From 32aff62a821d4ac04ae851912a81c8efd9890c54 Mon Sep 17 00:00:00 2001
From: D-Sketon <2055272094@qq.com>
Date: Fri, 3 Oct 2025 00:43:50 +0800
Subject: [PATCH 1/2] perf: faster strip_html

---
 lib/strip_html.ts | 153 ++++++++++++++++++++--------------------------
 1 file changed, 66 insertions(+), 87 deletions(-)

diff --git a/lib/strip_html.ts b/lib/strip_html.ts
index 492974ce..b279743b 100644
--- a/lib/strip_html.ts
+++ b/lib/strip_html.ts
@@ -2,6 +2,15 @@ const STATE_PLAINTEXT = Symbol('plaintext');
 const STATE_HTML = Symbol('html');
 const STATE_COMMENT = Symbol('comment');
 
+const CHAR_LT = 60; // '<'
+const CHAR_GT = 62; // '>'
+const CHAR_QUOTE = 34; // '"'
+const CHAR_APOS = 39; // "'"
+const CHAR_DASH = 45; // '-'
+const CHAR_SPACE = 32; // ' '
+const CHAR_NEWLINE = 10; // '\n'
+const CHAR_EXCLAIM = 33; // '!'
+
 // eslint-disable-next-line @typescript-eslint/ban-types
 function striptags(html: string | String = '') {
   // if not string, then safely return an empty string
@@ -10,114 +19,84 @@ function striptags(html: string | String = '') {
   }
 
   let state = STATE_PLAINTEXT;
-  let tag_buffer = '';
   let depth = 0;
-  let in_quote_char = '';
+  let in_quote_char = 0;
   let output = '';
+  let tag_start = -1;
+  let plain_text_start = 0;
 
   const { length } = html;
 
   for (let idx = 0; idx < length; idx++) {
-    const char = html[idx];
+    const charCode = html.charCodeAt(idx);
 
     if (state === STATE_PLAINTEXT) {
-      switch (char) {
-        case '<':
-          state = STATE_HTML;
-          tag_buffer = tag_buffer + char;
-          break;
-
-        default:
-          output += char;
-          break;
+      if (charCode === CHAR_LT) {
+        output += html.slice(plain_text_start, idx);
+        state = STATE_HTML;
+        tag_start = idx;
       }
     } else if (state === STATE_HTML) {
-      switch (char) {
-        case '<':
-          // ignore '<' if inside a quote
-          if (in_quote_char) break;
-
-          // we're seeing a nested '<'
-          depth++;
-          break;
-
-        case '>':
-          // ignore '>' if inside a quote
-          if (in_quote_char) {
-            break;
-          }
-
-          // something like this is happening: '<<>>'
+      if (charCode === CHAR_LT) {
+        // ignore '<' if inside a quote
+        if (!in_quote_char) depth++;
+      } else if (charCode === CHAR_GT) {
+        // ignore '>' if inside a quote
+        if (!in_quote_char) {
           if (depth) {
             depth--;
-
-            break;
-          }
-
-          // this is closing the tag in tag_buffer
-          in_quote_char = '';
-          state = STATE_PLAINTEXT;
-          // tag_buffer += '>';
-
-          tag_buffer = '';
-          break;
-
-        case '"':
-        case '\'':
-          // catch both single and double quotes
-
-          if (char === in_quote_char) {
-            in_quote_char = '';
           } else {
-            in_quote_char = in_quote_char || char;
-          }
-
-          tag_buffer = tag_buffer + char;
-          break;
-
-        case '-':
-          if (tag_buffer === '<!-') {
-            state = STATE_COMMENT;
-          }
-
-          tag_buffer = tag_buffer + char;
-          break;
-
-        case ' ':
-        case '\n':
-          if (tag_buffer === '<') {
+            // this is closing the tag in tag_buffer
+            in_quote_char = 0;
             state = STATE_PLAINTEXT;
-            output += '< ';
-            tag_buffer = '';
-
-            break;
+            tag_start = -1;
+            plain_text_start = idx + 1;
           }
-
-          tag_buffer = tag_buffer + char;
-          break;
-
-        default:
-          tag_buffer = tag_buffer + char;
-          break;
+        }
+      } else if (charCode === CHAR_QUOTE || charCode === CHAR_APOS) {
+        // catch both single and double quotes
+
+        if (charCode === in_quote_char) {
+          in_quote_char = 0;
+        } else {
+          in_quote_char = in_quote_char || charCode;
+        }
+      } else if (charCode === CHAR_DASH) {
+        // same as if (html.slice(tag_start, idx) === '<!-') {
+        if (idx - tag_start === 3
+          && html.charCodeAt(tag_start + 1) === CHAR_EXCLAIM
+          && html.charCodeAt(tag_start + 2) === CHAR_DASH
+        ) {
+          state = STATE_COMMENT;
+        }
+      } else if (charCode === CHAR_SPACE || charCode === CHAR_NEWLINE) {
+        // same as if (html.slice(tag_start, idx) === '<') {
+        if (idx - tag_start === 1) {
+          state = STATE_PLAINTEXT;
+          output += '< ';
+          tag_start = -1;
+          plain_text_start = idx + 1;
+        }
       }
     } else if (state === STATE_COMMENT) {
-      switch (char) {
-        case '>':
-          if (tag_buffer.slice(-2) === '--') {
-            // close the comment
-            state = STATE_PLAINTEXT;
-          }
-
-          tag_buffer = '';
-          break;
-
-        default:
-          tag_buffer = tag_buffer + char;
-          break;
+      if (charCode === CHAR_GT) {
+        // same as if (html.slice(idx - 2, idx) === '--') {
+        if (idx >= 2
+            && html.charCodeAt(idx - 1) === CHAR_DASH
+            && html.charCodeAt(idx - 2) === CHAR_DASH) {
+          // close the comment
+          state = STATE_PLAINTEXT;
+          plain_text_start = idx + 1;
+        }
+        tag_start = -1;
       }
     }
   }
 
+  if (state === STATE_PLAINTEXT && plain_text_start < length) {
+    output += html.slice(plain_text_start);
+  }
+
   return output;
 }
 

From 62b496ffa745ed40ca0a510182ab5e5ea2a482f6 Mon Sep 17 00:00:00 2001
From: D-Sketon <2055272094@qq.com>
Date: Fri, 3 Oct 2025 01:10:48 +0800
Subject: [PATCH 2/2] perf: use number as state

---
 lib/strip_html.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/strip_html.ts b/lib/strip_html.ts
index b279743b..24a5abd6 100644
--- a/lib/strip_html.ts
+++ b/lib/strip_html.ts
@@ -1,6 +1,6 @@
-const STATE_PLAINTEXT = Symbol('plaintext');
-const STATE_HTML = Symbol('html');
-const STATE_COMMENT = Symbol('comment');
+const STATE_PLAINTEXT = 0;
+const STATE_HTML = 1;
+const STATE_COMMENT = 2;
 
 const CHAR_LT = 60; // '<'
 const CHAR_GT = 62; // '>'