From a32716843ed97a0b1bee1d2a0c10ccc1ab75f401 Mon Sep 17 00:00:00 2001
From: Richard Xu <richard.xu@roadbotics.com>
Date: Thu, 22 Dec 2022 11:50:43 -0500
Subject: [PATCH] Add sell-in date tests

---
 .../java/com/gildedrose/GildedRoseTest.java   | 48 +++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/Java/src/test/java/com/gildedrose/GildedRoseTest.java b/Java/src/test/java/com/gildedrose/GildedRoseTest.java
index 5c000b8d..76d924b3 100644
--- a/Java/src/test/java/com/gildedrose/GildedRoseTest.java
+++ b/Java/src/test/java/com/gildedrose/GildedRoseTest.java
@@ -141,4 +141,52 @@ class GildedRoseTest {
         app.updateQuality();
         assertEquals(app.items[0].quality, 1);
     }
+
+    @Test
+    public void sellInDateDecreasesByOneEachDayForAgedBrie() {
+        Item[] items = new Item[] { new Item(GildedRose.AGED_BRIE, 5, 1) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(app.items[0].sellIn, 4);
+        app.updateQuality();
+        assertEquals(app.items[0].sellIn, 3);
+        app.updateQuality();
+        assertEquals(app.items[0].sellIn, 2);
+    }
+
+    @Test
+    public void sellInDateDecreasesByOneEachDayForBackstagePasses() {
+        Item[] items = new Item[] { new Item(GildedRose.BACKSTAGE_PASSES, 5, 1) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(app.items[0].sellIn, 4);
+        app.updateQuality();
+        assertEquals(app.items[0].sellIn, 3);
+        app.updateQuality();
+        assertEquals(app.items[0].sellIn, 2);
+    }
+
+    @Test
+    public void sellInDateDecreasesByOneEachDayForGenericItems() {
+        Item[] items = new Item[] { new Item("generic item", 5, 1) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(app.items[0].sellIn, 4);
+        app.updateQuality();
+        assertEquals(app.items[0].sellIn, 3);
+        app.updateQuality();
+        assertEquals(app.items[0].sellIn, 2);
+    }
+
+    @Test
+    public void sellInDateCanBeNegative() {
+        Item[] items = new Item[] { new Item("generic item", 1, 1) };
+        GildedRose app = new GildedRose(items);
+        app.updateQuality();
+        assertEquals(app.items[0].sellIn, 0);
+        app.updateQuality();
+        assertEquals(app.items[0].sellIn, -1);
+        app.updateQuality();
+        assertEquals(app.items[0].sellIn, -2);
+    }
 }