bugfix for version check (#298)

* bugfix for version check

* added comment

* merged if conditions

* newline to reduce line length

Corona-Warn-App/src/main/java/de/rki/coronawarnapp/update/VersionComparator.kt

 package de.rki.coronawarnapp.update
 
+/**
+ * Helper to compare 2 version strings
+ */
 object VersionComparator {
 
+    /**
+     * Checks if currentVersion is older than versionToCompareTo
+     *
+     * Expected input format: <major>.<minor>.<patch>
+     * major, minor and patch are Int
+     *
+     * @param currentVersion
+     * @param versionToCompareTo
+     * @return true if currentVersion is older than versionToCompareTo, else false
+     */
     fun isVersionOlder(currentVersion: String, versionToCompareTo: String): Boolean {
         var isVersionOlder = false
 
@@ -19,12 +32,15 @@ object VersionComparator {
 
         if (versionToCompareMajor > currentVersionMajor) {
             isVersionOlder = true
-        } else if (versionToCompareMinor > currentVersionMinor) {
-            isVersionOlder = true
-        } else if (versionToComparePatch > currentVersionPatch) {
-            isVersionOlder = true
+        } else if (versionToCompareMajor == currentVersionMajor) {
+            if (versionToCompareMinor > currentVersionMinor) {
+                isVersionOlder = true
+            } else if ((versionToCompareMinor == currentVersionMinor) &&
+                (versionToComparePatch > currentVersionPatch)
+            ) {
+                isVersionOlder = true
+            }
         }
-
         return isVersionOlder
     }
 }

Corona-Warn-App/src/test/java/de/rki/coronawarnapp/update/VerificationServiceTest.kt → Corona-Warn-App/src/test/java/de/rki/coronawarnapp/update/VersionComparatorTest.kt

@@ -4,7 +4,7 @@ import org.hamcrest.MatcherAssert.assertThat
 import org.hamcrest.Matchers.`is`
 import org.junit.Test
 
-class VerificationServiceTest {
+class VersionComparatorTest {
 
     @Test
     fun testVersionMajorOlder() {
@@ -47,4 +47,16 @@ class VerificationServiceTest {
         val result = VersionComparator.isVersionOlder("1.0.1", "1.0.1")
         assertThat(result, `is`(false))
     }
+
+    @Test
+    fun testIfMajorIsNewerButMinorSmallerNumber() {
+        val result = VersionComparator.isVersionOlder("3.1.0", "1.2.0")
+        assertThat(result, `is`(false))
+    }
+
+    @Test
+    fun testIfMinorIsNewerButPatchSmallerNumber() {
+        val result = VersionComparator.isVersionOlder("1.3.1", "1.2.4")
+        assertThat(result, `is`(false))
+    }
 }