diff --git a/client/backend.go b/client/backend.go
index c72d6cc..a26cb95 100644
--- a/client/backend.go
+++ b/client/backend.go
@@ -19,7 +19,7 @@ const (
 	jsonContentType  = "application/json"
 )
 
-// Backend client is used to verify license and to send telemetry reports
+// BackendClient is used to verify license and to send telemetry reports
 // for analyses (anonymous usage data statistics and crash reports)
 type BackendClient struct {
 	client http.Client
diff --git a/component/asciibox/asciibox.go b/component/asciibox/asciibox.go
index 64a0127..a1d1f31 100644
--- a/component/asciibox/asciibox.go
+++ b/component/asciibox/asciibox.go
@@ -12,6 +12,7 @@ import (
 	"strings"
 )
 
+// AsciiBox represents a component with ascii-style text
 type AsciiBox struct {
 	*ui.Block
 	*data.Consumer
diff --git a/component/barchart/barchart.go b/component/barchart/barchart.go
index 14913df..17844a8 100644
--- a/component/barchart/barchart.go
+++ b/component/barchart/barchart.go
@@ -17,17 +17,18 @@ const (
 	barIndent int = 1
 )
 
+// BarChart presents categorical data with rectangular bars
 type BarChart struct {
 	*ui.Block
 	*data.Consumer
-	bars     []Bar
+	bars     []bar
 	scale    int
 	maxValue float64
 	count    int64
 	palette  console.Palette
 }
 
-type Bar struct {
+type bar struct {
 	label string
 	color ui.Color
 	value float64
@@ -39,14 +40,14 @@ func NewBarChart(c config.BarChartConfig, palette console.Palette) *BarChart {
 	chart := BarChart{
 		Block:    component.NewBlock(c.Title, true, palette),
 		Consumer: data.NewConsumer(),
-		bars:     []Bar{},
+		bars:     []bar{},
 		scale:    *c.Scale,
 		maxValue: -math.MaxFloat64,
 		palette:  palette,
 	}
 
 	for _, i := range c.Items {
-		chart.AddBar(*i.Label, *i.Color)
+		chart.addBar(*i.Label, *i.Color)
 	}
 
 	go func() {
@@ -68,13 +69,14 @@ func (b *BarChart) consumeSample(sample *data.Sample) {
 	b.count++
 
 	float, err := util.ParseFloat(sample.Value)
+
 	if err != nil {
 		b.HandleConsumeFailure("Failed to parse a number", err, sample)
 		return
-	} else {
-		b.HandleConsumeSuccess()
 	}
 
+	b.HandleConsumeSuccess()
+
 	index := -1
 	for i, bar := range b.bars {
 		if bar.label == sample.Label {
@@ -97,8 +99,8 @@ func (b *BarChart) consumeSample(sample *data.Sample) {
 	}
 }
 
-func (b *BarChart) AddBar(label string, color ui.Color) {
-	b.bars = append(b.bars, Bar{label: label, color: color, value: 0})
+func (b *BarChart) addBar(label string, color ui.Color) {
+	b.bars = append(b.bars, bar{label: label, color: color, value: 0})
 }
 
 func (b *BarChart) reselectMaxValue() {
@@ -111,6 +113,7 @@ func (b *BarChart) reselectMaxValue() {
 	b.maxValue = maxValue
 }
 
+// Draw renders the barchart
 func (b *BarChart) Draw(buffer *ui.Buffer) {
 	b.Block.Draw(buffer)
 
diff --git a/component/gauge/gauge.go b/component/gauge/gauge.go
index 8712de7..542ba54 100644
--- a/component/gauge/gauge.go
+++ b/component/gauge/gauge.go
@@ -17,6 +17,7 @@ const (
 	CurValueLabel = "cur"
 )
 
+// Gauge displays cur value between specified min and max values
 type Gauge struct {
 	*ui.Block
 	*data.Consumer
diff --git a/component/layout/layout.go b/component/layout/layout.go
index 7fff6f3..ee95aac 100644
--- a/component/layout/layout.go
+++ b/component/layout/layout.go
@@ -13,6 +13,7 @@ import (
 	"time"
 )
 
+// Layout represents component arrangement on the screen
 type Layout struct {
 	ui.Block
 	Components       []*component.Component
diff --git a/component/runchart/grid.go b/component/runchart/grid.go
index 99ba77f..d78c8e9 100644
--- a/component/runchart/grid.go
+++ b/component/runchart/grid.go
@@ -10,7 +10,7 @@ import (
 
 const defaultValueLength = 4
 
-type ChartGrid struct {
+type chartGrid struct {
 	timeRange    TimeRange
 	timePerPoint time.Duration
 	valueExtrema ValueExtrema
@@ -19,12 +19,12 @@ type ChartGrid struct {
 	minTimeWidth int
 }
 
-func (c *RunChart) newChartGrid() ChartGrid {
+func (c *RunChart) newChartGrid() chartGrid {
 
 	linesCount := (c.Inner.Max.X - c.Inner.Min.X - c.grid.minTimeWidth) / xAxisGridWidth
 	timeRange := c.getTimeRange(linesCount)
 
-	return ChartGrid{
+	return chartGrid{
 		timeRange:    timeRange,
 		timePerPoint: c.timescale / time.Duration(xAxisGridWidth),
 		valueExtrema: getLocalExtrema(c.lines, timeRange),
diff --git a/component/runchart/legend.go b/component/runchart/legend.go
index d0885b7..b3139d5 100644
--- a/component/runchart/legend.go
+++ b/component/runchart/legend.go
@@ -18,7 +18,7 @@ const (
 	timeFormat = "15:04:05.000"
 )
 
-type Legend struct {
+type legend struct {
 	Enabled bool
 	Details bool
 }
@@ -102,15 +102,13 @@ func getColumnWidth(mode Mode, lines []TimeLine, scale int) int {
 func getDiffWithPreviousValue(line TimeLine) float64 {
 	if len(line.points) < 2 {
 		return 0
-	} else {
-		return line.points[len(line.points)-1].value - line.points[len(line.points)-2].value
 	}
+	return line.points[len(line.points)-1].value - line.points[len(line.points)-2].value
 }
 
 func getCurrentValue(line TimeLine) float64 {
 	if len(line.points) == 0 {
 		return 0
-	} else {
-		return line.points[len(line.points)-1].value
 	}
+	return line.points[len(line.points)-1].value
 }
diff --git a/component/runchart/runchart.go b/component/runchart/runchart.go
index 2ec7449..7801e03 100644
--- a/component/runchart/runchart.go
+++ b/component/runchart/runchart.go
@@ -38,17 +38,18 @@ const (
 	CommandMoveSelection    = "MOVE_SELECTION"
 )
 
+// RunChart displays observed data in a time sequence
 type RunChart struct {
 	*ui.Block
 	*data.Consumer
 	lines     []TimeLine
-	grid      ChartGrid
+	grid      chartGrid
 	timescale time.Duration
 	mutex     *sync.Mutex
 	mode      Mode
 	selection time.Time
 	scale     int
-	legend    Legend
+	legend    legend
 	palette   console.Palette
 }
 
@@ -87,7 +88,7 @@ func NewRunChart(c config.RunChartConfig, palette console.Palette) *RunChart {
 		mutex:     &sync.Mutex{},
 		scale:     *c.Scale,
 		mode:      ModeDefault,
-		legend:    Legend{Enabled: c.Legend.Enabled, Details: c.Legend.Details},
+		legend:    legend{Enabled: c.Legend.Enabled, Details: c.Legend.Details},
 		palette:   palette,
 	}
 
@@ -159,10 +160,10 @@ func (c *RunChart) consumeSample(sample *data.Sample) {
 	if err != nil {
 		c.HandleConsumeFailure("Failed to parse a number", err, sample)
 		return
-	} else {
-		c.HandleConsumeSuccess()
 	}
 
+	c.HandleConsumeSuccess()
+
 	c.mutex.Lock()
 
 	index := -1
@@ -318,13 +319,13 @@ func (c *RunChart) moveSelection(shift int) {
 		c.mode = ModePinpoint
 		c.selection = getMidRangeTime(c.grid.timeRange)
 		return
-	} else {
-		c.selection = c.selection.Add(c.grid.timePerPoint * time.Duration(shift))
-		if c.selection.After(c.grid.timeRange.max) {
-			c.selection = c.grid.timeRange.max
-		} else if c.selection.Before(c.grid.timeRange.min) {
-			c.selection = c.grid.timeRange.min
-		}
+	}
+
+	c.selection = c.selection.Add(c.grid.timePerPoint * time.Duration(shift))
+	if c.selection.After(c.grid.timeRange.max) {
+		c.selection = c.grid.timeRange.max
+	} else if c.selection.Before(c.grid.timeRange.min) {
+		c.selection = c.grid.timeRange.min
 	}
 
 	for i := range c.lines {
@@ -352,9 +353,9 @@ func calculateTimescale(rateMs int) time.Duration {
 
 	if timescale.Seconds() == 0 {
 		return time.Second
-	} else {
-		return timescale
 	}
+
+	return timescale
 }
 
 func braillePoint(point image.Point) image.Point {
diff --git a/component/sparkline/sparkline.go b/component/sparkline/sparkline.go
index 62ef153..27428a3 100644
--- a/component/sparkline/sparkline.go
+++ b/component/sparkline/sparkline.go
@@ -11,6 +11,7 @@ import (
 	"sync"
 )
 
+// SparkLine displays general shape of a measurement variation over time
 type SparkLine struct {
 	*ui.Block
 	*data.Consumer
diff --git a/component/textbox/textbox.go b/component/textbox/textbox.go
index a1501a8..19afeb6 100644
--- a/component/textbox/textbox.go
+++ b/component/textbox/textbox.go
@@ -9,6 +9,7 @@ import (
 	"image"
 )
 
+// TextBox represents a component with regular text
 type TextBox struct {
 	*ui.Block
 	*data.Consumer
diff --git a/component/util/geometry.go b/component/util/geometry.go
index dc10676..7dc9e97 100644
--- a/component/util/geometry.go
+++ b/component/util/geometry.go
@@ -2,7 +2,6 @@ package util
 
 import (
 	"image"
-	"math"
 )
 
 func GetRectLeftSideCenter(rect image.Rectangle) image.Point {
@@ -33,12 +32,6 @@ func GetRectBottomSideCenter(rect image.Rectangle) image.Point {
 	}
 }
 
-func GetDistance(p1 image.Point, p2 image.Point) float64 {
-	x := math.Abs(float64(p1.X - p2.X))
-	y := math.Abs(float64(p1.Y - p2.Y))
-	return math.Sqrt(x*x + y*y)
-}
-
 func GetRectCoordinates(area image.Rectangle, width int, height int) (int, int, int, int) {
 	x1 := area.Min.X + area.Dx()/2 - width/2
 	y1 := area.Min.Y + area.Dy()/2 - height
diff --git a/config/arrangement.go b/config/arrangement.go
index bf6b7da..18923b6 100644
--- a/config/arrangement.go
+++ b/config/arrangement.go
@@ -189,9 +189,8 @@ func countEmptyCellsBelow(grid [console.RowsCount][console.ColumnsCount]int, row
 	for r := row; r < console.RowsCount; r++ {
 		if grid[r][column] == 1 {
 			return count
-		} else {
-			count++
 		}
+		count++
 	}
 	return count
 }
diff --git a/config/component.go b/config/component.go
index 42897bb..0300970 100644
--- a/config/component.go
+++ b/config/component.go
@@ -36,9 +36,12 @@ func (c *ComponentConfig) GetSize() Size {
 func (c *ComponentConfig) GetRectangle() image.Rectangle {
 	if c.Position == nil || len(c.Position) == 0 {
 		return image.ZR
-	} else {
-		return image.Rect(c.Position[0][0], c.Position[0][1], c.Position[0][0]+c.Position[1][0], c.Position[0][1]+c.Position[1][1])
 	}
+	return image.Rect(
+		c.Position[0][0],
+		c.Position[0][1],
+		c.Position[0][0]+c.Position[1][0],
+		c.Position[0][1]+c.Position[1][1])
 }
 
 type TriggerConfig struct {
diff --git a/config/options.go b/config/options.go
index 1f2213b..6b63b9e 100644
--- a/config/options.go
+++ b/config/options.go
@@ -1,5 +1,6 @@
 package config
 
+// Options with cli flags
 type Options struct {
 	ConfigFile       *string  `short:"c" long:"config" description:"Path to YAML config file"`
 	LicenseKey       *string  `short:"l" long:"license" description:"License key. Visit www.sampler.dev for details"`
diff --git a/data/int_basic.go b/data/int_basic.go
index fb8c31a..3cd648a 100644
--- a/data/int_basic.go
+++ b/data/int_basic.go
@@ -10,6 +10,7 @@ import (
 	"time"
 )
 
+// BasicInteractiveShell represents non-PTY interactive shell sampling metadata
 type BasicInteractiveShell struct {
 	item      *Item
 	variables []string
@@ -93,7 +94,7 @@ func (s *BasicInteractiveShell) execute() (string, error) {
 			_ = s.cmd.Wait()
 			s.item.basicShell = nil // restart session
 		}
-		return "", errors.New(fmt.Sprintf("Failed to execute command: %s", err))
+		return "", fmt.Errorf("failed to execute command: %s", err)
 	}
 
 	timeout := make(chan bool, 1)
@@ -121,9 +122,8 @@ func (s *BasicInteractiveShell) execute() (string, error) {
 		case <-timeout:
 			if errorText.Len() > 0 {
 				return "", errors.New(errorText.String())
-			} else {
-				return s.item.transform(resultText.String())
 			}
+			return s.item.transform(resultText.String())
 		}
 	}
 }
diff --git a/data/int_pty.go b/data/int_pty.go
index 09e6b05..1f10525 100644
--- a/data/int_pty.go
+++ b/data/int_pty.go
@@ -1,8 +1,9 @@
+//+build !windows
+
 package data
 
 import (
 	"bufio"
-	"errors"
 	"fmt"
 	"github.com/kr/pty"
 	"github.com/lunixbochs/vtclean"
@@ -12,6 +13,7 @@ import (
 	"time"
 )
 
+// PtyInteractiveShell represents PTY interactive shell sampling metadata
 type PtyInteractiveShell struct {
 	item      *Item
 	variables []string
@@ -73,7 +75,7 @@ func (s *PtyInteractiveShell) execute() (string, error) {
 			_ = s.file.Close()
 			s.item.ptyShell = nil // restart session
 		}
-		return "", errors.New(fmt.Sprintf("Failed to execute command: %s", err))
+		return "", fmt.Errorf("failed to execute command: %s", err)
 	}
 
 	softTimeout := make(chan bool, 1)
diff --git a/data/item.go b/data/item.go
index b637110..38a8898 100644
--- a/data/item.go
+++ b/data/item.go
@@ -74,14 +74,17 @@ func (i *Item) execute(variables []string, script string) (string, error) {
 }
 
 func (i *Item) initInteractiveShell(v []string) error {
+
 	timeout := time.Duration(i.rateMs) * time.Millisecond * 3 / 4
+
 	if i.pty {
 		i.ptyShell = &PtyInteractiveShell{item: i, variables: v, timeout: timeout}
 		return i.ptyShell.init()
-	} else {
-		i.basicShell = &BasicInteractiveShell{item: i, variables: v, timeout: timeout}
-		return i.basicShell.init()
 	}
+
+	i.basicShell = &BasicInteractiveShell{item: i, variables: v, timeout: timeout}
+
+	return i.basicShell.init()
 }
 
 func (i *Item) transform(sample string) (string, error) {
diff --git a/metadata/license.go b/metadata/license.go
index a4d62e8..0ab75b1 100644
--- a/metadata/license.go
+++ b/metadata/license.go
@@ -23,20 +23,21 @@ const (
 const licenseFileName = "license.yml"
 
 func GetLicense() *License {
+
 	if !fileExists(licenseFileName) {
 		return nil
-	} else {
-		file := readStorageFile(getPlatformStoragePath(licenseFileName))
-
-		license := new(License)
-		err := yaml.Unmarshal(file, license)
-
-		if err != nil {
-			log.Fatalf("Failed to read license file: %v", err)
-		}
-
-		return license
 	}
+
+	file := readStorageFile(getPlatformStoragePath(licenseFileName))
+
+	license := new(License)
+	err := yaml.Unmarshal(file, license)
+
+	if err != nil {
+		log.Fatalf("Failed to read license file: %v", err)
+	}
+
+	return license
 }
 
 func SaveLicense(license License) {
diff --git a/metadata/statistics.go b/metadata/statistics.go
index 141ebff..1662793 100644
--- a/metadata/statistics.go
+++ b/metadata/statistics.go
@@ -9,7 +9,7 @@ import (
 	"runtime"
 )
 
-// Anonymous usage data, which we collect for analyses and improvements
+// Statistics represents anonymous usage data, which we collect for analyses and improvements
 // User can disable it, along with crash reports, using --telemetry flag
 type Statistics struct {
 	Version         string
@@ -22,6 +22,7 @@ type Statistics struct {
 
 const statisticsFileName = "statistics.yml"
 
+// PersistStatistics in file
 func PersistStatistics(config *config.Config) *Statistics {
 
 	statistics := new(Statistics)
@@ -65,7 +66,9 @@ func PersistStatistics(config *config.Config) *Statistics {
 	return statistics
 }
 
+// GetStatistics from file
 func GetStatistics(cfg *config.Config) *Statistics {
+
 	if !fileExists(statisticsFileName) {
 		return &Statistics{
 			Version:         console.AppVersion,
@@ -75,15 +78,17 @@ func GetStatistics(cfg *config.Config) *Statistics {
 			WindowHeight:    0,
 			ComponentsCount: countComponentsPerType(cfg),
 		}
-	} else {
-		file := readStorageFile(getPlatformStoragePath(statisticsFileName))
-		license := new(Statistics)
-		err := yaml.Unmarshal(file, license)
-		if err != nil {
-			log.Fatalf("Failed to read statistics file: %v", err)
-		}
-		return license
 	}
+
+	file := readStorageFile(getPlatformStoragePath(statisticsFileName))
+	license := new(Statistics)
+
+	err := yaml.Unmarshal(file, license)
+	if err != nil {
+		log.Fatalf("Failed to read statistics file: %v", err)
+	}
+
+	return license
 }
 
 func countComponentsPerType(config *config.Config) map[string]int {