Mermaid fig-width no longer works

[d-chambers]

Bug description

Following the documentation on sizing mermaid diagram, the latest nightly build (1.3.107) running on Ubuntu 20.04 no longer sizes the diagrams differently regardless of the fig-width parameter. I also tried this with the latest stable (1.2.313) and it has the same issue.

For example, in the following script the diagram under #Slide 1 is the exact same size as the diagram in #Slide 2. I have tried playing with both and fig-width and fig-height but neither seems to have any effect.

---
title: Bad Mermaid Sizing
format:
    revealjs
---

# Slide 1

```{mermaid}

%%| fig-width: 5

flowchart LR
  A[Hard edge] --> B(Round edge)
  B --> C{Decision}
```

# Slide 2

```{mermaid}

%%| fig-width: 15

flowchart LR

  A[Hard edge] --> B(Round edge)
  B --> C{Decision}
```

Maybe related to some of the fixes for #2607?

Checklist

• Please include a minimal, fully reproducible example in a single .qmd file? Please provide the whole file rather than the snippet you believe is causing the issue.
• Please format your issue so it is easier for us to read the bug report.
• Please document the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
• Please document the operating system you're running. If on Linux, please provide the specific distribution.

[d-chambers]

small update: The example above uses the revealjs format, but I can also reproduce the issue with PDF and HTML formats, so it is probably format independent.

[d-chambers]

While trying to find a workaround I made an interesting discovery; the fig_size actually does something. For example, in the following quarto file you can see changes from sizes 1 to 2 and 2 to 3, but from then on no changes. It seems there may be a max node size that prohibits the elements from getting any larger?

I tried this with the following quarto versions and the problem persists:

• 1.2.186
• 1.2.156
• 1.2.269
• 1.3.14
• 1.3.121

and mermaid doesn't appear to work at all on the pre-1.2 releases.

This is especially perplexing because it worked a month or so ago, but I am not 100% what quarto version was running last time it worked.

Any help would be very much appreciated. I am giving a presentation next week which makes heavy use of quarto and mermaid (40ish diagrams) but currently the diagrams are all too small to read and there is so many of them I have no idea how I would go about working around the issue. Thanks so much!

Contents of test.qmd:

---
title: Mermaid Sizing
format:
    revealjs
---

# Width 1

```{mermaid}
%%| fig-width: 1

flowchart LR
  A[Hard edge] --> B(Round edge)
```

# Width 2

```{mermaid}
%%| fig-width: 2

flowchart LR
  A[Hard edge] --> B(Round edge)
```
# Width 3

```{mermaid}
%%| fig-width: 3

flowchart LR
  A[Hard edge] --> B(Round edge)
```
# Width 4

```{mermaid}
%%| fig-width: 4

flowchart LR
  A[Hard edge] --> B(Round edge)
```
# Width 5

```{mermaid}
%%| fig-width: 5

flowchart LR
  A[Hard edge] --> B(Round edge)
```

[d-chambers]

Update: I found that on version v1.2.313 the mermaid graphs are sized as expected provided embed-resources: true is used, but are not on v1.3.124. I am simply going to pin the quarto version to v1.2.313 for now.

[cscheid]

That's likely because it uses an old version of mermaid. (a separate bug report needed mermaid to be upgraded..)

[d-chambers]

That's likely because it uses an old version of mermaid. (a separate bug report needed mermaid to be upgraded..)

Ah a bit of whack-a-mole then, that is unfortunate.

[cscheid]

(status update: I'll revisit this on mermaid 10.0.0, which we'll do on 1.4)

[aseyboldt]

It seems that this is still an issue. Are there any updates on a fix or workaround?

[QuintenSand]

I'm still facing the issue. I'm using Quarto 1.4.537

[mcanouil]

@QuintenSand When an issue has the status "open" it means it has not been solved/fixed.