Fixed score when using skips on non-daily habit

uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/models/ScoreList.kt

@@ -61,6 +61,31 @@ class ScoreList {
         return result
     }
 
+    /**
+     * Returns the number of skips after the offset in the interval used to calculate
+     * the percentage of completed days.
+     *
+     * If skips are found in the interval, it is expanded until the interval has the size of the
+     * sum of the denominator and the number of skips within the interval.
+     */
+    @Synchronized
+    fun getNumberOfSkipsByInterval(
+        values: IntArray,
+        firstIndexToCheck: Int,
+        lastIndexToCheck: Int
+    ): Int {
+        if (lastIndexToCheck < firstIndexToCheck) return 0
+        var nbOfSkips = 0
+        var nextLastIndex = lastIndexToCheck
+        for (i in firstIndexToCheck..lastIndexToCheck) {
+            if (values[i] == Entry.SKIP) {
+                nbOfSkips++
+                if (lastIndexToCheck + nbOfSkips < values.size) nextLastIndex++
+            }
+        }
+        return nbOfSkips + getNumberOfSkipsByInterval(values, lastIndexToCheck + 1, nextLastIndex)
+    }
+
     /**
      * Recomputes all scores between the provided [from] and [to] timestamps.
      */
@@ -124,8 +149,12 @@ class ScoreList {
                     rollingSum += 1.0
                 }
                 if (offset + denominator < values.size) {
-                    if (values[offset + denominator] == Entry.YES_MANUAL) {
-                        rollingSum -= 1.0
+                    val nbOfSkips =
+                        getNumberOfSkipsByInterval(values, offset, offset + denominator)
+                    if (offset + denominator + nbOfSkips < values.size) {
+                        if (values[offset + denominator + nbOfSkips] == Entry.YES_MANUAL) {
+                            if (values[offset] != Entry.SKIP) rollingSum -= 1.0
+                        }
                     }
                 }
                 if (values[offset] != Entry.SKIP) {

uhabits-core/src/jvmTest/java/org/isoron/uhabits/core/models/ScoreListTest.kt

@@ -28,6 +28,7 @@ import org.isoron.uhabits.core.utils.DateUtils.Companion.getToday
 import org.junit.Before
 import org.junit.Test
 import java.util.ArrayList
+import kotlin.test.assertEquals
 
 open class BaseScoreListTest : BaseUnitTest() {
     protected lateinit var habit: Habit
@@ -145,6 +146,93 @@ class YesNoScoreListTest : BaseScoreListTest() {
         checkScoreValues(expectedValues)
     }
 
+    @Test
+    fun test_getNumberOfSkipsByInterval_NoSkips() {
+        val vars = intArrayOf(-1, -1, -1, -1, 3, 2, 2, -1, 2, 2, -1, 2, 2, -1, 3, 2)
+        val nbOfSkips = habit.scores.getNumberOfSkipsByInterval(vars, 5, 13)
+        assertEquals(0, nbOfSkips)
+    }
+
+    @Test
+    fun test_getNumberOfSkipsByInterval_SkipsOnlyInInitialInterval() {
+        val vars = intArrayOf(-1, -1, -1, -1, 3, 2, 2, -1, 3, 3, -1, 2, 2, -1, 3, 2)
+        val nbOfSkips = habit.scores.getNumberOfSkipsByInterval(vars, 4, 9)
+        assertEquals(3, nbOfSkips)
+    }
+
+    @Test
+    fun test_getNumberOfSkipsByInterval_SkipsInSubsequentIntervals() {
+        val vars = intArrayOf(-1, -1, -1, -1, 3, 2, 2, -1, 3, 3, -1, 2, 2, -1, 3, 2)
+        val nbOfSkips = habit.scores.getNumberOfSkipsByInterval(vars, 4, 11)
+        assertEquals(4, nbOfSkips)
+    }
+
+    @Test
+    fun test_getValueNonDailyWithSkip() {
+        habit.frequency = Frequency(6, 7)
+        check(0, 18)
+        addSkip(10)
+        addSkip(11)
+        addSkip(12)
+        habit.recompute()
+        val expectedValues = doubleArrayOf(
+            0.365222,
+            0.333100,
+            0.299354,
+            0.263899,
+            0.226651,
+            0.191734,
+            0.159268,
+            0.129375,
+            0.102187,
+            0.077839,
+            0.056477,
+            0.056477,
+            0.056477,
+            0.056477,
+            0.038251,
+            0.023319,
+            0.011848,
+            0.004014,
+            0.000000,
+            0.000000,
+            0.000000
+        )
+        checkScoreValues(expectedValues)
+    }
+
+    @Test
+    fun test_perfectDailyWithSkips() {
+        // If the habit is performed daily and the user always either completes or
+        // skips the habit, score should converge to 100%.
+        habit.frequency = Frequency(1, 1)
+        val values = ArrayList<Int>()
+        check(0, 500)
+        for (k in 0..99) {
+            addSkip(7 * k + 5)
+            addSkip(7 * k + 6)
+        }
+        habit.recompute()
+        check(values)
+        assertThat(habit.scores[today].value, IsCloseTo.closeTo(1.0, E))
+    }
+
+    @Test
+    fun test_perfectNonDailyWithSkips() {
+        // If the habit is performed six times per week and the user always either completes or
+        // skips the habit, score should converge to 100%.
+        habit.frequency = Frequency(6, 7)
+        val values = ArrayList<Int>()
+        check(0, 500)
+        for (k in 0..99) {
+            addSkip(7 * k + 5)
+            addSkip(7 * k + 6)
+        }
+        habit.recompute()
+        check(values)
+        assertThat(habit.scores[today].value, IsCloseTo.closeTo(1.0, E))
+    }
+
     @Test
     fun test_imperfectNonDaily() {
         // If the habit should be performed 3 times per week and the user misses 1 repetition
@@ -268,7 +356,7 @@ class YesNoScoreListTest : BaseScoreListTest() {
 
     private fun addSkip(day: Int) {
         val entries = habit.originalEntries
-        entries.add(Entry(today.minus(day), Entry.SKIP))
+        entries.add(Entry(today.minus(day), SKIP))
     }
 }