diff --git a/tests/store.test.js b/tests/store.test.js
index 7016a64..2e73fe8 100644
--- a/tests/store.test.js
+++ b/tests/store.test.js
@@ -99,3 +99,20 @@ test('Store: getSummary returns computed summary for attribute', () => {
   assert.equal(sum.trainsToday, 2);
   assert.equal(sum.perDay, Math.floor((2 / 7) * 247));
 });
+
+test('Store: recordTrain rejects non-positive and non-number deltas', () => {
+  const s = freshStore();
+  assert.equal(s.recordTrain('strength', 0, NOW), false);
+  assert.equal(s.recordTrain('strength', -5, NOW), false);
+  assert.equal(s.recordTrain('strength', '10', NOW), false);
+  assert.equal(s.recordTrain('strength', NaN, NOW), false);
+  assert.equal(s.history.strength, undefined);
+});
+
+test('Store: getSummary on unknown attribute returns zeros', () => {
+  const s = freshStore();
+  const sum = s.getSummary('nonexistent', NOW);
+  assert.equal(sum.trainsToday, 0);
+  assert.equal(sum.sevenDayAvgPerDay, 0);
+  assert.equal(sum.perDay, 0);
+});