diff --git a/Libraries/LibWeb/CSS/StyleValues/TimeStyleValue.h b/Libraries/LibWeb/CSS/StyleValues/TimeStyleValue.h
index 580e8ca3fb3..2b3e37880fe 100644
--- a/Libraries/LibWeb/CSS/StyleValues/TimeStyleValue.h
+++ b/Libraries/LibWeb/CSS/StyleValues/TimeStyleValue.h
@@ -26,7 +26,12 @@ public:
virtual double value() const override { return m_time.raw_value(); }
virtual StringView unit() const override { return m_time.unit_name(); }
- virtual String to_string(SerializationMode) const override { return m_time.to_string(); }
+ virtual String to_string(SerializationMode serialization_mode) const override
+ {
+ if (serialization_mode == SerializationMode::ResolvedValue)
+ return MUST(String::formatted("{}s", m_time.to_seconds()));
+ return m_time.to_string();
+ }
bool equals(CSSStyleValue const& other) const override
{
diff --git a/Libraries/LibWeb/CSS/Time.cpp b/Libraries/LibWeb/CSS/Time.cpp
index ce8b3e4f33b..a9e7c70727b 100644
--- a/Libraries/LibWeb/CSS/Time.cpp
+++ b/Libraries/LibWeb/CSS/Time.cpp
@@ -28,7 +28,7 @@ Time Time::percentage_of(Percentage const& percentage) const
String Time::to_string() const
{
- return MUST(String::formatted("{}s", to_seconds()));
+ return MUST(String::formatted("{}{}", raw_value(), unit_name()));
}
double Time::to_seconds() const
diff --git a/Tests/LibWeb/Text/expected/wpt-import/css/css-transitions/parsing/transition-duration-valid.txt b/Tests/LibWeb/Text/expected/wpt-import/css/css-transitions/parsing/transition-duration-valid.txt
new file mode 100644
index 00000000000..81a7da6559c
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/wpt-import/css/css-transitions/parsing/transition-duration-valid.txt
@@ -0,0 +1,9 @@
+Harness status: OK
+
+Found 3 tests
+
+2 Pass
+1 Fail
+Pass e.style['transition-duration'] = "0s" should set the property value
+Pass e.style['transition-duration'] = "500ms" should set the property value
+Fail e.style['transition-duration'] = "1s, 2s" should set the property value
\ No newline at end of file
diff --git a/Tests/LibWeb/Text/input/wpt-import/css/css-transitions/parsing/transition-duration-valid.html b/Tests/LibWeb/Text/input/wpt-import/css/css-transitions/parsing/transition-duration-valid.html
new file mode 100644
index 00000000000..fbd43064992
--- /dev/null
+++ b/Tests/LibWeb/Text/input/wpt-import/css/css-transitions/parsing/transition-duration-valid.html
@@ -0,0 +1,19 @@
+
+
+
+
+CSS Transitions: parsing transition-duration with valid values
+
+
+
+
+
+
+
+
+
+