Relax error to warning

See #265

NEWS.md

@@ -1,9 +1,10 @@
 # frictionless (development version)
 
-# frictionless 1.2.0
-
+* `read_package()` now returns a warning rather than an error when a `datapackage.json` contains no resources. This allows use to create the JSON and then add resources with frictionless (#265).
 * `example_package()` now has a `version` parameter, allowing to load the example Data Package following the Data Package [v1](https://specs.frictionlessdata.io/) or [v2](https://datapackage.org/) specification (#249).
 
+# frictionless 1.2.0
+
 ## Changes for users
 
 * `add_resource()` now allows to replace an existing resource (#227).

R/read_package.R

@@ -32,14 +32,15 @@ read_package <- function(file = "datapackage.json") {
   }
   descriptor <- read_descriptor(file, safe = FALSE)
 
-  # Check resources are present
-  # Checking that they have a name is done when accessing, see check_package()
-  # https://specs.frictionlessdata.io/data-package/#metadata
+  # Warn if resources is absent
   if (length(descriptor$resources) == 0) {
-    cli::cli_abort(
-      "{.arg file} {.file {file}} must have a {.field resources} property
-       containing at least one resource.",
-      class = "frictionless_error_file_without_resources"
+    cli::cli_warn(
+      c(
+        "{.arg file} {.file {file}} should have a {.field resources} property
+         containing at least one resource.",
+        "i" = "Use {.fun add_resource} to add resources."
+      ),
+      class = "frictionless_warning_file_without_resources"
     )
   }
 

tests/testthat/test-read_package.R

@@ -45,7 +45,7 @@ test_that("read_package() returns a valid Data Package reading from url", {
   )
 })
 
-test_that("read_package() returns error on missing file and properties", {
+test_that("read_package() returns error on missing or invalid file", {
   skip_if_offline()
   # Incorrect type
   expect_error(
@@ -73,30 +73,37 @@ test_that("read_package() returns error on missing file and properties", {
     fixed = FALSE
   )
 
-  # No resources property
+  # No file remotely
   expect_error(
+    read_package("https://example.com/nofile.json"),
+    class = "frictionless_error_url_not_found"
+  )
+})
+
+test_that("read_package() warns if resources are missing", {
+  # No resources property
+  expect_warning(
     read_package(test_path("data/resources_missing.json")),
-    class = "frictionless_error_file_without_resources"
+    class = "frictionless_warning_file_without_resources"
   )
-  expect_error(
+  expect_warning(
     read_package(test_path("data/resources_missing.json")),
     regexp = paste(
       "`file` 'data/resources_missing.json' must have a resources property",
       "containing at least one resource."
     ),
     fixed = TRUE
   )
+  expect_warning(
+    read_package(test_path("data/resources_missing.json")),
+    regexp = "Use {.fun add_resource} to add resources.",
+    fixed = TRUE
+  )
 
   # Resources is empty list
-  expect_error(
+  expect_warning(
     read_package(test_path("data/resources_empty.json")),
-    class = "frictionless_error_file_without_resources"
-  )
-
-  # No file remotely
-  expect_error(
-    read_package("https://example.com/nofile.json"),
-    class = "frictionless_error_url_not_found"
+    class = "frictionless_warning_file_without_resources"
   )
 })