sourdough

Finished
1// Helper function to wrap text in HTML tags
12function wrap(text, tag) {
23 return `<${tag}>${text}</${tag}>`;
34}
45
6// Unused function - could be removed if not needed elsewhere
57function isTag(text, tag) {
68 return text.startsWith(`<${tag}>`);
79}
810
11// Generic parser for text formatting (bold, italic, etc.)
912function parser(markdown, delimiter, tag) {
1013 const pattern = new RegExp(`${delimiter}(.+)${delimiter}`);
1114 const replacement = `<${tag}>$1</${tag}>`;
1215 return markdown.replace(pattern, replacement);
1316}
1417
15function parse__(markdown) {
18// Parse bold text (__text__ -> <strong>text</strong>)
19function parseBold(markdown) {
1620 return parser(markdown, '__', 'strong');
1721}
1822
19function parse_(markdown) {
23// Parse italic text (_text_ -> <em>text</em>)
24function parseItalic(markdown) {
2025 return parser(markdown, '_', 'em');
2126}
2227
23function parseText(markdown, list) {
24 const parsedText = parse_(parse__(markdown));
25 if (list) {
26 return parsedText;
28// Parse formatted text and wrap in paragraph tags if not in a list
29function parseFormattedText(markdown, inList) {
30 // Apply text formatting (bold, italic)
31 const formattedText = parseItalic(parseBold(markdown));
32
33 // If we're in a list, don't wrap in paragraph tags
34 if (inList) {
35 return formattedText;
2736 } else {
28 return wrap(parsedText, 'p');
37 return wrap(formattedText, 'p');
2938 }
3039}
3140
32function parseHeader(markdown, list) {
33 let count = 0;
41// Parse header markdown (# Header -> <h1>Header</h1>)
42function parseHeader(markdown, currentlyInList) {
43 // Count consecutive # characters at the beginning
44 let headerLevel = 0;
3445 for (let i = 0; i < markdown.length; i++) {
3546 if (markdown[i] === '#') {
36 count += 1;
47 headerLevel++;
3748 } else {
3849 break;
3950 }
4051 }
41 if (count === 0 || count > 6) {
42 return [null, list];
52
53 // Valid headers have 1-6 # characters
54 if (headerLevel === 0 || headerLevel > 6) {
55 return [null, currentlyInList];
4356 }
44 const headerTag = `h${count}`;
45 const headerHtml = wrap(markdown.substring(count + 1), headerTag);
46 if (list) {
57
58 // Create the header tag (h1, h2, etc.)
59 const headerTag = `h${headerLevel}`;
60
61 // Extract header text (skip # characters and the following space)
62 const headerText = markdown.substring(headerLevel + 1);
63 const headerHtml = wrap(headerText, headerTag);
64
65 // If we were in a list, close it before the header
66 if (currentlyInList) {
4767 return [`</ul>${headerHtml}`, false];
4868 } else {
4969 return [headerHtml, false];
5070 }
5171}
5272
53function parseLineItem(markdown, list) {
73// Parse list item markdown (* item -> <li>item</li>)
74function parseListItem(markdown, currentlyInList) {
75 // Check if line starts with *
5476 if (markdown.startsWith('*')) {
55 const innerHtml = wrap(parseText(markdown.substring(2), true), 'li');
56 if (list) {
57 return [innerHtml, true];
77 // Extract list item text (skip '* ' prefix)
78 const itemText = markdown.substring(2);
79
80 // Parse formatted text without paragraph wrapping (since it's in a list)
81 const formattedItemText = parseFormattedText(itemText, true);
82 const listItemHtml = wrap(formattedItemText, 'li');
83
84 // If we're already in a list, just add the list item
85 // Otherwise, start a new list
86 if (currentlyInList) {
87 return [listItemHtml, true];
5888 } else {
59 return [`<ul>${innerHtml}`, true];
89 return [`<ul>${listItemHtml}`, true];
6090 }
6191 }
62 return [null, list];
92
93 return [null, currentlyInList];
6394}
6495
65function parseParagraph(markdown, list) {
66 if (!list) {
67 return [parseText(markdown, false), false];
96// Parse paragraph markdown (plain text -> <p>text</p>)
97function parseParagraph(markdown, currentlyInList) {
98 // Parse formatted text and wrap in paragraph tags
99 const paragraphHtml = parseFormattedText(markdown, false);
100
101 // If we were in a list, close it before the paragraph
102 if (currentlyInList) {
103 return [`</ul>${paragraphHtml}`, false];
68104 } else {
69 return [`</ul>${parseText(markdown, false)}`, false];
105 return [paragraphHtml, false];
70106 }
71107}
72108
73function parseLine(markdown, list) {
74 let [result, inListAfter] = parseHeader(markdown, list);
109// Parse a single line of markdown
110function parseLine(markdown, currentlyInList) {
111 // Handle empty lines - they should not create paragraphs
112 if (markdown.trim() === '') {
113 // If we were in a list, close it
114 if (currentlyInList) {
115 return ['</ul>', false];
116 }
117 // Otherwise, return empty result
118 return ['', false];
119 }
120
121 // Try parsing as header first
122 let [result, newListState] = parseHeader(markdown, currentlyInList);
123
124 // If not a header, try parsing as list item
75125 if (result === null) {
76 [result, inListAfter] = parseLineItem(markdown, list);
126 [result, newListState] = parseListItem(markdown, currentlyInList);
77127 }
128
129 // If not a list item, parse as paragraph
78130 if (result === null) {
79 [result, inListAfter] = parseParagraph(markdown, list);
131 [result, newListState] = parseParagraph(markdown, currentlyInList);
80132 }
133
134 // This should never happen with valid input
81135 if (result === null) {
82 throw new Error('Remove this line and implement the function');
136 throw new Error('Invalid markdown line');
83137 }
84 return [result, inListAfter];
138
139 return [result, newListState];
85140}
86141
87142/**
88 * @param {string} markdown
89 * @returns {string}
143 * Parse markdown text and convert it to HTML
144 * @param {string} markdown - The markdown text to parse
145 * @returns {string} - The resulting HTML
90146 */
91147export function parse(markdown) {
148 // Split markdown into lines
92149 const lines = markdown.split('\n');
93 let result = '';
94 let list = false;
95 for (let i = 0; i < lines.length; i++) {
96 let [lineResult, newList] = parseLine(lines[i], list);
97 result += lineResult;
98 list = newList;
150 let htmlResult = '';
151 let inList = false;
152
153 // Process each line
154 for (const line of lines) {
155 const [lineHtml, newListState] = parseLine(line, inList);
156 htmlResult += lineHtml;
157 inList = newListState;
99158 }
100 if (list) {
101 return result + '</ul>';
102 } else {
103 return result;
159
160 // Close any open list at the end
161 if (inList) {
162 htmlResult += '</ul>';
104163 }
164
165 return htmlResult;
105166}
Test NameStatus
parses normal text as a paragraph
Pass
parsing italics
Pass
parsing bold text
Pass
mixed normal, italics and bold text
Pass
with h1 header level
Pass
with h2 header level
Pass
with h3 header level
Pass
with h4 header level
Pass
with h5 header level
Pass
with h6 header level
Pass
with h7 header level
Pass
unordered lists
Pass
with a little bit of everything
Pass
with markdown symbols in the header text that should not be interpreted
Pass
with markdown symbols in the list item text that should not be interpreted
Pass
with markdown symbols in the paragraph text that should not be interpreted
Pass
unordered lists close properly with preceding and following lines
Pass

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