I tried for the first time my package monaco in a RMarkdown document:

---
title: "Monaco in Rmarkdown"
author: "Stéphane Laurent"
date: "02/05/2022"
output: 
  html_document: 
    highlight: tango
    theme: lumen
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
library(monaco)
```

## Monaco

```{r monaco}
contents <- c(
  "Select [A]",
  "    ,[year]",
  "    ,[model]",
  "   ....",
  "",
  "from",
  "(SELECT ....",
  "Where [year] between 2010 and 2020 and model ='1A' and [A] between 11 and 22..."
)
monaco(contents, language = "sql")
```

There's a problem with the rendering:

The body is black, and this is my fault; here is an extract of the JavaScript file I wrote:

  factory: function(el, width, height) {

    if(HTMLWidgets.shinyMode) {
      $(".monacoWidget").addClass("mWidget");
    } else {
      $("body").addClass("mWidgetBody");
    }

The black background comes from this CSS class, mWidgetBody. So I should not add it to the body of the document when this is a RMarkdown (or Flexdashboard) document. But how can we know that in the HTMLWidgets JavaScript file?