Rewrite MaxLineLength & TrailingWhitespace to avoid problematic offse…

…t calcs (#7270)

* Ensure positive integers passed when finding elements in provided range

Negative values are invalid as the text range must start and end within the
range 0 to file.text.length

* Rewrite MaxLineLength to avoid problematic offset calcs

* Tidy up

* Improve readability

* Rewrite TrailingWhitespace to avoid problematic offset calcs

detekt-rules-style/src/main/kotlin/io/gitlab/arturbosch/detekt/rules/style/Junk.kt

@@ -12,7 +12,7 @@ import org.jetbrains.kotlin.psi.psiUtil.getNonStrictParentOfType
  * the given [line] from a given offset in a [KtFile].
  */
 internal fun findKtElementInParents(file: KtFile, offset: Int, line: String): Sequence<PsiElement> {
-    return file.elementsInRange(TextRange.create(offset - line.length, offset))
+    return file.elementsInRange(TextRange.create(offset, offset + line.length))
         .asSequence()
         .plus(file.findElementAt(offset))
         .mapNotNull { it?.getNonStrictParentOfType() }

detekt-rules-style/src/main/kotlin/io/gitlab/arturbosch/detekt/rules/style/MaxLineLength.kt

@@ -1,5 +1,6 @@
 package io.gitlab.arturbosch.detekt.rules.style
 
+import io.github.detekt.psi.absolutePath
 import io.gitlab.arturbosch.detekt.api.ActiveByDefault
 import io.gitlab.arturbosch.detekt.api.CodeSmell
 import io.gitlab.arturbosch.detekt.api.Config
@@ -13,10 +14,13 @@ import io.gitlab.arturbosch.detekt.api.config
 import io.gitlab.arturbosch.detekt.rules.lastArgumentMatchesKotlinReferenceUrlSyntax
 import io.gitlab.arturbosch.detekt.rules.lastArgumentMatchesMarkdownUrlSyntax
 import io.gitlab.arturbosch.detekt.rules.lastArgumentMatchesUrl
+import org.jetbrains.kotlin.KtPsiSourceFileLinesMapping
+import org.jetbrains.kotlin.com.intellij.openapi.util.TextRange
 import org.jetbrains.kotlin.com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.diagnostics.DiagnosticUtils.getLineAndColumnRangeInPsiFile
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.psi.KtStringTemplateExpression
-import org.jetbrains.kotlin.psi.psiUtil.getParentOfType
+import org.jetbrains.kotlin.psi.psiUtil.getNonStrictParentOfType
 
 /**
  * This rule reports lines of code which exceed a defined maximum line length.
@@ -48,26 +52,25 @@ class MaxLineLength(config: Config) : Rule(
 
     override fun visitKtFile(file: KtFile) {
         super.visitKtFile(file)
-        var offset = 0
-        val lines = file.text.lines()
 
-        for (line in lines) {
-            offset += line.length
-            if (!isValidLine(file, offset, line)) {
+        val sourceFileLinesMapping = KtPsiSourceFileLinesMapping(file)
+
+        file.text.lines().withIndex()
+            .filterNot { (index, line) -> isValidLine(file, sourceFileLinesMapping.getLineStartOffset(index), line) }
+            .forEach { (index, line) ->
+                val offset = sourceFileLinesMapping.getLineStartOffset(index)
                 val ktElement = findFirstMeaningfulKtElementInParents(file, offset, line) ?: file
-                val location = Location.from(file, offset - line.length).let { location ->
+                val textRange = TextRange(offset, offset + line.length)
+                val lineAndColumnRange = getLineAndColumnRangeInPsiFile(file, textRange)
+                val location =
                     Location(
-                        source = location.source,
-                        endSource = SourceLocation(location.source.line, line.length + 1),
-                        text = TextLocation(offset - line.length, offset),
-                        path = location.path,
+                        source = SourceLocation(lineAndColumnRange.start.line, lineAndColumnRange.start.column),
+                        endSource = SourceLocation(lineAndColumnRange.end.line, lineAndColumnRange.end.column),
+                        text = TextLocation(offset, offset + line.length),
+                        path = file.absolutePath(),
                     )
-                }
                 report(CodeSmell(Entity.from(ktElement, location), description))
             }
-
-            offset += 1 // '\n'
-        }
     }
 
     private fun isValidLine(file: KtFile, offset: Int, line: String): Boolean {
@@ -123,5 +126,5 @@ class MaxLineLength(config: Config) : Rule(
 }
 
 private fun PsiElement.isInsideRawString(): Boolean {
-    return this is KtStringTemplateExpression || getParentOfType<KtStringTemplateExpression>(false) != null
+    return this is KtStringTemplateExpression || getNonStrictParentOfType<KtStringTemplateExpression>() != null
 }

detekt-rules-style/src/main/kotlin/io/gitlab/arturbosch/detekt/rules/style/TrailingWhitespace.kt

@@ -1,13 +1,18 @@
 package io.gitlab.arturbosch.detekt.rules.style
 
+import io.github.detekt.psi.absolutePath
 import io.gitlab.arturbosch.detekt.api.CodeSmell
 import io.gitlab.arturbosch.detekt.api.Config
 import io.gitlab.arturbosch.detekt.api.Entity
 import io.gitlab.arturbosch.detekt.api.Location
 import io.gitlab.arturbosch.detekt.api.Rule
+import io.gitlab.arturbosch.detekt.api.SourceLocation
 import io.gitlab.arturbosch.detekt.api.TextLocation
 import io.gitlab.arturbosch.detekt.rules.isPartOfString
+import org.jetbrains.kotlin.KtPsiSourceFileLinesMapping
+import org.jetbrains.kotlin.com.intellij.openapi.util.TextRange
 import org.jetbrains.kotlin.com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.diagnostics.DiagnosticUtils.getLineAndColumnRangeInPsiFile
 import org.jetbrains.kotlin.psi.KtFile
 
 /**
@@ -26,29 +31,29 @@ class TrailingWhitespace(config: Config) : Rule(
 
     override fun visitKtFile(file: KtFile) {
         super.visitKtFile(file)
-        var offset = 0
+
+        val sourceFileLinesMapping = KtPsiSourceFileLinesMapping(file)
+
         file.text.lineSequence().forEachIndexed { index, line ->
-            offset += line.length
             val trailingWhitespaces = countTrailingWhitespace(line)
             if (trailingWhitespaces > 0) {
-                val ktElement = findFirstKtElementInParentsOrNull(file, offset, line)
+                val lineEndOffset = sourceFileLinesMapping.getLineStartOffset(index) + line.length
+                val ktElement = findFirstKtElementInParentsOrNull(file, lineEndOffset, line)
                 if (ktElement == null || !ktElement.isPartOfString()) {
-                    val entity = Entity.from(file, offset - trailingWhitespaces).let { entity ->
-                        Entity(
-                            entity.name,
-                            entity.signature,
-                            location = Location(
-                                entity.location.source,
-                                entity.location.endSource,
-                                TextLocation(entity.location.text.start, offset),
-                                entity.location.path
-                            )
+                    val startOffset = lineEndOffset - trailingWhitespaces
+                    val textRange = TextRange(startOffset, lineEndOffset)
+                    val lineAndColumnRange = getLineAndColumnRangeInPsiFile(file, textRange)
+                    val location =
+                        Location(
+                            source = SourceLocation(lineAndColumnRange.start.line, lineAndColumnRange.start.column),
+                            endSource = SourceLocation(lineAndColumnRange.end.line, lineAndColumnRange.end.column),
+                            text = TextLocation(startOffset, lineEndOffset),
+                            path = file.absolutePath(),
                         )
-                    }
-                    report(CodeSmell(entity, createMessage(index)))
+
+                    report(CodeSmell(Entity.from(file, location), createMessage(index)))
                 }
             }
-            offset += 1 // '\n'
         }
     }