Guard resource and related-idea resolvers against blank references (prevents build crash)

gatsby/resolvers/resolvers.js

@@ -20,7 +20,7 @@ const createIdeaPostResolver = (reporter) => ({
     },
     relatedIdeas: {
         resolve: async (source, _args, context) => {
-            const names = resolveToArray(source.related_ideas);
+            const names = resolveToArray(source.related_ideas).filter(Boolean);
             const results = await Promise.all(
                 names.map((name) =>
                     context.nodeModel.findOne(ideaPostQuery(name)),
@@ -63,7 +63,7 @@ const createIdeaPostResolver = (reporter) => ({
     },
     resources: {
         resolve: async (source, _args, context) => {
-            const names = resolveToArray(source.resources);
+            const names = resolveToArray(source.resources).filter(Boolean);
             const results = await Promise.all(
                 names.map((name) =>
                     context.nodeModel.findOne(resourceQuery(name)),

gatsby/resolvers/test/resolvers.test.js

@@ -0,0 +1,56 @@
+import { describe, expect, it, vi } from "vitest";
+
+import { createIdeaPostResolver } from "../resolvers";
+
+/**
+ * Faithful stand-in for Gatsby's nodeModel.findOne. The real implementation
+ * (gatsby/dist/schema/node-model.js) begins with `const { query = {} } = args`,
+ * so calling it with a null/undefined query object throws a TypeError — exactly
+ * what happens when a resolver passes it the null returned by resourceQuery()/
+ * ideaPostQuery() for a blank reference name.
+ */
+const makeContext = (nodesBySlug) => ({
+    nodeModel: {
+        findOne: vi.fn(async (args) => {
+            const { query = {} } = args; // throws if args is null/undefined
+            const slug = query?.filter?.slug?.eq;
+            return nodesBySlug[slug] ?? null;
+        }),
+    },
+});
+
+const makeReporter = () => ({ error: vi.fn() });
+
+describe("createIdeaPostResolver relational lookups", () => {
+    it("resolves resources, skipping blank entries without crashing", async () => {
+        const reporter = makeReporter();
+        const resolver = createIdeaPostResolver(reporter);
+        const context = makeContext({
+            "/resource/simularium/": {
+                id: "res-1",
+                slug: "/resource/simularium/",
+            },
+        });
+        // A blank row (empty string) is easy to produce via the Decap CMS list widget.
+        const source = { title: "My Idea", resources: ["Simularium", ""] };
+
+        const result = await resolver.resources.resolve(source, {}, context);
+
+        expect(result).toEqual([
+            { id: "res-1", slug: "/resource/simularium/" },
+        ]);
+    });
+
+    it("resolves related ideas, skipping blank entries without crashing", async () => {
+        const reporter = makeReporter();
+        const resolver = createIdeaPostResolver(reporter);
+        const context = makeContext({
+            "/ideas/some-idea/": { id: "idea-1", slug: "/ideas/some-idea/" },
+        });
+        const source = { title: "My Idea", related_ideas: ["", "Some Idea"] };
+
+        const result = await resolver.relatedIdeas.resolve(source, {}, context);
+
+        expect(result).toEqual([{ id: "idea-1", slug: "/ideas/some-idea/" }]);
+    });
+});