From bd7348949aad21d28a19ffb991a5f4d945f2fb28 Mon Sep 17 00:00:00 2001
From: Tim Ledbetter <tim.ledbetter@ladybird.org>
Date: Tue, 9 Sep 2025 10:05:21 +0100
Subject: [PATCH] LibWeb: Make word-spacing and letter-spacing default value
 compute to 0

---
 Libraries/LibWeb/CSS/StyleComputer.cpp        |   5 +
 ...upported-properties-and-default-values.txt |   4 +-
 .../css/getComputedStyle-print-all.txt        |   2 +-
 .../letter-spacing-interpolation.txt          | 149 ++++++++++++++++++
 .../animations/word-spacing-interpolation.txt | 149 ++++++++++++++++++
 .../parsing/word-spacing-computed.txt         |  14 ++
 .../letter-spacing-interpolation.html         | 107 +++++++++++++
 .../word-spacing-interpolation.html           | 104 ++++++++++++
 .../parsing/word-spacing-computed.html        |  33 ++++
 9 files changed, 564 insertions(+), 3 deletions(-)
 create mode 100644 Tests/LibWeb/Text/expected/wpt-import/css/css-text/animations/letter-spacing-interpolation.txt
 create mode 100644 Tests/LibWeb/Text/expected/wpt-import/css/css-text/animations/word-spacing-interpolation.txt
 create mode 100644 Tests/LibWeb/Text/expected/wpt-import/css/css-text/parsing/word-spacing-computed.txt
 create mode 100644 Tests/LibWeb/Text/input/wpt-import/css/css-text/animations/letter-spacing-interpolation.html
 create mode 100644 Tests/LibWeb/Text/input/wpt-import/css/css-text/animations/word-spacing-interpolation.html
 create mode 100644 Tests/LibWeb/Text/input/wpt-import/css/css-text/parsing/word-spacing-computed.html

diff --git a/Libraries/LibWeb/CSS/StyleComputer.cpp b/Libraries/LibWeb/CSS/StyleComputer.cpp
index 94207111ad4..e83a71d31d0 100644
--- a/Libraries/LibWeb/CSS/StyleComputer.cpp
+++ b/Libraries/LibWeb/CSS/StyleComputer.cpp
@@ -3136,6 +3136,11 @@ NonnullRefPtr<StyleValue const> StyleComputer::compute_value_of_property(Propert
         return compute_border_or_outline_width(specified_value, get_property_specified_value(PropertyID::BorderTopStyle), computation_context);
     case PropertyID::OutlineWidth:
         return compute_border_or_outline_width(specified_value, get_property_specified_value(PropertyID::OutlineStyle), computation_context);
+    case PropertyID::LetterSpacing:
+    case PropertyID::WordSpacing:
+        if (specified_value->to_keyword() == Keyword::Normal)
+            return LengthStyleValue::create(Length::make_px(0));
+        return specified_value;
     case PropertyID::FillOpacity:
     case PropertyID::FloodOpacity:
     case PropertyID::Opacity:
diff --git a/Tests/LibWeb/Text/expected/css/CSSStyleProperties-all-supported-properties-and-default-values.txt b/Tests/LibWeb/Text/expected/css/CSSStyleProperties-all-supported-properties-and-default-values.txt
index 178b85b8114..80d013c26d1 100644
--- a/Tests/LibWeb/Text/expected/css/CSSStyleProperties-all-supported-properties-and-default-values.txt
+++ b/Tests/LibWeb/Text/expected/css/CSSStyleProperties-all-supported-properties-and-default-values.txt
@@ -735,8 +735,8 @@ All supported properties and their default values exposed from CSSStylePropertie
 'will-change': 'auto'
 'wordBreak': 'normal'
 'word-break': 'normal'
-'wordSpacing': 'normal'
-'word-spacing': 'normal'
+'wordSpacing': '0px'
+'word-spacing': '0px'
 'wordWrap': 'normal'
 'word-wrap': 'normal'
 'writingMode': 'horizontal-tb'
diff --git a/Tests/LibWeb/Text/expected/css/getComputedStyle-print-all.txt b/Tests/LibWeb/Text/expected/css/getComputedStyle-print-all.txt
index ada0f74f2d5..55039f01459 100644
--- a/Tests/LibWeb/Text/expected/css/getComputedStyle-print-all.txt
+++ b/Tests/LibWeb/Text/expected/css/getComputedStyle-print-all.txt
@@ -65,7 +65,7 @@ text-wrap-style: auto
 visibility: visible
 white-space-collapse: collapse
 word-break: normal
-word-spacing: normal
+word-spacing: 0px
 word-wrap: normal
 writing-mode: horizontal-tb
 align-content: normal
diff --git a/Tests/LibWeb/Text/expected/wpt-import/css/css-text/animations/letter-spacing-interpolation.txt b/Tests/LibWeb/Text/expected/wpt-import/css/css-text/animations/letter-spacing-interpolation.txt
new file mode 100644
index 00000000000..e611b8e396c
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/wpt-import/css/css-text/animations/letter-spacing-interpolation.txt
@@ -0,0 +1,149 @@
+Harness status: OK
+
+Found 144 tests
+
+144 Pass
+Pass	CSS Transitions: property <letter-spacing> from neutral to [20px] at (-0.3) should be [33px]
+Pass	CSS Transitions: property <letter-spacing> from neutral to [20px] at (0) should be [30px]
+Pass	CSS Transitions: property <letter-spacing> from neutral to [20px] at (0.3) should be [27px]
+Pass	CSS Transitions: property <letter-spacing> from neutral to [20px] at (0.6) should be [24px]
+Pass	CSS Transitions: property <letter-spacing> from neutral to [20px] at (1) should be [20px]
+Pass	CSS Transitions: property <letter-spacing> from neutral to [20px] at (1.5) should be [15px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from neutral to [20px] at (-0.3) should be [33px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from neutral to [20px] at (0) should be [30px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from neutral to [20px] at (0.3) should be [27px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from neutral to [20px] at (0.6) should be [24px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from neutral to [20px] at (1) should be [20px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from neutral to [20px] at (1.5) should be [15px]
+Pass	CSS Animations: property <letter-spacing> from neutral to [20px] at (-0.3) should be [33px]
+Pass	CSS Animations: property <letter-spacing> from neutral to [20px] at (0) should be [30px]
+Pass	CSS Animations: property <letter-spacing> from neutral to [20px] at (0.3) should be [27px]
+Pass	CSS Animations: property <letter-spacing> from neutral to [20px] at (0.6) should be [24px]
+Pass	CSS Animations: property <letter-spacing> from neutral to [20px] at (1) should be [20px]
+Pass	CSS Animations: property <letter-spacing> from neutral to [20px] at (1.5) should be [15px]
+Pass	Web Animations: property <letter-spacing> from neutral to [20px] at (-0.3) should be [33px]
+Pass	Web Animations: property <letter-spacing> from neutral to [20px] at (0) should be [30px]
+Pass	Web Animations: property <letter-spacing> from neutral to [20px] at (0.3) should be [27px]
+Pass	Web Animations: property <letter-spacing> from neutral to [20px] at (0.6) should be [24px]
+Pass	Web Animations: property <letter-spacing> from neutral to [20px] at (1) should be [20px]
+Pass	Web Animations: property <letter-spacing> from neutral to [20px] at (1.5) should be [15px]
+Pass	CSS Transitions: property <letter-spacing> from [initial] to [20px] at (-0.3) should be [-6px]
+Pass	CSS Transitions: property <letter-spacing> from [initial] to [20px] at (0) should be [normal]
+Pass	CSS Transitions: property <letter-spacing> from [initial] to [20px] at (0.3) should be [6px]
+Pass	CSS Transitions: property <letter-spacing> from [initial] to [20px] at (0.6) should be [12px]
+Pass	CSS Transitions: property <letter-spacing> from [initial] to [20px] at (1) should be [20px]
+Pass	CSS Transitions: property <letter-spacing> from [initial] to [20px] at (1.5) should be [30px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [initial] to [20px] at (-0.3) should be [-6px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [initial] to [20px] at (0) should be [normal]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [initial] to [20px] at (0.3) should be [6px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [initial] to [20px] at (0.6) should be [12px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [initial] to [20px] at (1) should be [20px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [initial] to [20px] at (1.5) should be [30px]
+Pass	CSS Animations: property <letter-spacing> from [initial] to [20px] at (-0.3) should be [-6px]
+Pass	CSS Animations: property <letter-spacing> from [initial] to [20px] at (0) should be [normal]
+Pass	CSS Animations: property <letter-spacing> from [initial] to [20px] at (0.3) should be [6px]
+Pass	CSS Animations: property <letter-spacing> from [initial] to [20px] at (0.6) should be [12px]
+Pass	CSS Animations: property <letter-spacing> from [initial] to [20px] at (1) should be [20px]
+Pass	CSS Animations: property <letter-spacing> from [initial] to [20px] at (1.5) should be [30px]
+Pass	Web Animations: property <letter-spacing> from [initial] to [20px] at (-0.3) should be [-6px]
+Pass	Web Animations: property <letter-spacing> from [initial] to [20px] at (0) should be [normal]
+Pass	Web Animations: property <letter-spacing> from [initial] to [20px] at (0.3) should be [6px]
+Pass	Web Animations: property <letter-spacing> from [initial] to [20px] at (0.6) should be [12px]
+Pass	Web Animations: property <letter-spacing> from [initial] to [20px] at (1) should be [20px]
+Pass	Web Animations: property <letter-spacing> from [initial] to [20px] at (1.5) should be [30px]
+Pass	CSS Transitions: property <letter-spacing> from [inherit] to [20px] at (-0.3) should be [-3.4px]
+Pass	CSS Transitions: property <letter-spacing> from [inherit] to [20px] at (0) should be [2px]
+Pass	CSS Transitions: property <letter-spacing> from [inherit] to [20px] at (0.3) should be [7.4px]
+Pass	CSS Transitions: property <letter-spacing> from [inherit] to [20px] at (0.6) should be [12.8px]
+Pass	CSS Transitions: property <letter-spacing> from [inherit] to [20px] at (1) should be [20px]
+Pass	CSS Transitions: property <letter-spacing> from [inherit] to [20px] at (1.5) should be [29px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [inherit] to [20px] at (-0.3) should be [-3.4px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [inherit] to [20px] at (0) should be [2px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [inherit] to [20px] at (0.3) should be [7.4px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [inherit] to [20px] at (0.6) should be [12.8px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [inherit] to [20px] at (1) should be [20px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [inherit] to [20px] at (1.5) should be [29px]
+Pass	CSS Animations: property <letter-spacing> from [inherit] to [20px] at (-0.3) should be [-3.4px]
+Pass	CSS Animations: property <letter-spacing> from [inherit] to [20px] at (0) should be [2px]
+Pass	CSS Animations: property <letter-spacing> from [inherit] to [20px] at (0.3) should be [7.4px]
+Pass	CSS Animations: property <letter-spacing> from [inherit] to [20px] at (0.6) should be [12.8px]
+Pass	CSS Animations: property <letter-spacing> from [inherit] to [20px] at (1) should be [20px]
+Pass	CSS Animations: property <letter-spacing> from [inherit] to [20px] at (1.5) should be [29px]
+Pass	Web Animations: property <letter-spacing> from [inherit] to [20px] at (-0.3) should be [-3.4px]
+Pass	Web Animations: property <letter-spacing> from [inherit] to [20px] at (0) should be [2px]
+Pass	Web Animations: property <letter-spacing> from [inherit] to [20px] at (0.3) should be [7.4px]
+Pass	Web Animations: property <letter-spacing> from [inherit] to [20px] at (0.6) should be [12.8px]
+Pass	Web Animations: property <letter-spacing> from [inherit] to [20px] at (1) should be [20px]
+Pass	Web Animations: property <letter-spacing> from [inherit] to [20px] at (1.5) should be [29px]
+Pass	CSS Transitions: property <letter-spacing> from [unset] to [20px] at (-0.3) should be [-3.4px]
+Pass	CSS Transitions: property <letter-spacing> from [unset] to [20px] at (0) should be [2px]
+Pass	CSS Transitions: property <letter-spacing> from [unset] to [20px] at (0.3) should be [7.4px]
+Pass	CSS Transitions: property <letter-spacing> from [unset] to [20px] at (0.6) should be [12.8px]
+Pass	CSS Transitions: property <letter-spacing> from [unset] to [20px] at (1) should be [20px]
+Pass	CSS Transitions: property <letter-spacing> from [unset] to [20px] at (1.5) should be [29px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [unset] to [20px] at (-0.3) should be [-3.4px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [unset] to [20px] at (0) should be [2px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [unset] to [20px] at (0.3) should be [7.4px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [unset] to [20px] at (0.6) should be [12.8px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [unset] to [20px] at (1) should be [20px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [unset] to [20px] at (1.5) should be [29px]
+Pass	CSS Animations: property <letter-spacing> from [unset] to [20px] at (-0.3) should be [-3.4px]
+Pass	CSS Animations: property <letter-spacing> from [unset] to [20px] at (0) should be [2px]
+Pass	CSS Animations: property <letter-spacing> from [unset] to [20px] at (0.3) should be [7.4px]
+Pass	CSS Animations: property <letter-spacing> from [unset] to [20px] at (0.6) should be [12.8px]
+Pass	CSS Animations: property <letter-spacing> from [unset] to [20px] at (1) should be [20px]
+Pass	CSS Animations: property <letter-spacing> from [unset] to [20px] at (1.5) should be [29px]
+Pass	Web Animations: property <letter-spacing> from [unset] to [20px] at (-0.3) should be [-3.4px]
+Pass	Web Animations: property <letter-spacing> from [unset] to [20px] at (0) should be [2px]
+Pass	Web Animations: property <letter-spacing> from [unset] to [20px] at (0.3) should be [7.4px]
+Pass	Web Animations: property <letter-spacing> from [unset] to [20px] at (0.6) should be [12.8px]
+Pass	Web Animations: property <letter-spacing> from [unset] to [20px] at (1) should be [20px]
+Pass	Web Animations: property <letter-spacing> from [unset] to [20px] at (1.5) should be [29px]
+Pass	CSS Transitions: property <letter-spacing> from [-10px] to [10px] at (-0.3) should be [-16px]
+Pass	CSS Transitions: property <letter-spacing> from [-10px] to [10px] at (0) should be [-10px]
+Pass	CSS Transitions: property <letter-spacing> from [-10px] to [10px] at (0.3) should be [-4px]
+Pass	CSS Transitions: property <letter-spacing> from [-10px] to [10px] at (0.6) should be [2px]
+Pass	CSS Transitions: property <letter-spacing> from [-10px] to [10px] at (1) should be [10px]
+Pass	CSS Transitions: property <letter-spacing> from [-10px] to [10px] at (1.5) should be [20px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [-10px] to [10px] at (-0.3) should be [-16px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [-10px] to [10px] at (0) should be [-10px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [-10px] to [10px] at (0.3) should be [-4px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [-10px] to [10px] at (0.6) should be [2px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [-10px] to [10px] at (1) should be [10px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [-10px] to [10px] at (1.5) should be [20px]
+Pass	CSS Animations: property <letter-spacing> from [-10px] to [10px] at (-0.3) should be [-16px]
+Pass	CSS Animations: property <letter-spacing> from [-10px] to [10px] at (0) should be [-10px]
+Pass	CSS Animations: property <letter-spacing> from [-10px] to [10px] at (0.3) should be [-4px]
+Pass	CSS Animations: property <letter-spacing> from [-10px] to [10px] at (0.6) should be [2px]
+Pass	CSS Animations: property <letter-spacing> from [-10px] to [10px] at (1) should be [10px]
+Pass	CSS Animations: property <letter-spacing> from [-10px] to [10px] at (1.5) should be [20px]
+Pass	Web Animations: property <letter-spacing> from [-10px] to [10px] at (-0.3) should be [-16px]
+Pass	Web Animations: property <letter-spacing> from [-10px] to [10px] at (0) should be [-10px]
+Pass	Web Animations: property <letter-spacing> from [-10px] to [10px] at (0.3) should be [-4px]
+Pass	Web Animations: property <letter-spacing> from [-10px] to [10px] at (0.6) should be [2px]
+Pass	Web Animations: property <letter-spacing> from [-10px] to [10px] at (1) should be [10px]
+Pass	Web Animations: property <letter-spacing> from [-10px] to [10px] at (1.5) should be [20px]
+Pass	CSS Transitions: property <letter-spacing> from [normal] to [10px] at (-0.3) should be [-3px]
+Pass	CSS Transitions: property <letter-spacing> from [normal] to [10px] at (0) should be [normal]
+Pass	CSS Transitions: property <letter-spacing> from [normal] to [10px] at (0.3) should be [3px]
+Pass	CSS Transitions: property <letter-spacing> from [normal] to [10px] at (0.6) should be [6px]
+Pass	CSS Transitions: property <letter-spacing> from [normal] to [10px] at (1) should be [10px]
+Pass	CSS Transitions: property <letter-spacing> from [normal] to [10px] at (1.5) should be [15px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [normal] to [10px] at (-0.3) should be [-3px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [normal] to [10px] at (0) should be [normal]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [normal] to [10px] at (0.3) should be [3px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [normal] to [10px] at (0.6) should be [6px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [normal] to [10px] at (1) should be [10px]
+Pass	CSS Transitions with transition: all: property <letter-spacing> from [normal] to [10px] at (1.5) should be [15px]
+Pass	CSS Animations: property <letter-spacing> from [normal] to [10px] at (-0.3) should be [-3px]
+Pass	CSS Animations: property <letter-spacing> from [normal] to [10px] at (0) should be [normal]
+Pass	CSS Animations: property <letter-spacing> from [normal] to [10px] at (0.3) should be [3px]
+Pass	CSS Animations: property <letter-spacing> from [normal] to [10px] at (0.6) should be [6px]
+Pass	CSS Animations: property <letter-spacing> from [normal] to [10px] at (1) should be [10px]
+Pass	CSS Animations: property <letter-spacing> from [normal] to [10px] at (1.5) should be [15px]
+Pass	Web Animations: property <letter-spacing> from [normal] to [10px] at (-0.3) should be [-3px]
+Pass	Web Animations: property <letter-spacing> from [normal] to [10px] at (0) should be [normal]
+Pass	Web Animations: property <letter-spacing> from [normal] to [10px] at (0.3) should be [3px]
+Pass	Web Animations: property <letter-spacing> from [normal] to [10px] at (0.6) should be [6px]
+Pass	Web Animations: property <letter-spacing> from [normal] to [10px] at (1) should be [10px]
+Pass	Web Animations: property <letter-spacing> from [normal] to [10px] at (1.5) should be [15px]
\ No newline at end of file
diff --git a/Tests/LibWeb/Text/expected/wpt-import/css/css-text/animations/word-spacing-interpolation.txt b/Tests/LibWeb/Text/expected/wpt-import/css/css-text/animations/word-spacing-interpolation.txt
new file mode 100644
index 00000000000..768525a72c0
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/wpt-import/css/css-text/animations/word-spacing-interpolation.txt
@@ -0,0 +1,149 @@
+Harness status: OK
+
+Found 144 tests
+
+144 Pass
+Pass	CSS Transitions: property <word-spacing> from neutral to [20px] at (-0.3) should be [7px]
+Pass	CSS Transitions: property <word-spacing> from neutral to [20px] at (0) should be [10px]
+Pass	CSS Transitions: property <word-spacing> from neutral to [20px] at (0.3) should be [13px]
+Pass	CSS Transitions: property <word-spacing> from neutral to [20px] at (0.6) should be [16px]
+Pass	CSS Transitions: property <word-spacing> from neutral to [20px] at (1) should be [20px]
+Pass	CSS Transitions: property <word-spacing> from neutral to [20px] at (1.5) should be [25px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from neutral to [20px] at (-0.3) should be [7px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from neutral to [20px] at (0) should be [10px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from neutral to [20px] at (0.3) should be [13px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from neutral to [20px] at (0.6) should be [16px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from neutral to [20px] at (1) should be [20px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from neutral to [20px] at (1.5) should be [25px]
+Pass	CSS Animations: property <word-spacing> from neutral to [20px] at (-0.3) should be [7px]
+Pass	CSS Animations: property <word-spacing> from neutral to [20px] at (0) should be [10px]
+Pass	CSS Animations: property <word-spacing> from neutral to [20px] at (0.3) should be [13px]
+Pass	CSS Animations: property <word-spacing> from neutral to [20px] at (0.6) should be [16px]
+Pass	CSS Animations: property <word-spacing> from neutral to [20px] at (1) should be [20px]
+Pass	CSS Animations: property <word-spacing> from neutral to [20px] at (1.5) should be [25px]
+Pass	Web Animations: property <word-spacing> from neutral to [20px] at (-0.3) should be [7px]
+Pass	Web Animations: property <word-spacing> from neutral to [20px] at (0) should be [10px]
+Pass	Web Animations: property <word-spacing> from neutral to [20px] at (0.3) should be [13px]
+Pass	Web Animations: property <word-spacing> from neutral to [20px] at (0.6) should be [16px]
+Pass	Web Animations: property <word-spacing> from neutral to [20px] at (1) should be [20px]
+Pass	Web Animations: property <word-spacing> from neutral to [20px] at (1.5) should be [25px]
+Pass	CSS Transitions: property <word-spacing> from [initial] to [20px] at (-0.3) should be [-6px]
+Pass	CSS Transitions: property <word-spacing> from [initial] to [20px] at (0) should be [0px]
+Pass	CSS Transitions: property <word-spacing> from [initial] to [20px] at (0.3) should be [6px]
+Pass	CSS Transitions: property <word-spacing> from [initial] to [20px] at (0.6) should be [12px]
+Pass	CSS Transitions: property <word-spacing> from [initial] to [20px] at (1) should be [20px]
+Pass	CSS Transitions: property <word-spacing> from [initial] to [20px] at (1.5) should be [30px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [initial] to [20px] at (-0.3) should be [-6px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [initial] to [20px] at (0) should be [0px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [initial] to [20px] at (0.3) should be [6px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [initial] to [20px] at (0.6) should be [12px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [initial] to [20px] at (1) should be [20px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [initial] to [20px] at (1.5) should be [30px]
+Pass	CSS Animations: property <word-spacing> from [initial] to [20px] at (-0.3) should be [-6px]
+Pass	CSS Animations: property <word-spacing> from [initial] to [20px] at (0) should be [0px]
+Pass	CSS Animations: property <word-spacing> from [initial] to [20px] at (0.3) should be [6px]
+Pass	CSS Animations: property <word-spacing> from [initial] to [20px] at (0.6) should be [12px]
+Pass	CSS Animations: property <word-spacing> from [initial] to [20px] at (1) should be [20px]
+Pass	CSS Animations: property <word-spacing> from [initial] to [20px] at (1.5) should be [30px]
+Pass	Web Animations: property <word-spacing> from [initial] to [20px] at (-0.3) should be [-6px]
+Pass	Web Animations: property <word-spacing> from [initial] to [20px] at (0) should be [0px]
+Pass	Web Animations: property <word-spacing> from [initial] to [20px] at (0.3) should be [6px]
+Pass	Web Animations: property <word-spacing> from [initial] to [20px] at (0.6) should be [12px]
+Pass	Web Animations: property <word-spacing> from [initial] to [20px] at (1) should be [20px]
+Pass	Web Animations: property <word-spacing> from [initial] to [20px] at (1.5) should be [30px]
+Pass	CSS Transitions: property <word-spacing> from [inherit] to [20px] at (-0.3) should be [33px]
+Pass	CSS Transitions: property <word-spacing> from [inherit] to [20px] at (0) should be [30px]
+Pass	CSS Transitions: property <word-spacing> from [inherit] to [20px] at (0.3) should be [27px]
+Pass	CSS Transitions: property <word-spacing> from [inherit] to [20px] at (0.6) should be [24px]
+Pass	CSS Transitions: property <word-spacing> from [inherit] to [20px] at (1) should be [20px]
+Pass	CSS Transitions: property <word-spacing> from [inherit] to [20px] at (1.5) should be [15px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [inherit] to [20px] at (-0.3) should be [33px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [inherit] to [20px] at (0) should be [30px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [inherit] to [20px] at (0.3) should be [27px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [inherit] to [20px] at (0.6) should be [24px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [inherit] to [20px] at (1) should be [20px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [inherit] to [20px] at (1.5) should be [15px]
+Pass	CSS Animations: property <word-spacing> from [inherit] to [20px] at (-0.3) should be [33px]
+Pass	CSS Animations: property <word-spacing> from [inherit] to [20px] at (0) should be [30px]
+Pass	CSS Animations: property <word-spacing> from [inherit] to [20px] at (0.3) should be [27px]
+Pass	CSS Animations: property <word-spacing> from [inherit] to [20px] at (0.6) should be [24px]
+Pass	CSS Animations: property <word-spacing> from [inherit] to [20px] at (1) should be [20px]
+Pass	CSS Animations: property <word-spacing> from [inherit] to [20px] at (1.5) should be [15px]
+Pass	Web Animations: property <word-spacing> from [inherit] to [20px] at (-0.3) should be [33px]
+Pass	Web Animations: property <word-spacing> from [inherit] to [20px] at (0) should be [30px]
+Pass	Web Animations: property <word-spacing> from [inherit] to [20px] at (0.3) should be [27px]
+Pass	Web Animations: property <word-spacing> from [inherit] to [20px] at (0.6) should be [24px]
+Pass	Web Animations: property <word-spacing> from [inherit] to [20px] at (1) should be [20px]
+Pass	Web Animations: property <word-spacing> from [inherit] to [20px] at (1.5) should be [15px]
+Pass	CSS Transitions: property <word-spacing> from [unset] to [20px] at (-0.3) should be [33px]
+Pass	CSS Transitions: property <word-spacing> from [unset] to [20px] at (0) should be [30px]
+Pass	CSS Transitions: property <word-spacing> from [unset] to [20px] at (0.3) should be [27px]
+Pass	CSS Transitions: property <word-spacing> from [unset] to [20px] at (0.6) should be [24px]
+Pass	CSS Transitions: property <word-spacing> from [unset] to [20px] at (1) should be [20px]
+Pass	CSS Transitions: property <word-spacing> from [unset] to [20px] at (1.5) should be [15px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [unset] to [20px] at (-0.3) should be [33px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [unset] to [20px] at (0) should be [30px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [unset] to [20px] at (0.3) should be [27px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [unset] to [20px] at (0.6) should be [24px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [unset] to [20px] at (1) should be [20px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [unset] to [20px] at (1.5) should be [15px]
+Pass	CSS Animations: property <word-spacing> from [unset] to [20px] at (-0.3) should be [33px]
+Pass	CSS Animations: property <word-spacing> from [unset] to [20px] at (0) should be [30px]
+Pass	CSS Animations: property <word-spacing> from [unset] to [20px] at (0.3) should be [27px]
+Pass	CSS Animations: property <word-spacing> from [unset] to [20px] at (0.6) should be [24px]
+Pass	CSS Animations: property <word-spacing> from [unset] to [20px] at (1) should be [20px]
+Pass	CSS Animations: property <word-spacing> from [unset] to [20px] at (1.5) should be [15px]
+Pass	Web Animations: property <word-spacing> from [unset] to [20px] at (-0.3) should be [33px]
+Pass	Web Animations: property <word-spacing> from [unset] to [20px] at (0) should be [30px]
+Pass	Web Animations: property <word-spacing> from [unset] to [20px] at (0.3) should be [27px]
+Pass	Web Animations: property <word-spacing> from [unset] to [20px] at (0.6) should be [24px]
+Pass	Web Animations: property <word-spacing> from [unset] to [20px] at (1) should be [20px]
+Pass	Web Animations: property <word-spacing> from [unset] to [20px] at (1.5) should be [15px]
+Pass	CSS Transitions: property <word-spacing> from [-10px] to [40px] at (-0.3) should be [-25px]
+Pass	CSS Transitions: property <word-spacing> from [-10px] to [40px] at (0) should be [-10px]
+Pass	CSS Transitions: property <word-spacing> from [-10px] to [40px] at (0.3) should be [5px]
+Pass	CSS Transitions: property <word-spacing> from [-10px] to [40px] at (0.6) should be [20px]
+Pass	CSS Transitions: property <word-spacing> from [-10px] to [40px] at (1) should be [40px]
+Pass	CSS Transitions: property <word-spacing> from [-10px] to [40px] at (1.5) should be [65px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [-10px] to [40px] at (-0.3) should be [-25px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [-10px] to [40px] at (0) should be [-10px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [-10px] to [40px] at (0.3) should be [5px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [-10px] to [40px] at (0.6) should be [20px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [-10px] to [40px] at (1) should be [40px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [-10px] to [40px] at (1.5) should be [65px]
+Pass	CSS Animations: property <word-spacing> from [-10px] to [40px] at (-0.3) should be [-25px]
+Pass	CSS Animations: property <word-spacing> from [-10px] to [40px] at (0) should be [-10px]
+Pass	CSS Animations: property <word-spacing> from [-10px] to [40px] at (0.3) should be [5px]
+Pass	CSS Animations: property <word-spacing> from [-10px] to [40px] at (0.6) should be [20px]
+Pass	CSS Animations: property <word-spacing> from [-10px] to [40px] at (1) should be [40px]
+Pass	CSS Animations: property <word-spacing> from [-10px] to [40px] at (1.5) should be [65px]
+Pass	Web Animations: property <word-spacing> from [-10px] to [40px] at (-0.3) should be [-25px]
+Pass	Web Animations: property <word-spacing> from [-10px] to [40px] at (0) should be [-10px]
+Pass	Web Animations: property <word-spacing> from [-10px] to [40px] at (0.3) should be [5px]
+Pass	Web Animations: property <word-spacing> from [-10px] to [40px] at (0.6) should be [20px]
+Pass	Web Animations: property <word-spacing> from [-10px] to [40px] at (1) should be [40px]
+Pass	Web Animations: property <word-spacing> from [-10px] to [40px] at (1.5) should be [65px]
+Pass	CSS Transitions: property <word-spacing> from [normal] to [10px] at (-0.3) should be [-3px]
+Pass	CSS Transitions: property <word-spacing> from [normal] to [10px] at (0) should be [0px]
+Pass	CSS Transitions: property <word-spacing> from [normal] to [10px] at (0.3) should be [3px]
+Pass	CSS Transitions: property <word-spacing> from [normal] to [10px] at (0.6) should be [6px]
+Pass	CSS Transitions: property <word-spacing> from [normal] to [10px] at (1) should be [10px]
+Pass	CSS Transitions: property <word-spacing> from [normal] to [10px] at (1.5) should be [15px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [normal] to [10px] at (-0.3) should be [-3px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [normal] to [10px] at (0) should be [0px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [normal] to [10px] at (0.3) should be [3px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [normal] to [10px] at (0.6) should be [6px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [normal] to [10px] at (1) should be [10px]
+Pass	CSS Transitions with transition: all: property <word-spacing> from [normal] to [10px] at (1.5) should be [15px]
+Pass	CSS Animations: property <word-spacing> from [normal] to [10px] at (-0.3) should be [-3px]
+Pass	CSS Animations: property <word-spacing> from [normal] to [10px] at (0) should be [0px]
+Pass	CSS Animations: property <word-spacing> from [normal] to [10px] at (0.3) should be [3px]
+Pass	CSS Animations: property <word-spacing> from [normal] to [10px] at (0.6) should be [6px]
+Pass	CSS Animations: property <word-spacing> from [normal] to [10px] at (1) should be [10px]
+Pass	CSS Animations: property <word-spacing> from [normal] to [10px] at (1.5) should be [15px]
+Pass	Web Animations: property <word-spacing> from [normal] to [10px] at (-0.3) should be [-3px]
+Pass	Web Animations: property <word-spacing> from [normal] to [10px] at (0) should be [0px]
+Pass	Web Animations: property <word-spacing> from [normal] to [10px] at (0.3) should be [3px]
+Pass	Web Animations: property <word-spacing> from [normal] to [10px] at (0.6) should be [6px]
+Pass	Web Animations: property <word-spacing> from [normal] to [10px] at (1) should be [10px]
+Pass	Web Animations: property <word-spacing> from [normal] to [10px] at (1.5) should be [15px]
\ No newline at end of file
diff --git a/Tests/LibWeb/Text/expected/wpt-import/css/css-text/parsing/word-spacing-computed.txt b/Tests/LibWeb/Text/expected/wpt-import/css/css-text/parsing/word-spacing-computed.txt
new file mode 100644
index 00000000000..9ac93b9bea3
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/wpt-import/css/css-text/parsing/word-spacing-computed.txt
@@ -0,0 +1,14 @@
+Harness status: OK
+
+Found 9 tests
+
+9 Pass
+Pass	Property word-spacing value 'normal'
+Pass	Property word-spacing value '0'
+Pass	Property word-spacing value '10px'
+Pass	Property word-spacing value '-20px'
+Pass	Property word-spacing value 'calc(10px - 0.5em)'
+Pass	Property word-spacing value '110%'
+Pass	Property word-spacing value '-5%'
+Pass	Property word-spacing value 'calc(10% - 20%)'
+Pass	Property word-spacing value 'calc(10px - (5% + 10%)'
\ No newline at end of file
diff --git a/Tests/LibWeb/Text/input/wpt-import/css/css-text/animations/letter-spacing-interpolation.html b/Tests/LibWeb/Text/input/wpt-import/css/css-text/animations/letter-spacing-interpolation.html
new file mode 100644
index 00000000000..941ae2943cb
--- /dev/null
+++ b/Tests/LibWeb/Text/input/wpt-import/css/css-text/animations/letter-spacing-interpolation.html
@@ -0,0 +1,107 @@
+<!DOCTYPE html>
+<meta charset="UTF-8">
+<link rel="help" href="https://drafts.csswg.org/css-text-3/#letter-spacing-property">
+<meta name="test" content="letter-spacing supports animation by computed value type">
+
+<script src="../../../resources/testharness.js"></script>
+<script src="../../../resources/testharnessreport.js"></script>
+<script src="../../../css/support/interpolation-testcommon.js"></script>
+
+<style>
+.parent {
+  letter-spacing: 2px;
+}
+.target {
+  font: 10px sans-serif;
+  font-weight: bold;
+  letter-spacing: 30px;
+}
+.expected {
+  color: green;
+  margin-right: 30px;
+}
+</style>
+
+<body>
+  <template id="target-template">TT</template>
+</body>
+
+<script>
+test_interpolation({
+  property: 'letter-spacing',
+  from: neutralKeyframe,
+  to: '20px',
+}, [
+  {at: -0.3, expect: '33px'},
+  {at: 0, expect: '30px'},
+  {at: 0.3, expect: '27px'},
+  {at: 0.6, expect: '24px'},
+  {at: 1, expect: '20px'},
+  {at: 1.5, expect: '15px'},
+]);
+
+test_interpolation({
+  property: 'letter-spacing',
+  from: 'initial',
+  to: '20px',
+}, [
+  {at: -0.3, expect: '-6px'},
+  {at: 0, expect: 'normal'},
+  {at: 0.3, expect: '6px'},
+  {at: 0.6, expect: '12px'},
+  {at: 1, expect: '20px'},
+  {at: 1.5, expect: '30px'},
+]);
+
+test_interpolation({
+  property: 'letter-spacing',
+  from: 'inherit',
+  to: '20px',
+}, [
+  {at: -0.3, expect: '-3.4px'},
+  {at: 0, expect: '2px'},
+  {at: 0.3, expect: '7.4px'},
+  {at: 0.6, expect: '12.8px'},
+  {at: 1, expect: '20px'},
+  {at: 1.5, expect: '29px'},
+]);
+
+test_interpolation({
+  property: 'letter-spacing',
+  from: 'unset',
+  to: '20px',
+}, [
+  {at: -0.3, expect: '-3.4px'},
+  {at: 0, expect: '2px'},
+  {at: 0.3, expect: '7.4px'},
+  {at: 0.6, expect: '12.8px'},
+  {at: 1, expect: '20px'},
+  {at: 1.5, expect: '29px'},
+]);
+
+test_interpolation({
+  property: 'letter-spacing',
+  from: '-10px',
+  to: '10px',
+}, [
+  {at: -0.3, expect: '-16px'},
+  {at: 0, expect: '-10px'},
+  {at: 0.3, expect: '-4px'},
+  {at: 0.6, expect: '2px'},
+  {at: 1, expect: '10px'},
+  {at: 1.5, expect: '20px'},
+]);
+
+test_interpolation({
+  property: 'letter-spacing',
+  from: 'normal',
+  to: '10px',
+}, [
+  {at: -0.3, expect: '-3px'},
+  {at: 0, expect: 'normal'},
+  {at: 0.3, expect: '3px'},
+  {at: 0.6, expect: '6px'},
+  {at: 1, expect: '10px'},
+  {at: 1.5, expect: '15px'},
+]);
+</script>
diff --git a/Tests/LibWeb/Text/input/wpt-import/css/css-text/animations/word-spacing-interpolation.html b/Tests/LibWeb/Text/input/wpt-import/css/css-text/animations/word-spacing-interpolation.html
new file mode 100644
index 00000000000..de294089705
--- /dev/null
+++ b/Tests/LibWeb/Text/input/wpt-import/css/css-text/animations/word-spacing-interpolation.html
@@ -0,0 +1,104 @@
+<!DOCTYPE html>
+<meta charset="UTF-8">
+<link rel="help" href="https://drafts.csswg.org/css-text-3/#word-spacing-property">
+<meta name="test" content="word-spacing supports animation by computed value type">
+
+<script src="../../../resources/testharness.js"></script>
+<script src="../../../resources/testharnessreport.js"></script>
+<script src="../../../css/support/interpolation-testcommon.js"></script>
+
+<style>
+.parent {
+  word-spacing: 30px;
+}
+.target {
+  font: 10px sans-serif;
+  word-spacing: 10px;
+}
+.expected {
+  color: green;
+}
+</style>
+
+<body>
+  <template id="target-template">A B C D</template>
+</body>
+
+<script>
+test_interpolation({
+  property: 'word-spacing',
+  from: neutralKeyframe,
+  to: '20px',
+}, [
+  {at: -0.3, expect: '7px'},
+  {at: 0, expect: '10px'},
+  {at: 0.3, expect: '13px'},
+  {at: 0.6, expect: '16px'},
+  {at: 1, expect: '20px'},
+  {at: 1.5, expect: '25px'},
+]);
+
+test_interpolation({
+  property: 'word-spacing',
+  from: 'initial',
+  to: '20px',
+}, [
+  {at: -0.3, expect: '-6px'},
+  {at: 0, expect: '0px'},
+  {at: 0.3, expect: '6px'},
+  {at: 0.6, expect: '12px'},
+  {at: 1, expect: '20px'},
+  {at: 1.5, expect: '30px'},
+]);
+
+test_interpolation({
+  property: 'word-spacing',
+  from: 'inherit',
+  to: '20px',
+}, [
+  {at: -0.3, expect: '33px'},
+  {at: 0, expect: '30px'},
+  {at: 0.3, expect: '27px'},
+  {at: 0.6, expect: '24px'},
+  {at: 1, expect: '20px'},
+  {at: 1.5, expect: '15px'},
+]);
+
+test_interpolation({
+  property: 'word-spacing',
+  from: 'unset',
+  to: '20px',
+}, [
+  {at: -0.3, expect: '33px'},
+  {at: 0, expect: '30px'},
+  {at: 0.3, expect: '27px'},
+  {at: 0.6, expect: '24px'},
+  {at: 1, expect: '20px'},
+  {at: 1.5, expect: '15px'},
+]);
+
+test_interpolation({
+  property: 'word-spacing',
+  from: '-10px',
+  to: '40px'
+}, [
+  {at: -0.3, expect: '-25px'},
+  {at: 0, expect: '-10px'},
+  {at: 0.3, expect: '5px'},
+  {at: 0.6, expect: '20px'},
+  {at: 1, expect: '40px'},
+  {at: 1.5, expect: '65px'},
+]);
+test_interpolation({
+  property: 'word-spacing',
+  from: 'normal',
+  to: '10px'
+}, [
+  {at: -0.3, expect: '-3px'},
+  {at: 0, expect: '0px'},
+  {at: 0.3, expect: '3px'},
+  {at: 0.6, expect: '6px'},
+  {at: 1, expect: '10px'},
+  {at: 1.5, expect: '15px'},
+]);
+</script>
diff --git a/Tests/LibWeb/Text/input/wpt-import/css/css-text/parsing/word-spacing-computed.html b/Tests/LibWeb/Text/input/wpt-import/css/css-text/parsing/word-spacing-computed.html
new file mode 100644
index 00000000000..56c24aa2519
--- /dev/null
+++ b/Tests/LibWeb/Text/input/wpt-import/css/css-text/parsing/word-spacing-computed.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>CSS Text: getComputedStyle().wordSpacing</title>
+<link rel="help" href="https://www.w3.org/TR/css-text-3/#propdef-word-spacing">
+<meta name="assert" content="word-spacing computed value is an absolute length and/or percentage.">
+<meta name="assert" content="'normal' computes to zero.">
+<script src="../../../resources/testharness.js"></script>
+<script src="../../../resources/testharnessreport.js"></script>
+<script src="../../../css/support/computed-testcommon.js"></script>
+<style>
+  #target {
+    font-size: 40px;
+  }
+</style>
+</head>
+<body>
+<div id="target"></div>
+<script>
+test_computed_value("word-spacing", "normal", "0px");
+test_computed_value("word-spacing", "0", "0px");
+
+test_computed_value("word-spacing", "10px");
+test_computed_value("word-spacing", "-20px");
+test_computed_value("word-spacing", "calc(10px - 0.5em)", "-10px");
+test_computed_value("word-spacing", "110%");
+test_computed_value("word-spacing", "-5%");
+test_computed_value("word-spacing", "calc(10% - 20%)", "-10%");
+test_computed_value("word-spacing", "calc(10px - (5% + 10%)", "calc(-15% + 10px)");
+</script>
+</body>
+</html>