Encode missing values as null instead of omitting them.

R/outpack_misc.R

@@ -45,16 +45,18 @@ git_info <- function(path) {
     return(NULL)
   }
 
+  sha <- tryCatch(gert::git_commit_id(repo = repo),
+                  error = function(e) NA)
+
   branch <- gert::git_branch(repo = repo)
-  if (identical(branch, "HEAD")) {
-    # HEAD isn't a valid branch name, and instead is what gets returned when a
+  if (is.null(branch) || identical(branch, "HEAD")) {
+    # NULL can be returned when working in a repo that has no commits yet.
+    # "HEAD" isn't a valid branch name and instead is what gets returned when a
     # detached head was checked out.
-    branch <- NULL
+    branch <- NA
   }
 
-  list(sha = ignore_errors(gert::git_commit_id(repo = repo)),
-       branch = branch,
-       url = gert::git_remote_list(repo = repo)$url)
+  list(sha = sha, branch = branch, url = gert::git_remote_list(repo = repo)$url)
 }
 
 

inst/schema/outpack/git.json

@@ -7,11 +7,11 @@
     "type": "object",
     "properties": {
         "sha": {
-            "type": "string",
+            "type": ["string", "null"],
             "pattern": "^[0-9a-f]+$"
         },
         "branch": {
-            "type": "string"
+            "type": ["string", "null"]
         },
         "url": {
             "type": "array",

tests/testthat/test-outpack-git.R

@@ -89,6 +89,7 @@ test_that("store git information when on a detached HEAD", {
   meta <- orderly_metadata(id, root = root$path)
   expect_mapequal(meta$git,
                   list(sha = git_info$sha,
+                       branch = NULL,
                        url = git_info$url))
 })
 
@@ -108,5 +109,7 @@ test_that("handle empty git repository correctly", {
   })
 
   meta <- orderly_metadata(id, root = root$path)
-  expect_mapequal(meta$git, list(url = "https://example.com/git"))
+  expect_mapequal(meta$git, list(sha = NULL,
+                                 branch = NULL,
+                                 url = "https://example.com/git"))
 })