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KambojRajan wants to merge 1 commit into from
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fix(cache): improve hasDirective function to handle various cases and… #4181

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21 changes: 7 additions & 14 deletions middleware/cache/cache.go
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Original file line number Diff line number Diff line change
Expand Up @@ -907,23 +907,16 @@ func New(config ...Config) fiber.Handler {

// hasDirective checks if a cache-control header contains a directive (case-insensitive)
func hasDirective(cc, directive string) bool {
ccLen := len(cc)
dirLen := len(directive)
for i := 0; i <= ccLen-dirLen; i++ {
if !utils.EqualFold(cc[i:i+dirLen], directive) {
continue
}
if i > 0 {
prev := cc[i-1]
if prev != ' ' && prev != ',' {
continue
}
}
if i+dirLen == ccLen || cc[i+dirLen] == ',' {
for _, part := range strings.Split(cc, ",") {
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@gemini-code-assist gemini-code-assist bot Apr 4, 2026

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medium

For better performance and to reduce allocations, consider using strings.SplitSeq instead of strings.Split. strings.SplitSeq provides an iterator over the substrings, avoiding the allocation of a slice to hold all of them at once. This is more memory-efficient, especially for Cache-Control headers with many directives.

This change would also be consistent with the implementation of parseVary in this file, which already uses strings.SplitSeq.

Suggested change
for _, part := range strings.Split(cc, ",") {
for part := range strings.SplitSeq(cc, ",") {

part = strings.TrimSpace(part)

key, _, _ := strings.Cut(part, "=")
key = strings.TrimSpace(key)

if strings.EqualFold(key, directive) {
Comment on lines +910 to +916
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@coderabbitai coderabbitai bot Apr 4, 2026

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⚠️ Potential issue | 🟡 Minor

Quoted commas can produce false directive matches

The current comma-split approach can misparse valid quoted directive values and report a directive that only appears inside a quoted string. Consider reusing parseCacheControlDirectives here for RFC-consistent tokenization.

Suggested fix 
 func hasDirective(cc, directive string) bool {
-	for _, part := range strings.Split(cc, ",") {
-		part = strings.TrimSpace(part)
-
-		key, _, _ := strings.Cut(part, "=")
-		key = strings.TrimSpace(key)
-
-		if strings.EqualFold(key, directive) {
-			return true
-		}
-	}
-	return false
+	found := false
+	parseCacheControlDirectives(utils.UnsafeBytes(cc), func(key, _ []byte) {
+		if !found && utils.EqualFold(utils.UnsafeString(key), directive) {
+			found = true
+		}
+	})
+	return found
 }
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
for _, part := range strings.Split(cc, ",") {
part = strings.TrimSpace(part)
key, _, _ := strings.Cut(part, "=")
key = strings.TrimSpace(key)
if strings.EqualFold(key, directive) {
func hasDirective(cc, directive string) bool {
found := false
parseCacheControlDirectives(utils.UnsafeBytes(cc), func(key, _ []byte) {
if !found && utils.EqualFold(utils.UnsafeString(key), directive) {
found = true
}
})
return found
}
🤖 Prompt for AI Agents 
Verify each finding against the current code and only fix it if needed.

In `@middleware/cache/cache.go` around lines 910 - 916, The loop that does
strings.Split(cc, ",") can misinterpret commas inside quoted directive values;
replace this ad-hoc comma-splitting with the RFC-aware tokenizer by calling
parseCacheControlDirectives(cc) and iterate its returned directives (or map of
key→value) instead of splitting, then use strings.EqualFold against the
directive variable to match keys (and use the provided value from
parseCacheControlDirectives when needed); update the logic in the function
containing the current loop so it consumes parseCacheControlDirectives' output
to avoid false matches from quoted commas.

return true
}
}

return false
}

Expand Down
105 changes: 105 additions & 0 deletions middleware/cache/cache_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -5091,3 +5091,108 @@ func Test_Cache_ConfigurationAndResponseHandling(t *testing.T) {
require.Equal(t, cacheMiss, rsp2.Header.Get("X-Cache"))
})
}

func Test_Cache_hasDirective(t *testing.T) {
t.Parallel()

tests := []struct {
name string
cc string
directive string
expected bool
}{
{
name: "directive at end of string",
cc: "no-cache",
directive: "no-cache",
expected: true,
},
{
name: "directive before comma",
cc: "no-cache, no-store",
directive: "no-cache",
expected: true,
},
{
name: "directive after comma",
cc: "no-store, no-cache",
directive: "no-cache",
expected: true,
},
{
name: "directive not present",
cc: "no-store, public",
directive: "no-cache",
expected: false,
},
{
name: "trailing space",
cc: "no-cache ",
directive: "no-cache",
expected: true,
},
{
name: "trailing tab",
cc: "no-cache\t",
directive: "no-cache",
expected: true,
},
{
name: "directive with value using equals",
cc: `no-cache="Set-Cookie"`,
directive: "no-cache",
expected: true,
},
{
name: "max-age with value",
cc: "max-age=604800",
directive: "max-age",
expected: true,
},
{
name: "private with trailing space",
cc: "private ",
directive: "private",
expected: true,
},
{
name: "s-maxage with value in middle",
cc: "public, s-maxage=3600, must-revalidate",
directive: "s-maxage",
expected: true,
},

{
name: "partial match should fail",
cc: "no-cache-extended",
directive: "no-cache",
expected: false,
},
{
name: "directive in middle with spaces",
cc: "public, no-cache , max-age=60",
directive: "no-cache",
expected: true,
},
{
name: "empty string",
cc: "",
directive: "no-cache",
expected: false,
},
{
name: "case insensitive match",
cc: "No-Cache",
directive: "no-cache",
expected: true,
},
}

for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
t.Parallel()
got := hasDirective(tt.cc, tt.directive)
require.Equal(t, tt.expected, got)
})
}
}
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