Fix golint warnings (#170)

* fix golint warnings

* Url should be URL

* fix ifElseChain: rewrite if-else to switch statement (gocritic)

* apply goimport

* fix typo

* fix duplicate warnings

* fix scopelint

* fix ST1005: error strings should not be capitalized

* simplify receiving a channel

* use time.Sleep(time.Nanosecond) instead of time.Sleep(1)

* fix ST1017: don't use Yoda conditions

* Using the variable on range scope `cons` in function literal

* LambdaTraceHeaderKey must be string type

* Sample is used to provide sampling decision.

* fix compile error

Co-authored-by: Bhautik Pipaliya <56270044+bhautikpip@users.noreply.github.com>

awsplugins/beanstalk/beanstalk.go

@@ -16,8 +16,10 @@ import (
 	"github.com/aws/aws-xray-sdk-go/internal/plugins"
 )
 
+// Origin is the type of AWS resource that runs your application.
 const Origin = "AWS::ElasticBeanstalk::Environment"
 
+// Init activates ElasticBeanstalkPlugin at runtime.
 func Init() {
 	if plugins.InstancePluginMetadata != nil && plugins.InstancePluginMetadata.BeanstalkMetadata == nil {
 		addPluginMetadata(plugins.InstancePluginMetadata)

awsplugins/ec2/ec2.go

@@ -15,8 +15,10 @@ import (
 	"github.com/aws/aws-xray-sdk-go/internal/plugins"
 )
 
+// Origin is the type of AWS resource that runs your application.
 const Origin = "AWS::EC2::Instance"
 
+// Init activates EC2Plugin at runtime.
 func Init() {
 	if plugins.InstancePluginMetadata != nil && plugins.InstancePluginMetadata.EC2Metadata == nil {
 		addPluginMetadata(plugins.InstancePluginMetadata)

awsplugins/ecs/ecs.go

@@ -15,8 +15,10 @@ import (
 	"github.com/aws/aws-xray-sdk-go/internal/plugins"
 )
 
+// Origin is the type of AWS resource that runs your application.
 const Origin = "AWS::ECS::Container"
 
+// Init activates ECSPlugin at runtime.
 func Init() {
 	if plugins.InstancePluginMetadata != nil && plugins.InstancePluginMetadata.ECSMetadata == nil {
 		addPluginMetadata(plugins.InstancePluginMetadata)

daemoncfg/daemon_config.go

@@ -5,6 +5,7 @@
 //     http://aws.amazon.com/apache2.0/
 //
 // or in the "license" file accompanying this file. This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
+
 package daemoncfg
 
 import (
@@ -21,12 +22,12 @@ var addressDelimiter = " " // delimiter between tcp and udp addresses
 var udpKey = "udp"
 var tcpKey = "tcp"
 
-/// DaemonEndpoints stores X-Ray daemon configuration about the ip address and port for UDP and TCP port. It gets the address
-/// string from "AWS_TRACING_DAEMON_ADDRESS" and then from recorder's configuration for DaemonAddr.
-/// A notation of '127.0.0.1:2000' or 'tcp:127.0.0.1:2000 udp:127.0.0.2:2001' or 'udp:127.0.0.1:2000 tcp:127.0.0.2:2001'
-/// are both acceptable. The first one means UDP and TCP are running at the same address.
-/// Notation 'hostname:2000' or 'tcp:hostname:2000 udp:hostname:2001' or 'udp:hostname:2000 tcp:hostname:2001' are also acceptable.
-/// By default it assumes a X-Ray daemon running at 127.0.0.1:2000 listening to both UDP and TCP traffic.
+// DaemonEndpoints stores X-Ray daemon configuration about the ip address and port for UDP and TCP port. It gets the address
+// string from "AWS_TRACING_DAEMON_ADDRESS" and then from recorder's configuration for DaemonAddr.
+// A notation of '127.0.0.1:2000' or 'tcp:127.0.0.1:2000 udp:127.0.0.2:2001' or 'udp:127.0.0.1:2000 tcp:127.0.0.2:2001'
+// are both acceptable. The first one means UDP and TCP are running at the same address.
+// Notation 'hostname:2000' or 'tcp:hostname:2000 udp:hostname:2001' or 'udp:hostname:2000 tcp:hostname:2001' are also acceptable.
+// By default it assumes a X-Ray daemon running at 127.0.0.1:2000 listening to both UDP and TCP traffic.
 type DaemonEndpoints struct {
 	// UDPAddr represents UDP endpoint for segments to be sent by emitter.
 	UDPAddr *net.UDPAddr
@@ -93,13 +94,13 @@ func GetDaemonEndpointsFromString(dAddr string) (*DaemonEndpoints, error) {
 
 func resolveAddress(dAddr string) (*DaemonEndpoints, error) {
 	addr := strings.Split(dAddr, addressDelimiter)
-	if len(addr) == 1 {
+	switch len(addr) {
+	case 1:
 		return parseSingleForm(addr[0])
-	} else if len(addr) == 2 {
+	case 2:
 		return parseDoubleForm(addr)
-	} else {
-		return nil, errors.New("invalid daemon address: " + dAddr)
 	}
+	return nil, errors.New("invalid daemon address: " + dAddr)
 }
 
 func parseDoubleForm(addr []string) (*DaemonEndpoints, error) {

header/header.go

@@ -54,11 +54,12 @@ const (
 )
 
 func samplingDecision(s string) SamplingDecision {
-	if s == string(Sampled) {
+	switch s {
+	case string(Sampled):
 		return Sampled
-	} else if s == string(NotSampled) {
+	case string(NotSampled):
 		return NotSampled
-	} else if s == string(Requested) {
+	case string(Requested):
 		return Requested
 	}
 	return Unknown
@@ -84,13 +85,14 @@ func FromString(s string) *Header {
 		p := strings.TrimSpace(parts[i])
 		value, valid := valueFromKeyValuePair(p)
 		if valid {
-			if strings.HasPrefix(p, RootPrefix) {
+			switch {
+			case strings.HasPrefix(p, RootPrefix):
 				ret.TraceID = value
-			} else if strings.HasPrefix(p, ParentPrefix) {
+			case strings.HasPrefix(p, ParentPrefix):
 				ret.ParentID = value
-			} else if strings.HasPrefix(p, SampledPrefix) {
+			case strings.HasPrefix(p, SampledPrefix):
 				ret.SamplingDecision = samplingDecision(p)
-			} else if !strings.HasPrefix(p, SelfPrefix) {
+			case !strings.HasPrefix(p, SelfPrefix):
 				key, valid := keyFromKeyValuePair(p)
 				if valid {
 					ret.AdditionalData[key] = value

internal/logger/logger.go

@@ -17,7 +17,7 @@ import (
 
 // This internal package hides the actual logging functions from the user.
 
-// The Logger instance used by xray to log. Set via xray.SetLogger().
+// Logger instance used by xray to log. Set via xray.SetLogger().
 var Logger xraylog.Logger = xraylog.NewDefaultLogger(os.Stdout, xraylog.LogLevelInfo)
 
 func Debugf(format string, args ...interface{}) {

internal/plugins/plugin.go

@@ -9,8 +9,13 @@
 package plugins
 
 const (
-	EBServiceName  = "elastic_beanstalk"
+	// EBServiceName is the key name for metadata of ElasticBeanstalkPlugin.
+	EBServiceName = "elastic_beanstalk"
+
+	// EC2ServiceName is the key name for metadata of EC2Plugin.
 	EC2ServiceName = "ec2"
+
+	// ECSServiceName is the key name for metadata of ECSPlugin.
 	ECSServiceName = "ecs"
 )
 

pattern/search_pattern.go

@@ -14,16 +14,16 @@ package pattern
 import "strings"
 
 // WildcardMatchCaseInsensitive returns true if text matches pattern (case-insensitive); returns false otherwise.
-func WildcardMatchCaseInsensitive(pattern string, text string) bool {
+func WildcardMatchCaseInsensitive(pattern, text string) bool {
 	return WildcardMatch(pattern, text, true)
 }
 
 // WildcardMatch returns true if text matches pattern at the given case-sensitivity; returns false otherwise.
-func WildcardMatch(pattern string, text string, caseInsensitive bool) bool {
+func WildcardMatch(pattern, text string, caseInsensitive bool) bool {
 	patternLen := len(pattern)
 	textLen := len(text)
-	if 0 == patternLen {
-		return 0 == textLen
+	if patternLen == 0 {
+		return textLen == 0
 	}
 
 	if pattern == "*" {
@@ -41,23 +41,29 @@ func WildcardMatch(pattern string, text string, caseInsensitive bool) bool {
 	pStar := 0
 
 	for i < textLen {
-		if p < patternLen && pattern[p] == text[i] {
-			i++
-			p++
-		} else if p < patternLen && '?' == pattern[p] {
-			i++
-			p++
-		} else if p < patternLen && pattern[p] == '*' {
-			iStar = i
-			pStar = p
-			p++
-		} else if iStar != textLen {
-			iStar++
-			i = iStar
-			p = pStar + 1
-		} else {
+		if p < patternLen {
+			switch pattern[p] {
+			case text[i]:
+				i++
+				p++
+				continue
+			case '?':
+				i++
+				p++
+				continue
+			case '*':
+				iStar = i
+				pStar = p
+				p++
+				continue
+			}
+		}
+		if iStar == textLen {
 			return false
 		}
+		iStar++
+		i = iStar
+		p = pStar + 1
 	}
 
 	for p < patternLen && pattern[p] == '*' {

pattern/search_pattern_test.go

@@ -28,7 +28,7 @@ func TestMatchExactNegative(t *testing.T) {
 	assert.False(t, WildcardMatchCaseInsensitive("foo", "bar"))
 }
 
-func TestSignleWildcardPositive(t *testing.T) {
+func TestSingleWildcardPositive(t *testing.T) {
 	assert.True(t, WildcardMatchCaseInsensitive("fo?", "foo"))
 }
 

plugins/beanstalk/beanstalk.go

@@ -10,7 +10,8 @@ package beanstalk
 
 import "github.com/aws/aws-xray-sdk-go/awsplugins/beanstalk"
 
-const Origin = "AWS::ElasticBeanstalk::Environment"
+// Origin is the type of AWS resource that runs your application.
+const Origin = beanstalk.Origin
 
 func init() {
 	beanstalk.Init()

plugins/ec2/ec2.go

@@ -10,7 +10,8 @@ package ec2
 
 import "github.com/aws/aws-xray-sdk-go/awsplugins/ec2"
 
-const Origin = "AWS::EC2::Instance"
+// Origin is the type of AWS resource that runs your application.
+const Origin = ec2.Origin
 
 func init() {
 	ec2.Init()

plugins/ecs/ecs.go

@@ -10,7 +10,8 @@ package ecs
 
 import "github.com/aws/aws-xray-sdk-go/awsplugins/ecs"
 
-const Origin = "AWS::ECS::Container"
+// Origin is the type of AWS resource that runs your application.
+const Origin = ecs.Origin
 
 func init() {
 	ecs.Init()

strategy/sampling/centralized.go

@@ -140,7 +140,7 @@ func (ss *CentralizedStrategy) ShouldTrace(request *Request) *Decision {
 	logger.Debugf(
 		"Determining ShouldTrace decision for:\n\thost: %s\n\tpath: %s\n\tmethod: %s\n\tservicename: %s\n\tservicetype: %s",
 		request.Host,
-		request.Url,
+		request.URL,
 		request.Method,
 		request.ServiceName,
 		request.ServiceType,

strategy/sampling/centralized_test.go

@@ -84,7 +84,7 @@ func TestShouldTracePositive1(t *testing.T) {
 
 	sr := &Request{
 		Host:        host1,
-		Url:         url1,
+		URL:         url1,
 		Method:      method1,
 		ServiceName: serviceName1,
 		ServiceType: servType1,
@@ -180,7 +180,7 @@ func TestShouldTracePositive2(t *testing.T) {
 	// serviceType missing
 	sr := &Request{
 		Host:        host1,
-		Url:         url1,
+		URL:         url1,
 		Method:      method1,
 		ServiceName: serviceName1,
 	}
@@ -321,7 +321,7 @@ func TestShouldTraceDefaultPositive(t *testing.T) {
 
 	sr := &Request{
 		Host:   "www.foo.bar.com",
-		Url:    "/resource/bat",
+		URL:    "/resource/bat",
 		Method: "GET",
 	}
 
@@ -415,7 +415,7 @@ func TestShouldTraceExpiredManifest(t *testing.T) {
 
 	sr := &Request{
 		Host:   "www.foo.bar.com",
-		Url:    "/resource/bar",
+		URL:    "/resource/bar",
 		Method: "POST",
 	}
 
@@ -2597,7 +2597,7 @@ func TestLoadDaemonEndpoints1(t *testing.T) {
 
 	sr := &Request{
 		Host:        host1,
-		Url:         url1,
+		URL:         url1,
 		Method:      method1,
 		ServiceName: serviceName1,
 		ServiceType: servType1,
@@ -2622,7 +2622,7 @@ func TestLoadDaemonEndpoints2(t *testing.T) {
 
 	sr := &Request{
 		Host:        host1,
-		Url:         url1,
+		URL:         url1,
 		Method:      method1,
 		ServiceName: serviceName1,
 		ServiceType: servType1,

strategy/sampling/localized.go

@@ -60,10 +60,10 @@ func NewLocalizedStrategyFromJSONBytes(b []byte) (*LocalizedStrategy, error) {
 // ShouldTrace consults the LocalizedStrategy's rule set to determine
 // if the given request should be traced or not.
 func (lss *LocalizedStrategy) ShouldTrace(rq *Request) *Decision {
-	logger.Debugf("Determining ShouldTrace decision for:\n\thost: %s\n\tpath: %s\n\tmethod: %s", rq.Host, rq.Url, rq.Method)
+	logger.Debugf("Determining ShouldTrace decision for:\n\thost: %s\n\tpath: %s\n\tmethod: %s", rq.Host, rq.URL, rq.Method)
 	if nil != lss.manifest.Rules {
 		for _, r := range lss.manifest.Rules {
-			if r.AppliesTo(rq.Host, rq.Url, rq.Method) {
+			if r.AppliesTo(rq.Host, rq.URL, rq.Method) {
 				logger.Debugf("Applicable rule:\n\tfixed_target: %d\n\trate: %f\n\thost: %s\n\turl_path: %s\n\thttp_method: %s", r.FixedTarget, r.Rate, r.Host, r.URLPath, r.HTTPMethod)
 				return r.Sample()
 			}

strategy/sampling/reservoir.go

@@ -6,11 +6,12 @@
 //
 // or in the "license" file accompanying this file. This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
 
-// Reservoirs allow a specified (`perSecond`) amount of `Take()`s per second.
 package sampling
 
 import "github.com/aws/aws-xray-sdk-go/utils"
 
+// Reservoirs allow a specified (`perSecond`) amount of `Take()`s per second.
+
 // reservoir is a set of properties common to all reservoirs
 type reservoir struct {
 	// Total size of reservoir

strategy/sampling/sampling_attributes.go

@@ -5,6 +5,7 @@
 //     http://aws.amazon.com/apache2.0/
 //
 // or in the "license" file accompanying this file. This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
+
 package sampling
 
 // Decision contains sampling decision and the rule matched for an incoming request
@@ -17,7 +18,7 @@ type Decision struct {
 type Request struct {
 	Host        string
 	Method      string
-	Url         string
+	URL         string
 	ServiceName string
 	ServiceType string
 }

strategy/sampling/sampling_rule.go

@@ -40,7 +40,7 @@ func (p *Properties) AppliesTo(host, path, method string) bool {
 // Assumes lock is already held, if required.
 func (r *CentralizedRule) AppliesTo(request *Request) bool {
 	return (request.Host == "" || pattern.WildcardMatchCaseInsensitive(r.Host, request.Host)) &&
-		(request.Url == "" || pattern.WildcardMatchCaseInsensitive(r.URLPath, request.Url)) &&
+		(request.URL == "" || pattern.WildcardMatchCaseInsensitive(r.URLPath, request.URL)) &&
 		(request.Method == "" || pattern.WildcardMatchCaseInsensitive(r.HTTPMethod, request.Method)) &&
 		(request.ServiceName == "" || pattern.WildcardMatchCaseInsensitive(r.ServiceName, request.ServiceName)) &&
 		(request.ServiceType == "" || pattern.WildcardMatchCaseInsensitive(r.serviceType, request.ServiceType))
@@ -190,7 +190,7 @@ func (r *CentralizedRule) snapshot() *xraySvc.SamplingStatisticsDocument {
 	return s
 }
 
-// Local Sampling Rule
+// Rule is local sampling rule.
 type Rule struct {
 	reservoir *Reservoir
 
@@ -203,6 +203,7 @@ type Rule struct {
 	mu sync.RWMutex
 }
 
+// Sample is used to provide sampling decision.
 func (r *Rule) Sample() *Decision {
 	var sd Decision
 	r.mu.Lock()