diff --git a/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt b/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
index 069ea5fc..7286743c 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
@@ -48,7 +48,7 @@ data class ParsedArgs(
       return parseOptions(arguments)
     }
 
-    val HELP_TEXT =
+    val HELP_TEXT: String =
         """
         |ktfmt - command line Kotlin source code pretty-printer
         |
diff --git a/core/src/main/java/com/facebook/ktfmt/format/EnumEntryList.kt b/core/src/main/java/com/facebook/ktfmt/format/EnumEntryList.kt
index 9d76c5f9..ec380de3 100644
--- a/core/src/main/java/com/facebook/ktfmt/format/EnumEntryList.kt
+++ b/core/src/main/java/com/facebook/ktfmt/format/EnumEntryList.kt
@@ -35,7 +35,7 @@ private constructor(
 ) {
   companion object {
     fun extractParentList(enumEntry: KtEnumEntry): EnumEntryList {
-      return extractChildList(enumEntry.parent as KtClassBody)!!
+      return checkNotNull(extractChildList(enumEntry.parent as KtClassBody))
     }
 
     fun extractChildList(classBody: KtClassBody): EnumEntryList? {
@@ -61,10 +61,12 @@ private constructor(
       var semicolon: PsiElement? = null
       var comma: PsiElement? = null
       val lastToken =
-          enumEntries
-              .last()
-              .lastChild
-              .getPrevSiblingIgnoringWhitespaceAndComments(withItself = true)!!
+          checkNotNull(
+              enumEntries
+                  .last()
+                  .lastChild
+                  .getPrevSiblingIgnoringWhitespaceAndComments(withItself = true),
+          )
       when (lastToken.text) {
         "," -> {
           comma = lastToken
diff --git a/core/src/main/java/com/facebook/ktfmt/format/Formatter.kt b/core/src/main/java/com/facebook/ktfmt/format/Formatter.kt
index aedb2a34..d1d47e70 100644
--- a/core/src/main/java/com/facebook/ktfmt/format/Formatter.kt
+++ b/core/src/main/java/com/facebook/ktfmt/format/Formatter.kt
@@ -104,7 +104,7 @@ object Formatter {
         .let { dropRedundantElements(it, options) }
         .let { prettyPrint(it, options, "\n") }
         .let { addRedundantElements(it, options) }
-        .let { convertLineSeparators(it, Newlines.guessLineSeparator(kotlinCode)!!) }
+        .let { convertLineSeparators(it, checkNotNull(Newlines.guessLineSeparator(kotlinCode))) }
         .let { if (shebang.isEmpty()) it else shebang + "\n" + it }
   }
 
diff --git a/core/src/main/java/com/facebook/ktfmt/format/KotlinInput.kt b/core/src/main/java/com/facebook/ktfmt/format/KotlinInput.kt
index f1efe5d7..c0bb120c 100644
--- a/core/src/main/java/com/facebook/ktfmt/format/KotlinInput.kt
+++ b/core/src/main/java/com/facebook/ktfmt/format/KotlinInput.kt
@@ -219,9 +219,9 @@ class KotlinInput(private val text: String, file: KtFile) : Input() {
 
   override fun getText(): String = text
 
-  override fun getLineNumber(inputPosition: Int) =
+  override fun getLineNumber(inputPosition: Int): Int =
       StringUtil.offsetToLineColumn(text, inputPosition).line + 1
 
-  override fun getColumnNumber(inputPosition: Int) =
+  override fun getColumnNumber(inputPosition: Int): Int =
       StringUtil.offsetToLineColumn(text, inputPosition).column
 }
diff --git a/core/src/main/java/com/facebook/ktfmt/format/KotlinInputAstVisitor.kt b/core/src/main/java/com/facebook/ktfmt/format/KotlinInputAstVisitor.kt
index c55c3e08..fdf9e486 100644
--- a/core/src/main/java/com/facebook/ktfmt/format/KotlinInputAstVisitor.kt
+++ b/core/src/main/java/com/facebook/ktfmt/format/KotlinInputAstVisitor.kt
@@ -2427,9 +2427,9 @@ class KotlinInputAstVisitor(
       visit(enumEntry.modifierList)
       builder.token(enumEntry.nameIdentifier?.text ?: fail())
       enumEntry.initializerList?.initializers?.forEach { visit(it) }
-      enumEntry.body?.let {
+      enumEntry.body?.let { enumBody ->
         builder.space()
-        visit(it)
+        visit(enumBody)
       }
     }
   }
diff --git a/core/src/main/java/com/facebook/ktfmt/format/ParseError.kt b/core/src/main/java/com/facebook/ktfmt/format/ParseError.kt
index 432c6643..6c19b524 100644
--- a/core/src/main/java/com/facebook/ktfmt/format/ParseError.kt
+++ b/core/src/main/java/com/facebook/ktfmt/format/ParseError.kt
@@ -30,7 +30,7 @@ class ParseError(val errorDescription: String, val lineColumn: LineColumn) :
 
   companion object {
     private fun positionOf(element: PsiElement): LineColumn {
-      val doc = element.containingFile.viewProvider.document!!
+      val doc = checkNotNull(element.containingFile.viewProvider.document)
       val offset = element.textOffset
       val lineZero = doc.getLineNumber(offset)
       val colZero = offset - doc.getLineStartOffset(lineZero)
diff --git a/core/src/main/java/com/facebook/ktfmt/format/Parser.kt b/core/src/main/java/com/facebook/ktfmt/format/Parser.kt
index d8e47914..16235883 100644
--- a/core/src/main/java/com/facebook/ktfmt/format/Parser.kt
+++ b/core/src/main/java/com/facebook/ktfmt/format/Parser.kt
@@ -61,9 +61,8 @@ object Parser {
   fun parse(code: String): KtFile {
     val virtualFile = LightVirtualFile("temp.kts", KotlinFileType.INSTANCE, code)
     val ktFile = PsiManager.getInstance(env.project).findFile(virtualFile) as KtFile
-    ktFile.collectDescendantsOfType<PsiErrorElement>().let {
-      if (it.isNotEmpty()) throwParseError(code, it[0])
-    }
+    val descendants = ktFile.collectDescendantsOfType<PsiErrorElement>()
+    if (descendants.isNotEmpty()) throwParseError(code, descendants[0])
     return ktFile
   }
 
diff --git a/core/src/main/java/com/facebook/ktfmt/format/RedundantImportDetector.kt b/core/src/main/java/com/facebook/ktfmt/format/RedundantImportDetector.kt
index 323ac347..21d59582 100644
--- a/core/src/main/java/com/facebook/ktfmt/format/RedundantImportDetector.kt
+++ b/core/src/main/java/com/facebook/ktfmt/format/RedundantImportDetector.kt
@@ -166,11 +166,11 @@ internal class RedundantImportDetector(val enabled: Boolean) {
     val identifierCounts =
         importCleanUpCandidates.groupBy { it.identifier }.mapValues { it.value.size }
 
-    return importCleanUpCandidates.filter {
-      val isUsed = it.identifier in usedReferences
-      val isFromThisPackage = it.importedFqName?.parent() == thisPackage
-      val hasAlias = it.alias != null
-      val isOverload = requireNotNull(identifierCounts[it.identifier]) > 1
+    return importCleanUpCandidates.filter { importCandidate ->
+      val isUsed = importCandidate.identifier in usedReferences
+      val isFromThisPackage = importCandidate.importedFqName?.parent() == thisPackage
+      val hasAlias = importCandidate.alias != null
+      val isOverload = requireNotNull(identifierCounts[importCandidate.identifier]) > 1
       // Remove if...
       !isUsed || (isFromThisPackage && !hasAlias && !isOverload)
     }
diff --git a/core/src/main/java/com/facebook/ktfmt/format/WhitespaceTombstones.kt b/core/src/main/java/com/facebook/ktfmt/format/WhitespaceTombstones.kt
index 816e137f..87e857c7 100644
--- a/core/src/main/java/com/facebook/ktfmt/format/WhitespaceTombstones.kt
+++ b/core/src/main/java/com/facebook/ktfmt/format/WhitespaceTombstones.kt
@@ -23,7 +23,7 @@ object WhitespaceTombstones {
   /** See [replaceTrailingWhitespaceWithTombstone]. */
   const val SPACE_TOMBSTONE = '\u0003'
 
-  fun String.indexOfWhitespaceTombstone() = this.indexOf(SPACE_TOMBSTONE)
+  fun String.indexOfWhitespaceTombstone(): Int = this.indexOf(SPACE_TOMBSTONE)
 
   /**
    * Google-java-format removes trailing spaces when it emits formatted code, which is a problem for
diff --git a/core/src/main/java/com/facebook/ktfmt/kdoc/CommentType.kt b/core/src/main/java/com/facebook/ktfmt/kdoc/CommentType.kt
index aba6176e..b767e1c1 100644
--- a/core/src/main/java/com/facebook/ktfmt/kdoc/CommentType.kt
+++ b/core/src/main/java/com/facebook/ktfmt/kdoc/CommentType.kt
@@ -1,3 +1,19 @@
+/*
+ * Portions Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 /*
  * Copyright (c) Tor Norbye.
  *
diff --git a/core/src/main/java/com/facebook/ktfmt/kdoc/Escaping.kt b/core/src/main/java/com/facebook/ktfmt/kdoc/Escaping.kt
index d3d3c103..d37991a8 100644
--- a/core/src/main/java/com/facebook/ktfmt/kdoc/Escaping.kt
+++ b/core/src/main/java/com/facebook/ktfmt/kdoc/Escaping.kt
@@ -22,7 +22,7 @@ object Escaping {
 
   private const val STAR_SLASH_ESCAPE = "\u0005\u0004"
 
-  fun indexOfCommentEscapeSequences(s: String) =
+  fun indexOfCommentEscapeSequences(s: String): Int =
       s.indexOfAny(listOf(SLASH_STAR_ESCAPE, STAR_SLASH_ESCAPE))
 
   /**
diff --git a/core/src/main/java/com/facebook/ktfmt/kdoc/FormattingTask.kt b/core/src/main/java/com/facebook/ktfmt/kdoc/FormattingTask.kt
index 4f195db7..d0ceb1c6 100644
--- a/core/src/main/java/com/facebook/ktfmt/kdoc/FormattingTask.kt
+++ b/core/src/main/java/com/facebook/ktfmt/kdoc/FormattingTask.kt
@@ -1,3 +1,19 @@
+/*
+ * Portions Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 /*
  * Copyright (c) Tor Norbye.
  *
diff --git a/core/src/main/java/com/facebook/ktfmt/kdoc/KDocCommentsHelper.kt b/core/src/main/java/com/facebook/ktfmt/kdoc/KDocCommentsHelper.kt
index a9450a2a..313efb52 100644
--- a/core/src/main/java/com/facebook/ktfmt/kdoc/KDocCommentsHelper.kt
+++ b/core/src/main/java/com/facebook/ktfmt/kdoc/KDocCommentsHelper.kt
@@ -1,3 +1,19 @@
+/*
+ * Portions Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 /*
  * Copyright 2015 Google Inc.
  *
@@ -33,11 +49,11 @@ class KDocCommentsHelper(private val lineSeparator: String, private val maxLineL
 
   private val kdocFormatter =
       KDocFormatter(
-          KDocFormattingOptions(maxLineLength, maxLineLength).also {
-            it.allowParamBrackets = true // TODO Do we want this?
-            it.convertMarkup = false
-            it.nestedListIndent = 4
-            it.optimal = false // Use greedy line breaking for predictability.
+          KDocFormattingOptions(maxLineLength, maxLineLength).apply {
+            allowParamBrackets = true // TODO Do we want this?
+            convertMarkup = false
+            nestedListIndent = 4
+            optimal = false // Use greedy line breaking for predictability.
           })
 
   override fun rewrite(tok: Tok, maxWidth: Int, column0: Int): String {
diff --git a/core/src/main/java/com/facebook/ktfmt/kdoc/KDocFormatter.kt b/core/src/main/java/com/facebook/ktfmt/kdoc/KDocFormatter.kt
index d44561ce..afc414d6 100644
--- a/core/src/main/java/com/facebook/ktfmt/kdoc/KDocFormatter.kt
+++ b/core/src/main/java/com/facebook/ktfmt/kdoc/KDocFormatter.kt
@@ -1,3 +1,19 @@
+/*
+ * Portions Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 /*
  * Copyright (c) Tor Norbye.
  *
@@ -129,7 +145,7 @@ class KDocFormatter(private val options: KDocFormattingOptions) {
       }
       sb.append("*/")
     } else if (sb.endsWith(lineSeparator)) {
-      @Suppress("ReturnValueIgnored") sb.removeSuffix(lineSeparator)
+      @Suppress("NoOp", "ReturnValueIgnored") sb.removeSuffix(lineSeparator)
     }
 
     val formatted =
diff --git a/core/src/main/java/com/facebook/ktfmt/kdoc/KDocToken.kt b/core/src/main/java/com/facebook/ktfmt/kdoc/KDocToken.kt
index 51801c88..8d4f5a84 100644
--- a/core/src/main/java/com/facebook/ktfmt/kdoc/KDocToken.kt
+++ b/core/src/main/java/com/facebook/ktfmt/kdoc/KDocToken.kt
@@ -1,3 +1,19 @@
+/*
+ * Portions Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 /*
  * Copyright 2016 Google Inc.
  *
diff --git a/core/src/main/java/com/facebook/ktfmt/kdoc/KDocWriter.kt b/core/src/main/java/com/facebook/ktfmt/kdoc/KDocWriter.kt
index 8d7db5db..a70226df 100644
--- a/core/src/main/java/com/facebook/ktfmt/kdoc/KDocWriter.kt
+++ b/core/src/main/java/com/facebook/ktfmt/kdoc/KDocWriter.kt
@@ -1,3 +1,19 @@
+/*
+ * Portions Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 /*
  * Copyright 2016 Google Inc.
  *
diff --git a/core/src/main/java/com/facebook/ktfmt/kdoc/NestingCounter.kt b/core/src/main/java/com/facebook/ktfmt/kdoc/NestingCounter.kt
index e744089d..f5a8bbba 100644
--- a/core/src/main/java/com/facebook/ktfmt/kdoc/NestingCounter.kt
+++ b/core/src/main/java/com/facebook/ktfmt/kdoc/NestingCounter.kt
@@ -1,3 +1,19 @@
+/*
+ * Portions Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 /*
  * Copyright 2016 Google Inc.
  *
diff --git a/core/src/main/java/com/facebook/ktfmt/kdoc/Paragraph.kt b/core/src/main/java/com/facebook/ktfmt/kdoc/Paragraph.kt
index a3e6cbd3..1ca0d141 100644
--- a/core/src/main/java/com/facebook/ktfmt/kdoc/Paragraph.kt
+++ b/core/src/main/java/com/facebook/ktfmt/kdoc/Paragraph.kt
@@ -38,8 +38,8 @@ class Paragraph(private val task: FormattingTask) {
   private val options: KDocFormattingOptions
     get() = task.options
 
-  var content = StringBuilder()
-  val text
+  var content: StringBuilder = StringBuilder()
+  val text: String
     get() = content.toString()
 
   var prev: Paragraph? = null
@@ -348,7 +348,7 @@ class Paragraph(private val task: FormattingTask) {
   private fun reflow(words: List<String>, lineWidth: Int, hangingIndentSize: Int): List<String> {
     if (options.alternate ||
         !options.optimal ||
-        hanging && hangingIndentSize > 0 ||
+        (hanging && hangingIndentSize > 0) ||
         // An unbreakable long word may make other lines shorter and won't look good
         words.any { it.length > lineWidth }) {
       // Switch to greedy if explicitly turned on, and for hanging indent
@@ -430,7 +430,7 @@ class Paragraph(private val task: FormattingTask) {
 
     if (!word.first().isLetter()) {
       val wordWithSpace = "$word " // for regex matching in below checks
-      if (wordWithSpace.isListItem() && !word.equals("<li>", true) || wordWithSpace.isQuoted()) {
+      if ((wordWithSpace.isListItem() && !word.equals("<li>", true)) || wordWithSpace.isQuoted()) {
         return false
       }
     }
@@ -468,7 +468,7 @@ class Paragraph(private val task: FormattingTask) {
     val end = words.size
     while (from < end) {
       val start =
-          if (from == 0 && (quoted || hanging && !text.isKDocTag())) {
+          if (from == 0 && (quoted || (hanging && !text.isKDocTag()))) {
             from + 2
           } else {
             from + 1
diff --git a/core/src/main/java/com/facebook/ktfmt/kdoc/ParagraphList.kt b/core/src/main/java/com/facebook/ktfmt/kdoc/ParagraphList.kt
index a45d73fa..476f46cb 100644
--- a/core/src/main/java/com/facebook/ktfmt/kdoc/ParagraphList.kt
+++ b/core/src/main/java/com/facebook/ktfmt/kdoc/ParagraphList.kt
@@ -1,3 +1,19 @@
+/*
+ * Portions Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 /*
  * Copyright (c) Tor Norbye.
  *
@@ -22,7 +38,7 @@ package com.facebook.ktfmt.kdoc
  * front of it.
  */
 class ParagraphList(private val paragraphs: List<Paragraph>) : Iterable<Paragraph> {
-  fun isSingleParagraph() = paragraphs.size <= 1
+  fun isSingleParagraph(): Boolean = paragraphs.size <= 1
 
   override fun iterator(): Iterator<Paragraph> = paragraphs.iterator()
 
diff --git a/core/src/main/java/com/facebook/ktfmt/kdoc/ParagraphListBuilder.kt b/core/src/main/java/com/facebook/ktfmt/kdoc/ParagraphListBuilder.kt
index 2ec9989d..c01a4479 100644
--- a/core/src/main/java/com/facebook/ktfmt/kdoc/ParagraphListBuilder.kt
+++ b/core/src/main/java/com/facebook/ktfmt/kdoc/ParagraphListBuilder.kt
@@ -1,3 +1,19 @@
+/*
+ * Portions Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 /*
  * Copyright (c) Tor Norbye.
  *
@@ -236,7 +252,7 @@ class ParagraphListBuilder(
           // Make sure it's not just deeply indented inside a different block
           (paragraph.prev == null ||
               lineWithIndentation.length - lineWithoutIndentation.length >=
-                  paragraph.prev!!.originalIndent + 4)) {
+                  checkNotNull(paragraph.prev).originalIndent + 4)) {
         i = addPreformatted(i - 1, includeEnd = false, expectClose = false) { !it.startsWith(" ") }
       } else if (lineWithoutIndentation.startsWith("-") &&
           lineWithoutIndentation.containsOnly('-', '|', ' ')) {
@@ -361,7 +377,7 @@ class ParagraphListBuilder(
                 })
         newParagraph(i)
       } else if (lineWithoutIndentation.isListItem() ||
-          lineWithoutIndentation.isKDocTag() && task.type == CommentType.KDOC ||
+          (lineWithoutIndentation.isKDocTag() && task.type == CommentType.KDOC) ||
           lineWithoutIndentation.isTodo()) {
         i--
         newParagraph(i).hanging = true
@@ -388,10 +404,10 @@ class ParagraphListBuilder(
                         w.isLine() ||
                         w.isHeader() ||
                         // Not indented by at least two spaces following a blank line?
-                        s.length > 2 &&
+                        (s.length > 2 &&
                             (!s[0].isWhitespace() || !s[1].isWhitespace()) &&
                             j < lines.size - 1 &&
-                            lineContent(lines[j - 1]).isBlank()
+                            lineContent(lines[j - 1]).isBlank())
                   }
                 },
                 shouldBreak = { w, _ -> w.isBlank() },
@@ -455,7 +471,7 @@ class ParagraphListBuilder(
           newParagraph(i - 1).block = true
           if (lineWithoutIndentation.equals("<p>", true) ||
               lineWithoutIndentation.equals("<p/>", true) ||
-              options.convertMarkup && lineWithoutIndentation.equals("</p>", true)) {
+              (options.convertMarkup && lineWithoutIndentation.equals("</p>", true))) {
             if (options.convertMarkup) {
               // Replace <p> with a blank line
               paragraph.separate = true
@@ -630,8 +646,8 @@ class ParagraphListBuilder(
             override fun compare(l1: List<Paragraph>, l2: List<Paragraph>): Int {
               val p1 = l1.first()
               val p2 = l2.first()
-              val o1 = order[p1]!!
-              val o2 = order[p2]!!
+              val o1 = checkNotNull(order[p1])
+              val o2 = checkNotNull(order[p2])
               val isPriority1 = p1.doc && docTagIsPriority(p1.text) && o1 < firstNonPriorityDocTag
               val isPriority2 = p2.doc && docTagIsPriority(p2.text) && o2 < firstNonPriorityDocTag
 
@@ -750,7 +766,7 @@ class ParagraphListBuilder(
         if (paragraph.doc || text.startsWith("<li>", true) || text.isTodo()) {
           paragraph.hangingIndent = getIndent(options.hangingIndent)
         } else if (paragraph.continuation && paragraph.prev != null) {
-          paragraph.hangingIndent = paragraph.prev!!.hangingIndent
+          paragraph.hangingIndent = checkNotNull(paragraph.prev).hangingIndent
           // Dedent to match hanging indent
           val s = paragraph.text.trimStart()
           paragraph.content.clear()
@@ -830,7 +846,7 @@ class ParagraphListBuilder(
       return
     }
     val last = paragraphs.last()
-    if (last.preformatted || last.doc || last.hanging && !last.continuation || last.isEmpty()) {
+    if (last.preformatted || last.doc || (last.hanging && !last.continuation) || last.isEmpty()) {
       return
     }
 
@@ -862,7 +878,7 @@ fun String.containsOnly(vararg s: Char): Boolean {
   return true
 }
 
-fun StringBuilder.startsWithUpperCaseLetter() =
+fun StringBuilder.startsWithUpperCaseLetter(): Boolean =
     this.isNotEmpty() && this[0].isUpperCase() && this[0].isLetter()
 
-fun Char.isCloseSquareBracket() = this == ']'
+fun Char.isCloseSquareBracket(): Boolean = this == ']'
diff --git a/core/src/main/java/com/facebook/ktfmt/kdoc/Table.kt b/core/src/main/java/com/facebook/ktfmt/kdoc/Table.kt
index a4c837cc..8d07cb3a 100644
--- a/core/src/main/java/com/facebook/ktfmt/kdoc/Table.kt
+++ b/core/src/main/java/com/facebook/ktfmt/kdoc/Table.kt
@@ -1,3 +1,19 @@
+/*
+ * Portions Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 /*
  * Copyright (c) Tor Norbye.
  *
@@ -138,8 +154,8 @@ class Table(
       }
 
       val rowsAndDivider = rows + dividerRow
-      if (rowsAndDivider.all {
-        val first = it.cells.firstOrNull()
+      if (rowsAndDivider.all { row ->
+        val first = row.cells.firstOrNull()
         first != null && first.isBlank()
       }) {
         rowsAndDivider.forEach { if (it.cells.isNotEmpty()) it.cells.removeAt(0) }
@@ -198,8 +214,8 @@ class Table(
         } else if (c == '-' &&
             (s.startsWith("--", i) ||
                 s.startsWith("-:", i) ||
-                i > 1 && s.startsWith(":-:", i - 2) ||
-                i > 1 && s.startsWith(":--", i - 2))) {
+                (i > 1 && s.startsWith(":-:", i - 2)) ||
+                (i > 1 && s.startsWith(":--", i - 2)))) {
           while (i < s.length && s[i] == '-') {
             i++
           }
@@ -265,6 +281,6 @@ class Table(
   }
 
   class Row {
-    val cells = mutableListOf<String>()
+    val cells: MutableList<String> = mutableListOf()
   }
 }
diff --git a/core/src/main/java/com/facebook/ktfmt/kdoc/Utilities.kt b/core/src/main/java/com/facebook/ktfmt/kdoc/Utilities.kt
index 4b0f9ec4..ff07200a 100644
--- a/core/src/main/java/com/facebook/ktfmt/kdoc/Utilities.kt
+++ b/core/src/main/java/com/facebook/ktfmt/kdoc/Utilities.kt
@@ -1,3 +1,19 @@
+/*
+ * Portions Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 /*
  * Copyright (c) Tor Norbye.
  *
@@ -57,7 +73,7 @@ fun String.isListItem(): Boolean {
   return startsWith("- ") ||
       startsWith("* ") ||
       startsWith("+ ") ||
-      firstOrNull()?.isDigit() == true && numberPattern.matcher(this).find() ||
+      (firstOrNull()?.isDigit() == true && numberPattern.matcher(this).find()) ||
       startsWith("<li>", ignoreCase = true)
 }
 
@@ -108,8 +124,8 @@ fun String.isExpectingMore(): Boolean {
  * lines which has to be checked by the caller)
  */
 fun String.isLine(minCount: Int = 3): Boolean {
-  return startsWith('-') && containsOnly('-', ' ') && count { it == '-' } >= minCount ||
-      startsWith('_') && containsOnly('_', ' ') && count { it == '_' } >= minCount
+  return (startsWith('-') && containsOnly('-', ' ') && count { it == '-' } >= minCount) ||
+      (startsWith('_') && containsOnly('_', ' ') && count { it == '_' } >= minCount)
 }
 
 fun String.isKDocTag(): Boolean {
diff --git a/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt b/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
index a6994f58..e5babc4b 100644
--- a/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
+++ b/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
@@ -166,7 +166,7 @@ class ParsedArgsTest {
     val file = root.resolve("existing-file")
     file.writeText("--google-style\n--dry-run\n--set-exit-if-changed\nFile1.kt\nFile2.kt\n")
 
-    val result = ParsedArgs.processArgs(arrayOf("@" + file.absolutePath))
+    val result = ParsedArgs.processArgs(arrayOf("@" + file.canonicalPath))
     assertThat(result).isInstanceOf(ParseResult.Ok::class.java)
 
     val parsed = (result as ParseResult.Ok).parsedValue
diff --git a/core/src/test/java/com/facebook/ktfmt/kdoc/KDocFormatterTest.kt b/core/src/test/java/com/facebook/ktfmt/kdoc/KDocFormatterTest.kt
index 2fa3cb6e..aa28129f 100644
--- a/core/src/test/java/com/facebook/ktfmt/kdoc/KDocFormatterTest.kt
+++ b/core/src/test/java/com/facebook/ktfmt/kdoc/KDocFormatterTest.kt
@@ -737,7 +737,7 @@ class KDocFormatterTest {
   }
 
   @Test
-  fun testWrapingOfLinkText() {
+  fun testWrappingOfLinkText() {
     val source =
         """
              /**
@@ -5072,7 +5072,7 @@ class KDocFormatterTest {
           end++
         }
         val word = s.substring(i, end)
-        if (i > 0 && s[i - 1] == '@' || word == "http" || word == "https" || word == "com") {
+        if ((i > 0 && s[i - 1] == '@') || word == "http" || word == "https" || word == "com") {
           // Don't translate URL prefix/suffixes and doc tags
           sb.append(word)
         } else {
diff --git a/core/src/test/java/com/facebook/ktfmt/testutil/KtfmtTruth.kt b/core/src/test/java/com/facebook/ktfmt/testutil/KtfmtTruth.kt
index f8435161..299630df 100644
--- a/core/src/test/java/com/facebook/ktfmt/testutil/KtfmtTruth.kt
+++ b/core/src/test/java/com/facebook/ktfmt/testutil/KtfmtTruth.kt
@@ -81,6 +81,7 @@ fun assertThatFormatting(@Language("kts") code: String): FormattedCodeSubject {
   return Truth.assertAbout(codes()).that(code)
 }
 
+@Suppress("ClassNameDoesNotMatchFileName")
 class FormattedCodeSubject(metadata: FailureMetadata, private val code: String) :
     Subject(metadata, code) {
   private var options: FormattingOptions = defaultTestFormattingOptions
diff --git a/ktfmt_idea_plugin/src/main/kotlin/com/facebook/ktfmt/intellij/KtfmtSettings.kt b/ktfmt_idea_plugin/src/main/kotlin/com/facebook/ktfmt/intellij/KtfmtSettings.kt
index e5c9f673..0284c89d 100644
--- a/ktfmt_idea_plugin/src/main/kotlin/com/facebook/ktfmt/intellij/KtfmtSettings.kt
+++ b/ktfmt_idea_plugin/src/main/kotlin/com/facebook/ktfmt/intellij/KtfmtSettings.kt
@@ -123,16 +123,16 @@ internal class KtfmtSettings(private val project: Project) :
   }
 
   internal class State : BaseState() {
-    @Deprecated("Deprecated in V2. Use enableKtfmt instead.") var enabled by string()
+    @Deprecated("Deprecated in V2. Use enableKtfmt instead.") var enabled: String? by string()
 
-    var enableKtfmt by enum<EnabledState>(Unknown)
-    var uiFormatterStyle by enum<UiFormatterStyle>(Meta)
+    var enableKtfmt: EnabledState by enum(Unknown)
+    var uiFormatterStyle: UiFormatterStyle by enum(Meta)
 
-    var customMaxLineLength by property(Formatter.META_FORMAT.maxWidth)
-    var customBlockIndent by property(Formatter.META_FORMAT.blockIndent)
-    var customContinuationIndent by property(Formatter.META_FORMAT.continuationIndent)
-    var customManageTrailingCommas by property(Formatter.META_FORMAT.manageTrailingCommas)
-    var customRemoveUnusedImports by property(Formatter.META_FORMAT.removeUnusedImports)
+    var customMaxLineLength: Int by property(Formatter.META_FORMAT.maxWidth)
+    var customBlockIndent: Int by property(Formatter.META_FORMAT.blockIndent)
+    var customContinuationIndent: Int by property(Formatter.META_FORMAT.continuationIndent)
+    var customManageTrailingCommas: Boolean by property(Formatter.META_FORMAT.manageTrailingCommas)
+    var customRemoveUnusedImports: Boolean by property(Formatter.META_FORMAT.removeUnusedImports)
 
     fun applyCustomFormattingOptions(formattingOptions: FormattingOptions) {
       customMaxLineLength = formattingOptions.maxWidth
diff --git a/ktfmt_idea_plugin/src/main/kotlin/com/facebook/ktfmt/intellij/KtfmtSettingsMigration.kt b/ktfmt_idea_plugin/src/main/kotlin/com/facebook/ktfmt/intellij/KtfmtSettingsMigration.kt
index 84353733..39447452 100644
--- a/ktfmt_idea_plugin/src/main/kotlin/com/facebook/ktfmt/intellij/KtfmtSettingsMigration.kt
+++ b/ktfmt_idea_plugin/src/main/kotlin/com/facebook/ktfmt/intellij/KtfmtSettingsMigration.kt
@@ -38,7 +38,7 @@ internal class KtfmtSettingsMigration :
   //
   // v2 enabled [bool] -> enableKtfmt [enum], custom styles (0.52+)
   // v1 initial version - enabled is a boolean, only preset styles
-  var stateVersion
+  var stateVersion: Int
     get() = state.stateVersion.takeIf { it > 0 } ?: 1
     set(value) {
       state.stateVersion = value
@@ -63,7 +63,7 @@ internal class KtfmtSettingsMigration :
   }
 
   class MigrationState : BaseState() {
-    var stateVersion by property(-1)
+    var stateVersion: Int by property(-1)
   }
 
   companion object {