9 files changed, 615 insertions, 53 deletions
diff --git a/test/data/html/test-document1.html b/test/data/html/test-document1.html
index 0754a314..98a6fb44 100644
--- a/test/data/html/test-document1.html
+++ b/test/data/html/test-document1.html
@@ -103,6 +103,7 @@
         data-end-node-selector="img"
         data-end-offset="0"
         data-result-type="TextSourceElement"
+        data-sentence-extent="100"
         data-sentence="よみちゃん"
     >
         <img src="data:image/gif;base64,R0lGODdhBwAHAIABAAAAAP///ywAAAAABwAHAAACDIRvEaC32FpCbEkKCgA7" alt="よみちゃん" title="よみちゃん" style="width: 70px; height: 70px; image-rendering: crisp-edges; image-rendering: pixelated; display: block;" />
diff --git a/test/data/html/test-document2-frame1.html b/test/data/html/test-document2-frame1.html
index 3b85cdc5..e572e3c4 100644
--- a/test/data/html/test-document2-frame1.html
+++ b/test/data/html/test-document2-frame1.html
@@ -33,10 +33,8 @@ a, a:visited {
     ありがとう
 </div>
 <div>
-    <a href="#" id="fullscreen-link">Toggle fullscreen</a>
-    <script>
-document.querySelector('#fullscreen-link').addEventListener('click', () => toggleFullscreen(document.body), false);
-    </script>
+    <a href="#" class="fullscreen-link">Toggle fullscreen</a>
+    <script>setup(document.body, document.body);</script>
 </div>
 </div></body>
 </html>
 \ No newline at end of file
diff --git a/test/data/html/test-document2-script.js b/test/data/html/test-document2-script.js
index bd5a570d..ab516a4e 100644
--- a/test/data/html/test-document2-script.js
+++ b/test/data/html/test-document2-script.js
@@ -39,3 +39,27 @@ function toggleFullscreen(element) {
         requestFullscreen(element);
     }
 }
+
+function setup(container, fullscreenElement=null) {
+    const fullscreenLink = container.querySelector('.fullscreen-link');
+    if (fullscreenLink !== null) {
+        if (fullscreenElement === null) {
+            fullscreenElement = container.querySelector('.fullscreen-element');
+        }
+        fullscreenLink.addEventListener('click', (e) => {
+            toggleFullscreen(fullscreenElement);
+            e.preventDefault();
+            return false;
+        }, false);
+    }
+
+    const template = container.querySelector('template');
+    const templateContentContainer = container.querySelector('.template-content-container');
+    if (template !== null && templateContentContainer !== null) {
+        const mode = container.dataset.shadowMode;
+        const shadow = templateContentContainer.attachShadow({mode});
+        const content = document.importNode(template.content, true);
+        setup(content);
+        shadow.appendChild(content);
+    }
+}
diff --git a/test/data/html/test-document2.html b/test/data/html/test-document2.html
index 3a22a5bf..6d174571 100644
--- a/test/data/html/test-document2.html
+++ b/test/data/html/test-document2.html
@@ -11,71 +11,78 @@
 <body>
 
     <h1>Yomichan Manual Tests</h1>
-    <p class="description">Manual tests involving fullscreen elements, &lt;iframe&gt;s, and shadow DOMs.</p>
+    <y-description>Manual tests involving fullscreen elements, &lt;iframe&gt;s, and shadow DOMs.</y-description>
 
-    <div class="test">
-        <div class="description">Standard content.</div>
-        <div id="fullscreen-element1" style="width: 100%; height: 200px; border: 1px solid #d8d8d8; position: relative;"><div style="background-color: #f8f8f8; padding: 0.5em; position: absolute; left: 0; top: 0; bottom: 0; right: 0;">
+    <y-test>
+        <y-description>Standard content.</y-description>
+        <div class="fullscreen-element" style="width: 100%; height: 200px; border: 1px solid #d8d8d8; position: relative;"><div style="background-color: #f8f8f8; padding: 0.5em; position: absolute; left: 0; top: 0; bottom: 0; right: 0;">
             <div>
                 ありがとう
             </div>
             <div>
-                <a href="#" id="fullscreen-link1">Toggle fullscreen</a>
+                <a href="#" class="fullscreen-link">Toggle fullscreen</a>
             </div>
         </div></div>
-        <script>
-document.querySelector('#fullscreen-link1').addEventListener('click', () => toggleFullscreen(document.querySelector('#fullscreen-element1')), false);
-        </script>
-    </div>
+    </y-test>
 
-    <div class="test">
-        <div class="description">Content inside of a shadow DOM.</div>
-        <div id="shadow-content-container"></div>
-        <template id="shadow-content-container-content-template">
+    <y-test data-shadow-mode="open">
+        <y-description>Content inside of an open shadow DOM.</y-description>
+        <div class="template-content-container"></div>
+        <template>
             <link rel="stylesheet" href="test-stylesheet.css" />
-            <div id="fullscreen-element2" style="width: 100%; height: 200px; border: 1px solid #d8d8d8; position: relative;"><div style="background-color: #f8f8f8; padding: 0.5em; position: absolute; left: 0; top: 0; bottom: 0; right: 0;">
+            <div class="fullscreen-element" style="width: 100%; height: 200px; border: 1px solid #d8d8d8; position: relative;"><div style="background-color: #f8f8f8; padding: 0.5em; position: absolute; left: 0; top: 0; bottom: 0; right: 0;">
                 <div>
                     ありがとう
                 </div>
                 <div>
-                    <a href="#" id="fullscreen-link2">Toggle fullscreen</a>
+                    <a href="#" class="fullscreen-link">Toggle fullscreen</a>
                 </div>
             </div></div>
         </template>
-        <script>
-(() => {
-    const shadowIframeContainer = document.querySelector('#shadow-content-container');
-    const shadow = shadowIframeContainer.attachShadow({mode: 'closed'});
-    const template = document.querySelector('#shadow-content-container-content-template').content;
-    const content = document.importNode(template, true);
-    const fullscreenElement = content.querySelector('#fullscreen-element2');
-    content.querySelector('#fullscreen-link2').addEventListener('click', () => toggleFullscreen(fullscreenElement), false);
-    shadow.appendChild(content);
-})();
-        </script>
-    </div>
+    </y-test>
 
-    <div class="test">
-        <div class="description">&lt;iframe&gt; element.</div>
+    <y-test data-shadow-mode="closed">
+        <y-description>Content inside of a closed shadow DOM.</y-description>
+        <div class="template-content-container"></div>
+        <template>
+            <link rel="stylesheet" href="test-stylesheet.css" />
+            <div class="fullscreen-element" style="width: 100%; height: 200px; border: 1px solid #d8d8d8; position: relative;"><div style="background-color: #f8f8f8; padding: 0.5em; position: absolute; left: 0; top: 0; bottom: 0; right: 0;">
+                <div>
+                    ありがとう
+                </div>
+                <div>
+                    <a href="#" class="fullscreen-link">Toggle fullscreen</a>
+                </div>
+            </div></div>
+        </template>
+    </y-test>
+
+    <y-test>
+        <y-description>&lt;iframe&gt; element.</y-description>
         <iframe src="test-document2-frame1.html" allowfullscreen="true" style="width: 100%; height: 200px; border: 1px solid #d8d8d8;"></iframe>
-    </div>
+    </y-test>
+
+    <y-test data-shadow-mode="open">
+        <y-description>&lt;iframe&gt; element inside of an open shadow DOM.</y-description>
+        <div class="template-content-container"></div>
+        <template>
+            <iframe src="test-document2-frame1.html" allowfullscreen="true" style="width: 100%; height: 200px; border: 1px solid #d8d8d8;"></iframe>
+        </template>
+    </y-test>
 
-    <div class="test">
-        <div class="description">&lt;iframe&gt; element inside of a shadow DOM.</div>
-        <div id="shadow-iframe-container"></div>
-        <template id="shadow-iframe-container-content-template">
+    <y-test data-shadow-mode="closed">
+        <y-description>&lt;iframe&gt; element inside of a closed shadow DOM.</y-description>
+        <div class="template-content-container"></div>
+        <template>
             <iframe src="test-document2-frame1.html" allowfullscreen="true" style="width: 100%; height: 200px; border: 1px solid #d8d8d8;"></iframe>
         </template>
-        <script>
-(() => {
-    const shadowIframeContainer = document.querySelector('#shadow-iframe-container');
-    const shadow = shadowIframeContainer.attachShadow({mode: 'closed'});
-    const template = document.querySelector('#shadow-iframe-container-content-template').content;
-    const content = document.importNode(template, true);
-    shadow.appendChild(content);
-})();
-        </script>
-    </div>
+    </y-test>
+
+    <script>
+for (const element of document.querySelectorAll('y-test')) {
+    setup(element);
+}
+    </script>
 
 </body>
-</html>
-\ No newline at end of file
+</html>
diff --git a/test/data/html/test-document3-frame1.html b/test/data/html/test-document3-frame1.html
new file mode 100644
index 00000000..2ae906d2
--- /dev/null
+++ b/test/data/html/test-document3-frame1.html
@@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="UTF-8">
+        <meta name="viewport" content="width=device-width,initial-scale=1" />
+        <title>Yomichan Manual Performance Tests</title>
+        <link rel="stylesheet" href="test-stylesheet.css" />
+    </head>
+<body><div class="content">
+
+    <div class="description">Add elements</div>
+
+    <div>
+        <a href="#" id="add-elements-1000">1000</a>
+        <a href="#" id="add-elements-10000">10000</a>
+        <a href="#" id="add-elements-100000">100000</a>
+        <a href="#" id="add-elements-1000000">1000000</a>
+        <script>
+document.querySelector('#add-elements-1000').addEventListener('click',    () => addElements(1000), false);
+document.querySelector('#add-elements-10000').addEventListener('click',   () => addElements(10000), false);
+document.querySelector('#add-elements-100000').addEventListener('click',  () => addElements(100000), false);
+document.querySelector('#add-elements-1000000').addEventListener('click', () => addElements(1000000), false);
+
+let counter = 0;
+
+function addElements(amount) {
+    const container = document.querySelector('#container');
+    for (let i = 0; i < amount; i++) {
+        const element = document.createElement('div');
+        element.textContent = 'ありがとう';
+        container.appendChild(element);
+    }
+
+    counter += amount;
+    document.querySelector('#counter').textContent = counter;
+}
+        </script>
+    </div>
+
+    <div id="counter"></div>
+    <div id="container"></div>
+
+</div></body>
+</html>
diff --git a/test/data/html/test-document3-frame2.html b/test/data/html/test-document3-frame2.html
new file mode 100644
index 00000000..c486e04b
--- /dev/null
+++ b/test/data/html/test-document3-frame2.html
@@ -0,0 +1,62 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="UTF-8">
+        <meta name="viewport" content="width=device-width,initial-scale=1" />
+        <title>Yomichan Manual Performance Tests</title>
+        <link rel="stylesheet" href="test-stylesheet.css" />
+    </head>
+<body><div class="content">
+
+    <div class="description">&lt;iframe&gt; element inside of an open shadow DOM.</div>
+
+    <div id="shadow-iframe-container-open"></div>
+    <template id="shadow-iframe-container-open-content-template">
+        <iframe src="test-document2-frame1.html" allowfullscreen="true" style="width: 100%; height: 50px; border: 1px solid #d8d8d8;"></iframe>
+    </template>
+    <script>
+(() => {
+    const shadowIframeContainer = document.querySelector('#shadow-iframe-container-open');
+    const shadow = shadowIframeContainer.attachShadow({mode: 'open'});
+    const template = document.querySelector('#shadow-iframe-container-open-content-template').content;
+    const content = document.importNode(template, true);
+    shadow.appendChild(content);
+})();
+    </script>
+
+    <div class="description">Add elements</div>
+
+    <div>
+        <a href="#" id="add-elements-1000">1000</a>
+        <a href="#" id="add-elements-10000">10000</a>
+        <a href="#" id="add-elements-100000">100000</a>
+        <a href="#" id="add-elements-1000000">1000000</a>
+    </div>
+
+    <div id="counter"></div>
+    <div id="container"></div>
+    <script>
+(() => {
+    document.querySelector('#add-elements-1000').addEventListener('click',    () => addElements(1000), false);
+    document.querySelector('#add-elements-10000').addEventListener('click',   () => addElements(10000), false);
+    document.querySelector('#add-elements-100000').addEventListener('click',  () => addElements(100000), false);
+    document.querySelector('#add-elements-1000000').addEventListener('click', () => addElements(1000000), false);
+
+    let counter = 0;
+
+    function addElements(amount) {
+        const container = document.querySelector('#container');
+        for (let i = 0; i < amount; i++) {
+            const element = document.createElement('div');
+            element.textContent = 'ありがとう';
+            container.appendChild(element);
+        }
+
+        counter += amount;
+        document.querySelector('#counter').textContent = counter;
+    }
+})();
+    </script>
+
+</div></body>
+</html>
diff --git a/test/data/html/test-document3.html b/test/data/html/test-document3.html
new file mode 100644
index 00000000..3e7d5236
--- /dev/null
+++ b/test/data/html/test-document3.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="UTF-8">
+        <meta name="viewport" content="width=device-width,initial-scale=1" />
+        <title>Yomichan Manual Performance Tests</title>
+        <link rel="icon" type="image/gif" href="data:image/gif;base64,R0lGODlhEAAQAKEBAAAAAP///////////yH5BAEKAAIALAAAAAAQABAAAAImFI6Zpt0B4YkS0TCpq07xbmEgcGVRUpLaI46ZG7ppalY0jDCwUAAAOw==" />
+        <link rel="stylesheet" href="test-stylesheet.css" />
+    </head>
+<body>
+
+    <h1>Yomichan Manual Performance Tests</h1>
+    <p class="description">Testing Yomichan performance with artificially demanding cases in a real browser</p>
+
+    <div class="test">
+        <div class="description">&lt;iframe&gt; element.</div>
+        <iframe src="test-document3-frame1.html" allowfullscreen="true" style="width: 100%; height: 200px; border: 1px solid #d8d8d8;"></iframe>
+    </div>
+
+    <div class="test">
+        <div class="description">&lt;iframe&gt; element containing an &lt;iframe&gt; element inside of an open shadow DOM.</div>
+        <iframe src="test-document3-frame2.html" allowfullscreen="true" style="width: 100%; height: 200px; border: 1px solid #d8d8d8;"></iframe>
+    </div>
+
+</body>
+</html>
diff --git a/test/data/html/test-dom-text-scanner.html b/test/data/html/test-dom-text-scanner.html
new file mode 100644
index 00000000..dc06eb64
--- /dev/null
+++ b/test/data/html/test-dom-text-scanner.html
@@ -0,0 +1,393 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="UTF-8">
+        <meta name="viewport" content="width=device-width,initial-scale=1" />
+        <title>Yomichan DOMTextScanner Tests</title>
+        <link rel="icon" type="image/gif" href="data:image/gif;base64,R0lGODlhEAAQAKEBAAAAAP///////////yH5BAEKAAIALAAAAAAQABAAAAImFI6Zpt0B4YkS0TCpq07xbmEgcGVRUpLaI46ZG7ppalY0jDCwUAAAOw==" />
+        <link rel="stylesheet" href="test-stylesheet.css" />
+    </head>
+<body>
+
+    <h1>Yomichan DOMTextScanner Tests</h1>
+
+    <y-test
+        data-test-data='{
+            "node": "div:nth-of-type(1)",
+            "offset": 0,
+            "length": 15,
+            "expected": {
+                "node": "div:nth-of-type(2)>div::text",
+                "offset": 3,
+                "content": "小ぢん\nまり1\n小ぢん\nまり2"
+            }
+        }'
+    >
+        <y-description>Layout newlines expected due to entering and exiting display:block nodes.</y-description>
+<div><div>小ぢん</div>まり1</div>
+<div>小ぢん<div>まり2</div></div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "div:nth-of-type(1)::text",
+            "offset": 0,
+            "length": 13,
+            "expected": {
+                "node": "div:nth-of-type(2)::text",
+                "offset": 6,
+                "content": "小ぢんまり1\n小ぢんまり2"
+            }
+        }'
+    >
+        <y-description>Layout newline expected due to sequential display:block elements.</y-description>
+<div>小ぢんまり1</div><div>小ぢんまり2</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "div:nth-of-type(1)::text",
+            "offset": 0,
+            "length": 13,
+            "expected": {
+                "node": "div:nth-of-type(2)::text",
+                "offset": 6,
+                "content": "小ぢんまり1\n小ぢんまり2"
+            }
+        }'
+    >
+        <y-description>Layout newline expected due to sequential display:block elements separated by a newline.</y-description>
+<div>小ぢんまり1</div>
+<div>小ぢんまり2</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "span:nth-of-type(1)::text",
+            "offset": 0,
+            "length": 12,
+            "expected": {
+                "node": "span:nth-of-type(2)::text",
+                "offset": 6,
+                "content": "小ぢんまり1小ぢんまり2"
+            }
+        }'
+    >
+        <y-description>No newlines expected due to display:inline.</y-description>
+<span>小ぢんまり1</span><span>小ぢんまり2</span>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "span:nth-of-type(1)::text",
+            "offset": 0,
+            "length": 13,
+            "expected": {
+                "node": "span:nth-of-type(2)::text",
+                "offset": 6,
+                "content": "小ぢんまり1 小ぢんまり2"
+            }
+        }'
+    >
+        <y-description>No newlines expected due to white-space:normal.</y-description>
+<span>小ぢんまり1</span>
+<span>小ぢんまり2</span>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "span:nth-of-type(1)::text",
+            "offset": 0,
+            "length": 13,
+            "expected": {
+                "node": "span:nth-of-type(2)::text",
+                "offset": 6,
+                "content": "小ぢんまり1\n小ぢんまり2"
+            }
+        }'
+    >
+        <y-description>Newline expected due to white-space:pre.</y-description>
+<pre>
+<span>小ぢんまり1</span>
+<span>小ぢんまり2</span>
+</pre>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "span:nth-of-type(1)::text",
+            "offset": 0,
+            "length": 12,
+            "expected": {
+                "node": "span:nth-of-type(2)::text",
+                "offset": 6,
+                "content": "小ぢんまり1小ぢんまり2"
+            }
+        }'
+    >
+        <y-description>No newlines expected due to display:inline-block. Actual layout flow cannot be determined by DOM/CSS alone.</y-description>
+<span style="display: inline-block;">小ぢんまり1</span><span style="display: inline-block;">小ぢんまり2</span>
+    </y-test>
+
+    <y-test
+        style="position: relative;"
+        data-test-data='{
+            "node": "div:nth-of-type(1)::text",
+            "offset": 0,
+            "length": 13,
+            "expected": {
+                "node": "div:nth-of-type(2)::text",
+                "offset": 6,
+                "content": "小ぢんまり1\n小ぢんまり2"
+            }
+        }'
+    >
+        <y-description>Single newline expected due to display:block layout.</y-description>
+<div>小ぢんまり1</div><div style="position: relative;">小ぢんまり2</div>
+    </y-test>
+
+    <y-test
+        style="position: relative; overflow: hidden;"
+        data-test-data='{
+            "node": "div:nth-of-type(1)::text",
+            "offset": 0,
+            "length": 14,
+            "expected": {
+                "node": "div:nth-of-type(2)::text",
+                "offset": 6,
+                "content": "小ぢんまり1\n\n小ぢんまり2"
+            }
+        }'
+    >
+        <y-description>Two newlines expected due to position:absolute causing a significant layout change.</y-description>
+<div>小ぢんまり1</div><div style="position: absolute;">小ぢんまり2</div>
+    </y-test>
+
+    <y-test
+        style="position: relative; overflow: hidden;"
+        data-test-data='{
+            "node": "div:nth-of-type(1)::text",
+            "offset": 0,
+            "length": 14,
+            "expected": {
+                "node": "div:nth-of-type(2)::text",
+                "offset": 6,
+                "content": "小ぢんまり1\n\n小ぢんまり2"
+            }
+        }'
+    >
+        <y-description>Two newlines expected due to position:fixed causing a significant layout change.</y-description>
+<div>小ぢんまり1</div><div style="position: fixed;">小ぢんまり2</div>
+    </y-test>
+
+    <y-test
+        style="position: relative;"
+        data-test-data='{
+            "node": "div:nth-of-type(1)::text",
+            "offset": 0,
+            "length": 14,
+            "expected": {
+                "node": "div:nth-of-type(2)::text",
+                "offset": 6,
+                "content": "小ぢんまり1\n\n小ぢんまり2"
+            }
+        }'
+    >
+        <y-description>Two newlines expected due to position:sticky being able to cause a significant layout change.</y-description>
+<div>小ぢんまり1</div><div style="position: sticky;">小ぢんまり2</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "rt",
+            "offset": 0,
+            "length": 6,
+            "expected": {
+                "node": "div::text",
+                "offset": 5,
+                "content": "小ぢんまり1"
+            }
+        }'
+    >
+        <y-description>Scanning text starting in an &lt;rt&gt; element. Should start scanning at the start of the &lt;ruby&gt; tag instead.</y-description>
+<div><ruby>小<rp>(</rp><rt>こ</rt><rp>)</rp></ruby>ぢんまり1</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "div",
+            "offset": 0,
+            "length": 6,
+            "expected": {
+                "node": "div::nth-text(2)",
+                "offset": 3,
+                "content": "小ぢんまり1"
+            }
+        }'
+    >
+        <y-description>Skip &lt;script&gt; content.</y-description>
+<div>小ぢん<script>/*comment*/</script>まり1</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "div",
+            "offset": 0,
+            "length": 6,
+            "expected": {
+                "node": "div::nth-text(2)",
+                "offset": 3,
+                "content": "小ぢんまり1"
+            }
+        }'
+    >
+        <y-description>Skip &lt;style&gt; content.</y-description>
+<div>小ぢん<style>/*comment*/</style>まり1</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "div",
+            "offset": 0,
+            "length": 6,
+            "expected": {
+                "node": "div::nth-text(2)",
+                "offset": 3,
+                "content": "小ぢんまり1"
+            }
+        }'
+    >
+        <y-description>Skip &lt;textarea&gt; content.</y-description>
+<div>小ぢん<textarea>textarea content</textarea>まり1</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "div",
+            "offset": 0,
+            "length": 6,
+            "expected": {
+                "node": "div::nth-text(2)",
+                "offset": 3,
+                "content": "小ぢんまり1"
+            }
+        }'
+    >
+        <y-description>Skip &lt;input&gt; content.</y-description>
+<div>小ぢん<input value="content" />まり1</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "div",
+            "offset": 0,
+            "length": 6,
+            "expected": {
+                "node": "div::nth-text(2)",
+                "offset": 3,
+                "content": "小ぢんまり1"
+            }
+        }'
+    >
+        <y-description>Skip &lt;button&gt; content.</y-description>
+<div>小ぢん<button>content</button>まり1</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "div",
+            "offset": 0,
+            "length": 6,
+            "expected": {
+                "node": "div::nth-text(2)",
+                "offset": 3,
+                "content": "小ぢんまり1"
+            }
+        }'
+    >
+        <y-description>Skip content with font-size:0.</y-description>
+<div>小ぢん<span style="font-size: 0;">content</span>まり1</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "div",
+            "offset": 0,
+            "length": 6,
+            "expected": {
+                "node": "div::nth-text(2)",
+                "offset": 3,
+                "content": "小ぢんまり1"
+            }
+        }'
+    >
+        <y-description>Skip content with opacity:0.</y-description>
+<div>小ぢん<span style="opacity: 0;">content</span>まり1</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "div",
+            "offset": 0,
+            "length": 6,
+            "expected": {
+                "node": "div::nth-text(2)",
+                "offset": 3,
+                "content": "小ぢんまり1"
+            }
+        }'
+    >
+        <y-description>Skip content with visibility:hidden.</y-description>
+<div>小ぢん<span style="visibility: hidden;">content</span>まり1</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "div",
+            "offset": 0,
+            "length": 6,
+            "expected": {
+                "node": "div::nth-text(2)",
+                "offset": 3,
+                "content": "小ぢんまり1"
+            }
+        }'
+    >
+        <y-description>Skip content with display:none.</y-description>
+<div>小ぢん<span style="display: none;">content</span>まり1</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "div",
+            "offset": 0,
+            "length": 6,
+            "expected": {
+                "node": "div::nth-text(2)",
+                "offset": 3,
+                "content": "小ぢんまり1"
+            }
+        }'
+    >
+        <y-description>Don't skip content with user-select:none.</y-description>
+<div>小ぢ<span style="user-select: none;">ん</span>まり1</div>
+    </y-test>
+
+    <y-test
+        data-test-data='{
+            "node": "div",
+            "offset": 0,
+            "length": 6,
+            "expected": {
+                "node": "div::nth-text(2)",
+                "offset": 3,
+                "content": "小ぢんまり1"
+            }
+        }'
+    >
+        <y-description>Skip content with user-select:none <em>and</em> a transparent color.</y-description>
+<div>小ぢん<span style="user-select: none; color: rgba(0, 0, 0, 0);">content</span>まり1</div>
+    </y-test>
+
+</body>
+</html>
+\ No newline at end of file
diff --git a/test/data/html/test-stylesheet.css b/test/data/html/test-stylesheet.css
index f63d2481..b4d2e255 100644
--- a/test/data/html/test-stylesheet.css
+++ b/test/data/html/test-stylesheet.css
@@ -19,7 +19,8 @@ p {
     margin: 0.33em 0;
 }
 
-h1+p {
+h1+p,
+h1+y-description {
     margin-top: -0.67em;
 }
 
@@ -28,7 +29,9 @@ a, a:visited {
     text-decoration: underline;
 }
 
-.test {
+.test,
+y-test {
+    display: block;
     background-color: #ffffff;
     margin: 1em 0;
     padding: 0.5em;
@@ -36,7 +39,8 @@ a, a:visited {
     border-radius: 4px;
 }
 
-.test:before {
+.test:before,
+y-test:before {
     content: "Test " counter(test-id);
     display: block;
     counter-increment: test-id;
@@ -45,7 +49,10 @@ a, a:visited {
     font-weight: bold;
 }
 
-.description {
+.description,
+y-description {
     color: #444444;
     font-style: italic;
+    display: block;
+    padding-bottom: 0.5em;
 }