pkg/html: split off URL helpers

The existing pkg/html package transitively takes too many dependencies,
which complicates the reuse of some of its methods.

Split off a pkg/html/urlutil package.

3 files changed, 57 insertions, 45 deletions

diff --git a/pkg/html/html.go b/pkg/html/html.go
index 4893b8377..9d15c8777 100644
--- a/pkg/html/html.go
+++ b/pkg/html/html.go
@@ -6,7 +6,6 @@ package html
 import (
 	"fmt"
 	"html/template"
-	"net/url"
 	"path/filepath"
 	"reflect"
 	"strings"
@@ -214,46 +213,3 @@ func dereferencePointer(v interface{}) interface{} {
 func commitLink(repo, commit string) string {
 	return vcs.CommitLink(repo, commit)
 }
-
-func AmendURL(baseURL, key, value string) string {
-	return TransformURL(baseURL, key, func(_ []string) []string {
-		if value == "" {
-			return nil
-		}
-		return []string{value}
-	})
-}
-
-func DropParam(baseURL, key, value string) string {
-	return TransformURL(baseURL, key, func(oldValues []string) []string {
-		if value == "" {
-			return nil
-		}
-		var newValues []string
-		for _, iterVal := range oldValues {
-			if iterVal != value {
-				newValues = append(newValues, iterVal)
-			}
-		}
-		return newValues
-	})
-}
-
-func TransformURL(baseURL, key string, f func([]string) []string) string {
-	if baseURL == "" {
-		return ""
-	}
-	parsed, err := url.Parse(baseURL)
-	if err != nil {
-		return ""
-	}
-	values := parsed.Query()
-	ret := f(values[key])
-	if len(ret) == 0 {
-		values.Del(key)
-	} else {
-		values[key] = ret
-	}
-	parsed.RawQuery = values.Encode()
-	return parsed.String()
-}
diff --git a/pkg/html/urlutil/urls.go b/pkg/html/urlutil/urls.go
new file mode 100644
index 000000000..42ab505c8
--- /dev/null
+++ b/pkg/html/urlutil/urls.go
@@ -0,0 +1,56 @@
+// Copyright 2025 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package urlutil
+
+import "net/url"
+
+// SetParam overrides the specific key from the URL.
+// It does not take into account that there may be multiple parameters with the same name.
+func SetParam(baseURL, key, value string) string {
+	return TransformParam(baseURL, key, func(_ []string) []string {
+		if value == "" {
+			return nil
+		}
+		return []string{value}
+	})
+}
+
+// DropParam removes the specific key=value pair from the URL
+// (it's possible to have many of parameters with the same name).
+// Set value="" to remove the key regardless of the value.
+func DropParam(baseURL, key, value string) string {
+	return TransformParam(baseURL, key, func(oldValues []string) []string {
+		if value == "" {
+			return nil
+		}
+		var newValues []string
+		for _, iterVal := range oldValues {
+			if iterVal != value {
+				newValues = append(newValues, iterVal)
+			}
+		}
+		return newValues
+	})
+}
+
+// TransformParam is a generic method that transforms the set of values
+// for the specified URL parameter key.
+func TransformParam(baseURL, key string, f func([]string) []string) string {
+	if baseURL == "" {
+		return ""
+	}
+	parsed, err := url.Parse(baseURL)
+	if err != nil {
+		return ""
+	}
+	values := parsed.Query()
+	ret := f(values[key])
+	if len(ret) == 0 {
+		values.Del(key)
+	} else {
+		values[key] = ret
+	}
+	parsed.RawQuery = values.Encode()
+	return parsed.String()
+}
diff --git a/pkg/html/html_test.go b/pkg/html/urlutil/urls_test.go
index d824e0246..a8782c35e 100644
--- a/pkg/html/html_test.go
+++ b/pkg/html/urlutil/urls_test.go
@@ -1,7 +1,7 @@
 // Copyright 2023 syzkaller project authors. All rights reserved.
 // Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
 
-package html
+package urlutil
 
 import (
 	"testing"