Test with generated testcases which cover all paths

Kotlin/README.md

@@ -22,6 +22,8 @@ You should make sure the gradle commands shown above work when you execute them
 There are instructions in the [TextTest Readme](../texttests/README.md) for setting up TextTest. What's unusual for the Java version is there are two executables listed in [config.gr](../texttests/config.gr) for Java. One uses Gradle wrapped in a python script, the other relies on your CLASSPATH being set correctly in [environment.gr](../texttests/environment.gr).
 
 
+## Starting Point 
+
 ### Project info
 1. Code is highly unreadable and impossible to extend
 2. Algorithm and test cases are unknown, I do not trust that `TexttestFixtures` covers all paths so I want to validate it with jacoco
@@ -33,7 +35,8 @@ There are instructions in the [TextTest Readme](../texttests/README.md) for sett
 3. understand algorithm and propose better solution
 
 
-### Execution
+## Execution
+### Testing TexttestFixtures
 TexttestFixtures indeed do not cover all paths, based on jacoco coverage: 
  ![img.png](img.png)
 
@@ -43,3 +46,13 @@ There are two ways to advance:
  
 I prefer to go with (2) because it seems to me to be more resilient way. I need to check if execution 
 time is not bloated. Also minimize number of test cases.
+
+### Test cases generation
+I copied GildedRose class to PlatinumRose and implemented a test which executes both app 
+and then compare results. Time of execution is under 500ms which is great. Also all paths are covered:
+
+![img_1.png](img_1.png)
+
+One noticeable fact i that items are declared as `var` which makes it possible to update during/after execution.
+In my opinion this is a design issue, code-smell and I'm going to change it to `val`.
+So far I only changed Item to data class so that object comparison is easier, also it seems to be DTO/record so it suppose to be a data class

Kotlin/src/main/kotlin/com/gildedrose/Item.kt

@@ -1,6 +1,6 @@
 package com.gildedrose
 
-open class Item(var name: String, var sellIn: Int, var quality: Int) {
+data class Item(var name: String, var sellIn: Int, var quality: Int) {
     override fun toString(): String {
         return this.name + ", " + this.sellIn + ", " + this.quality
     }

Kotlin/src/main/kotlin/com/gildedrose/PlatinumRose.kt

@@ -0,0 +1,58 @@
+package com.gildedrose
+
+class PlatinumRose(var items: List<Item>) {
+
+    fun updateQuality() {
+        for (i in items.indices) {
+            if (items[i].name != "Aged Brie" && items[i].name != "Backstage passes to a TAFKAL80ETC concert") {
+                if (items[i].quality > 0) {
+                    if (items[i].name != "Sulfuras, Hand of Ragnaros") {
+                        items[i].quality = items[i].quality - 1
+                    }
+                }
+            } else {
+                if (items[i].quality < 50) {
+                    items[i].quality = items[i].quality + 1
+
+                    if (items[i].name == "Backstage passes to a TAFKAL80ETC concert") {
+                        if (items[i].sellIn < 11) {
+                            if (items[i].quality < 50) {
+                                items[i].quality = items[i].quality + 1
+                            }
+                        }
+
+                        if (items[i].sellIn < 6) {
+                            if (items[i].quality < 50) {
+                                items[i].quality = items[i].quality + 1
+                            }
+                        }
+                    }
+                }
+            }
+
+            if (items[i].name != "Sulfuras, Hand of Ragnaros") {
+                items[i].sellIn = items[i].sellIn - 1
+            }
+
+            if (items[i].sellIn < 0) {
+                if (items[i].name != "Aged Brie") {
+                    if (items[i].name != "Backstage passes to a TAFKAL80ETC concert") {
+                        if (items[i].quality > 0) {
+                            if (items[i].name != "Sulfuras, Hand of Ragnaros") {
+                                items[i].quality = items[i].quality - 1
+                            }
+                        }
+                    } else {
+                        items[i].quality = items[i].quality - items[i].quality
+                    }
+                } else {
+                    if (items[i].quality < 50) {
+                        items[i].quality = items[i].quality + 1
+                    }
+                }
+            }
+        }
+    }
+
+}
+

Kotlin/src/main/kotlin/com/gildedrose/TestcasesGenerator.kt

@@ -0,0 +1,43 @@
+package com.gildedrose
+
+import java.util.*
+
+
+fun generateTestCasesInRanger(names: List<String>, sellInRange: IntRange, qualityRange: IntRange): List<Item> {
+    val items = LinkedList<Item>()
+    for (name in names) {
+        for (sellIn in sellInRange) {
+            for (quality in qualityRange) {
+                items.add(Item(name, sellIn, quality))
+            }
+        }
+    }
+    return items
+}
+
+fun main(args: Array<String>) {
+    val names = listOf(
+        "Aged Brie",
+        "Backstage passes to a TAFKAL80ETC concert",
+        "Sulfuras, Hand of Ragnaros",
+        "new none-existing on code name"
+    )
+    val sellInRange = -100..100
+    val qualityRange = -100..100
+    val allTestCases = generateTestCasesInRanger(names, sellInRange, qualityRange)
+
+
+    var testCasesCounter = 0
+    for (testCase in allTestCases) {
+        val app = GildedRose(listOf(Item(testCase.name, testCase.sellIn, testCase.quality)))
+        app.updateQuality()
+
+
+        if (testCase.sellIn != app.items[0].sellIn || testCase.quality != app.items[0].quality) {
+            //println("$testCasesCounter: $testCase vs ${app.items[0]}")
+            testCasesCounter += 1
+        }
+    }
+    println("Found $testCasesCounter testCasesCounter of out ${allTestCases.size} allTestCases")
+
+}

Kotlin/src/main/kotlin/com/gildedrose/TexttestFixture.kt

@@ -6,15 +6,15 @@ fun main(args: Array<String>) {
 
     val items = listOf(
         Item("+5 Dexterity Vest", 10, 20), //
-            Item("Aged Brie", 2, 0), //
+        Item("Aged Brie", 2, 0), //
-            Item("Elixir of the Mongoose", 5, 7), //
+        Item("Elixir of the Mongoose", 5, 7), //
-            Item("Sulfuras, Hand of Ragnaros", 0, 80), //
+        Item("Sulfuras, Hand of Ragnaros", 0, 80), //
-            Item("Sulfuras, Hand of Ragnaros", -1, 80),
+        Item("Sulfuras, Hand of Ragnaros", -1, 80),
-            Item("Backstage passes to a TAFKAL80ETC concert", 15, 20),
+        Item("Backstage passes to a TAFKAL80ETC concert", 15, 20),
-            Item("Backstage passes to a TAFKAL80ETC concert", 10, 49),
+        Item("Backstage passes to a TAFKAL80ETC concert", 10, 49),
-            Item("Backstage passes to a TAFKAL80ETC concert", 5, 49),
+        Item("Backstage passes to a TAFKAL80ETC concert", 5, 49),
-            // this conjured item does not work properly yet
+        // this conjured item does not work properly yet
-            Item("Conjured Mana Cake", 3, 6)
+        Item("Conjured Mana Cake", 3, 6)
     )
 
     val app = GildedRose(items)

Kotlin/src/test/kotlin/com/gildedrose/GildedRoseTest.kt

@@ -20,7 +20,16 @@ internal class GildedRoseTest {
         val app = GildedRose(items)
         app.updateQuality()
         assertEquals("foo", app.items[0].name)
+    }
 
+    @Test
+    fun `should execute without exception for empty list`() {
+        val items = listOf<Item>()
+        val app = GildedRose(items)
+        app.updateQuality()
+        assertAll(
+            { assertEquals(items, app.items) }
+        )
     }
 
     @ParameterizedTest
@@ -53,7 +62,6 @@ internal class GildedRoseTest {
             )
         }
     }
-
 }
 
 

Kotlin/src/test/kotlin/com/gildedrose/PlatinumRoseTest.kt

@@ -0,0 +1,48 @@
+package com.gildedrose
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+import java.util.*
+
+class PlatinumRoseTest {
+
+    @Test
+    fun `should update quality for generated test cases and compare with GlidedRose`() {
+        val names = listOf(
+            "Aged Brie",
+            "Backstage passes to a TAFKAL80ETC concert",
+            "Sulfuras, Hand of Ragnaros",
+            "new none-existing on code name"
+        )
+        val sellInRange = -100..100
+        val qualityRange = -100..100
+        val allTestCases = generateTestCasesInRanger(names, sellInRange, qualityRange)
+
+
+        for (testCase in allTestCases) {
+            val platinumRose = PlatinumRose(listOf(Item(testCase.name, testCase.sellIn, testCase.quality)))
+            val gildedRose = GildedRose(listOf(Item(testCase.name, testCase.sellIn, testCase.quality)))
+
+            platinumRose.updateQuality()
+            gildedRose.updateQuality()
+
+            assertEquals(gildedRose.items, platinumRose.items)
+        }
+    }
+
+    private fun generateTestCasesInRanger(
+        names: List<String>,
+        sellInRange: IntRange,
+        qualityRange: IntRange
+    ): List<Item> {
+        val items = LinkedList<Item>()
+        for (name in names) {
+            for (sellIn in sellInRange) {
+                for (quality in qualityRange) {
+                    items.add(Item(name, sellIn, quality))
+                }
+            }
+        }
+        return items
+    }
+}