chore: Fix linter findings for unparam and revive.unused-parameter

.golangci.yml

@@ -17,6 +17,7 @@ linters:
     - staticcheck
     - typecheck
     - unconvert
+    - unparam
     - unused
 
 linters-settings:
@@ -73,7 +74,7 @@ linters-settings:
         arguments: [ "outputBuffer.Write", "fmt.Printf", "fmt.Println", "fmt.Print", "fmt.Fprintf", "fmt.Fprint", "fmt.Fprintln" ]
       - name: unnecessary-stmt
       - name: unreachable-code
-      # - name: unused-parameter
+      - name: unused-parameter
       - name: var-declaration
       - name: var-naming
       - name: waitgroup-by-value

agent/agent.go

@@ -24,11 +24,11 @@ type Agent struct {
 }
 
 // NewAgent returns an Agent for the given Config.
-func NewAgent(cfg *config.Config) (*Agent, error) {
+func NewAgent(cfg *config.Config) *Agent {
 	a := &Agent{
 		Config: cfg,
 	}
-	return a, nil
+	return a
 }
 
 // inputUnit is a group of input plugins and the shared channel they write to.

agent/agent_test.go

@@ -4,108 +4,107 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/influxdata/telegraf/config"
 	_ "github.com/influxdata/telegraf/plugins/inputs/all"
 	_ "github.com/influxdata/telegraf/plugins/outputs/all"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 )
 
 func TestAgent_OmitHostname(t *testing.T) {
 	c := config.NewConfig()
 	c.Agent.OmitHostname = true
-	_, err := NewAgent(c)
-	assert.NoError(t, err)
-	assert.NotContains(t, c.Tags, "host")
+	_ = NewAgent(c)
+	require.NotContains(t, c.Tags, "host")
 }
 
 func TestAgent_LoadPlugin(t *testing.T) {
 	c := config.NewConfig()
 	c.InputFilters = []string{"mysql"}
 	err := c.LoadConfig("../config/testdata/telegraf-agent.toml")
-	assert.NoError(t, err)
-	a, _ := NewAgent(c)
-	assert.Equal(t, 1, len(a.Config.Inputs))
+	require.NoError(t, err)
+	a := NewAgent(c)
+	require.Equal(t, 1, len(a.Config.Inputs))
 
 	c = config.NewConfig()
 	c.InputFilters = []string{"foo"}
 	err = c.LoadConfig("../config/testdata/telegraf-agent.toml")
-	assert.NoError(t, err)
-	a, _ = NewAgent(c)
-	assert.Equal(t, 0, len(a.Config.Inputs))
+	require.NoError(t, err)
+	a = NewAgent(c)
+	require.Equal(t, 0, len(a.Config.Inputs))
 
 	c = config.NewConfig()
 	c.InputFilters = []string{"mysql", "foo"}
 	err = c.LoadConfig("../config/testdata/telegraf-agent.toml")
-	assert.NoError(t, err)
-	a, _ = NewAgent(c)
-	assert.Equal(t, 1, len(a.Config.Inputs))
+	require.NoError(t, err)
+	a = NewAgent(c)
+	require.Equal(t, 1, len(a.Config.Inputs))
 
 	c = config.NewConfig()
 	c.InputFilters = []string{"mysql", "redis"}
 	err = c.LoadConfig("../config/testdata/telegraf-agent.toml")
-	assert.NoError(t, err)
-	a, _ = NewAgent(c)
-	assert.Equal(t, 2, len(a.Config.Inputs))
+	require.NoError(t, err)
+	a = NewAgent(c)
+	require.Equal(t, 2, len(a.Config.Inputs))
 
 	c = config.NewConfig()
 	c.InputFilters = []string{"mysql", "foo", "redis", "bar"}
 	err = c.LoadConfig("../config/testdata/telegraf-agent.toml")
-	assert.NoError(t, err)
-	a, _ = NewAgent(c)
-	assert.Equal(t, 2, len(a.Config.Inputs))
+	require.NoError(t, err)
+	a = NewAgent(c)
+	require.Equal(t, 2, len(a.Config.Inputs))
 }
 
 func TestAgent_LoadOutput(t *testing.T) {
 	c := config.NewConfig()
 	c.OutputFilters = []string{"influxdb"}
 	err := c.LoadConfig("../config/testdata/telegraf-agent.toml")
-	assert.NoError(t, err)
-	a, _ := NewAgent(c)
-	assert.Equal(t, 2, len(a.Config.Outputs))
+	require.NoError(t, err)
+	a := NewAgent(c)
+	require.Equal(t, 2, len(a.Config.Outputs))
 
 	c = config.NewConfig()
 	c.OutputFilters = []string{"kafka"}
 	err = c.LoadConfig("../config/testdata/telegraf-agent.toml")
-	assert.NoError(t, err)
-	a, _ = NewAgent(c)
-	assert.Equal(t, 1, len(a.Config.Outputs))
+	require.NoError(t, err)
+	a = NewAgent(c)
+	require.Equal(t, 1, len(a.Config.Outputs))
 
 	c = config.NewConfig()
 	c.OutputFilters = []string{}
 	err = c.LoadConfig("../config/testdata/telegraf-agent.toml")
-	assert.NoError(t, err)
-	a, _ = NewAgent(c)
-	assert.Equal(t, 3, len(a.Config.Outputs))
+	require.NoError(t, err)
+	a = NewAgent(c)
+	require.Equal(t, 3, len(a.Config.Outputs))
 
 	c = config.NewConfig()
 	c.OutputFilters = []string{"foo"}
 	err = c.LoadConfig("../config/testdata/telegraf-agent.toml")
-	assert.NoError(t, err)
-	a, _ = NewAgent(c)
-	assert.Equal(t, 0, len(a.Config.Outputs))
+	require.NoError(t, err)
+	a = NewAgent(c)
+	require.Equal(t, 0, len(a.Config.Outputs))
 
 	c = config.NewConfig()
 	c.OutputFilters = []string{"influxdb", "foo"}
 	err = c.LoadConfig("../config/testdata/telegraf-agent.toml")
-	assert.NoError(t, err)
-	a, _ = NewAgent(c)
-	assert.Equal(t, 2, len(a.Config.Outputs))
+	require.NoError(t, err)
+	a = NewAgent(c)
+	require.Equal(t, 2, len(a.Config.Outputs))
 
 	c = config.NewConfig()
 	c.OutputFilters = []string{"influxdb", "kafka"}
 	err = c.LoadConfig("../config/testdata/telegraf-agent.toml")
-	assert.NoError(t, err)
-	assert.Equal(t, 3, len(c.Outputs))
-	a, _ = NewAgent(c)
-	assert.Equal(t, 3, len(a.Config.Outputs))
+	require.NoError(t, err)
+	require.Equal(t, 3, len(c.Outputs))
+	a = NewAgent(c)
+	require.Equal(t, 3, len(a.Config.Outputs))
 
 	c = config.NewConfig()
 	c.OutputFilters = []string{"influxdb", "foo", "kafka", "bar"}
 	err = c.LoadConfig("../config/testdata/telegraf-agent.toml")
-	assert.NoError(t, err)
-	a, _ = NewAgent(c)
-	assert.Equal(t, 3, len(a.Config.Outputs))
+	require.NoError(t, err)
+	a = NewAgent(c)
+	require.Equal(t, 3, len(a.Config.Outputs))
 }
 
 func TestWindow(t *testing.T) {

agent/tick.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/benbjohnson/clock"
+
 	"github.com/influxdata/telegraf/internal"
 )
 
@@ -137,7 +138,7 @@ func NewUnalignedTicker(interval, jitter, offset time.Duration) *UnalignedTicker
 	return t
 }
 
-func (t *UnalignedTicker) start(clk clock.Clock) *UnalignedTicker {
+func (t *UnalignedTicker) start(clk clock.Clock) {
 	t.ch = make(chan time.Time, 1)
 	ctx, cancel := context.WithCancel(context.Background())
 	t.cancel = cancel
@@ -153,8 +154,6 @@ func (t *UnalignedTicker) start(clk clock.Clock) *UnalignedTicker {
 		defer t.wg.Done()
 		t.run(ctx, ticker, clk)
 	}()
-
-	return t
 }
 
 func sleep(ctx context.Context, duration time.Duration, clk clock.Clock) error {
@@ -234,7 +233,7 @@ func NewRollingTicker(interval, jitter time.Duration) *RollingTicker {
 	return t
 }
 
-func (t *RollingTicker) start(clk clock.Clock) *RollingTicker {
+func (t *RollingTicker) start(clk clock.Clock) {
 	t.ch = make(chan time.Time, 1)
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -248,8 +247,6 @@ func (t *RollingTicker) start(clk clock.Clock) *RollingTicker {
 		defer t.wg.Done()
 		t.run(ctx, timer)
 	}()
-
-	return t
 }
 
 func (t *RollingTicker) next() time.Duration {

cmd/telegraf/main_test.go

@@ -27,7 +27,7 @@ func NewMockTelegraf() *MockTelegraf {
 	return &MockTelegraf{}
 }
 
-func (m *MockTelegraf) Init(serverErr <-chan error, f Filters, g GlobalFlags, w WindowFlags) {
+func (m *MockTelegraf) Init(_ <-chan error, _ Filters, g GlobalFlags, w WindowFlags) {
 	m.GlobalFlags = g
 	m.WindowFlags = w
 }
@@ -47,7 +47,7 @@ func NewMockConfig(buffer io.Writer) *MockConfig {
 	}
 }
 
-func (m *MockConfig) CollectDeprecationInfos(inFilter, outFilter, aggFilter, procFilter []string) map[string][]config.PluginDeprecationInfo {
+func (m *MockConfig) CollectDeprecationInfos(_, _, _, _ []string) map[string][]config.PluginDeprecationInfo {
 	return m.ExpectedDeprecatedPlugins
 }
 
@@ -65,7 +65,7 @@ func NewMockServer() *MockServer {
 	return &MockServer{}
 }
 
-func (m *MockServer) Start(address string) {
+func (m *MockServer) Start(_ string) {
 	m.Address = "localhost:6060"
 }
 

cmd/telegraf/telegraf.go

@@ -251,10 +251,7 @@ func (t *Telegraf) runAgent(ctx context.Context) error {
 		log.Printf("W! Deprecated outputs: %d and %d options", count[0], count[1])
 	}
 
-	ag, err := agent.NewAgent(c)
-	if err != nil {
-		return err
-	}
+	ag := agent.NewAgent(c)
 
 	// Notify systemd that telegraf is ready
 	// SdNotify() only tries to notify if the NOTIFY_SOCKET environment is set, so it's safe to call when systemd isn't present.

config/config.go

@@ -728,17 +728,13 @@ func (c *Config) addParser(parentcategory, parentname string, table *ast.Table)
 	}
 	parser := creator(parentname)
 
-	conf, err := c.buildParser(parentname, table)
-	if err != nil {
-		return nil, err
-	}
-
+	conf := c.buildParser(parentname, table)
 	if err := c.toml.UnmarshalTable(table, parser); err != nil {
 		return nil, err
 	}
 
 	running := models.NewRunningParser(parser, conf)
-	err = running.Init()
+	err := running.Init()
 	return running, err
 }
 
@@ -1043,16 +1039,16 @@ func (c *Config) buildAggregator(name string, tbl *ast.Table) (*models.Aggregato
 // buildParser parses Parser specific items from the ast.Table,
 // builds the filter and returns a
 // models.ParserConfig to be inserted into models.RunningParser
-func (c *Config) buildParser(name string, tbl *ast.Table) (*models.ParserConfig, error) {
-	var dataformat string
-	c.getFieldString(tbl, "data_format", &dataformat)
+func (c *Config) buildParser(name string, tbl *ast.Table) *models.ParserConfig {
+	var dataFormat string
+	c.getFieldString(tbl, "data_format", &dataFormat)
 
 	conf := &models.ParserConfig{
 		Parent:     name,
-		DataFormat: dataformat,
+		DataFormat: dataFormat,
 	}
 
-	return conf, nil
+	return conf
 }
 
 // buildProcessor parses Processor specific items from the ast.Table,