[Bug] Fix crash and add unit test to cover the issue.

Author: notandyvee

aztec/build.gradle

@@ -67,6 +67,8 @@ dependencies {
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0', {
         exclude group: 'com.android.support', module: 'support-annotations'
     }
+    testImplementation "org.mockito:mockito-inline:$mockitoVersion"
+    testImplementation "org.mockito.kotlin:mockito-kotlin:$mockitoKotlinVersion"
 
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$kotlinCoroutinesVersion"
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$kotlinCoroutinesVersion"

aztec/src/main/kotlin/org/wordpress/aztec/spans/MarkSpan.kt

@@ -3,6 +3,7 @@ package org.wordpress.aztec.spans
 import android.graphics.Color
 import android.text.TextPaint
 import android.text.style.CharacterStyle
+import androidx.annotation.VisibleForTesting
 import org.wordpress.aztec.AztecAttributes
 import org.wordpress.aztec.source.CssStyleFormatter
 
@@ -25,8 +26,9 @@ class MarkSpan : CharacterStyle, IAztecInlineSpan {
         textColorValue = safelyParseColor(colorString)
     }
 
-    private fun safelyParseColor(colorString: String?): Int? {
-        if (colorString == null) {
+    @VisibleForTesting
+    internal fun safelyParseColor(colorString: String?): Int? {
+        if (colorString.isNullOrBlank()) {
             return null
         }
         return try {

aztec/src/test/kotlin/org/wordpress/aztec/MarkSpanTest.kt

@@ -0,0 +1,52 @@
+package org.wordpress.aztec
+
+import org.junit.Assert
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mock
+import org.mockito.Mockito
+import org.robolectric.RobolectricTestRunner
+import org.wordpress.aztec.spans.MarkSpan
+
+@RunWith(RobolectricTestRunner::class)
+class MarkSpanTest {
+    @Mock
+    val markSpan = Mockito.mock(MarkSpan::class.java)
+    /**
+     * Test used to confirm two crashes related are fixed.
+     *
+     * https://github.com/wordpress-mobile/WordPress-Android/issues/20738
+     */
+    @Test
+    fun `Calling MarkSpan#safelyParseColor with empty string should not cause a crash`() {
+        var error = false
+        var result: Int? = null
+        try {
+            Mockito.`when`(markSpan.safelyParseColor("")).thenCallRealMethod()
+            result = markSpan.safelyParseColor("")
+        } catch (e: Exception) {
+            error = true
+        }
+        Assert.assertFalse(error)
+        Assert.assertEquals(null, result)
+    }
+
+    /**
+     * Test used to confirm two crashes related are fixed.
+     *
+     * https://github.com/wordpress-mobile/WordPress-Android/issues/20694
+     */
+    @Test
+    fun `Calling MarkSpan#safelyParseColor with null string should not cause a crash`() {
+        var error = false
+        var result: Int? = null
+        try {
+            Mockito.`when`(markSpan.safelyParseColor(null)).thenCallRealMethod()
+            result = markSpan.safelyParseColor(null)
+        } catch (e: Exception) {
+            error = true
+        }
+        Assert.assertFalse(error)
+        Assert.assertEquals(null, result)
+    }
+}

build.gradle

@@ -80,6 +80,8 @@ ext {
     jSoupVersion = '1.11.3'
     wordpressUtilsVersion = '3.5.0'
     espressoVersion = '3.0.1'
+    mockitoVersion = '4.5.1'
+    mockitoKotlinVersion = '4.1.0'
 
     // other
     wordpressLintVersion = '2.0.0'