abstract and add test for chart alias display

test/display/test_chart_alias_for_peer.js

@@ -0,0 +1,42 @@
+const {test} = require('tap');
+
+const {chartAliasForPeer} = require('./../../display');
+
+const tests = [
+  {
+    args: {
+      alias: 'alias',
+      public_key: Buffer.alloc(33).toString('hex'),
+    },
+    description: 'A chart alias is returned',
+    expected: {display: 'alias'},
+  },
+  {
+    args: {
+      alias: '',
+      public_key: Buffer.alloc(33).toString('hex'),
+    },
+    description: 'A chart alias with short key is returned',
+    expected: {display: Buffer.alloc(8).toString('hex')},
+  },
+  {
+    args: {
+      alias: '',
+      is_disconnected: true,
+      is_inactive: true,
+      public_key: Buffer.alloc(33).toString('hex'),
+    },
+    description: 'A chart alias with emojis is returned',
+    expected: {display: '🚪 💀 0000000000000000'},
+  },
+];
+
+tests.forEach(({args, description, expected}) => {
+  return test(description, ({end, equal, throws}) => {
+    const {display} = chartAliasForPeer(args);
+
+    equal(display, expected.display, 'Got expected output');
+
+    return end();
+  });
+});