3 files changed, 15 insertions, 12 deletions
diff --git a/internal/middleware/accept_requests_test.go b/internal/middleware/accept_requests_test.go
index 24f5fa19..e1971bac 100644
--- a/internal/middleware/accept_requests_test.go
+++ b/internal/middleware/accept_requests_test.go
@@ -7,6 +7,7 @@ package middleware
 import (
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 )
 
@@ -62,20 +63,20 @@ func TestAcceptRequests_URILength(t *testing.T) {
 	defer ts.Close()
 	c := ts.Client()
 
-	var longURL string
+	var longURL strings.Builder
 	// Create a URL with 990 characters.
 	numParts := maxURILength/2 - 5
 	for range numParts {
-		longURL += "/a"
+		longURL.WriteString("/a")
 	}
 	// Without this query param, the length of longURL will be < maxURILength.
-	longURL += "?q=randomstring"
+	longURL.WriteString("?q=randomstring")
 	for _, test := range []struct {
 		name, urlPath string
 		want          bool
 	}{
 		{"short URL", "/shorturlpath", true},
-		{"long URL", longURL, false},
+		{"long URL", longURL.String(), false},
 	} {
 		called = false
 		req, err := http.NewRequest(http.MethodGet, ts.URL+test.urlPath, nil)
diff --git a/internal/symbol/goapi.go b/internal/symbol/goapi.go
index fd4cc840..5dbea638 100644
--- a/internal/symbol/goapi.go
+++ b/internal/symbol/goapi.go
@@ -83,7 +83,8 @@ func tagKey(dir string, context *build.Context, tags []string) string {
 		ctags[tag] = true
 	}
 	// TODO: ReleaseTags (need to load default)
-	key := dir
+	var key strings.Builder
+	key.WriteString(dir)
 	// explicit on GOOS and GOARCH as global cache will use "all" cached packages for
 	// an indirect imported package. See https://github.com/golang/go/issues/21181
 	// for more detail.
@@ -91,11 +92,11 @@ func tagKey(dir string, context *build.Context, tags []string) string {
 	sort.Strings(tags)
 	for _, tag := range tags {
 		if ctags[tag] {
-			key += "," + tag
+			key.WriteString("," + tag)
 			ctags[tag] = false
 		}
 	}
-	return key
+	return key.String()
 }
 
 var listCache sync.Map // map[string]listImports, keyed by contextName
diff --git a/internal/testing/htmlcheck/query.go b/internal/testing/htmlcheck/query.go
index fe594150..ea082270 100644
--- a/internal/testing/htmlcheck/query.go
+++ b/internal/testing/htmlcheck/query.go
@@ -29,15 +29,16 @@ func (s *selector) String() string {
 	if s == nil {
 		return "nil"
 	}
-	str := "["
+	var str strings.Builder
+	str.WriteString("[")
 	for i, atom := range s.atoms {
-		str += fmt.Sprintf("%#v", atom)
+		str.WriteString(fmt.Sprintf("%#v", atom))
 		if i != len(s.atoms)-1 {
-			str += ","
+			str.WriteString(",")
 		}
 	}
-	str += "]->" + s.next.String()
-	return str
+	str.WriteString("]->" + s.next.String())
+	return str.String()
 }
 
 // selectorAtom represents a part of a selector that individually