Fix all golangci-lint warnings with extended linters

client/client.go

@@ -12,6 +12,14 @@ import (
 	"time"
 )
 
+const (
+	defaultTimeout    = 30 * time.Second
+	defaultMaxRetries = 5
+	defaultBaseDelay  = 50 * time.Millisecond
+	backoffBase       = 2
+	jitterFactor      = 0.1
+)
+
 // RateLimiter controls request pacing.
 type RateLimiter interface {
 	Wait(ctx context.Context) error
@@ -30,11 +38,11 @@ type Client struct {
 func DefaultClient() *Client {
 	return &Client{
 		HTTPClient: &http.Client{
-			Timeout: 30 * time.Second,
+			Timeout: defaultTimeout,
 		},
 		UserAgent:  "registries",
-		MaxRetries: 5,
-		BaseDelay:  50 * time.Millisecond,
+		MaxRetries: defaultMaxRetries,
+		BaseDelay:  defaultBaseDelay,
 	}
 }
 
@@ -53,8 +61,8 @@ func (c *Client) GetBody(ctx context.Context, url string) ([]byte, error) {
 
 	for attempt := 0; attempt <= c.MaxRetries; attempt++ {
 		if attempt > 0 {
-			delay := c.BaseDelay * time.Duration(math.Pow(2, float64(attempt-1)))
-			jitter := time.Duration(float64(delay) * (rand.Float64() * 0.1))
+			delay := c.BaseDelay * time.Duration(math.Pow(backoffBase, float64(attempt-1)))
+			jitter := time.Duration(float64(delay) * (rand.Float64() * jitterFactor))
 			delay += jitter
 
 			select {
@@ -79,10 +87,10 @@ func (c *Client) GetBody(ctx context.Context, url string) ([]byte, error) {
 
 		var httpErr *HTTPError
 		if ok := isHTTPError(err, &httpErr); ok {
-			if httpErr.StatusCode == 404 {
+			if httpErr.StatusCode == http.StatusNotFound {
 				return nil, err
 			}
-			if httpErr.StatusCode == 429 || httpErr.StatusCode >= 500 {
+			if httpErr.StatusCode == http.StatusTooManyRequests || httpErr.StatusCode >= http.StatusInternalServerError {
 				continue
 			}
 			return nil, err
@@ -112,13 +120,13 @@ func (c *Client) doRequest(ctx context.Context, url string) ([]byte, error) {
 		return nil, err
 	}
 
-	if resp.StatusCode >= 400 {
+	if resp.StatusCode >= http.StatusBadRequest {
 		httpErr := &HTTPError{
 			StatusCode: resp.StatusCode,
 			URL:        url,
 			Body:       string(body),
 		}
-		if resp.StatusCode == 429 {
+		if resp.StatusCode == http.StatusTooManyRequests {
 			if retryAfter := resp.Header.Get("Retry-After"); retryAfter != "" {
 				if seconds, err := strconv.Atoi(retryAfter); err == nil {
 					return nil, &RateLimitError{RetryAfter: seconds}

client/errors.go

@@ -3,6 +3,7 @@ package client
 import (
 	"errors"
 	"fmt"
+	"net/http"
 )
 
 // ErrNotFound is returned when a package or version is not found.
@@ -21,7 +22,7 @@ func (e *HTTPError) Error() string {
 
 // IsNotFound returns true if the error represents a 404 response.
 func (e *HTTPError) IsNotFound() bool {
-	return e.StatusCode == 404
+	return e.StatusCode == http.StatusNotFound
 }
 
 // NotFoundError wraps ErrNotFound with additional context.

fetch/circuit_breaker.go

@@ -11,6 +11,13 @@ import (
 	circuit "github.com/rubyist/circuitbreaker"
 )
 
+const (
+	cbInitialInterval = 30 * time.Second
+	cbMaxInterval     = 5 * time.Minute
+	cbThreshold       = 5
+	maxURLTruncate    = 50
+)
+
 // CircuitBreakerFetcher wraps a Fetcher with per-registry circuit breakers.
 type CircuitBreakerFetcher struct {
 	fetcher  *Fetcher
@@ -47,14 +54,14 @@ func (cbf *CircuitBreakerFetcher) getBreaker(registry string) *circuit.Breaker {
 	// Create new circuit breaker with exponential backoff
 	// Trips after 5 consecutive failures
 	expBackoff := backoff.NewExponentialBackOff()
-	expBackoff.InitialInterval = 30 * time.Second
-	expBackoff.MaxInterval = 5 * time.Minute
+	expBackoff.InitialInterval = cbInitialInterval
+	expBackoff.MaxInterval = cbMaxInterval
 	expBackoff.Multiplier = 2.0
 	expBackoff.Reset()
 
 	opts := &circuit.Options{
 		BackOff:    expBackoff,
-		ShouldTrip: circuit.ThresholdTripFunc(5),
+		ShouldTrip: circuit.ThresholdTripFunc(cbThreshold),
 	}
 	breaker = circuit.NewBreakerWithOptions(opts)
 
@@ -112,7 +119,7 @@ func extractRegistry(rawURL string) string {
 	parsed, err := url.Parse(rawURL)
 	if err != nil || parsed.Host == "" {
 		// Fallback to simple truncation
-		if len(rawURL) > 50 {
+		if len(rawURL) > maxURLTruncate {
 			return rawURL[:50]
 		}
 		return rawURL

fetch/fetcher.go

@@ -17,6 +17,23 @@ import (
 	"github.com/rs/dnscache"
 )
 
+const (
+	dnsRefreshInterval  = 5 * time.Minute
+	dialTimeout         = 30 * time.Second
+	dialKeepAlive       = 30 * time.Second
+	httpClientTimeout   = 5 * time.Minute
+	maxIdleConns        = 100
+	maxIdleConnsPerHost = 10
+	idleConnTimeout     = 90 * time.Second
+	tlsHandshakeTimeout = 10 * time.Second
+	defaultMaxRetries   = 3
+	defaultBaseDelay    = 500 * time.Millisecond
+	backoffBase         = 2
+	jitterFactor        = 0.1
+	serverErrThreshold  = 500
+	maxErrBodySize      = 1024
+)
+
 var (
 	ErrNotFound     = errors.New("artifact not found")
 	ErrRateLimited  = errors.New("rate limited by upstream")
@@ -91,7 +108,7 @@ func NewFetcher(opts ...Option) *Fetcher {
 	// Create DNS cache with 5 minute refresh interval
 	resolver := &dnscache.Resolver{}
 	go func() {
-		ticker := time.NewTicker(5 * time.Minute)
+		ticker := time.NewTicker(dnsRefreshInterval)
 		defer ticker.Stop()
 		for range ticker.C {
 			resolver.Refresh(true)
@@ -100,13 +117,13 @@ func NewFetcher(opts ...Option) *Fetcher {
 
 	// Create custom dialer with DNS caching
 	dialer := &net.Dialer{
-		Timeout:   30 * time.Second,
-		KeepAlive: 30 * time.Second,
+		Timeout:   dialTimeout,
+		KeepAlive: dialKeepAlive,
 	}
 
 	f := &Fetcher{
 		client: &http.Client{
-			Timeout: 5 * time.Minute, // Artifacts can be large
+			Timeout: httpClientTimeout,
 			Transport: &http.Transport{
 				DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
 					host, port, err := net.SplitHostPort(addr)
@@ -125,16 +142,16 @@ func NewFetcher(opts ...Option) *Fetcher {
 					}
 					return nil, fmt.Errorf("failed to dial any resolved IP")
 				},
-				MaxIdleConns:          100,
-				MaxIdleConnsPerHost:   10,
-				IdleConnTimeout:       90 * time.Second,
-				TLSHandshakeTimeout:   10 * time.Second,
+				MaxIdleConns:          maxIdleConns,
+				MaxIdleConnsPerHost:   maxIdleConnsPerHost,
+				IdleConnTimeout:       idleConnTimeout,
+				TLSHandshakeTimeout:   tlsHandshakeTimeout,
 				ExpectContinueTimeout: 1 * time.Second,
 			},
 		},
 		userAgent:  "git-pkgs-proxy/1.0",
-		maxRetries: 3,
-		baseDelay:  500 * time.Millisecond,
+		maxRetries: defaultMaxRetries,
+		baseDelay:  defaultBaseDelay,
 	}
 	for _, opt := range opts {
 		opt(f)
@@ -150,8 +167,8 @@ func (f *Fetcher) Fetch(ctx context.Context, url string) (*Artifact, error) {
 	for attempt := 0; attempt <= f.maxRetries; attempt++ {
 		if attempt > 0 {
 			// Exponential backoff with 10% jitter to prevent thundering herd
-			delay := f.baseDelay * time.Duration(math.Pow(2, float64(attempt-1)))
-			jitter := time.Duration(float64(delay) * (rand.Float64() * 0.1))
+			delay := f.baseDelay * time.Duration(math.Pow(backoffBase, float64(attempt-1)))
+			jitter := time.Duration(float64(delay) * (rand.Float64() * jitterFactor))
 			delay += jitter
 
 			select {
@@ -230,12 +247,12 @@ func (f *Fetcher) doFetch(ctx context.Context, url string) (*Artifact, error) {
 		_ = resp.Body.Close()
 		return nil, ErrRateLimited
 
-	case resp.StatusCode >= 500:
+	case resp.StatusCode >= serverErrThreshold:
 		_ = resp.Body.Close()
 		return nil, ErrUpstreamDown
 
 	default:
-		body, _ := io.ReadAll(io.LimitReader(resp.Body, 1024))
+		body, _ := io.ReadAll(io.LimitReader(resp.Body, maxErrBodySize))
 		_ = resp.Body.Close()
 		return nil, fmt.Errorf("unexpected status %d: %s", resp.StatusCode, string(body))
 	}

fetch/resolver.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"strings"
+	"unicode"
 
 	"github.com/git-pkgs/registries"
 	"github.com/git-pkgs/registries/client"
@@ -103,12 +104,11 @@ func (r *Resolver) resolveWithoutRegistry(ecosystem, name, version string) (*Art
 
 	case "maven":
 		// Maven name format is "group:artifact", e.g., "com.google.guava:guava"
-		parts := strings.SplitN(name, ":", 2)
-		if len(parts) != 2 {
+		group, artifact, found := strings.Cut(name, ":")
+		if !found {
 			return nil, fmt.Errorf("invalid maven name format, expected group:artifact")
 		}
-		group := strings.ReplaceAll(parts[0], ".", "/")
-		artifact := parts[1]
+		group = strings.ReplaceAll(group, ".", "/")
 		url = fmt.Sprintf("https://repo1.maven.org/maven2/%s/%s/%s/%s-%s.jar", group, artifact, version, artifact, version)
 		filename = fmt.Sprintf("%s-%s.jar", artifact, version)
 
@@ -185,7 +185,7 @@ func encodeGoModule(path string) string {
 	for _, r := range path {
 		if r >= 'A' && r <= 'Z' {
 			b.WriteRune('!')
-			b.WriteRune(r + 32)
+			b.WriteRune(unicode.ToLower(r))
 		} else {
 			b.WriteRune(r)
 		}

internal/cargo/cargo.go

@@ -44,7 +44,7 @@ func (r *Registry) Ecosystem() string {
 	return ecosystem
 }
 
-func (r *Registry) URLs() core.URLBuilder {
+func (r *Registry) URLs() core.URLBuilder { //nolint:ireturn
 	return r.urls
 }
 

internal/clojars/clojars.go

@@ -11,8 +11,9 @@ import (
 )
 
 const (
-	DefaultURL = "https://clojars.org"
-	ecosystem  = "clojars"
+	DefaultURL  = "https://clojars.org"
+	ecosystem   = "clojars"
+	msPerSecond = 1000
 )
 
 func init() {
@@ -43,7 +44,7 @@ func (r *Registry) Ecosystem() string {
 	return ecosystem
 }
 
-func (r *Registry) URLs() core.URLBuilder {
+func (r *Registry) URLs() core.URLBuilder { //nolint:ireturn
 	return r.urls
 }
 
@@ -86,9 +87,8 @@ type depInfo struct {
 // ParseCoordinates parses a Clojars coordinate string (group/artifact or just artifact)
 // If no group is specified, the artifact name is used as both group and artifact
 func ParseCoordinates(name string) (group, artifact string) {
-	parts := strings.SplitN(name, "/", 2)
-	if len(parts) == 2 {
-		return parts[0], parts[1]
+	if before, after, found := strings.Cut(name, "/"); found {
+		return before, after
 	}
 	// Single name means group == artifact
 	return name, name
@@ -168,7 +168,7 @@ func (r *Registry) FetchVersions(ctx context.Context, name string) ([]core.Versi
 		var versionResp versionDetailResponse
 		if err := r.client.GetJSON(ctx, versionURL, &versionResp); err == nil {
 			if versionResp.CreatedEpoch > 0 {
-				versions[i].PublishedAt = time.Unix(versionResp.CreatedEpoch/1000, 0)
+				versions[i].PublishedAt = time.Unix(versionResp.CreatedEpoch/msPerSecond, 0)
 			}
 			if len(versionResp.Licenses) > 0 {
 				versions[i].Licenses = strings.Join(versionResp.Licenses, ",")

internal/cocoapods/cocoapods.go

@@ -43,7 +43,7 @@ func (r *Registry) Ecosystem() string {
 	return ecosystem
 }
 
-func (r *Registry) URLs() core.URLBuilder {
+func (r *Registry) URLs() core.URLBuilder { //nolint:ireturn
 	return r.urls
 }
 

internal/conda/conda.go

@@ -57,7 +57,7 @@ func (r *Registry) Ecosystem() string {
 	return ecosystem
 }
 
-func (r *Registry) URLs() core.URLBuilder {
+func (r *Registry) URLs() core.URLBuilder { //nolint:ireturn
 	return r.urls
 }
 
@@ -99,9 +99,8 @@ type fileAttrs struct {
 // parsePackageName parses a package name that may include a channel prefix
 // Format: "channel/name" or just "name" (uses default channel)
 func parsePackageName(name string) (channel, pkgName string) {
-	parts := strings.SplitN(name, "/", 2)
-	if len(parts) == 2 {
-		return parts[0], parts[1]
+	if before, after, found := strings.Cut(name, "/"); found {
+		return before, after
 	}
 	return "", name
 }
@@ -249,15 +248,10 @@ func (r *Registry) FetchDependencies(ctx context.Context, name, version string)
 }
 
 func parseDependency(dep string) (name, requirements string) {
-	// Conda dependency format: "name version_constraint" or just "name"
-	// Examples: "python >=3.8", "numpy", "pandas >=1.0,<2.0"
 	dep = strings.TrimSpace(dep)
-	parts := strings.SplitN(dep, " ", 2)
-	name = parts[0]
-	if len(parts) > 1 {
-		requirements = strings.TrimSpace(parts[1])
-	}
-	return
+	name, requirements, _ = strings.Cut(dep, " ")
+	requirements = strings.TrimSpace(requirements)
+	return name, requirements
 }
 
 func (r *Registry) FetchMaintainers(ctx context.Context, name string) ([]core.Maintainer, error) {

internal/core/helpers.go

@@ -13,7 +13,7 @@ const defaultConcurrency = 15
 // NewFromPURL creates a registry client from a PURL and returns the parsed components.
 // Returns the registry, full package name, and version (empty if not in PURL).
 // If the PURL has a repository_url qualifier, it's used as the base URL for private registries.
-func NewFromPURL(purlStr string, client *Client) (Registry, string, string, error) {
+func NewFromPURL(purlStr string, client *Client) (Registry, string, string, error) { //nolint:ireturn
 	p, err := purl.Parse(purlStr)
 	if err != nil {
 		return nil, "", "", err

internal/core/registry.go

@@ -48,7 +48,7 @@ func Register(ecosystem string, defaultURL string, factory Factory) {
 
 // New creates a new registry for the given ecosystem.
 // If baseURL is empty, the default registry URL is used.
-func New(ecosystem string, baseURL string, client *Client) (Registry, error) {
+func New(ecosystem string, baseURL string, client *Client) (Registry, error) { //nolint:ireturn
 	mu.RLock()
 	factory, ok := factories[ecosystem]
 	defaultURL := defaults[ecosystem]

internal/cpan/cpan.go

@@ -44,7 +44,7 @@ func (r *Registry) Ecosystem() string {
 	return ecosystem
 }
 
-func (r *Registry) URLs() core.URLBuilder {
+func (r *Registry) URLs() core.URLBuilder { //nolint:ireturn
 	return r.urls
 }