Merge pull request #30 from mrc-ide/mrc-4384

New function for reading metadata

NAMESPACE

@@ -31,6 +31,7 @@ export(outpack_log)
 export(outpack_log_debug)
 export(outpack_log_info)
 export(outpack_log_trace)
+export(outpack_metadata)
 export(outpack_metadata_read)
 export(outpack_packet_add_custom)
 export(outpack_packet_cancel)

R/outpack_metadata.R

@@ -1,3 +1,27 @@
+##' Read metadata for a particular id. You may want to use
+##' [orderly2::outpack_search] to find an id corresponding to a
+##' particular query.
+##'
+##' @title Read outpack metadata
+##'
+##' @param id The id to fetch metadata for. An error will be thrown if
+##'   this id is not known
+##'
+##' @param root The outpack root, typically the path to the root. The
+##'   default value of `NULL` looks for the root from the current
+##'   directory which is typically correct.
+##'
+##' @return A list of metadata. See the outpack schema for details
+##'   (https://github.com/mrc-ide/outpack)
+##'
+##' @export
+outpack_metadata <- function(id, root = NULL) {
+  validate_outpack_id(id)
+  root <- outpack_root_open(root, locate = TRUE)
+  root$metadata(id, full = TRUE)
+}
+
+
 ##' Low-level function for reading metadata and deserialising it. This
 ##' function can be used to directly read a metadata json file without
 ##' reference to a root which contains it. It may be useful in the

tests/testthat/test-outpack-metadata.R

@@ -60,9 +60,11 @@ test_that("Validate hashes", {
 test_that("reading metadata via top-level function is same as from root", {
   root <- create_temporary_root(use_file_store = TRUE)
   id <- create_random_packet(root)
+  meta <- root$metadata(id, TRUE)
   expect_identical(
     outpack_metadata_read(file.path(root$path, ".outpack", "metadata", id)),
-    root$metadata(id, TRUE))
+    meta)
+  expect_identical(outpack_metadata(id, root), meta)
 })
 
 
@@ -71,3 +73,20 @@ test_that("Sensible error if metadata file not found", {
     outpack_metadata_read(tempfile()),
     "File does not exist: ")
 })
+
+
+test_that("Sensible error if metadata file not found", {
+  root <- create_temporary_root(use_file_store = TRUE)
+  expect_error(
+    outpack_metadata(1, root),
+    "'id' must be character")
+  expect_error(
+    outpack_metadata(letters, root),
+    "'id' must be a scalar")
+  expect_error(
+    outpack_metadata("some-id", root),
+    "Malformed id 'some-id'")
+  expect_error(
+    outpack_metadata(outpack_id(), root),
+    "id '.+' not found in index")
+})