[Compile Warnings As Errors] Resolve Warnings & Enable All Warnings as Errors

app/src/androidTest/kotlin/org/wordpress/aztec/demo/BaseTest.kt

@@ -1,3 +1,5 @@
+@file:Suppress("DEPRECATION")
+
 package org.wordpress.aztec.demo
 
 import android.util.Log

app/src/androidTest/kotlin/org/wordpress/aztec/demo/tests/GutenbergCompatTests.kt

@@ -328,7 +328,7 @@ class GutenbergCompatTests : BaseTest() {
         val editorPage = EditorPage()
         val audioShortcodePlugin = AudioShortcodePlugin()
         val aztecText = mActivityIntentsTestRule.activity.findViewById<AztecText>(R.id.aztec)
-        aztecText.plugins?.add(audioShortcodePlugin)
+        aztecText.plugins.add(audioShortcodePlugin)
 
         // let's test the plugin works as expected, i.e. it preserves the Gutenberg block structure
         editorPage

app/src/main/kotlin/org/wordpress/aztec/demo/MainActivity.kt

@@ -253,15 +253,13 @@ open class MainActivity : AppCompatActivity(),
 
     override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
         if (resultCode == Activity.RESULT_OK) {
-            var bitmap: Bitmap
-
             when (requestCode) {
                 REQUEST_MEDIA_CAMERA_PHOTO -> {
                     // By default, BitmapFactory.decodeFile sets the bitmap's density to the device default so, we need
                     //  to correctly set the input density to 160 ourselves.
                     val options = BitmapFactory.Options()
                     options.inDensity = DisplayMetrics.DENSITY_DEFAULT
-                    bitmap = BitmapFactory.decodeFile(mediaPath, options)
+                    val bitmap = BitmapFactory.decodeFile(mediaPath, options)
                     insertImageAndSimulateUpload(bitmap, mediaPath)
                 }
                 REQUEST_MEDIA_PHOTO -> {
@@ -271,7 +269,7 @@ open class MainActivity : AppCompatActivity(),
                     //  to correctly set the input density to 160 ourselves.
                     val options = BitmapFactory.Options()
                     options.inDensity = DisplayMetrics.DENSITY_DEFAULT
-                    bitmap = BitmapFactory.decodeStream(stream, null, options)
+                    val bitmap = BitmapFactory.decodeStream(stream, null, options)
 
                     insertImageAndSimulateUpload(bitmap, mediaPath)
                 }
@@ -287,7 +285,7 @@ open class MainActivity : AppCompatActivity(),
 
                         override fun onThumbnailLoaded(drawable: Drawable?) {
                             val conf = Bitmap.Config.ARGB_8888 // see other conf types
-                            bitmap = Bitmap.createBitmap(drawable!!.intrinsicWidth, drawable.intrinsicHeight, conf)
+                            val bitmap = Bitmap.createBitmap(drawable!!.intrinsicWidth, drawable.intrinsicHeight, conf)
                             val canvas = Canvas(bitmap)
                             drawable.setBounds(0, 0, canvas.width, canvas.height)
                             drawable.draw(canvas)
@@ -527,7 +525,7 @@ open class MainActivity : AppCompatActivity(),
         super.onSaveInstanceState(outState)
 
         if (mediaUploadDialog != null && mediaUploadDialog!!.isShowing) {
-            outState?.putBoolean("isMediaUploadDialogVisible", true)
+            outState.putBoolean("isMediaUploadDialogVisible", true)
         }
     }
 

aztec/src/main/kotlin/org/wordpress/aztec/AztecTagHandler.kt

@@ -53,6 +53,7 @@ import org.wordpress.aztec.spans.createTaskListSpan
 import org.wordpress.aztec.spans.createUnorderedListSpan
 import org.wordpress.aztec.util.getLast
 import org.xml.sax.Attributes
+import java.util.Locale
 
 class AztecTagHandler(val context: Context, val plugins: List<IAztecPlugin> = ArrayList(), private val alignmentRendering: AlignmentRendering
 ) : Html.TagHandler {
@@ -75,7 +76,7 @@ class AztecTagHandler(val context: Context, val plugins: List<IAztecPlugin> = Ar
             return true
         }
 
-        when (tag.toLowerCase()) {
+        when (tag.lowercase(Locale.getDefault())) {
             LIST_LI -> {
                 val span = createListItemSpan(nestingLevel, alignmentRendering, AztecAttributes(attributes))
                 handleElement(output, opening, span)

aztec/src/main/kotlin/org/wordpress/aztec/AztecText.kt

@@ -132,6 +132,7 @@ import java.security.MessageDigest
 import java.security.NoSuchAlgorithmException
 import java.util.Arrays
 import java.util.LinkedList
+import java.util.Locale
 
 @Suppress("UNUSED_PARAMETER")
 open class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknownHtmlTappedListener, IEventInjector {
@@ -705,7 +706,7 @@ open class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknown
             temp
         }
 
-        val emptyEditTextBackspaceDetector = InputFilter { source, start, end, dest, dstart, dend ->
+        val emptyEditTextBackspaceDetector = InputFilter { source, start, _, _, dstart, dend ->
             if (selectionStart == 0 && selectionEnd == 0
                     && start == 0
                     && dstart == 0 && dend == 0
@@ -897,7 +898,9 @@ open class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknown
         history.inputLast = InstanceStateUtils.readAndPurgeTempInstance<String>(INPUT_LAST_KEY, "", savedState.state)
         visibility = customState.getInt(VISIBILITY_KEY)
 
-        initialEditorContentParsedSHA256 = customState.getByteArray(RETAINED_INITIAL_HTML_PARSED_SHA256_KEY)
+        customState.getByteArray(RETAINED_INITIAL_HTML_PARSED_SHA256_KEY)?.let {
+            initialEditorContentParsedSHA256 = it
+        }
         val retainedHtml = InstanceStateUtils.readAndPurgeTempInstance<String>(RETAINED_HTML_KEY, "", savedState.state)
         fromHtml(retainedHtml)
 
@@ -942,9 +945,9 @@ open class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknown
         return false
     }
 
-    override fun onSaveInstanceState(): Parcelable {
+    override fun onSaveInstanceState(): Parcelable? {
         val superState = super.onSaveInstanceState()
-        val savedState = SavedState(superState)
+        val savedState = superState?.let { SavedState(it) }
         val bundle = Bundle()
         InstanceStateUtils.writeTempInstance(context, externalLogger, HISTORY_LIST_KEY, ArrayList<String>(history.historyList), bundle)
         bundle.putInt(HISTORY_CURSOR_KEY, history.historyCursor)
@@ -977,7 +980,7 @@ open class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknown
 
         bundle.putBoolean(IS_MEDIA_ADDED_KEY, isMediaAdded)
 
-        savedState.state = bundle
+        savedState?.state = bundle
         return savedState
     }
 
@@ -987,7 +990,9 @@ open class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknown
         constructor(superState: Parcelable) : super(superState)
 
         constructor(parcel: Parcel) : super(parcel) {
-            state = parcel.readBundle(javaClass.classLoader)
+            parcel.readBundle(javaClass.classLoader)?.let {
+                state = it
+            }
         }
 
         override fun writeToParcel(out: Parcel, flags: Int) {
@@ -1818,7 +1823,7 @@ open class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknown
             // Android 8 Ref: https://github.com/wordpress-mobile/WordPress-Android/issues/8827
             clipboardIdentifier -> {
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && Build.VERSION.SDK_INT < Build.VERSION_CODES.P
-                        && Build.MANUFACTURER.toLowerCase().equals("samsung")) {
+                        && Build.MANUFACTURER.lowercase(Locale.getDefault()).equals("samsung")) {
                     // Nope return true
                     Toast.makeText(context, context.getString(R.string.samsung_disabled_custom_clipboard, Build.VERSION.RELEASE), Toast.LENGTH_LONG).show()
                 } else {
@@ -2078,8 +2083,8 @@ open class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknown
 
         unknownBlockSpanStart = text.getSpanStart(unknownHtmlSpan)
         blockEditorDialog = builder.create()
-        blockEditorDialog!!.window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE)
-        blockEditorDialog!!.show()
+        blockEditorDialog?.window?.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE)
+        blockEditorDialog?.show()
     }
 
     private fun deleteInlineStyleFromTheBeginning() {

aztec/src/main/kotlin/org/wordpress/aztec/formatting/BlockFormatter.kt

@@ -823,7 +823,7 @@ class BlockFormatter(editor: AztecText,
             for (i in lines.indices) {
                 val lineLength = lines[i].length
 
-                val lineStart = (0 until i).sumBy { lines[it].length + 1 }
+                val lineStart = (0 until i).sumOf { lines[it].length + 1 }
 
                 val lineEnd = (lineStart + lineLength).let {
                     if ((start + it) != editableText.length) it + 1 else it // include the newline or not
@@ -843,7 +843,7 @@ class BlockFormatter(editor: AztecText,
         for (i in lines.indices) {
             val splitLength = lines[i].length
 
-            val lineStart = start + (0 until i).sumBy { lines[it].length + 1 }
+            val lineStart = start + (0 until i).sumOf { lines[it].length + 1 }
             val lineEnd = (lineStart + splitLength + 1).coerceAtMost(end) // +1 to include the newline
 
             val lineLength = lineEnd - lineStart
@@ -860,7 +860,7 @@ class BlockFormatter(editor: AztecText,
         for (i in lines.indices) {
             val splitLength = lines[i].length
 
-            val lineStart = start + (0 until i).sumBy { lines[it].length + 1 }
+            val lineStart = start + (0 until i).sumOf { lines[it].length + 1 }
             val lineEnd = (lineStart + splitLength + 1).coerceAtMost(end) // +1 to include the newline
 
             val lineLength = lineEnd - lineStart
@@ -901,7 +901,7 @@ class BlockFormatter(editor: AztecText,
         val list = ArrayList<Int>()
 
         for (i in lines.indices) {
-            val lineStart = (0 until i).sumBy { lines[it].length + 1 }
+            val lineStart = (0 until i).sumOf { lines[it].length + 1 }
             val lineEnd = lineStart + lines[i].length
 
             if (lineStart > lineEnd) {
@@ -947,7 +947,7 @@ class BlockFormatter(editor: AztecText,
             return emptyList()
         }
 
-        val start = (0 until index).sumBy { lines[it].length + 1 }
+        val start = (0 until index).sumOf { lines[it].length + 1 }
         val end = start + lines[index].length
 
         if (start > end) {
@@ -983,7 +983,7 @@ class BlockFormatter(editor: AztecText,
         val list = ArrayList<Int>()
 
         for (i in lines.indices) {
-            val lineStart = (0 until i).sumBy { lines[it].length + 1 }
+            val lineStart = (0 until i).sumOf { lines[it].length + 1 }
             val lineEnd = lineStart + lines[i].length
 
             if (lineStart >= lineEnd) {
@@ -1017,7 +1017,7 @@ class BlockFormatter(editor: AztecText,
             return false
         }
 
-        val start = (0 until index).sumBy { lines[it].length + 1 }
+        val start = (0 until index).sumOf { lines[it].length + 1 }
         val end = start + lines[index].length
 
         if (start >= end) {
@@ -1113,7 +1113,7 @@ class BlockFormatter(editor: AztecText,
         val list = ArrayList<Int>()
 
         for (i in lines.indices) {
-            val lineStart = (0 until i).sumBy { lines[it].length + 1 }
+            val lineStart = (0 until i).sumOf { lines[it].length + 1 }
             val lineEnd = lineStart + lines[i].length
 
             if (lineStart >= lineEnd) {
@@ -1146,7 +1146,7 @@ class BlockFormatter(editor: AztecText,
             return false
         }
 
-        val start = (0 until index).sumBy { lines[it].length + 1 }
+        val start = (0 until index).sumOf { lines[it].length + 1 }
         val end = start + lines[index].length
 
         if (start >= end) {

aztec/src/main/kotlin/org/wordpress/aztec/formatting/InlineFormatter.kt

@@ -64,7 +64,7 @@ class InlineFormatter(editor: AztecText, val codeStyle: CodeStyle, private val h
     fun toggleAny(textFormats: Set<ITextFormat>) {
         if (!textFormats
                 .filter { containsInlineStyle(it) }
-                .fold(false) { found, containedTextFormat -> removeInlineStyle(containedTextFormat); true }) {
+                .fold(false) { _, containedTextFormat -> removeInlineStyle(containedTextFormat); true }) {
             removeAllExclusiveFormats()
             applyInlineStyle(textFormats.first())
         }
@@ -211,7 +211,7 @@ class InlineFormatter(editor: AztecText, val codeStyle: CodeStyle, private val h
         joinStyleSpans(start, end)
     }
 
-    private fun applyMarkInlineStyle(start: Int = selectionStart, end: Int = selectionEnd, attrs: AztecAttributes = AztecAttributes()) {
+    private fun applyMarkInlineStyle(start: Int = selectionStart, end: Int = selectionEnd) {
         val previousSpans = editableText.getSpans(start, end, MarkSpan::class.java)
         previousSpans.forEach {
             it.applyInlineStyleAttributes(editableText, start, end)

aztec/src/main/kotlin/org/wordpress/aztec/formatting/LineBlockFormatter.kt

@@ -30,7 +30,7 @@ class LineBlockFormatter(editor: AztecText) : AztecFormatter(editor) {
         val list = ArrayList<Int>()
 
         for (i in lines.indices) {
-            val lineStart = (0..i - 1).sumBy { lines[it].length + 1 }
+            val lineStart = (0..i - 1).sumOf { lines[it].length + 1 }
             val lineEnd = lineStart + lines[i].length
 
             if (lineStart >= lineEnd) {
@@ -64,7 +64,7 @@ class LineBlockFormatter(editor: AztecText) : AztecFormatter(editor) {
             return false
         }
 
-        val start = (0..index - 1).sumBy { lines[it].length + 1 }
+        val start = (0..index - 1).sumOf { lines[it].length + 1 }
         val end = start + lines[index].length
 
         if (start >= end) {

aztec/src/main/kotlin/org/wordpress/aztec/source/SourceViewEditText.kt

@@ -98,7 +98,9 @@ open class SourceViewEditText : AppCompatEditText, TextWatcher {
         visibility = customState.getInt("visibility")
         val retainedContent = InstanceStateUtils.readAndPurgeTempInstance<String>(RETAINED_CONTENT_KEY, "", savedState.state)
         setText(retainedContent)
-        initialEditorContentParsedSHA256 = customState.getByteArray(AztecText.RETAINED_INITIAL_HTML_PARSED_SHA256_KEY)
+        customState.getByteArray(AztecText.RETAINED_INITIAL_HTML_PARSED_SHA256_KEY)?.let {
+            initialEditorContentParsedSHA256 = it
+        }
     }
 
     // Do not include the content of the editor when saving state to bundle.
@@ -109,15 +111,15 @@ open class SourceViewEditText : AppCompatEditText, TextWatcher {
         return false
     }
 
-    override fun onSaveInstanceState(): Parcelable {
+    override fun onSaveInstanceState(): Parcelable? {
         val bundle = Bundle()
         bundle.putByteArray(org.wordpress.aztec.AztecText.RETAINED_INITIAL_HTML_PARSED_SHA256_KEY,
                 initialEditorContentParsedSHA256)
         InstanceStateUtils.writeTempInstance(context, null, RETAINED_CONTENT_KEY, text.toString(), bundle)
         val superState = super.onSaveInstanceState()
-        val savedState = SavedState(superState)
+        val savedState = superState?.let { SavedState(it) }
         bundle.putInt("visibility", visibility)
-        savedState.state = bundle
+        savedState?.state = bundle
         return savedState
     }
 
@@ -127,7 +129,9 @@ open class SourceViewEditText : AppCompatEditText, TextWatcher {
         constructor(superState: Parcelable) : super(superState)
 
         constructor(parcel: Parcel) : super(parcel) {
-            state = parcel.readBundle(javaClass.classLoader)
+            parcel.readBundle(javaClass.classLoader)?.let {
+                state = it
+            }
         }
 
         override fun writeToParcel(out: Parcel, flags: Int) {
@@ -265,7 +269,7 @@ open class SourceViewEditText : AppCompatEditText, TextWatcher {
         val str: String
 
         if (withCursorTag) {
-            val withCursor = StringBuffer(text)
+            val withCursor = StringBuffer(text.toString())
             if (!isCursorInsideTag()) {
                 withCursor.insert(selectionEnd, "<aztec_cursor></aztec_cursor>")
             } else {

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

@@ -20,7 +20,7 @@ fun createHeadingSpan(nestingLevel: Int,
                       alignmentRendering: AlignmentRendering,
                       headerStyle: BlockFormatter.HeaderStyles = BlockFormatter.HeaderStyles(0, emptyMap())
 ): AztecHeadingSpan {
-    val textFormat = when (tag.toLowerCase(Locale.getDefault())) {
+    val textFormat = when (tag.lowercase(Locale.getDefault())) {
         "h1" -> AztecTextFormat.FORMAT_HEADING_1
         "h2" -> AztecTextFormat.FORMAT_HEADING_2
         "h3" -> AztecTextFormat.FORMAT_HEADING_3

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

@@ -83,7 +83,7 @@ open class AztecOrderedListSpan(
         p.color = listStyle.indicatorColor
         p.style = Paint.Style.FILL
 
-        val start = if (attributes.hasAttribute("start") == true) {
+        val startAttribute = if (attributes.hasAttribute("start") == true) {
             attributes.getValue("start").toInt()
         } else {
             0
@@ -92,9 +92,9 @@ open class AztecOrderedListSpan(
         var textToDraw = ""
         getIndexOfProcessedLine(text, end)?.let {
             val isReversed = attributes.hasAttribute("reversed")
-            val lineIndex = if (start > 0) {
-                if (isReversed) start - (it - 1)
-                else start + (it - 1)
+            val lineIndex = if (startAttribute > 0) {
+                if (isReversed) startAttribute - (it - 1)
+                else startAttribute + (it - 1)
             } else {
                 val number = getNumberOfItemsInProcessedLine(text)
                 if (isReversed) number - (it - 1)