add option for appending lockfile to reprex

[kevinushey]

This is a speculative PR. When renv_lockfile is set, a lockfile capturing the dependencies of the script is appended to the generated output.

Some open questions:

1. Do we want to include rmarkdown + its recursive dependencies as part of the lockfile? (Since those are required to generate the reprex.)

2. Do we have any preferences on the formatting of output? I figured making it easy to copy + paste would be a high priority.

3. Any other concerns about behavior / configurability we'd like to add or control here?

Closes #313.

---

print("Hello, renv!")
#> [1] "Hello, renv!"

^{Created on 2020-02-20 by the reprex package (v0.3.0.9001)}

Lockfile

{
  "R": {
    "Version": "3.6.2",
    "Repositories": [
      {
        "Name": "CRAN",
        "URL": "https://cran.rstudio.com"
      }
    ]
  },
  "Packages": {
    "R6": {
      "Package": "R6",
      "Version": "2.4.1",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "292b54f8f4b94669b08f94e5acce6be2"
    },
    "Rcpp": {
      "Package": "Rcpp",
      "Version": "1.0.3",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "f3ca785924863b0e4c8cb23b6a5c75a1"
    },
    "base64enc": {
      "Package": "base64enc",
      "Version": "0.1-3",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "543776ae6848fde2f48ff3816d0628bc"
    },
    "callr": {
      "Package": "callr",
      "Version": "3.4.2",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "d16f6e202179e69c1400cc1f845bfc09"
    },
    "clipr": {
      "Package": "clipr",
      "Version": "0.7.0",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "08cf4045c149a0f0eaf405324c7495bd"
    },
    "digest": {
      "Package": "digest",
      "Version": "0.6.24",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "dc0030cea0d85397ba3ba5b930c82c6a"
    },
    "evaluate": {
      "Package": "evaluate",
      "Version": "0.14",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "ec8ca05cffcc70569eaaad8469d2a3a7"
    },
    "fs": {
      "Package": "fs",
      "Version": "1.3.1",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "0e26be4558dbbc713d7cfe4a4c361f38"
    },
    "glue": {
      "Package": "glue",
      "Version": "1.3.1",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "d4e25697c450c01b202c79ef35694a83"
    },
    "highr": {
      "Package": "highr",
      "Version": "0.8",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "4dc5bb88961e347a0f4d8aad597cbfac"
    },
    "htmltools": {
      "Package": "htmltools",
      "Version": "0.4.0",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "2d7691222f82f41e93f6d30f169bd5e1"
    },
    "jsonlite": {
      "Package": "jsonlite",
      "Version": "1.6.1",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "84b0ee361e2f78d6b7d670db9471c0c5"
    },
    "knitr": {
      "Package": "knitr",
      "Version": "1.28",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "915a6f0134cdbdf016d7778bc80b2eda"
    },
    "magrittr": {
      "Package": "magrittr",
      "Version": "1.5",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "1bb58822a20301cee84a41678e25d9b7"
    },
    "markdown": {
      "Package": "markdown",
      "Version": "1.1",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "61e4a10781dd00d7d81dd06ca9b94e95"
    },
    "mime": {
      "Package": "mime",
      "Version": "0.9",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "e87a35ec73b157552814869f45a63aa3"
    },
    "processx": {
      "Package": "processx",
      "Version": "3.4.2",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "20a082f2bde0ffcd8755779fd476a274"
    },
    "ps": {
      "Package": "ps",
      "Version": "1.3.2",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "98777535b61c57d1749344345e2a4ccd"
    },
    "renv": {
      "Package": "renv",
      "Version": "0.9.3-28",
      "Source": "GitHub",
      "RemoteType": "github",
      "RemoteHost": "api.github.com",
      "RemoteUsername": "rstudio",
      "RemoteRepo": "renv",
      "RemoteRef": "master",
      "RemoteSha": "a94bc1eb94874cd6b6662420b58c28dd48b75ed7",
      "Hash": "f59f1c023fe7d3f9636f445d92ad247e"
    },
    "reprex": {
      "Package": "reprex",
      "Version": "0.3.0.9001",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "21563e18f3234aec27a0e1c62c12cf5c"
    },
    "rlang": {
      "Package": "rlang",
      "Version": "0.4.4",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "09a36f36a13436be327dad3d000c8dd3"
    },
    "rmarkdown": {
      "Package": "rmarkdown",
      "Version": "2.1",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "9d1c61d476c448350c482d6664e1b28b"
    },
    "stringi": {
      "Package": "stringi",
      "Version": "1.4.6",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "e99d8d656980d2dd416a962ae55aec90"
    },
    "stringr": {
      "Package": "stringr",
      "Version": "1.4.0",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "0759e6b6c0957edb1311028a49a35e76"
    },
    "tinytex": {
      "Package": "tinytex",
      "Version": "0.19",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "b1c0c22cab714ec9ce9472a8073b6922"
    },
    "withr": {
      "Package": "withr",
      "Version": "2.1.2",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "aa57ed55ff2df4bea697a07df528993d"
    },
    "xfun": {
      "Package": "xfun",
      "Version": "0.12",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "ccd8453a7b9e380628f6cd2862e46cad"
    },
    "yaml": {
      "Package": "yaml",
      "Version": "2.2.1",
      "Source": "Repository",
      "Repository": "CRAN",
      "Hash": "2826c5d9efb0a88f657c7a679c7106db"
    }
  }
}

^{Lockfile generated by [the renv package](https://rstudio.github.io/renv/) (v0.9.3.28)}

[wlandau]

After highlighting and copying the lockfile in the example, I appreciate #313 (comment) even more. A couple thoughts:

• Maybe we could insert an inline clipboard button in the R Markdown? klippy seems lightweight as a dependency (except for stringi, which reprex depends on through glue anyway). Could be a long shot though. Not sure if GitHub-flavored Markdown will pick it up.
• What if the renv_lockfile argument had choices "none", "inline", and "gist"?

[wlandau]

I think I spoke too soon about klippy specifically. It is not on CRAN (yet) and the klippy button requires the document to be rendered to HTML.

[jennybc]

This looks really interesting. Just want to check in before I return to my current project (googlesheets4/gargle releaeses). I can't dig in to this now but will before next reprex release.

[kevinushey]

Notes for myself: it seems like (for R invoked from the console?) we need to ensure that we move to the reprex tempdir before invoking renv's APIs.

[jennybc]

Closing, explanation in #313.