feat: add nonEmptyRecord refiner

packages/examples/packages/browserify-plugin/snap.manifest.json

@@ -7,7 +7,7 @@
     "url": "https://github.com/MetaMask/snaps.git"
   },
   "source": {
-    "shasum": "2WLcpc3RXg2Up0zeSMxWS/2rsVI1bC1iHCHAhzc3DOA=",
+    "shasum": "03Y0FecvVHqC2DG+GpXwwNPtWFl2b5tA3PLjMK7d3hw=",
     "location": {
       "npm": {
         "filePath": "dist/bundle.js",

packages/examples/packages/browserify/snap.manifest.json

@@ -7,7 +7,7 @@
     "url": "https://github.com/MetaMask/snaps.git"
   },
   "source": {
-    "shasum": "LQYiFCEu2fQXCuzfYHVpFfqffCbzzUjaqH7kPwgBfNc=",
+    "shasum": "I/C34T7c3uxkDeFC91tMUg3raVe104ocTkr5F4ciGyQ=",
     "location": {
       "npm": {
         "filePath": "dist/bundle.js",

packages/snaps-sdk/src/index.ts

@@ -26,4 +26,5 @@ export * from './errors';
 export * from './error-wrappers';
 export * from './images';
 export * from './types';
+export * from './structs';
 export * from './ui';

packages/snaps-sdk/src/structs.test.ts

@@ -0,0 +1,20 @@
+import { any, is, string } from '@metamask/superstruct';
+
+import { nonEmptyRecord } from './structs';
+
+describe('nonEmptyRecord', () => {
+  it.each([[1, 2, 3], { foo: 'bar' }])('validates "%p"', (value) => {
+    const struct = nonEmptyRecord(string(), any());
+
+    expect(is(value, struct)).toBe(true);
+  });
+
+  it.each(['foo', 42, null, undefined, [], {}])(
+    'does not validate "%p"',
+    (value) => {
+      const struct = nonEmptyRecord(string(), any());
+
+      expect(is(value, struct)).toBe(false);
+    },
+  );
+});

packages/snaps-sdk/src/structs.ts

@@ -0,0 +1,21 @@
+import type { Struct } from '@metamask/superstruct';
+import { record, refine } from '@metamask/superstruct';
+
+/**
+ * Refine a struct to be a non-empty record.
+ *
+ * @param Key - The struct for the record key.
+ * @param Value - The struct for the record value.
+ * @returns The refined struct.
+ */
+export function nonEmptyRecord<Key extends string, Value>(
+  Key: Struct<Key>,
+  Value: Struct<Value>,
+) {
+  return refine(record(Key, Value), 'Non-empty record', (value) => {
+    return (
+      (Array.isArray(value) && value.length > 0) ||
+      Object.keys(value).length > 0
+    );
+  });
+}