Bug Report: spanner wrong in docx rendering

[raffaem]

Consider the following Quarto MWE:

---
title: "Title"
format:
  pdf: default
  docx: default
---

```{r}
#| label: tbl-bug
#| echo: false
#| output: true
mod1 <- gtsummary::tbl_regression(lm(mpg ~ wt, data = mtcars))
mod2 <- gtsummary::tbl_regression(lm(mpg ~ wt+gear, data = mtcars))
spanner <- c("Model 1", "Model2")
gtsummary::tbl_merge(list(mod1, mod2), tab_spanner=spanner)
```

This is how is rendered in PDF (good):

This is how it is rendered in docx.
The spanner is wrong, as the first header covers only one column instead of 3:

[ddsjoberg]

Thanks for the post @raffaem !

If you don't include the #| label: tbl-bug tag, the table renders properly. This looks like a Quarto+gt bug to me?

---
title: "Untitled"
format: docx
---

## Quarto

```{r}
library(gtsummary)
packageVersion("gtsummary")

list(
  tbl_regression(lm(mpg ~ wt, data = mtcars)),
  tbl_regression(lm(mpg ~ wt+gear, data = mtcars))
) |> 
  tbl_merge(tab_spanner=c("Model 1", "Model2"))
```

[raffaem]

So how can I get the gt code to reproduce that table, so I can report it upstream?

[ddsjoberg]

You can use as_gt(return_calls = TRUE), but that will give you a lot of extra code. Probably best to just use a small dummy example and add two spanning headers with gt::tab_spanner()

list(
  tbl_regression(lm(mpg ~ wt, data = mtcars)),
  tbl_regression(lm(mpg ~ wt+gear, data = mtcars))
) |> 
  tbl_merge(tab_spanner=c("Model 1", "Model2")) |> 
  as_gt(return_calls = TRUE)

[raffaem]

rstudio/gt#1898