test: Increase pkg/common/utils coverage to more than 93% (cloudwego#…

…1108)

pkg/common/utils/utils_test.go

@@ -49,7 +49,34 @@ import (
 
 // test assert func
 func TestUtilsAssert(t *testing.T) {
-	// nothing to test
+	assertPanic := func() (panicked bool) {
+		defer func() {
+			if r := recover(); r != nil {
+				panicked = true
+			}
+		}()
+		Assert(false, "should panic")
+		return false
+	}
+
+	// Checking if the assertPanic function results in a panic as expected.
+	// We expect a true value because it should panic.
+	assert.DeepEqual(t, true, assertPanic())
+
+	// Checking if a true assertion does not result in a panic.
+	// We create a wrapper around Assert to capture if it panics when it should not.
+	noPanic := func() (panicked bool) {
+		defer func() {
+			if r := recover(); r != nil {
+				panicked = true
+			}
+		}()
+		Assert(true, "should not panic")
+		return false
+	}
+
+	// We expect a false value because it should not panic.
+	assert.DeepEqual(t, false, noPanic())
 }
 
 func TestUtilsIsTrueString(t *testing.T) {
@@ -142,3 +169,18 @@ func TestFilterContentType(t *testing.T) {
 	contentType = FilterContentType(contentType)
 	assert.DeepEqual(t, "text/plain", contentType)
 }
+
+func TestNormalizeHeaderKeyEdgeCases(t *testing.T) {
+	empty := []byte("")
+	NormalizeHeaderKey(empty, false)
+	assert.DeepEqual(t, []byte(""), empty)
+	NormalizeHeaderKey(empty, true)
+	assert.DeepEqual(t, []byte(""), empty)
+}
+
+func TestFilterContentTypeEdgeCases(t *testing.T) {
+	simpleContentType := "text/plain"
+	assert.DeepEqual(t, "text/plain", FilterContentType(simpleContentType))
+	complexContentType := "text/html; charset=utf-8; format=flowed"
+	assert.DeepEqual(t, "text/html", FilterContentType(complexContentType))
+}