fix code blocks

2 files changed, 375 insertions, 103 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 532fec7..88b040d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,10 +2,9 @@ use std::collections::HashMap;
 
 use pyo3::prelude::*;
 
-const KEYWORDS: [char; 5] = ['*', '_', '~', '`', '|'];
+const KEYWORDS: [char; 4] = ['*', '_', '~', '`'];
 const NO_SUB_PARSING_KEYWORDS: [char; 1] = ['`'];
 const QUOTE_KEYWORDS: [char; 1] = ['>'];
-const BLOCK_KEYWORDS: [(char, usize); 2] = [('`', 2), ('|', 1)];
 const PLACEHOLDER: &str = "\u{200B}\u{200B}\u{200B}\u{200B}\u{200B}\u{200B}\u{200B}\u{200B}\u{200B}\u{200B}";
 
 #[pyfunction]
@@ -14,31 +13,32 @@ fn format_body(body: String, new_tags: HashMap<String, (String, String)>) -> PyR
     if chars.len() < 1 {
         return Ok(body);
     }
-    let styles: Vec<(String, usize, usize)> = parse_with_limits(&chars, 0, chars.len() - 1, 0);
+    let styles: Vec<(String, usize, usize, usize, usize)> = parse_with_limits(&chars, 0, chars.len() - 1, 0);
     let parse_quotes = new_tags.contains_key(&">".to_string());
 
-    let mut tags: Vec<(usize, String, String, bool)> = vec![];
+    let mut tags: Vec<(usize, String, usize)> = vec![];
     for style in styles {
-        let (keyword, start, end) = style;
+        let (keyword, start, remove_start, end, remove_end) = style;
         if new_tags.contains_key(&keyword) {
-            tags.push((start, keyword.clone(), new_tags.get(&keyword).unwrap().0.clone(), false));
-            tags.push((end, keyword.clone(), new_tags.get(&keyword).unwrap().1.clone(), QUOTE_KEYWORDS.contains(&keyword.chars().next().unwrap())));
+            let opening_tag = if keyword == "```language" {
+                new_tags.get(&keyword).unwrap().0.clone()
+                .replace("{}", &chars[start+3..remove_start-1]
+                .into_iter()
+                .collect::<String>())
+            } else {
+                new_tags.get(&keyword).unwrap().0.clone()
+            };
+            tags.push((start, opening_tag, remove_start));
+            tags.push((end, new_tags.get(&keyword).unwrap().1.clone(), remove_end));
         } else if keyword == ">>" && parse_quotes {
-            tags.push((start, keyword.clone(), "".to_string(), false));
+            tags.push((start, "".to_string(), start+1));
         }
     }
 
     tags.sort_by(|a, b| b.0.cmp(&a.0));
 
     for tag in tags {
-        let (index, keyword, tag, is_end_quote_block) = tag;
-        let end = if is_end_quote_block {
-            index
-        } else if keyword == ">>" {
-            index + 1
-        } else {
-            index + keyword.len()
-        };
+        let (index, tag, end) = tag;
         chars = [chars[..index].to_vec(), tag.chars().collect(), chars[end..].to_vec()].concat();
     }
 
@@ -51,11 +51,10 @@ fn remove_non_escaped_backslashes(text: String) -> String {
     tmp_string.replace(PLACEHOLDER, "\\")
 }
 
-fn parse_with_limits(chars: &Vec<char>, start: usize, end: usize, depth: usize) -> Vec<(String, usize, usize)> {
+fn parse_with_limits(chars: &Vec<char>, start: usize, end: usize, depth: usize) -> Vec<(String, usize, usize, usize, usize)> {
     let mut styles = Vec::new();
     let mut index = start;
     let end = end.min(chars.len() - 1);
-    println!("parse with limits start {}, end {}", start, end);
 
     while index <= end {
         if preceeded_by_backslash(chars, index, start) {
@@ -64,58 +63,83 @@ fn parse_with_limits(chars: &Vec<char>, start: usize, end: usize, depth: usize)
         }
 
         let c = chars[index];
-        if c == '|' && !is_char_repeating(chars, c, index, end) {
-            index += 1;
-            continue;
-        }
-
         if QUOTE_KEYWORDS.contains(&c) {
             if is_quote_start(chars, index, depth) {
                 let to = seek_end_of_quote(chars, index, end, depth);
-                styles.push((">".to_string(), index, to));
+                styles.push((">".to_string(), index, index + 1, to, to));
                 styles.append(&mut parse_with_limits(chars, index + 1, to, depth + 1));
                 index = to;
                 continue;
             }
-            if depth > 0 {
-                styles.push((">>".to_string(), index, index + 1));
+            if is_nested_quote(chars, index, depth) {
+                styles.push((">>".to_string(), index, index + 1, index + 1, index + 1));
             }
             index += 1;
             continue;
         }
 
-        if !preceeded_by_whitespace(chars, index, start) || followed_by_whitespace(chars, index, end) {
-            index += 1;
+        if c == '`' && is_char_repeating(chars, c, 2, index + 1, end) {
+            let end_of_line = seek_end_of_line(chars, index + 1, end);
+            if end_of_line == end {
+                index += 3;
+                continue;
+            }
+            match seek_end_block(chars, c, end_of_line, end, depth) {
+                Some(to) => {
+                    if to != index + 3 && is_quote_start(chars, index, depth) {
+                        let keyword = if end_of_line == index + 3 {
+                            "```".to_string()
+                        } else {
+                            "```language".to_string()
+                        };
+                        let remove_end = if depth > 0 && to == end {
+                            to
+                        } else {
+                            to + 4 + depth
+                        };
+                        styles.push((keyword, index, end_of_line + 1, to, remove_end));
+                        styles.append(&mut parse_quotes_in_code_block(chars, index + 3, to, depth));
+                    }
+                    index = to + 3;
+                    continue;
+                }
+                None => ()
+            }
+            index += 3;
             continue;
         }
 
-        if !KEYWORDS.contains(&c) {
+        if !preceeded_by_whitespace(chars, index, start) || followed_by_whitespace(chars, index, end) {
             index += 1;
             continue;
         }
 
-        if BLOCK_KEYWORDS.iter().any(|&(k, _)| k == c) && is_char_repeating(chars, c, index, end) {
-            let block_indicator_size = get_block_indicator_size(c);
-            match seek_end_block(chars, c, index + block_indicator_size + 1, end) {
+        if c == '|' && is_char_repeating(chars, c, 1, index + 1, end) {
+            match seek_end(chars, c, index + 2, 1, end) {
                 Some(to) => {
-                    if to != index + block_indicator_size * 2 - 1 {
-                        let keyword = c.to_string().repeat(block_indicator_size+1);
-                        styles.push((keyword, index, to));
-                        if !NO_SUB_PARSING_KEYWORDS.contains(&c) {
-                            styles.append(&mut parse_with_limits(chars, index + block_indicator_size + 1, to - 1, depth));
-                        }
+                    if to != index + 2 {
+                        let keyword = "||".to_string();
+                        styles.push((keyword, index, index + 2, to, to + 2));
+                        styles.append(&mut parse_with_limits(chars, index + 2, to - 1, depth));
                     }
-                    index = to + block_indicator_size;
+                    index = to + 2;
                     continue;
                 }
                 None => ()
             }
+            index += 2;
+            continue;
         }
 
-        match seek_end(chars, c, index + 1, end) {
+        if !KEYWORDS.contains(&c) {
+            index += 1;
+            continue;
+        }
+
+        match seek_end(chars, c, index + 1, 0, end) {
             Some (to) => {
                 if to != index + 1 {
-                    styles.push((c.to_string(), index, to));
+                    styles.push((c.to_string(), index, index + 1, to, to + 1));
                     if !NO_SUB_PARSING_KEYWORDS.contains(&c) {
                         styles.append(&mut parse_with_limits(chars, index + 1, to - 1, depth));
                     }
@@ -129,10 +153,51 @@ fn parse_with_limits(chars: &Vec<char>, start: usize, end: usize, depth: usize)
     styles
 }
 
-fn is_char_repeating(chars: &Vec<char>, keyword: char, index: usize, end: usize) -> bool {
-    let block_indicator_size = get_block_indicator_size(keyword);
+fn parse_quotes_in_code_block(chars: &Vec<char>, start: usize, end: usize, depth: usize) -> Vec<(String, usize, usize, usize, usize)> {
+    let mut quotes = Vec::new();
+    let mut index = start;
+    let end = end.min(chars.len() - 1);
+
+    if depth < 1 {
+        return quotes;
+    }
+
+    while index <= end {
+        let c = chars[index];
+        if QUOTE_KEYWORDS.contains(&c) {
+            if is_nested_quote(chars, index, depth) {
+                quotes.push((">>".to_string(), index, index + 1, index + 1, index + 1));
+            }
+            index += 1;
+            continue;
+        }
+        index += 1;
+    }
+    quotes
+}
+
+fn is_nested_quote(chars: &Vec<char>, start: usize, depth: usize) -> bool {
+    let mut index = start;
+    let mut count = 0;
 
-    (0..block_indicator_size as usize)
+    while index > 0 {
+        if chars[index] == '\n' {
+            return true;
+        }
+        if !QUOTE_KEYWORDS.contains(&chars[index]) {
+            return false;
+        }
+        count += 1;
+        if count > depth {
+            return false;
+        }
+        index -= 1;
+    }
+    true
+}
+
+fn is_char_repeating(chars: &Vec<char>, keyword: char, repetitions: usize, index: usize, end: usize) -> bool {
+    (0..repetitions as usize)
         .all(|i| index + i <= end && chars[index + i] == keyword)
 }
 
@@ -144,7 +209,7 @@ fn followed_by_whitespace(chars: &Vec<char>, index: usize, end: usize) -> bool {
     index >= end || chars[index + 1].is_whitespace()
 }
 
-fn seek_end(chars: &Vec<char>, keyword: char, start: usize, end: usize) -> Option<usize> {
+fn seek_end(chars: &Vec<char>, keyword: char, start: usize, repetitions: usize, end: usize) -> Option<usize> {
     for i in start..=end {
         let c = chars[i];
         if c == '\n' {
@@ -153,10 +218,11 @@ fn seek_end(chars: &Vec<char>, keyword: char, start: usize, end: usize) -> Optio
         if c == keyword
             && !chars[i - 1].is_whitespace()
             && !preceeded_by_backslash(chars, i, start)
+            && is_char_repeating(chars, keyword, repetitions, i + 1, end)
         {
-            match seek_higher_order_end(chars, c, i + 1, end) {
-                Some(higher_order_index) => {
-                    return Some(higher_order_index);
+            match seek_higher_order_end(chars, c, i + 1, repetitions, end) {
+                Some(higher_order_i) => {
+                    return Some(higher_order_i);
                 }
                 None => {
                     return Some(i);
@@ -167,7 +233,7 @@ fn seek_end(chars: &Vec<char>, keyword: char, start: usize, end: usize) -> Optio
     None
 }
 
-fn seek_higher_order_end(chars: &Vec<char>, keyword: char, start: usize, end: usize) -> Option<usize> {
+fn seek_higher_order_end(chars: &Vec<char>, keyword: char, start: usize, repetitions: usize, end: usize) -> Option<usize> {
     for i in start..=end {
         let c = chars[i];
         if c == '\n' {
@@ -177,6 +243,7 @@ fn seek_higher_order_end(chars: &Vec<char>, keyword: char, start: usize, end: us
             && chars[i - 1].is_whitespace()
             && !followed_by_whitespace(chars, i, end)
             && !preceeded_by_backslash(chars, i, start)
+            && is_char_repeating(chars, keyword, repetitions, i + 1, end)
         {
             return None; // "*bold* *<--- beginning of new bold>*"
         }
@@ -184,6 +251,7 @@ fn seek_higher_order_end(chars: &Vec<char>, keyword: char, start: usize, end: us
             && !chars[i - 1].is_whitespace()
             && followed_by_whitespace(chars, i, end)
             && !preceeded_by_backslash(chars, i, start)
+            && is_char_repeating(chars, keyword, repetitions, i + 1, end)
         {
             return Some(i);
         }
@@ -191,6 +259,14 @@ fn seek_higher_order_end(chars: &Vec<char>, keyword: char, start: usize, end: us
     None
 }
 
+fn seek_end_of_line(chars: &Vec<char>, start: usize, end: usize) -> usize {
+    chars[start..=end]
+        .iter()
+        .enumerate()
+        .find(|&(_, &c)| c == '\n')
+        .map_or(end + 1, |(i, _)| start + i)
+}
+
 fn seek_end_of_quote(chars: &Vec<char>, start: usize, end: usize, depth: usize) -> usize {
     for i in start..=end {
         if chars[i] == '\n' {
@@ -205,16 +281,21 @@ fn seek_end_of_quote(chars: &Vec<char>, start: usize, end: usize, depth: usize)
     end + 1
 }
 
-fn seek_end_block(chars: &Vec<char>, keyword: char, start: usize, end: usize) -> Option<usize> {
+fn seek_end_block(chars: &Vec<char>, keyword: char, start: usize, end: usize, depth: usize) -> Option<usize> {
     for i in start..=end {
-        if chars[i] == keyword
-            && is_char_repeating(chars, keyword, i + 1, end)
-            && !preceeded_by_backslash(chars, i, start)
+        if chars[i] == '\n'
+            && i + 4 + depth > end
+            && (depth == 0 || chars[i + 1..i + 1 + depth].iter().all(|&c| QUOTE_KEYWORDS.contains(&c)))
+            && chars[i + 1 + depth] == keyword
+            && is_char_repeating(chars, keyword, 2, i + 1 + depth, end)
         {
             return Some(i);
         }
     }
-    None
+    if end == chars.len() - 1 {
+        return None;
+    }
+    Some(end)
 }
 
 fn is_quote_start(chars: &Vec<char>, index: usize, depth: usize) -> bool {
@@ -232,15 +313,6 @@ fn preceeded_by_backslash(chars: &Vec<char>, index: usize, start: usize) -> bool
     num_backslashes % 2 == 1
 }
 
-fn get_block_indicator_size(keyword: char) -> usize {
-    for &(k, v) in BLOCK_KEYWORDS.iter() {
-        if k == keyword {
-            return v;
-        }
-    }
-    1 // shouldn't ever happen
-}
-
 #[pymodule]
 fn slidge_style_parser(_py: Python, m: &PyModule) -> PyResult<()> {
     m.add_function(wrap_pyfunction!(format_body, m)?)?;
diff --git a/tests/test_style_parser.py b/tests/test_style_parser.py
index 671af64..fd02597 100644
--- a/tests/test_style_parser.py
+++ b/tests/test_style_parser.py
@@ -6,67 +6,267 @@ MATRIX_FORMATS = {
     "~": ("<strike>", "</strike>"),
     "`": ("<code>", "</code>"),
     "```": ("<pre><code>", "</code></pre>"),
+    "```language": ("<pre><code class=\"language-{}\">", "</code></pre>"),
     ">": ("<blockquote>", "</blockquote>"),
     "||": ("<span data-mx-spoiler>", "</span>")
 }
 
 def test_basic():
-    assert(format_body("_underline_", MATRIX_FORMATS) == "<em>underline</em>")
-    assert(format_body("*bold*", MATRIX_FORMATS) == "<strong>bold</strong>")
-    assert(format_body("~strikethrough~", MATRIX_FORMATS) == "<strike>strikethrough</strike>")
-    assert(format_body("`code span`", MATRIX_FORMATS) == "<code>code span</code>")
-    assert(format_body("```code\nblock```", MATRIX_FORMATS) == "<pre><code>code\nblock</code></pre>")
-    assert(format_body("||spoiler||", MATRIX_FORMATS) == "<span data-mx-spoiler>spoiler</span>")
+    test = "_underline_"
+    formatted_body = "<em>underline</em>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "*bold*"
+    formatted_body = "<strong>bold</strong>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "~strikethrough~"
+    formatted_body = "<strike>strikethrough</strike>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "`code span`"
+    formatted_body = "<code>code span</code>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = """
+    ```python
+        def test_basic():
+            test = "_underline_"
+            formatted_body = "<em>underline</em>"
+            assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+    ```
+    """
+    formatted_body = test = """
+    <pre><code class="language-python">def test_basic():
+        test = "_underline_"
+        formatted_body = "<em>underline</em>"
+        assert(format_body(test, MATRIX_FORMATS) == (test, formatted_body))</pre></code>
+    """
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "```\ncode block\n```"
+    formatted_body = "<pre><code>code block</code></pre>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "||this message contains a spoiler||"
+    formatted_body = "<span data-mx-spoiler>this message contains a spoiler</span>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
 
 def test_quotes():
-    assert(format_body(">single", MATRIX_FORMATS) == "<blockquote>single</blockquote>")
-    assert(format_body(">single\n>grouped", MATRIX_FORMATS) == "<blockquote>single\ngrouped</blockquote>")
-    assert(format_body(">>double", MATRIX_FORMATS) == "<blockquote><blockquote>double</blockquote></blockquote>")
-    assert(format_body(">>double\n>grouped single", MATRIX_FORMATS) == "<blockquote><blockquote>double</blockquote>\ngrouped single</blockquote>")
-    assert(format_body(">>>tripple\n>single\n>>double", MATRIX_FORMATS) == "<blockquote><blockquote><blockquote>tripple</blockquote></blockquote>\nsingle\n<blockquote>double</blockquote></blockquote>")
+    test = ">single"
+    formatted_body = "<blockquote>single</blockquote>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">single arrow ->"
+    formatted_body = "<blockquote>single arrow -></blockquote>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">single\n>grouped"
+    formatted_body = "<blockquote>single\ngrouped</blockquote>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">>double"
+    formatted_body = "<blockquote><blockquote>double</blockquote></blockquote>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">>double\n>>double"
+    formatted_body = "<blockquote><blockquote>double\ndouble</blockquote></blockquote>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">>double\n&>not quote"
+    formatted_body = "<blockquote><blockquote>double</blockquote></blockquote>\n&>not quote"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">>double\n>grouped single"
+    formatted_body = "<blockquote><blockquote>double</blockquote>\ngrouped single</blockquote>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">>>tripple\n>single\n>>double"
+    formatted_body = "<blockquote><blockquote><blockquote>tripple</blockquote></blockquote>\nsingle\n<blockquote>double</blockquote></blockquote>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+CODE_BLOCK_TEST_CASE = \
+"""
+Code test
+```python3
+def who_is_awesome():
+    return "you!"
+```
+Nope
+"""
+
+CODE_BLOCK_TEST_CASE_OUTPUT = \
+"""
+Code test
+<pre><code>
+def who_is_awesome():
+    return \"you!\"
+</code></pre>
+Nope
+"""
+
+def test_code_blocks():
+    test = "```\nhacker\ncode\n```"
+    formatted_body = "<pre><code>hacker\ncode</code></pre>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "```python\nhacker code\n```"
+    formatted_body = "<pre><code class=\"language-python\">hacker code</code></pre>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">```java\n>why are you quoting a code block\n>```"
+    formatted_body = "<blockquote><pre><code class=\"language-java\">why are you quoting a code block</code></pre></blockquote>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">```\n>please stop trying to break my parser ;-;\n>```"
+    formatted_body = "<blockquote><pre><code>please stop trying to break my parser ;-;</code></pre></blockquote>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">>```\n>>double quote code block\n>single quote not in code block\nnormal text"
+    formatted_body = "<blockquote><blockquote><pre><code>double quote code block</code></pre></blockquote>\nsingle quote not in code block</blockquote>\nnormal text"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">>```\n>>>>double quote code block\n>single quote not in code block\nnormal text"
+    formatted_body = "<blockquote><blockquote><pre><code>>>double quote code block</code></pre></blockquote>\nsingle quote not in code block</blockquote>\nnormal text"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "_```_ignored\ninvalid code block\n```"
+    formatted_body = "<em>```</em>ignored\ninvalid code block\n```"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
 
 def test_escaped():
-    assert(format_body("\\_no underline_", MATRIX_FORMATS) == "_no underline_")
-    assert(format_body("\\\\_no underline_", MATRIX_FORMATS) == "\\_no underline_")
-    assert(format_body(">>>tripple\n\\>none\n>>double", MATRIX_FORMATS) == "<blockquote><blockquote><blockquote>tripple</blockquote></blockquote></blockquote>\n>none\n<blockquote><blockquote>double</blockquote></blockquote>")
+    test = "\\_no underline_"
+    formatted_body = "_no underline_"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "\\\\_no underline_"
+    formatted_body = "\\_no underline_"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">>>tripple\n\\>none\n>>double"
+    formatted_body = "<blockquote><blockquote><blockquote>tripple</blockquote></blockquote></blockquote>\n>none\n<blockquote><blockquote>double</blockquote></blockquote>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
 
 def test_nested():
-    assert(format_body("`*~_code span_~*`", MATRIX_FORMATS) == "<code>*~_code span_~*</code>")
-    assert(format_body("*_~`code span`~_*", MATRIX_FORMATS) == "<strong><em><strike><code>code span</code></strike></em></strong>")
-    assert(format_body(">*_~`code span`~_*", MATRIX_FORMATS) == "<blockquote><strong><em><strike><code>code span</code></strike></em></strong></blockquote>")
-    assert(format_body("*bold star >*< star bold*", MATRIX_FORMATS) == "<strong>bold star >*< star bold</strong>")
-    assert(format_body("*_bold*_", MATRIX_FORMATS) == "<strong>_bold</strong>_")
-    assert(format_body("__underlined__", MATRIX_FORMATS) == "<em><em>underlined</em></em>")
+    test = "`*~_code span_~*`"
+    formatted_body = "<code>*~_code span_~*</code>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "*_~`code span`~_*"
+    formatted_body = "<strong><em><strike><code>code span</code></strike></em></strong>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">*_~`code span`~_*"
+    formatted_body = "<blockquote><strong><em><strike><code>code span</code></strike></em></strong></blockquote>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "*bold star >*< star bold*"
+    formatted_body = "<strong>bold star >*< star bold</strong>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "*_bold*_"
+    formatted_body = "<strong>_bold</strong>_"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "__underlined__"
+    formatted_body = "<em><em>underlined</em></em>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
 
 def test_no_changes():
-    assert(format_body("", MATRIX_FORMATS) == "")
-    assert(format_body("~~ empty `````` styles **", MATRIX_FORMATS) == "~~ empty `````` styles **")
-    assert(format_body("this is not an empty string", MATRIX_FORMATS) == "this is not an empty string")
-    assert(format_body("arrow ->", MATRIX_FORMATS) == "arrow ->")
-    assert(format_body("  > no quote", MATRIX_FORMATS) == "  > no quote")
-    assert(format_body("_not underlined", MATRIX_FORMATS) == "_not underlined")
-    assert(format_body("|not a spoiler|", MATRIX_FORMATS) == "|not a spoiler|")
-    assert(format_body("`no code\nblock here`", MATRIX_FORMATS) == "`no code\nblock here`")
+    test = ""
+    formatted_body = ""
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "~~ empty `````` styles **"
+    formatted_body = "~~ empty `````` styles **"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "this is not an empty string"
+    formatted_body = "this is not an empty string"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "arrow ->"
+    formatted_body = "arrow ->"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = " > no quote"
+    formatted_body = " > no quote"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "_not underlined"
+    formatted_body = "_not underlined"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "|not a spoiler|"
+    formatted_body = "|not a spoiler|"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "||\nalso\nnot\na\nspoiler||"
+    formatted_body = "||\nalso\nnot\na\nspoiler||"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "`no code\nblock here`"
+    formatted_body = "`no code\nblock here`"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "invalid ```\ncode block\n```"
+    formatted_body = "invalid ```\ncode block\n```"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "```\ncode block\ninvalid```"
+    formatted_body = "```\ncode block\ninvalid```"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "```\ncode block\n```invalid"
+    formatted_body = "```\ncode block\n```invalid"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
 
 def test_assorted():
-    assert(format_body("at the ```end```", MATRIX_FORMATS) == "at the <pre><code>end</code></pre>")
-    assert(format_body("in the ~middle~ here", MATRIX_FORMATS) == "in the <strike>middle</strike> here")
-    assert(format_body("_underline_ *bold* ~strikethrough~ >not quote ||spoiler||\n>quote\nnothing\nnothing\n>>>>another quote with ||~_*```four```*_~||", MATRIX_FORMATS) == "<em>underline</em> <strong>bold</strong> <strike>strikethrough</strike> >not quote <span data-mx-spoiler>spoiler</span>\n<blockquote>quote</blockquote>\nnothing\nnothing\n<blockquote><blockquote><blockquote><blockquote>another quote with <span data-mx-spoiler><strike><em><strong><pre><code>four</code></pre></strong></em></strike></span></blockquote></blockquote></blockquote></blockquote>")
+    test = "at the ||end||"
+    formatted_body = "at the <span data-mx-spoiler>end</span>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "in the ~middle~ here"
+    formatted_body = "in the <strike>middle</strike> here"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "_underline_ *bold* ~strikethrough~ >not quote ||spoiler||\n>quote\nnothing\nnothing\n>>>>another quote with ||~_*```four```*_~||"
+    formatted_body = "<em>underline</em> <strong>bold</strong> <strike>strikethrough</strike> >not quote <span data-mx-spoiler>spoiler</span>\n<blockquote>quote</blockquote>\nnothing\nnothing\n<blockquote><blockquote><blockquote><blockquote>another quote with <span data-mx-spoiler><strike><em><strong>```four```</strong></em></strike></span></blockquote></blockquote></blockquote></blockquote>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
 
 def test_weird_utf8():
-    assert(format_body("❤️💓💕💖💗 ```💙💚💛💜🖤``` 💝💞💟❣️", MATRIX_FORMATS) == "❤️💓💕💖💗 <pre><code>💙💚💛💜🖤</code></pre> 💝💞💟❣️")
-    assert(format_body("👨‍👩‍👧‍👧 _underline_👩‍👩‍👦‍👧", MATRIX_FORMATS) == "👨‍👩‍👧‍👧 <em>underline</em>👩‍👩‍👦‍👧")
-    assert(format_body("\u202eRight to left", MATRIX_FORMATS) == "\u202eRight to left")
-    assert(format_body(">\u202eRight to left quote?", MATRIX_FORMATS) == "<blockquote>\u202eRight to left quote?</blockquote>")
-    assert(format_body("_Invisible\u200bseparator_", MATRIX_FORMATS) == "<em>Invisible\u200bseparator</em>")
-    assert(format_body("~\u200b~", MATRIX_FORMATS) == "<strike>\u200b</strike>")
+    test = "❤️💓💕💖💗 ||💙💚💛💜🖤|| 💝💞💟❣️"
+    formatted_body = "❤️💓💕💖💗 <span data-mx-spoiler>💙💚💛💜🖤</span> 💝💞💟❣️"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "👨‍👩‍👧‍👧 _underline_👩‍👩‍👦‍👧"
+    formatted_body = "👨‍👩‍👧‍👧 <em>underline</em>👩‍👩‍👦‍👧"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "\u202eRight to left"
+    formatted_body = "\u202eRight to left"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = ">\u202eRight to left quote?"
+    formatted_body = "<blockquote>\u202eRight to left quote?</blockquote>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "_Invisible\u200bseparator_"
+    formatted_body = "<em>Invisible\u200bseparator</em>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
+
+    test = "~\u200b~"
+    formatted_body = "<strike>\u200b</strike>"
+    assert(format_body(test, MATRIX_FORMATS) == formatted_body)
 
 LIMITED_FORMATS = {
     "_": ("<em>", "</em>"),
     "~": ("<strike>", "</strike>"),
-    "`": ("<code>", "</code>"),
-    "||": ("<span data-mx-spoiler>", "</span>")
+    "`": ("<code>", "</code>")
 }
 
 def test_limited():
-    assert(format_body("_underline_ *bold* ~strikethrough~ >not quote ||spoiler||\n>quote\nnothing\nnothing\n>>>>another quote with ||~_*```four```*_~||", LIMITED_FORMATS) == "<em>underline</em> *bold* <strike>strikethrough</strike> >not quote <span data-mx-spoiler>spoiler</span>\n>quote\nnothing\nnothing\n>>>>another quote with <span data-mx-spoiler><strike><em>*```four```*</em></strike></span>")
+    test = "_underline_ *bold* ~strikethrough~ >not quote ||spoiler||\n>quote\nnothing\nnothing\n>>>>another quote with ||~_*```four```*_~||"
+    formatted_body = "<em>underline</em> *bold* <strike>strikethrough</strike> >not quote ||spoiler||\n>quote\nnothing\nnothing\n>>>>another quote with ||<strike><em>*```four```*</em></strike>||"
+    assert(format_body(test, LIMITED_FORMATS) == formatted_body)