sugar, checks: withNestedProp+filterReferenceErrors: enter arrays

2 files changed, 10 insertions, 2 deletions

diff --git a/src/common-util/sugar.js b/src/common-util/sugar.js
index 90d47b7c..89699f60 100644
--- a/src/common-util/sugar.js
+++ b/src/common-util/sugar.js
@@ -356,11 +356,19 @@ export function splitKeys(key) {
 }
 
 // Follows a key path like 'foo.bar.baz' to get an item nested deeply inside
-// an object.
+// an object. If a value partway through the chain is an array, the values
+// down the rest of the chain are gotten for each item in the array.
+//
+// obj: {x: [{y: ['a']}, {y: ['b', 'c']}]}
+// key: 'x.y'
+//   -> [['a'], ['b', 'c']]
+//
 export function getNestedProp(obj, key) {
   const recursive = (o, k) =>
     (k.length === 1
       ? o[k[0]]
+   : Array.isArray(o[k[0]])
+      ? o[k[0]].map(v => recursive(v, k.slice(1)))
       : recursive(o[k[0]], k.slice(1)));
 
   return recursive(obj, splitKeys(key));
diff --git a/src/data/checks.js b/src/data/checks.js
index 9a859165..57d0c1a4 100644
--- a/src/data/checks.js
+++ b/src/data/checks.js
@@ -237,7 +237,7 @@ export function filterReferenceErrors(wikiData, {
   const aggregate = openAggregate({message: `Errors validating between-thing references in data`});
   for (const [thingDataProp, propSpec] of referenceSpec) {
     const thingData = getNestedProp(wikiData, thingDataProp);
-    const things = Array.isArray(thingData) ? thingData : [thingData];
+    const things = Array.isArray(thingData) ? thingData.flat(Infinity) : [thingData];
     aggregate.nest({message: `Reference errors in ${colors.green('wikiData.' + thingDataProp)}`}, ({nest}) => {
       for (const thing of things) {
         nest({message: `Reference errors in ${inspect(thing)}`}, ({nest, push, filter}) => {