Support .mmd (mermaid extension) and improve mermaid rendering

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Is your feature request related to a problem? Please describe.
can't detect mmd extension files
And renders with mermaid (in md files) are far from perfect.
with P1[1. ATTENTION]

text cut even if enough space in width

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Can you provide a .mmd file that renders exceptions?（or .md）

I'm not sure if the latest version of mermaid covers your needs.

https://cdn.jsdelivr.net/npm/mermaid@11.13.0/dist/mermaid.min.js

This explanation is insufficient for users of the MSI version. I’ve performed a deep search on my drive (using 'Everything'), and the mermaid.min.js file is nowhere to be found in the QuickLook installation folders.

It seems the Markdown plugin is now directly integrated into the source files rather than being a standalone, modifiable package. Could you clarify how we are supposed to apply this update manually, or plan to include this fix in the next official release?

Finally after a long fight, helped by claude sonnet 4.6
yes this script solve the "Unsupported markdown: list" problem

I can't use Visual Studio my disk is too small... So I used dnSpy. But impossible to find how to do it through the interface so Claude made me a script

close outlook and dnSpy

# ============================================================
# Embed mermaid.min.js into QuickLook.Plugin.MarkdownViewer.dll
# Fixes "Unsupported markdown: list" / mermaid diagrams not rendering
# Requires: dnlib.dll (included with dnSpy)
# Requires: mermaid.min.js (download from https://cdn.jsdelivr.net/npm/mermaid/dist/mermaid.min.js)
# ============================================================

# --- Edit these paths ---
$dnlibPath = "C:\Users\xxx\Downloads\dnSpy-net-win64\bin\dnlib.dll"
$dllPath   = "C:\Users\xxx\AppData\Local\Programs\QuickLook\QuickLook.Plugin\QuickLook.Plugin.MarkdownViewer\QuickLook.Plugin.MarkdownViewer.dll"
$jsPath    = "C:\Users\xxx\Desktop\mermaid.min.js"
# ------------------------

# Resource key expected by md2html.html (<script src="js/mermaid.min.js">)
$resName = "QuickLook.Plugin.MarkdownViewer.Resources.js\mermaid.min.js"

# Load dnlib (part of dnSpy) to manipulate the .NET assembly
Add-Type -Path $dnlibPath

$module  = [dnlib.DotNet.ModuleDefMD]::Load($dllPath)
$jsBytes = [System.IO.File]::ReadAllBytes($jsPath)

# Remove existing entry if present (e.g. when re-running the script)
$existing = $module.Resources | Where-Object { $_.Name -eq $resName }
if ($existing) { $module.Resources.Remove($existing) | Out-Null }

# Embed mermaid.min.js as a binary resource inside the DLL
$res = [dnlib.DotNet.EmbeddedResource]::new($resName, $jsBytes, [dnlib.DotNet.ManifestResourceAttributes]::Public)
$module.Resources.Add($res)

# Write to a temp file first to avoid file-lock issues, then replace
$tmpPath = $dllPath + ".tmp"
$module.Write($tmpPath)
Move-Item -Force $tmpPath $dllPath

Write-Host "Done."

to run it

 & "C:\Users\xxx\Desktop\script.ps1" 2>&1 | Tee-Object -FilePath "C:\Users\xxx\Desktop\output.txt"

I give the process if it can help someone else

About the other issue: node labels truncated in mermaid diagrams
When QuickLook opens, mermaid renders the diagram based on the initial window size. Node labels that exceed the box width get clipped and are not fully displayed. There is no scrollbar, and resizing the window to fullscreen does not trigger a re-render, so the truncated text stays as-is.
A possible workaround could be to force a mermaid re-render when the window is resized or maximized, though this would require changes to md2html.html.

Do you have any suggestions for improving md2html.html?
I don’t have any Mermaid code to reproduce this issue.

I update the mermaid.min.js after commit c23731d

you ask to a llm to generate a mermaid example. claude chat is very good
BTW, little detail, .mmd is not rendering mermaids.

issue-1893-mermaid.zip

I said I can't reproduce it.

ak ok (maximise the view to make the mermaid appear)
raw code:

graph TD
    subgraph Test_Bug
        direction TB
        Node1["1. PREMIER_ITEM"]
        Node1 -->|Lien A| SubNodeA["Détail A"]
        
        Node2["2. DEUXIEME_ITEM"]
        Node2 -->|Lien B| SubNodeB["Détail B"]
    end

    Start --> Node1
    Start --> Node2

Mermaid with list items

graph TD
    subgraph Test_Bug
        direction TB
        Node1["1. PREMIER_ITEM"]
        Node1 -->|Lien A| SubNodeA["Détail A"]
        
        Node2["2. DEUXIEME_ITEM"]
        Node2 -->|Lien B| SubNodeB["Détail B"]
    end

    Start --> Node1
    Start --> Node2

N.B:

.mmd from your example → no render
the other one → titles incomplete, \n not taken into account (still not supported with the last mermaid script you gave above)

These effects are consistent with the rendering effects of https://mermaid.live/

Add Mermaid support and .mmd detection #1893

@emako

@emako Hi. I saw the updates around this. We can see the problem is still there on Obsidian with num lists but something else is appearing in this picture a problem with color frame and arrow not visible. You can see the expected result lower behind

@3C0D

@3C0D

depending of the sun in room... 🤣 Well it's not invisible it's hardly visible

Add Mermaid support and .mmd detection QL-Win#1893

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Support .mmd (mermaid extension) and improve mermaid rendering #1893

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Support .mmd (mermaid extension) and improve mermaid rendering #1893

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emako commented on Mar 18, 2026

emako commented on Mar 18, 2026

3C0D commented on Mar 23, 2026

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emako commented on Mar 24, 2026

emako commented on Mar 24, 2026

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emako commented on Mar 24, 2026

3C0D commented on Mar 24, 2026

Mermaid with list items

emako commented on Mar 27, 2026

3C0D commented on Jul 26, 2026

emako commented on Jul 27, 2026

3C0D commented on Jul 28, 2026

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