README.Rmd

---
output: github_document
---

<!-- README.md is generated from README.Rmd. Please edit that file -->

```{r, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)
```

# Reproducible Example of Test for Target Version and Mermaid Rendering Issues

## Problem

A mermaid graph embedded in an Rmarkdown document that is rendered via a `targets` workflow is erroring with the following message:

```R
argument "store" is missing, with no default
```

This document used to render properly without issues at earlier stages of project but after a few months and a few `targets` versions later (started at v1.1.3 and currently at v1.3.2), the error above was encountered.

Hence the suspicion that maybe `targets` version was the culprit more so that there is [discussion online](https://github.com/ropensci/targets/pull/802#issuecomment-1071142712) that the initial version of `targets` that introduces the `tar_mermaid()` functionality has had some major bugs with regard to mermaid graph rendering within Rmarkdown documents.


## Test

We recreated a targets workflow in the repository using example created by Will Landau [here](https://github.com/ropensci/targets/pull/802) which is also an example in the function documentation for `tar_mermaid()`.

We added a target for rendering an Rmarkdown report found inside a specific library called `reports` which mimics the structure of the project in which the issue/problem was occurring.

To be able to control the version of `targets` used, this repository uses `renv`.

We first installed `targets` version 1.3.2:

```R
renv::install("targets@1.3.2")
```

and then ran the workflow with `targets::tar_make()`

This reproduced the same error we were encountering in existing project.

Then, we installed `targets` version 1.4.1:

```R
renv::install("targets@1.4.1")
```

and then ran the workflow.

Workflow completed without errors and HTML output in `reports` directory was produced as expected.

Finally, we tested using `targets` version 1.1.3 which is the version used at the start of the project. After installing this version and running the workflow, we completed the and rendered the document without errors/issues.