Replace "\" in filepath with "/" before comparing the path with a glo…

…b in which always uses "/" as separator

Closes pinterest#1599

ktlint/src/main/kotlin/com/pinterest/ktlint/internal/FileUtils.kt

@@ -15,6 +15,7 @@ import java.nio.file.Path
 import java.nio.file.Paths
 import java.nio.file.SimpleFileVisitor
 import java.nio.file.attribute.BasicFileAttributes
+import kotlin.io.path.absolutePathString
 import kotlin.io.path.isDirectory
 import kotlin.system.exitProcess
 import kotlin.system.measureTimeMillis
@@ -95,8 +96,14 @@ internal fun FileSystem.fileSequence(
                     filePath: Path,
                     fileAttrs: BasicFileAttributes,
                 ): FileVisitResult {
-                    if (negatedPathMatchers.none { it.matches(filePath) } &&
-                        pathMatchers.any { it.matches(filePath) }
+                    val path =
+                        if (onWindowsOS) {
+                            Paths.get(filePath.absolutePathString().replace(File.separatorChar, '/'))
+                        } else {
+                            filePath
+                        }
+                    if (negatedPathMatchers.none { it.matches(path) } &&
+                        pathMatchers.any { it.matches(path) }
                     ) {
                         logger.trace { "- File: $filePath: Include" }
                         result.add(filePath)

ktlint/src/test/kotlin/com/pinterest/ktlint/internal/FileUtilsTest.kt

@@ -7,15 +7,20 @@ import java.io.File
 import java.nio.file.FileSystem
 import java.nio.file.Files
 import java.nio.file.Path
+import java.nio.file.Paths
+import kotlin.io.path.absolutePathString
+import kotlin.io.path.isDirectory
 import mu.KotlinLogging
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.AfterEach
 import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Nested
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.condition.DisabledOnOs
 import org.junit.jupiter.api.condition.EnabledOnOs
 import org.junit.jupiter.api.condition.OS
 import org.junit.jupiter.params.ParameterizedTest
+import org.junit.jupiter.params.provider.CsvSource
 import org.junit.jupiter.params.provider.ValueSource
 
 private val logger = KotlinLogging.logger {}.initKtLintKLogger()
@@ -256,6 +261,61 @@ internal class FileUtilsTest {
             .doesNotContain(ktFile2InProjectSubDirectory)
     }
 
+    @EnabledOnOs(OS.WINDOWS)
+    @Nested
+    inner class ExploreFileSystem {
+        val rootPath = Paths.get(rootDir)
+
+        @Test
+        fun `Is absolute path`() {
+            assertThat(rootPath.isAbsolute).isTrue
+        }
+
+        @Test
+        fun `Is directory`() {
+            assertThat(rootPath.isDirectory()).isTrue
+        }
+
+        @Test
+        fun `Has root dir name`() {
+            assertThat(rootPath.absolutePathString()).isEqualTo("C:\\")
+        }
+
+        @ParameterizedTest(name = "Path: {0}, expected result: {1}")
+        @CsvSource(
+            value = [
+                ", C:\\",
+                "project1, C:\\project1",
+                "project1/src, C:\\project1\\src",
+                "project1/src/main, C:\\project1\\src\\main",
+                "project1/src/main/kotlin, C:\\project1\\src\\main\\kotlin",
+                "project1/src/main/kotlin.One.kt, C:\\project1\\src\\main\\kotlin\\One.kt",
+            ],
+        )
+        fun `Resolve`(path: String?, expected: String) {
+            val actual = rootPath.resolve(Paths.get(path ?: ""))
+
+            assertThat(actual).isEqualTo(expected)
+        }
+
+        @ParameterizedTest(name = "Path: {0}, expected result: {1}")
+        @CsvSource(
+            value = [
+                ", C:\\",
+                "project1, C:\\project1",
+                "project1/src, C:\\project1\\src",
+                "project1/src/main, C:\\project1\\src\\main",
+                "project1/src/main/kotlin, C:\\project1\\src\\main\\kotlin",
+                "project1/src/main/kotlin.One.kt, C:\\project1\\src\\main\\kotlin\\One.kt",
+            ],
+        )
+        fun `Resolve normalized`(path: String?, expected: String) {
+            val actual = rootPath.resolve(Paths.get(path?.normalizePath() ?: ""))
+
+            assertThat(actual).isEqualTo(expected)
+        }
+    }
+
     private fun String.normalizePath() = replace('/', File.separatorChar)
 
     private fun FileSystem.createFile(it: String) {