refactor: apply the Go 1.27 go fix modernizers

acls_grant_test.go

@@ -287,8 +287,7 @@ func TestACLs_GrantReadFails(t *testing.T) {
 	if changed != nil || !errors.Is(err, ErrNotFound) {
 		t.Fatalf("Grant = %v, %v; want nil, ErrNotFound", changed, err)
 	}
-	var ce *ACLChangeError
-	if errors.As(err, &ce) {
+	if _, ok := errors.AsType[*ACLChangeError](err); ok {
 		t.Errorf("a failed read should not be an ACLChangeError: %v", err)
 	}
 }

chefignore.go

@@ -70,7 +70,7 @@ func readChefignore(p string) (found bool, ci *Chefignore, err error) {
 // "#"). Surrounding whitespace is trimmed from each pattern.
 func parseChefignore(data []byte) []string {
 	var patterns []string
-	for _, line := range strings.Split(string(data), "\n") {
+	for line := range strings.SplitSeq(string(data), "\n") {
 		line = strings.TrimSpace(line)
 		if line == "" || strings.HasPrefix(line, "#") {
 			continue

cookbooks_test.go

@@ -1058,9 +1058,9 @@ func TestAllFiles_DedupesByPath(t *testing.T) {
 // Download must fetch and write each cookbook file exactly once, even when the
 // manifest lists it in both shapes.
 func TestDownload_FetchesEachFileOnce(t *testing.T) {
-	var fetches int64
+	var fetches atomic.Int64
 	files := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
-		atomic.AddInt64(&fetches, 1)
+		fetches.Add(1)
 		w.Write([]byte("# default recipe\n"))
 	}))
 	defer files.Close()
@@ -1077,7 +1077,7 @@ func TestDownload_FetchesEachFileOnce(t *testing.T) {
 	if err := c.Cookbooks.Download(context.Background(), "nginx", "1.0.0", dest); err != nil {
 		t.Fatalf("Download: %v", err)
 	}
-	if got := atomic.LoadInt64(&fetches); got != 1 {
+	if got := fetches.Load(); got != 1 {
 		t.Errorf("bookshelf fetches = %d, want 1", got)
 	}
 }

integration/suite/raw.go

@@ -3,6 +3,7 @@ package suite
 import (
 	"bytes"
 	"io"
+	"maps"
 	"net/http"
 	"strings"
 	"testing"
@@ -34,9 +35,7 @@ func rawRequest(t *testing.T, tgt Target, method, path, apiVersion string, body
 	if err != nil {
 		t.Fatalf("build %s %s: %v", method, path, err)
 	}
-	for k, v := range hdrs {
-		req.Header[k] = v
-	}
+	maps.Copy(req.Header, hdrs)
 	req.Header.Set("X-Chef-Version", "16.0.0")
 	req.Header.Set("Accept", "application/json")
 	req.Header.Set("Content-Type", "application/json")

search_test.go

@@ -65,10 +65,7 @@ func TestSearch_AllWithStart(t *testing.T) {
 		requestStarts = append(requestStarts, start)
 
 		// Build a page of rows beginning at 'start'.
-		end := start + pageSize
-		if end > totalRows {
-			end = totalRows
-		}
+		end := min(start+pageSize, totalRows)
 		var rows []string
 		for i := start; i < end; i++ {
 			rows = append(rows, fmt.Sprintf(`{"idx":%d}`, i))

transport.go

@@ -9,6 +9,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"maps"
 	"net/http"
 	"strconv"
 	"strings"
@@ -161,8 +162,7 @@ func (e *transportErr) Unwrap() error { return e.err }
 // Context cancellation and deadlines never retry: the caller is done waiting.
 // Neither does a failed TLS handshake that will fail the same way next time.
 func isRetriable(err error) bool {
-	var te *transportErr
-	if !errors.As(err, &te) {
+	if _, ok := errors.AsType[*transportErr](err); !ok {
 		return false
 	}
 	if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
@@ -218,8 +218,8 @@ func (c *Client) doOnce(ctx context.Context, method, path string, body []byte) (
 	// Strip the query string from the path used for signing only; the v1.3
 	// signing spec requires the canonical path to exclude the query string.
 	signPath := path
-	if i := strings.IndexByte(path, '?'); i >= 0 {
-		signPath = path[:i]
+	if before, _, ok := strings.Cut(path, "?"); ok {
+		signPath = before
 	}
 	apiVersion, _ := ctx.Value(apiVersionKey{}).(string)
 	hdrs, err := signing.SignHeaders(signing.Request{
@@ -230,9 +230,7 @@ func (c *Client) doOnce(ctx context.Context, method, path string, body []byte) (
 	if err != nil {
 		return nil, nil, err
 	}
-	for k, v := range hdrs {
-		req.Header[k] = v
-	}
+	maps.Copy(req.Header, hdrs)
 	req.Header.Set("X-Chef-Version", c.opts.chefVersion)
 	req.Header.Set("User-Agent", c.opts.userAgent)
 	req.Header.Set("Accept", "application/json")

transport_test.go

@@ -571,9 +571,9 @@ func recordSleeps(c *Client) *[]time.Duration {
 // A 5xx is retried, and the client waits longer before each attempt rather
 // than firing every attempt inside the same microsecond.
 func TestRetry_BacksOffBetweenAttempts(t *testing.T) {
-	var attempts int32
+	var attempts atomic.Int32
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
-		atomic.AddInt32(&attempts, 1)
+		attempts.Add(1)
 		w.WriteHeader(500)
 	}))
 	defer srv.Close()
@@ -583,7 +583,7 @@ func TestRetry_BacksOffBetweenAttempts(t *testing.T) {
 	if _, _, err := do[map[string]any](context.Background(), c, "GET", "/nodes/x", nil); err == nil {
 		t.Fatal("want an error from a persistent 500")
 	}
-	if got := atomic.LoadInt32(&attempts); got != 3 {
+	if got := attempts.Load(); got != 3 {
 		t.Errorf("attempts = %d, want 3 (initial + 2 retries)", got)
 	}
 	if len(*sleeps) != 2 {