add a bunch of tests.

filter.test.js

@@ -0,0 +1,42 @@
+/* eslint-env jest */
+
+const {matchFilters} = require('./cjs')
+
+test('test if filters match', () => {
+  ;[
+    {
+      filters: [{ids: ['i']}],
+      good: [{id: 'i'}],
+      bad: [{id: 'j'}]
+    },
+    {
+      filters: [{authors: ['abc']}, {kinds: [1, 3]}],
+      good: [
+        {pubkey: 'xyz', kind: 3},
+        {pubkey: 'abc', kind: 12},
+        {pubkey: 'abc', kind: 1}
+      ],
+      bad: [{pubkey: 'hhh', kind: 12}]
+    },
+    {
+      filters: [{'#e': ['yyy'], since: 444}],
+      good: [
+        {
+          tags: [
+            ['e', 'uuu'],
+            ['e', 'yyy']
+          ],
+          created_at: 555
+        }
+      ],
+      bad: [{tags: [['e', 'uuu']], created_at: 111}]
+    }
+  ].forEach(({filters, good, bad}) => {
+    good.forEach(ev => {
+      expect(matchFilters(filters, ev)).toBeTruthy()
+    })
+    bad.forEach(ev => {
+      expect(matchFilters(filters, ev)).toBeFalsy()
+    })
+  })
+})