diff --git a/frontend_tests/node_tests/input_pill.js b/frontend_tests/node_tests/input_pill.js
new file mode 100644
index 0000000000..a446c9885a
--- /dev/null
+++ b/frontend_tests/node_tests/input_pill.js
@@ -0,0 +1,177 @@
+set_global('$', global.make_zjquery());
+zrequire('input_pill');
+
+set_global('blueslip', {
+});
+
+var noop = function () {};
+
+set_global('ui_util', {
+    place_caret_at_end: noop,
+});
+
+var id_seq = 0;
+
+(function set_up_ids() {
+    // just get coverage on a simple one-liner:
+    input_pill.random_id();
+
+    input_pill.random_id = function () {
+        id_seq += 1;
+        return 'some_id' + id_seq;
+    };
+}());
+
+
+function pill_html(value, data_id) {
+    var exit_div = "<div class='exit'>&times;</div>";
+    var html = "<div class='pill' data-id='" + data_id + "' tabindex=0>" + value + exit_div + "</div>";
+    return html;
+}
+
+(function test_basics() {
+    var error;
+
+    var config = {};
+
+    blueslip.error = function (err) {
+        error = err;
+    };
+
+    input_pill.create(config);
+    assert.equal(error, 'Pill needs container.');
+
+    var pill_input = $.create('pill_input');
+    var container = $.create('container');
+    container.set_find_results('.input', pill_input);
+
+    config.container = container;
+    input_pill.create(config);
+    assert.equal(error, 'Pill needs create_item_from_text');
+
+    config.create_item_from_text = noop;
+    input_pill.create(config);
+    assert.equal(error, 'Pill needs get_text_from_item');
+
+    blueslip.error = function () {
+        throw "unexpected error";
+    };
+
+    config.get_text_from_item = noop;
+    var widget = input_pill.create(config);
+
+    var item = {
+        display_value: 'JavaScript',
+        language: 'js',
+    };
+
+    var inserted_before;
+    var expected_html = pill_html('JavaScript', 'some_id1');
+
+    pill_input.before = function (elem) {
+        inserted_before = true;
+        assert.equal(elem.html(), expected_html);
+    };
+
+    widget.appendValidatedData(item);
+    assert(inserted_before);
+
+    assert.deepEqual(widget.items(), [item]);
+}());
+
+(function test_insert_remove() {
+    set_global('$', global.make_zjquery());
+    var items = {
+        blue: {
+            display_value: 'BLUE',
+            description: 'color of the sky',
+        },
+
+        red: {
+            display_value: 'RED',
+            description: 'color of stop signs',
+        },
+
+        yellow: {
+            display_value: 'YELLOW',
+            description: 'color of bananas',
+        },
+    };
+
+    var pill_input = $.create('pill_input');
+
+    var inserted_html = [];
+    pill_input.before = function (elem) {
+        inserted_html.push(elem.html());
+    };
+
+    var create_item_from_text = function (text) {
+        return items[text];
+    };
+
+    var container = $.create('container');
+    container.set_find_results('.input', pill_input);
+
+    var config = {
+        container: container,
+        create_item_from_text: create_item_from_text,
+        get_text_from_item: noop,
+    };
+
+    id_seq = 0;
+
+
+    // FINALLY CREATE THE WIDGET!!
+    var widget = input_pill.create(config);
+
+    var created;
+    var removed;
+
+    widget.onPillCreate(function () {
+        created = true;
+    });
+
+    widget.onPillRemove(function () {
+        removed = true;
+    });
+
+    widget.appendValue('blue,chartreuse,red,yellow,mauve');
+
+    assert(created);
+    assert(!removed);
+
+    assert.deepEqual(inserted_html, [
+        pill_html('BLUE', 'some_id1'),
+        pill_html('RED', 'some_id2'),
+        pill_html('YELLOW', 'some_id3'),
+    ]);
+
+    assert.deepEqual(widget.items(), [
+        items.blue,
+        items.red,
+        items.yellow,
+    ]);
+
+    assert.equal(pill_input.text(), 'chartreuse, mauve');
+
+    widget.clear_text();
+    assert.equal(pill_input.text(), '');
+
+    var BACKSPACE = 8;
+    var key_handler = container.get_on_handler('keydown', '.input');
+
+    key_handler({
+        keyCode: BACKSPACE,
+        target: {
+            innerText: '',
+        },
+        preventDefault: noop,
+    });
+
+    assert(removed);
+
+    assert.deepEqual(widget.items(), [
+        items.blue,
+        items.red,
+    ]);
+}());
diff --git a/static/js/input_pill.js b/static/js/input_pill.js
index 7c491b40c7..003f92a929 100644
--- a/static/js/input_pill.js
+++ b/static/js/input_pill.js
@@ -2,6 +2,10 @@ var input_pill = (function () {
 
 var exports = {};
 
+exports.random_id = function () {
+    return Math.random().toString(16);
+};
+
 exports.create = function (opts) {
     // a dictionary of the key codes that are associated with each key
     // to make if/else more human readable.
@@ -75,7 +79,7 @@ exports.create = function (opts) {
         // This is generally called by typeahead logic, where we have all
         // the data we need (as opposed to, say, just a user-typed email).
         appendValidatedData: function (item) {
-            var id = Math.random().toString(16);
+            var id = exports.random_id();
 
             if (!item.display_value) {
                 blueslip.error('no display_value returned');