refactor(web): extract groupDefinitions helper; object-detail uses it (#45)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/src/lib/group-fields.test.ts

@@ -0,0 +1,40 @@
+import { expect, test } from "vitest";
+import { groupDefinitions } from "./group-fields";
+import type { components } from "../api/schema";
+
+type FieldDefinitionView = components["schemas"]["FieldDefinitionView"];
+type MinDef = Pick<FieldDefinitionView, "key" | "group">;
+
+const def = (key: string, group: string | null): MinDef => ({
+  key,
+  group: group as FieldDefinitionView["group"],
+});
+
+function keysByGroup(defs: MinDef[]) {
+  return groupDefinitions(defs as FieldDefinitionView[], "Other").map((g) => ({
+    group: g.group,
+    keys: g.defs.map((d) => d.key),
+  }));
+}
+
+test("preserves definition order within and across groups; Other is last", () => {
+  const result = keysByGroup([
+    def("a", "Description"),
+    def("b", null),
+    def("c", "Description"),
+    def("d", "Provenance"),
+    def("e", "  "),
+  ]);
+
+  expect(result).toEqual([
+    { group: "Description", keys: ["a", "c"] },
+    { group: "Provenance", keys: ["d"] },
+    { group: "Other", keys: ["b", "e"] },
+  ]);
+});
+
+test("all-ungrouped → a single trailing Other group", () => {
+  expect(keysByGroup([def("x", null), def("y", null)])).toEqual([
+    { group: "Other", keys: ["x", "y"] },
+  ]);
+});

web/src/lib/group-fields.ts

@@ -0,0 +1,30 @@
+import type { components } from "../api/schema";
+
+type FieldDefinitionView = components["schemas"]["FieldDefinitionView"];
+
+export type FieldGroup = { group: string; defs: FieldDefinitionView[] };
+
+/** Group field definitions by `def.group` (trimmed), preserving definition order
+ *  within and across groups; ungrouped defs fall into a trailing `otherLabel` bucket. */
+export function groupDefinitions(
+  definitions: FieldDefinitionView[],
+  otherLabel: string,
+): FieldGroup[] {
+  const groups: FieldGroup[] = [];
+
+  for (const def of definitions) {
+    const group = def.group?.trim() ? def.group : otherLabel;
+    let bucket = groups.find((g) => g.group === group);
+
+    if (!bucket) {
+      bucket = { group, defs: [] };
+      groups.push(bucket);
+    }
+
+    bucket.defs.push(def);
+  }
+
+  groups.sort((a, b) => Number(a.group === otherLabel) - Number(b.group === otherLabel));
+
+  return groups;
+}