok || section == DEFAULT_SECTION {
+	if !ok || section == DefaultSection {
 		return false
 	}
 
-	for o, _ := range c.data[section] {
+	for o := range c.data[section] {
 		delete(c.data[section], o) // *value
 	}
 	delete(c.data, section)
 
-	delete(c.lastIdOption, section)
+	delete(c.lastIDOption, section)
 	delete(c.idSection, section)
 
 	return true
@@ -75,7 +75,7 @@ func (c *Config) Sections() (sections []string) {
 	sections = make([]string, len(c.idSection))
 	pos := 0 // Position in sections
 
-	for i := 0; i < c.lastIdSection; i++ {
+	for i := 0; i < c.lastIDSection; i++ {
 		for section, id := range c.idSection {
 			if id == i {
 				sections[pos] = section
diff --git a/type.go b/type.go
index 4ca38d2..d938aad 100644
--- a/type.go
+++ b/type.go
@@ -27,7 +27,7 @@ import (
 func (c *Config) computeVar(beforeValue *string, regx *regexp.Regexp, headsz, tailsz int, withVar func(*string) string) (*string, error) {
 	var i int
 	computedVal := beforeValue
-	for i = 0; i < _DEPTH_VALUES; i++ { // keep a sane depth
+	for i = 0; i < DepthValues; i++ { // keep a sane depth
 
 		vr := regx.FindStringSubmatchIndex(*computedVal)
 		if len(vr) == 0 {
@@ -37,7 +37,7 @@ func (c *Config) computeVar(beforeValue *string, regx *regexp.Regexp, headsz, ta
 		varname := (*computedVal)[vr[headsz]:vr[headsz+1]]
 		varVal := withVar(&varname)
 		if varVal == "" {
-			return &varVal, errors.New(fmt.Sprintf("Option not found: %s", varname))
+			return &varVal, fmt.Errorf("Option not found: %s", varname)
 		}
 
 		// substitute by new value and take off leading '%(' and trailing ')s'
@@ -47,10 +47,10 @@ func (c *Config) computeVar(beforeValue *string, regx *regexp.Regexp, headsz, ta
 		computedVal = &newVal
 	}
 
-	if i == _DEPTH_VALUES {
+	if i == DepthValues {
 		retVal := ""
 		return &retVal,
-			fmt.Errorf("Possible cycle while unfolding variables: max depth of %d reached", _DEPTH_VALUES)
+			fmt.Errorf("Possible cycle while unfolding variables: max depth of %d reached", DepthValues)
 	}
 
 	return computedVal, nil
@@ -111,7 +111,7 @@ func (c *Config) RawString(section string, option string) (value string, err err
 //
 // It returns an error if the option does not exist in the DEFAULT section.
 func (c *Config) RawStringDefault(option string) (value string, err error) {
-	if tValue, ok := c.data[DEFAULT_SECTION][option]; ok {
+	if tValue, ok := c.data[DefaultSection][option]; ok {
 		return tValue.v, nil
 	}
 	return "", OptionError(option)
@@ -120,7 +120,7 @@ func (c *Config) RawStringDefault(option string) (value string, err error) {
 // String gets the string value for the given option in the section.
 // If the value needs to be unfolded (see e.g. %(host)s example in the beginning
 // of this documentation), then String does this unfolding automatically, up to
-// _DEPTH_VALUES number of iterations.
+// `DepthValues` number of iterations.
 //
 // It returns an error if either the section or the option do not exist, or the
 // unfolding cycled.
@@ -134,7 +134,7 @@ func (c *Config) String(section string, option string) (value string, err error)
 	computedVal, err := c.computeVar(&value, varRegExp, 2, 2, func(varName *string) string {
 		lowerVar := *varName
 		// search variable in default section as well as current section
-		varVal, _ := c.data[DEFAULT_SECTION][lowerVar]
+		varVal, _ := c.data[DefaultSection][lowerVar]
 		if _, ok := c.data[section][lowerVar]; ok {
 			varVal = c.data[section][lowerVar]
 		}
diff --git a/write.go b/write.go
index 68cc8f5..9af6f4e 100644
--- a/write.go
+++ b/write.go
@@ -34,7 +34,7 @@ func (c *Config) WriteFile(fname string, perm os.FileMode, header string) error
 	if err = c.write(buf, header); err != nil {
 		return err
 	}
-	buf.Flush()
+	_ = buf.Flush()
 
 	return file.Close()
 }
@@ -56,7 +56,7 @@ func (c *Config) write(buf *bufio.Writer, header string) (err error) {
 			if section == orderedSection {
 
 				// Skip default section if empty.
-				if section == DEFAULT_SECTION && len(sectionMap) == 0 {
+				if section == DefaultSection && len(sectionMap) == 0 {
 					continue
 				}
 
@@ -65,7 +65,7 @@ func (c *Config) write(buf *bufio.Writer, header string) (err error) {
 				}
 
 				// Follow the input order in options.
-				for i := 0; i < c.lastIdOption[section]; i++ {
+				for i := 0; i < c.lastIDOption[section]; i++ {
 					for option, tValue := range sectionMap {
 
 						if tValue.position == i {
@@ -82,9 +82,6 @@ func (c *Config) write(buf *bufio.Writer, header string) (err error) {
 		}
 	}
 
-	if _, err = buf.WriteString("\n"); err != nil {
-		return err
-	}
-
-	return nil
+	_, err = buf.WriteString("\n")
+	return err
 }