# Markdown Stress Testing # Markdown parity — complete manual fixture START OF FIXTURE — this sentence should remain visible in both published posts. ## 01. Headings # Heading level 1 ## Heading level 2 ### Heading level 3 #### Heading level 4 ##### Heading level 5 ###### Heading level 6 Setext heading level 1 ====================== Setext heading level 2 ---------------------- ### Repeated heading First occurrence, for checking table-of-contents links. ### Repeated heading Second occurrence; its table-of-contents link should reach this occurrence. ## 02. Paragraphs, spacing, and line breaks This is the first paragraph. It contains ordinary prose. This is the second paragraph. This line has a soft break. This follows the soft break. This line ends with two spaces. This follows a Markdown hard break. This line ends with a backslash.\ This follows a backslash hard break. This uses an explicit HTML break.
This follows the HTML break. ## 03. Emphasis and inline formatting **Bold with asterisks**, __bold with underscores__, *italic with asterisks*, and _italic with underscores_. ***Bold and italic***, **bold with _italic inside_**, and *italic with **bold inside***. ~~Strikethrough~~ and ~~**bold strikethrough**~~. Underlined text and highlighted text. Press Ctrl + K, or ⌘ + K. Water is H₂O. A square is x². HTML has a tooltip. snake_case_word and camelCaseWord should remain ordinary words. ## 04. Escaping, entities, and Unicode Escaped punctuation: \*asterisks\*, \_underscores\_, \[brackets\], \#hash, \>greater-than, and \|pipe. Literal backslashes: C:\\Users\\Example\\Documents. These entities should remain visible as text: <article>, &, "quoted", 'apostrophe', and ©. The text `<article>` should show the entity spelling inside code. The `

` element is mentioned inside inline code, not used as an HTML block. Emoji: 😀 🚀 ✅ 💡 🧪. Punctuation: “quotes”, ‘apostrophe’, an em dash — and an ellipsis … Unicode text: café, naïve, 日本語, हिन्दी, العربية. ## 05. Links [Ordinary link](https://example.com) [Link with a title](https://example.com "Example link title") [**Bold link text**](https://example.com/bold "Bold link title") and [*italic link text*](https://example.com/italic). [`code` inside a link](https://example.com/code). [A URL containing parentheses](https://example.com/path_(example)). [Query parameters](https://example.com/search?q=markdown&sort=newest). Autolink: . Bare URL: https://example.com/bare_url. Email link: [Example email](mailto:hello@example.com). Email autolink: . [Reference-style link][reference-link], [collapsed reference][], and [shortcut reference]. [Jump to the final section](#end-of-fixture). [reference-link]: https://example.com/reference "Reference link title" [collapsed reference]: https://example.com/collapsed [shortcut reference]: https://example.com/shortcut ## 06. Unordered lists - First bullet - Second bullet with **bold** and a [link](https://example.com) - Nested bullet - Third-level bullet - Another nested bullet - Last top-level bullet * Star-marker item one * Star-marker item two + Plus-marker item one + Plus-marker item two ## 07. Ordered lists and starting numbers 1. First item 2. Second item 1. Nested first item 2. Nested second item 3. Third item An ordered list that starts at five: 5. Five 6. Six 7. Seven A zero-based list: 0. Zero 1. One Parenthesis-style list markers: 1) Parenthesis first 2) Parenthesis second ## 08. Loose lists and mixed nesting - First loose item. Second paragraph belonging to the first item. - Second loose item. > A quote inside the second item. - Third loose item. ```js const insideList = true; ``` 1. An ordered item with bullets: - Nested bullet one - Nested bullet two 2. Another ordered item. ## 09. Task lists - [ ] Unchecked task - [x] Checked task - [X] Uppercase checked marker - [ ] Task with **bold**, *italic*, and a [link](https://example.com) - [x] Completed nested task - [ ] Incomplete nested task Empty task items, including an empty item with a nested list: - [ ] - [x] - [X] - [ ] - [x] Child of an empty task - [x] Sibling after the empty task An empty task in a loose list: - [ ] This explanation belongs to the empty task above. - [x] Finished loose-list task. Mixed task and ordinary bullet items: - [x] Checked task - Ordinary bullet - [ ] Unchecked task Ordered task markers: 1. [ ] Ordered unchecked task 2. [x] Ordered checked task Literal markers that should not accidentally become empty tasks: - [ ]not-a-task - \[ \] - `[ ]` ## 10. Blockquotes > A simple blockquote with **bold**, *italic*, and a [link](https://example.com). > First paragraph in a quote. > > Second paragraph in the same quote. > > > A nested blockquote. > > - A bullet in the quote > - Another bullet > - [ ] Quoted unchecked task > - [x] Quoted checked task ## 11. Horizontal rules Dash rule: --- Asterisk rule: *** Underscore rule: ___ ## 12. Tables | Left aligned | Center aligned | Right aligned | | :--- | :---: | ---: | | Alpha | Beta | 123 | | **Bold** | *Italic* | ~~Strike~~ | | [Link](https://example.com) | `inline code` | 45.67 | | Escaped pipe: a \| b | Line one
Line two | 0 | | | Empty left cell | | | H₂O | x² | K | | No explicit | Alignment | | --- | --- | | One | Two | A table without outer pipes: Name | Value --- | --- First | 1 Second | 2 ## 13. Inline code Run `npm install` and inspect `src/lib/markdown.ts`. Use double backticks to include a backtick: ``a `backtick` inside code``. Formatting stays literal: `**not bold**`, `

not an element

`, and `[not a link](https://example.com)`. Dollar math stays literal in code: `$x^2 + y_1$`. Backslash math stays literal in code: `$x^2 + y_1$`. ## 14. Fenced code and language aliases ```js const greeting = "Hello, Hashnode"; console.log(greeting); ``` ```ts type Result = { ok: boolean; count: number }; const result: Result = { ok: true, count: 3 }; ``` ```tsx export const Greeting = () => Hello; ``` ```python def square(value: int) -> int: return value ** 2 ``` ```bash printf '%s\n' "$HOME" echo 'Dollar signs: $5 and $10' ``` ```json { "enabled": true, "items": [1, 2, 3], "message": "

& literal text" } ``` ```html

This is source code, not a rendered heading

``` ```css .example { display: grid; gap: 1rem; } ``` ```sql SELECT id, title FROM posts WHERE is_active = true; ``` ```diff - const version = "old"; + const version = "new"; ``` ```plaintext This block explicitly requests plain text. SELECT * FROM posts; body { color: red; } ``` ``` This block has no language label. SELECT * FROM posts; body { color: red; } It should not receive a guessed SQL or CSS language. ``` ```not-a-real-language Unknown language labels should still leave readable code. ``` ~~~js const tildeFence = true; ~~~ ````markdown An outer fence can contain a shorter fence: ```js const nestedFence = true; ``` ```` ## 15. Indented code blocks The following lines have four leading spaces: const indentedCode = true; console.log("Keep the indentation"); ## 16. Math and currency Inline backslash math: $x^2 + y_1 = z^2$. Legacy doubled-backslash math: \$a^2 + b^2 = c^2\$. Inline dollar math: $x^2 + y_1 = z^2$. LaTeX commands: $\frac{a}{b} + \alpha = \beta$. A comparison inside math: $a < b$. Display math: $$ E = mc^2 $$ Another display formula: $$ \sum_{i=1}^{n} i = \frac{n(n+1)}{2} $$ Currency must remain ordinary text: it costs $5 to $10. Plans cost $100 and $200. Literal numeric range: $5-10$. Code still takes precedence: ```text $x^2 + y_1$ $x^2 + y_1$ $$ E = mc^2 $$ ``` ## 17. Footnotes A numeric footnote[^1], a named footnote[^named], and the same numeric footnote again[^1]. A single-word definition[^word] and a URL-only definition[^url]. Labels with an underscore[^under_score] and an asterisk[^star*label]. A footnote with multiple paragraphs and a list[^long-note]. Adjacent definitions are referenced here: first[^adjacent-a], then second[^adjacent-b]. [^1]: Numeric note with **bold**, *italic*, and `code`. [^named]: A named note with a [link](https://example.com). [^word]: Yes [^url]: https://example.com/footnote [^under_score]: An underscore-label definition. [^star*label]: An asterisk-label definition. [^long-note]: First paragraph of the long note. Second paragraph of the same note. - First item in the note. - Second item in the note. [^adjacent-a]: First adjacent definition. [^adjacent-b]: Second adjacent definition. ## 18. Images, titles, alignment, and sizing The image samples reuse Hashnode's logo so their alignment and sizing can be compared. Plain Markdown image: ![Hashnode logo](https://cdn.hashnode.com/res/hashnode/image/upload/v1611902473383/CDyAuTy75.png) Image with a title: ![Logo with a title](https://cdn.hashnode.com/res/hashnode/image/upload/v1611902473383/CDyAuTy75.png "Image title / caption probe") Empty alternative text: ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1611902473383/CDyAuTy75.png) Hashnode left alignment: ![Left aligned](https://cdn.hashnode.com/res/hashnode/image/upload/v1611902473383/CDyAuTy75.png align="left") Hashnode center alignment: ![Centered](https://cdn.hashnode.com/res/hashnode/image/upload/v1611902473383/CDyAuTy75.png align="center") Hashnode right alignment: ![Right aligned](https://cdn.hashnode.com/res/hashnode/image/upload/v1611902473383/CDyAuTy75.png align="right") HTML image with a title, size, and alignment: Sized and right aligned

Linked image: [![Clickable logo](https://cdn.hashnode.com/res/hashnode/image/upload/v1611902473383/CDyAuTy75.png)](https://hashnode.com) Reference-style image: ![Reference image][logo-image] [logo-image]: https://cdn.hashnode.com/res/hashnode/image/upload/v1611902473383/CDyAuTy75.png "Reference image title" ## 19. Hashnode mentions Hello @[Fazle](@fazlerocks), this is a Hashnode mention. A mention in a sentence: thanks to @[Hashnode](@hashnode) for reading. ## 20. Callouts

💡

A tip callout with bold, italic, and a link.

⚠️

A warning callout.

A second paragraph inside the callout.

## 21. Collapsible details

Raw HTML details — click to expand

This paragraph is inside the details element.

First item
Second item

Editor-style details — click to expand

This uses the editor's details attributes.

Keep this second paragraph.

## 22. Hashnode embeds Standalone YouTube embed: %[https://www.youtube.com/watch?v=jNQXAC9IVRw] Inline embed, with text on both sides: BEFORE INLINE EMBED %[https://www.youtube.com/watch?v=jNQXAC9IVRw] AFTER INLINE EMBED. An ordinary website card: %[https://example.com] Two inline embeds: FIRST %[https://www.youtube.com/watch?v=jNQXAC9IVRw] MIDDLE %[https://example.com] LAST. ## 23. Hashnode widgets and embed combinations Replace every occurrence of verify-widget in the source with a real widget ID from this publication before using these cases. Without a configured widget, compare placeholder preservation only. Standalone widget: %%[verify-widget] Inline widget: BEFORE WIDGET %%[verify-widget] AFTER WIDGET. Widget before embed: %%[verify-widget] %[https://www.youtube.com/watch?v=jNQXAC9IVRw] Embed before widget: %[https://www.youtube.com/watch?v=jNQXAC9IVRw] %%[verify-widget] Widget and embed without a separating space: %%[verify-widget]%[https://www.youtube.com/watch?v=jNQXAC9IVRw] Embed and widget without a separating space: %[https://www.youtube.com/watch?v=jNQXAC9IVRw]%%[verify-widget] Repeated widgets: %%[verify-widget] %%[verify-widget] Several tokens between prose: ARTICLE START %%[verify-widget] BETWEEN %[https://example.com] AGAIN %%[verify-widget] ARTICLE END. The paragraph after the widgets and embeds must remain visible. ## 24. Additional HTML

A paragraph containing strong, emphasis, ~~deleted~~, and inserted text.

An explicit HTML figure caption.

## 25. Compatibility probes — support is not assumed These cases deliberately exercise syntax or editor round trips that may not be fully supported. Record differences; do not assume every construct should gain special formatting. ### Definition-list syntax Term one : Definition one Term two : Definition two ### GitHub-style alert syntax > [!NOTE] > A GitHub-style note may render as an ordinary blockquote here. > [!WARNING] > A GitHub-style warning may render as an ordinary blockquote here. ### Other Markdown extensions ==Highlight shorthand==, H~2~O, x^2^, and :smile: are extension probes. The explicit HTML equivalents appear earlier. ### Mermaid fence ```mermaid flowchart LR Author --> Markdown Markdown --> PublishedPost ``` ### Additional math forms Simple math without operators: $x$ and $x$. Display bracket delimiters: \[ a^2 + b^2 = c^2 \] LaTeX spacing command: $$ \int_0^1 x^2\,dx = \frac{1}{3} $$ ### Literal custom syntax inside code `%[https://example.com]` and `%%[verify-widget]` are intended as literal code samples here. ```markdown %[https://example.com] %%[verify-widget] - [ ] [^literal]: This is code, not a footnote definition. ``` ### Raw alignment, comments, and open details

This raw div requests centered text.

Initially open details probe

Check whether the open state survives.

## End of fixture END OF FIXTURE — this heading and sentence must remain visible after all embeds, widgets, code blocks, and HTML. Use the footnote back-links to return to their references. The hidden Footnotes label should not become a visible table-of-contents entry.