Handle numerical habits with target value of zero

Fixes #903

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## [2.0.2] - Unreleased
+
+### Fixed
+- Fix crash caused by numerical habits with zero target (#903)
+
 ## [2.0.1] - 2021-05-09
 
 ### Added

uhabits-android/build.gradle.kts

@@ -37,8 +37,8 @@ android {
     compileSdkVersion(30)
 
     defaultConfig {
-        versionCode(20001)
-        versionName("2.0.1")
+        versionCode(20002)
+        versionName("2.0.2")
         minSdkVersion(23)
         targetSdkVersion(30)
         applicationId("org.isoron.uhabits")

uhabits-android/src/main/java/org/isoron/uhabits/activities/common/views/TargetChart.kt

@@ -117,7 +117,11 @@ class TargetChart : View {
         barRect[rect.left + stop + padding, rect.top + baseSize * 0.05f, rect.right - padding] =
             rect.bottom - baseSize * 0.05f
         canvas.drawRoundRect(barRect, round, round, paint!!)
-        var percentage = (values[row] / targets[row]).toFloat()
+        var percentage = if (targets[row] > 0) {
+            (values[row] / targets[row]).toFloat()
+        } else {
+            1.0f
+        }
         percentage = min(1.0f, percentage)
 
         // Draw completed box

uhabits-android/src/main/play/release-notes/en-US/default.txt

@@ -1,3 +1,5 @@
+2.0.2:
+* Bug fixes
 2.0:
 * Track numeric habits (e.g. how many pages did you read?)
 * Skip days without breaking your streak

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

@@ -22,6 +22,7 @@ import org.isoron.uhabits.core.models.Score.Companion.compute
 import java.util.ArrayList
 import java.util.HashMap
 import javax.annotation.concurrent.ThreadSafe
+import kotlin.math.max
 import kotlin.math.min
 
 @ThreadSafe
@@ -93,11 +94,15 @@ class ScoreList {
         for (i in values.indices) {
             val offset = values.size - i - 1
             if (isNumerical) {
-                rollingSum += values[offset]
+                rollingSum += max(0, values[offset])
                 if (offset + denominator < values.size) {
                     rollingSum -= values[offset + denominator]
                 }
-                val percentageCompleted = min(1.0, rollingSum / 1000 / targetValue)
+                val percentageCompleted = if (targetValue > 0) {
+                    min(1.0, rollingSum / 1000 / targetValue)
+                } else {
+                    1.0
+                }
                 previousValue = compute(freq, previousValue, percentageCompleted)
             } else {
                 if (values[offset] == Entry.YES_MANUAL) {

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

@@ -18,6 +18,7 @@
  */
 package org.isoron.uhabits.core.models
 
+import junit.framework.Assert.assertTrue
 import org.hamcrest.MatcherAssert.assertThat
 import org.hamcrest.number.IsCloseTo
 import org.hamcrest.number.OrderingComparison
@@ -121,6 +122,14 @@ class ScoreListTest : BaseUnitTest() {
         checkScoreValues(expectedValues)
     }
 
+    @Test
+    fun test_withZeroTarget() {
+        habit = fixtures.createNumericalHabit()
+        habit.targetValue = 0.0
+        habit.recompute()
+        assertTrue(habit.scores[today].value.isFinite())
+    }
+
     @Test
     fun test_imperfectNonDaily() {
         // If the habit should be performed 3 times per week and the user misses 1 repetition