wip: enable a bunch of new linting rules at once

.golangci.yaml

@@ -2,16 +2,25 @@ linters:
   disable-all: true
   enable:
   - errcheck
+  - gci
+#  - goconst
+  - gocritic
+  - gocyclo
+  - gofmt
+  - goimports
   - gosimple
   - govet
-  - gofmt
-  - gci
-  - revive
   - ineffassign
+  - megacheck
+  - misspell
+  - revive
   - staticcheck
+  - typecheck
+  - unconvert
 issues:
   exclude-rules:
   - path: example.*_test\.go
     linters:
     - ineffassign
     - revive
+  exclude-use-default: false

application/heartbeater.go

@@ -67,7 +67,7 @@ func (hb *heartbeater) beat() {
 		hb.send(tags)
 	}
 
-	//send customTags heartbeat
+	// send customTags heartbeat
 	hb.mux.Lock()
 	for len(hb.customTags) > 0 {
 		tags := hb.customTags[0]

internal/sdkmetrics/registry_test.go

@@ -20,17 +20,17 @@ func (f *fakeSender) SendDeltaCounter(string, float64, string, map[string]string
 func (f *fakeSender) SendMetric(name string, _ float64, _ int64, _ string, tags map[string]string) error {
 	f.count = f.count + 1
 	if f.prefix != "" && !strings.HasPrefix(name, f.prefix) {
-		f.errors = f.errors + 1
+		f.errors++
 	}
 	if f.name != "" && f.prefix != "" && (name != f.prefix+"."+f.name) {
-		f.errors = f.errors + 1
+		f.errors++
 	}
 	for _, k := range f.tags {
 		if tags == nil {
-			f.errors = f.errors + 1
+			f.errors++
 		} else {
 			if _, ok := tags[k]; !ok {
-				f.errors = f.errors + 1
+				f.errors++
 			}
 		}
 	}

internal/span/formatter.go

@@ -9,7 +9,7 @@ import (
 	"github.com/wavefronthq/wavefront-sdk-go/internal"
 )
 
-// Line gets a span line in the Wavefront span data format:
+// Line returns a span line in the Wavefront span data format:
 // <tracingSpanName> source=<source> [pointTags] <start_millis> <duration_milli_seconds>
 // Example:
 // "getAllUsers source=localhost traceId=7b3bf470-9456-11e8-9eb6-529269fb1459 spanId=0313bafe-9457-11e8-9eb6-529269fb1459
@@ -80,6 +80,7 @@ func Line(name string, startMillis, durationMillis int64, source, traceID, spanI
 	return sb.String(), nil
 }
 
+// LogJSON returns Span Logs as a string in JSON format,
 func LogJSON(traceID, spanID string, spanLogs []Log, span string) (string, error) {
 	l := Logs{
 		TraceID: traceID,
@@ -91,7 +92,7 @@ func LogJSON(traceID, spanID string, spanLogs []Log, span string) (string, error
 	if err != nil {
 		return "", err
 	}
-	return string(out[:]) + "\n", nil
+	return string(out) + "\n", nil
 }
 
 func isUUIDFormat(str string) bool {

senders/auth.go

@@ -7,19 +7,16 @@ import (
 )
 
 func tokenServiceForCfg(cfg *configuration) auth.Service {
-	switch cfg.Authentication.(type) {
+	switch a := cfg.Authentication.(type) {
 	case auth.APIToken:
 		log.Println("The Wavefront SDK will use Direct Ingestion authenticated using an API Token.")
-		tokenAuth := cfg.Authentication.(auth.APIToken)
-		return auth.NewWavefrontTokenService(tokenAuth.Token)
+		return auth.NewWavefrontTokenService(a.Token)
 	case auth.CSPClientCredentials:
 		log.Println("The Wavefront SDK will use Direct Ingestion authenticated using CSP client credentials.")
-		cspAuth := cfg.Authentication.(auth.CSPClientCredentials)
-		return auth.NewCSPServerToServerService(cspAuth.BaseURL, cspAuth.ClientID, cspAuth.ClientSecret, cspAuth.OrgID)
+		return auth.NewCSPServerToServerService(a.BaseURL, a.ClientID, a.ClientSecret, a.OrgID)
 	case auth.CSPAPIToken:
 		log.Println("The Wavefront SDK will use Direct Ingestion authenticated using CSP API Token.")
-		cspAuth := cfg.Authentication.(auth.CSPAPIToken)
-		return auth.NewCSPTokenService(cspAuth.BaseURL, cspAuth.Token)
+		return auth.NewCSPTokenService(a.BaseURL, a.Token)
 	}
 
 	log.Println("The Wavefront SDK will communicate with a Wavefront Proxy.")

senders/option.go

@@ -44,8 +44,7 @@ func CSPBaseURL(baseURL string) CSPOption {
 // CSPOrgID sets an explicit orgID for Client Credentials authentication
 func CSPOrgID(orgID string) CSPOption {
 	return func(authentication any) {
-		switch a := authentication.(type) {
-		case auth.CSPClientCredentials:
+		if a, ok := authentication.(auth.CSPClientCredentials); ok {
 			a.OrgID = &orgID
 		}
 	}

senders/real_sender.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"strconv"
+	"strings"
 
 	"github.com/wavefronthq/wavefront-sdk-go/event"
 	"github.com/wavefronthq/wavefront-sdk-go/histogram"
@@ -197,29 +198,24 @@ func (sender *realSender) Close() {
 }
 
 func (sender *realSender) Flush() error {
-	errStr := ""
-	err := sender.pointHandler.Flush()
-	if err != nil {
-		errStr = errStr + err.Error() + "\n"
-	}
-	err = sender.histoHandler.Flush()
-	if err != nil {
-		errStr = errStr + err.Error() + "\n"
-	}
-	err = sender.spanHandler.Flush()
-	if err != nil {
-		errStr = errStr + err.Error()
-	}
-	err = sender.spanLogHandler.Flush()
-	if err != nil {
-		errStr = errStr + err.Error()
-	}
-	err = sender.eventHandler.Flush()
-	if err != nil {
-		errStr = errStr + err.Error()
+	return combineErrorMessages(
+		sender.pointHandler.Flush(),
+		sender.histoHandler.Flush(),
+		sender.spanHandler.Flush(),
+		sender.spanLogHandler.Flush(),
+		sender.eventHandler.Flush(),
+	)
+}
+
+func combineErrorMessages(errs ...error) error {
+	var nonNilErrMessages []string
+	for _, err := range errs {
+		if err != nil {
+			nonNilErrMessages = append(nonNilErrMessages, err.Error())
+		}
 	}
-	if errStr != "" {
-		return fmt.Errorf(errStr)
+	if len(nonNilErrMessages) > 0 {
+		return fmt.Errorf(strings.Join(nonNilErrMessages, "\n"))
 	}
 	return nil
 }