Add grammar util

This contains the function `toNounSeriesText` which can be used to build
i18n noun series fragments (i.e. "A, B, and C").

1 files changed, 35 insertions, 0 deletions

diff --git a/spec/javascripts/lib/utils/grammar_spec.js b/spec/javascripts/lib/utils/grammar_spec.js
new file mode 100644
index 00000000000..377b2ffb48c
--- /dev/null
+++ b/spec/javascripts/lib/utils/grammar_spec.js
@@ -0,0 +1,35 @@
+import * as grammar from '~/lib/utils/grammar';
+
+describe('utils/grammar', () => {
+  describe('toNounSeriesText', () => {
+    it('with empty items returns empty string', () => {
+      expect(grammar.toNounSeriesText([])).toBe('');
+    });
+
+    it('with single item returns item', () => {
+      const items = ['Lorem Ipsum'];
+
+      expect(grammar.toNounSeriesText(items)).toBe(items[0]);
+    });
+
+    it('with 2 items returns item1 and item2', () => {
+      const items = ['Dolar', 'Sit Amit'];
+
+      expect(grammar.toNounSeriesText(items)).toBe(`${items[0]} and ${items[1]}`);
+    });
+
+    it('with 3 items returns comma separated series', () => {
+      const items = ['Lorem', 'Ipsum', 'dolar'];
+      const expected = 'Lorem, Ipsum, and dolar';
+
+      expect(grammar.toNounSeriesText(items)).toBe(expected);
+    });
+
+    it('with 6 items returns comma separated series', () => {
+      const items = ['Lorem', 'ipsum', 'dolar', 'sit', 'amit', 'consectetur'];
+      const expected = 'Lorem, ipsum, dolar, sit, amit, and consectetur';
+
+      expect(grammar.toNounSeriesText(items)).toBe(expected);
+    });
+  });
+});