Fix formatting when text includes a special char (#112)

* Fix formatting when text includes a special char

* Release docs

* Remove claude permissions

Author: ryan-rushton

CHANGELOG.md

@@ -4,6 +4,10 @@
 
 ## [Unreleased]
 
+- Fix issue where characters with special character encodings were causing the supplied range to the dprint daemon to
+  be incorrect. This is a side effect of https://github.com/dprint/dprint-intellij/pull/107 as IJ now sends a full file
+  range when the internal IJ formatter is overridden.
+
 ## 0.8.3 - 2025-06-07
 
 - While range formatting is not currently available, allow format fragment flows to come through so logging occurs.

README.md

@@ -5,6 +5,8 @@ This plugin adds support for dprint, a flexible and extensible code formatter ([
 in active early development, please report bugs and feature requests to
 our [github](https://github.com/dprint/dprint-intellij/issues).
 
+N.B. Currently only UTF-8 file formats are supported correctly.
+
 To use this plugin:
 
 - Install and configure dprint for your repository, [dprint.dev/setup](https://dprint.dev/setup/)
@@ -48,12 +50,13 @@ be your project SDK.
 
 ### Dprint setup
 
-To test this plugin, you will require dprint installed. To install on a mac with homebrew run `brew install dprint`. 
+To test this plugin, you will require dprint installed. To install on a mac with homebrew run `brew install dprint`.
 When running the plugin via the `Run Plugin` configuration, add a default dprint config file by running `dprint init`.
 
 ### Intellij Setup
 
-- Set up linting settings, run <kbd>Gradle</kbd> > <kbd>Tasks</kbd> > <kbd>help</kbd> > <kbd>ktlintGernateBaseline</kbd>.
+- Set up linting settings, run <kbd>Gradle</kbd> > <kbd>Tasks</kbd> > <kbd>help</kbd> > <kbd>
+  ktlintGernateBaseline</kbd>.
   This sets up intellij with appropriate formatting settings.
 
 ### Running

gradle.properties

@@ -2,7 +2,7 @@
 # -> https://plugins.jetbrains.com/docs/intellij/intellij-artifacts.html
 pluginGroup=com.dprint.intellij.plugin
 pluginName=dprint
-pluginVersion=0.8.3
+pluginVersion=0.8.4
 # See https://plugins.jetbrains.com/docs/intellij/build-number-ranges.html
 # for insight into build numbers and IntelliJ Platform versions.
 pluginSinceBuild=241

src/main/kotlin/com/dprint/services/editorservice/v5/EditorServiceV5.kt

@@ -149,6 +149,7 @@ class EditorServiceV5Impl(
             (result.type == MessageType.CanFormatResponse && result.data is Boolean) -> {
                 onFinished(result.data)
             }
+
             (result.type == MessageType.ErrorResponse && result.data is String) -> {
                 infoLogWithConsole(
                     DprintBundle.message("editor.service.format.check.failed", filePath, result.data),
@@ -157,10 +158,12 @@ class EditorServiceV5Impl(
                 )
                 onFinished(null)
             }
+
             (result.type === MessageType.Dropped) -> {
                 // do nothing
                 onFinished(null)
             }
+
             else -> {
                 infoLogWithConsole(
                     DprintBundle.message("editor.service.unsupported.message.type", result.type),
@@ -225,14 +228,41 @@ class EditorServiceV5Impl(
     ): OutgoingMessage {
         val outgoingMessage = OutgoingMessage(formatId ?: getNextMessageId(), MessageType.FormatFile)
         outgoingMessage.addString(filePath)
-        // TODO We need to properly handle string index to byte index here
-        outgoingMessage.addInt(startIndex ?: 0) // for range formatting add starting index
-        outgoingMessage.addInt(endIndex ?: content.encodeToByteArray().size) // add ending index
+
+        // Converting string indices to bytes
+        val startByteIndex =
+            if (startIndex != null) {
+                getByteIndex(content, startIndex)
+            } else {
+                0
+            }
+
+        val endByteIndex =
+            if (endIndex != null) {
+                getByteIndex(content, endIndex)
+            } else {
+                content.encodeToByteArray().size
+            }
+
+        outgoingMessage.addInt(startByteIndex) // for range formatting add starting index
+        outgoingMessage.addInt(endByteIndex) // add ending index
         outgoingMessage.addInt(0) // Override config
         outgoingMessage.addString(content)
         return outgoingMessage
     }
 
+    private fun getByteIndex(
+        content: String,
+        stringIndex: Int,
+    ): Int {
+        // Handle edge cases
+        if (stringIndex <= 0) return 0
+        if (stringIndex >= content.length) return content.encodeToByteArray().size
+
+        // Get substring up to the string index and convert to bytes
+        return content.substring(0, stringIndex).encodeToByteArray().size
+    }
+
     private fun mapResultToFormatResult(
         result: PendingMessages.Result,
         filePath: String,
@@ -247,6 +277,7 @@ class EditorServiceV5Impl(
                 infoLogWithConsole(successMessage, project, LOGGER)
                 FormatResult(formattedContent = result.data)
             }
+
             (result.type == MessageType.ErrorResponse && result.data is String) -> {
                 warnLogWithConsole(
                     DprintBundle.message("editor.service.format.failed", filePath, result.data),
@@ -255,6 +286,7 @@ class EditorServiceV5Impl(
                 )
                 FormatResult(error = result.data)
             }
+
             (result.type != MessageType.Dropped) -> {
                 val errorMessage = DprintBundle.message("editor.service.unsupported.message.type", result.type)
                 warnLogWithConsole(
@@ -263,7 +295,9 @@ class EditorServiceV5Impl(
                     LOGGER,
                 )
                 FormatResult(error = errorMessage)
-            } else -> {
+            }
+
+            else -> {
                 FormatResult()
             }
         }

src/test/kotlin/com/dprint/services/editorservice/v5/EditorServiceV5ImplTest.kt

@@ -162,4 +162,109 @@ class EditorServiceV5ImplTest : FunSpec({
         verify { pendingMessages.take(testId) }
         verify { editorProcess.writeBuffer(expectedOutgoingMessage.build()) }
     }
+
+    test("fmt converts string indices to byte indices correctly for ASCII text") {
+        val testFile = "/test/File.kt"
+        val testContent = "hello world"
+        val onFinished = mockk<(FormatResult) -> Unit>()
+
+        every { editorProcess.writeBuffer(any()) } returns Unit
+        every { pendingMessages.store(any(), any()) } returns Unit
+        every { onFinished(any()) } returns Unit
+
+        editorServiceV5.fmt(1, testFile, testContent, 6, 11, onFinished)
+
+        val expectedOutgoingMessage = OutgoingMessage(1, MessageType.FormatFile)
+        expectedOutgoingMessage.addString(testFile)
+        expectedOutgoingMessage.addInt(6) // "hello " = 6 bytes
+        expectedOutgoingMessage.addInt(11) // "hello world" = 11 bytes
+        expectedOutgoingMessage.addInt(0)
+        expectedOutgoingMessage.addString(testContent)
+
+        verify(exactly = 1) { editorProcess.writeBuffer(expectedOutgoingMessage.build()) }
+    }
+
+    test("fmt converts string indices to byte indices correctly for Unicode text") {
+        val testFile = "/test/File.kt"
+        val testContent = "🚀 rocket"
+        val onFinished = mockk<(FormatResult) -> Unit>()
+
+        every { editorProcess.writeBuffer(any()) } returns Unit
+        every { pendingMessages.store(any(), any()) } returns Unit
+        every { onFinished(any()) } returns Unit
+
+        editorServiceV5.fmt(1, testFile, testContent, 2, 8, onFinished)
+
+        val expectedOutgoingMessage = OutgoingMessage(1, MessageType.FormatFile)
+        expectedOutgoingMessage.addString(testFile)
+        expectedOutgoingMessage.addInt(4) // 🚀 is 2 bytes then another 2 for ' r'
+        expectedOutgoingMessage.addInt(10)
+        expectedOutgoingMessage.addInt(0)
+        expectedOutgoingMessage.addString(testContent)
+
+        verify(exactly = 1) { editorProcess.writeBuffer(expectedOutgoingMessage.build()) }
+    }
+
+    test("fmt handles edge case with start index 0") {
+        val testFile = "/test/File.kt"
+        val testContent = "test"
+        val onFinished = mockk<(FormatResult) -> Unit>()
+
+        every { editorProcess.writeBuffer(any()) } returns Unit
+        every { pendingMessages.store(any(), any()) } returns Unit
+        every { onFinished(any()) } returns Unit
+
+        editorServiceV5.fmt(1, testFile, testContent, 0, 2, onFinished)
+
+        val expectedOutgoingMessage = OutgoingMessage(1, MessageType.FormatFile)
+        expectedOutgoingMessage.addString(testFile)
+        expectedOutgoingMessage.addInt(0) // start at 0
+        expectedOutgoingMessage.addInt(2) // "te" = 2 bytes
+        expectedOutgoingMessage.addInt(0)
+        expectedOutgoingMessage.addString(testContent)
+
+        verify(exactly = 1) { editorProcess.writeBuffer(expectedOutgoingMessage.build()) }
+    }
+
+    test("fmt handles edge case with index beyond content length") {
+        val testFile = "/test/File.kt"
+        val testContent = "test"
+        val onFinished = mockk<(FormatResult) -> Unit>()
+
+        every { editorProcess.writeBuffer(any()) } returns Unit
+        every { pendingMessages.store(any(), any()) } returns Unit
+        every { onFinished(any()) } returns Unit
+
+        editorServiceV5.fmt(1, testFile, testContent, 10, 20, onFinished)
+
+        val expectedOutgoingMessage = OutgoingMessage(1, MessageType.FormatFile)
+        expectedOutgoingMessage.addString(testFile)
+        expectedOutgoingMessage.addInt(4) // beyond length returns full content byte size
+        expectedOutgoingMessage.addInt(4) // beyond length returns full content byte size
+        expectedOutgoingMessage.addInt(0)
+        expectedOutgoingMessage.addString(testContent)
+
+        verify(exactly = 1) { editorProcess.writeBuffer(expectedOutgoingMessage.build()) }
+    }
+
+    test("fmt handles mixed Unicode characters correctly") {
+        val testFile = "/test/File.kt"
+        val testContent = "café 🎉 test"
+        val onFinished = mockk<(FormatResult) -> Unit>()
+
+        every { editorProcess.writeBuffer(any()) } returns Unit
+        every { pendingMessages.store(any(), any()) } returns Unit
+        every { onFinished(any()) } returns Unit
+
+        editorServiceV5.fmt(1, testFile, testContent, 5, 7, onFinished)
+
+        val expectedOutgoingMessage = OutgoingMessage(1, MessageType.FormatFile)
+        expectedOutgoingMessage.addString(testFile)
+        expectedOutgoingMessage.addInt(testContent.substring(0, 5).encodeToByteArray().size) // Dynamic calculation
+        expectedOutgoingMessage.addInt(testContent.substring(0, 7).encodeToByteArray().size) // Dynamic calculation
+        expectedOutgoingMessage.addInt(0)
+        expectedOutgoingMessage.addString(testContent)
+
+        verify(exactly = 1) { editorProcess.writeBuffer(expectedOutgoingMessage.build()) }
+    }
 })