fix: prevent "TextEditor is closed/disposed" warnings

- Add disposal tracking and checks to DecorationController
- Add try-catch blocks around TextEditor property access
- Properly dispose decoration controllers in DiffViewProvider
- Add comprehensive tests for disposal handling
- Protect editor access in getEnvironmentDetails and registerCommands

Fixes #5954

Author: roomote

src/activate/registerCommands.ts

@@ -238,7 +238,16 @@ export const openClineInNewTab = async ({ context, outputChannel }: Omit<Registe
 	}
 
 	const tabProvider = new ClineProvider(context, outputChannel, "editor", contextProxy, codeIndexManager, mdmService)
-	const lastCol = Math.max(...vscode.window.visibleTextEditors.map((editor) => editor.viewColumn || 0))
+	const lastCol = Math.max(
+		...vscode.window.visibleTextEditors.map((editor) => {
+			try {
+				return editor.viewColumn || 0
+			} catch {
+				// Editor might be disposed
+				return 0
+			}
+		}),
+	)
 
 	// Check if there are any visible text editors, otherwise open a new group
 	// to the right.

src/core/environment/getEnvironmentDetails.ts

@@ -37,8 +37,15 @@ export async function getEnvironmentDetails(cline: Task, includeFileDetails: boo
 	details += "\n\n# VSCode Visible Files"
 
 	const visibleFilePaths = vscode.window.visibleTextEditors
-		?.map((editor) => editor.document?.uri?.fsPath)
-		.filter(Boolean)
+		?.map((editor) => {
+			try {
+				return editor.document?.uri?.fsPath
+			} catch {
+				// Editor might be disposed
+				return null
+			}
+		})
+		.filter((fsPath): fsPath is string => fsPath !== null && fsPath !== undefined)
 		.map((absolutePath) => path.relative(cline.cwd, absolutePath))
 		.slice(0, maxWorkspaceFiles)
 

src/integrations/editor/DecorationController.ts

@@ -19,6 +19,7 @@ export class DecorationController {
 	private decorationType: DecorationType
 	private editor: vscode.TextEditor
 	private ranges: vscode.Range[] = []
+	private isDisposed: boolean = false
 
 	constructor(decorationType: DecorationType, editor: vscode.TextEditor) {
 		this.decorationType = decorationType
@@ -35,8 +36,13 @@ export class DecorationController {
 	}
 
 	addLines(startIndex: number, numLines: number) {
-		// Guard against invalid inputs
-		if (startIndex < 0 || numLines <= 0) {
+		// Guard against invalid inputs or disposed state
+		if (startIndex < 0 || numLines <= 0 || this.isDisposed) {
+			return
+		}
+
+		// Check if editor is still valid before using it
+		if (!this.isEditorValid()) {
 			return
 		}
 
@@ -48,15 +54,43 @@ export class DecorationController {
 			this.ranges.push(new vscode.Range(startIndex, 0, endLine, Number.MAX_SAFE_INTEGER))
 		}
 
-		this.editor.setDecorations(this.getDecoration(), this.ranges)
+		try {
+			this.editor.setDecorations(this.getDecoration(), this.ranges)
+		} catch (error) {
+			// Editor was disposed between check and use
+			console.debug("DecorationController: Failed to set decorations, editor may be disposed", error)
+		}
 	}
 
 	clear() {
+		if (this.isDisposed) {
+			return
+		}
+
 		this.ranges = []
-		this.editor.setDecorations(this.getDecoration(), this.ranges)
+
+		if (!this.isEditorValid()) {
+			return
+		}
+
+		try {
+			this.editor.setDecorations(this.getDecoration(), this.ranges)
+		} catch (error) {
+			// Editor was disposed between check and use
+			console.debug("DecorationController: Failed to clear decorations, editor may be disposed", error)
+		}
 	}
 
 	updateOverlayAfterLine(line: number, totalLines: number) {
+		if (this.isDisposed) {
+			return
+		}
+
+		// Check if editor is still valid before using it
+		if (!this.isEditorValid()) {
+			return
+		}
+
 		// Remove any existing ranges that start at or after the current line
 		this.ranges = this.ranges.filter((range) => range.end.line < line)
 
@@ -71,11 +105,55 @@ export class DecorationController {
 		}
 
 		// Apply the updated decorations
-		this.editor.setDecorations(this.getDecoration(), this.ranges)
+		try {
+			this.editor.setDecorations(this.getDecoration(), this.ranges)
+		} catch (error) {
+			// Editor was disposed between check and use
+			console.debug("DecorationController: Failed to update overlay, editor may be disposed", error)
+		}
 	}
 
 	setActiveLine(line: number) {
+		if (this.isDisposed) {
+			return
+		}
+
+		// Check if editor is still valid before using it
+		if (!this.isEditorValid()) {
+			return
+		}
+
 		this.ranges = [new vscode.Range(line, 0, line, Number.MAX_SAFE_INTEGER)]
-		this.editor.setDecorations(this.getDecoration(), this.ranges)
+
+		try {
+			this.editor.setDecorations(this.getDecoration(), this.ranges)
+		} catch (error) {
+			// Editor was disposed between check and use
+			console.debug("DecorationController: Failed to set active line, editor may be disposed", error)
+		}
+	}
+
+	/**
+	 * Checks if the editor is still valid and not disposed
+	 */
+	private isEditorValid(): boolean {
+		try {
+			// Try to access a property that would throw if disposed
+			// The document property is a good indicator
+			const _ = this.editor.document
+			return true
+		} catch {
+			// Editor is disposed
+			this.isDisposed = true
+			return false
+		}
+	}
+
+	/**
+	 * Marks this controller as disposed
+	 */
+	dispose() {
+		this.isDisposed = true
+		this.clear()
 	}
 }

src/integrations/editor/DiffViewProvider.ts

@@ -99,8 +99,12 @@ export class DiffViewProvider {
 		this.fadedOverlayController = new DecorationController("fadedOverlay", this.activeDiffEditor)
 		this.activeLineController = new DecorationController("activeLine", this.activeDiffEditor)
 		// Apply faded overlay to all lines initially.
-		this.fadedOverlayController.addLines(0, this.activeDiffEditor.document.lineCount)
-		this.scrollEditorToLine(0) // Will this crash for new files?
+		try {
+			this.fadedOverlayController.addLines(0, this.activeDiffEditor.document.lineCount)
+			this.scrollEditorToLine(0)
+		} catch (error) {
+			console.debug("DiffViewProvider: Failed to initialize decorations", error)
+		}
 		this.streamedLines = []
 	}
 
@@ -117,16 +121,28 @@ export class DiffViewProvider {
 		}
 
 		const diffEditor = this.activeDiffEditor
-		const document = diffEditor?.document
+
+		// Check if editor is still valid
+		let document: vscode.TextDocument | undefined
+		try {
+			document = diffEditor?.document
+		} catch {
+			throw new Error("Text editor is disposed, unable to edit file...")
+		}
 
 		if (!diffEditor || !document) {
 			throw new Error("User closed text editor, unable to edit file...")
 		}
 
 		// Place cursor at the beginning of the diff editor to keep it out of
 		// the way of the stream animation, but do this without stealing focus
-		const beginningOfDocument = new vscode.Position(0, 0)
-		diffEditor.selection = new vscode.Selection(beginningOfDocument, beginningOfDocument)
+		try {
+			const beginningOfDocument = new vscode.Position(0, 0)
+			diffEditor.selection = new vscode.Selection(beginningOfDocument, beginningOfDocument)
+		} catch (error) {
+			// Editor might be disposed, continue with the update
+			console.debug("DiffViewProvider: Failed to set selection", error)
+		}
 
 		const endLine = accumulatedLines.length
 		// Replace all content up to the current line with accumulated lines.
@@ -176,12 +192,15 @@ export class DiffViewProvider {
 			await vscode.workspace.applyEdit(finalEdit)
 
 			// Clear all decorations at the end (after applying final edit).
-			this.fadedOverlayController.clear()
-			this.activeLineController.clear()
+			this.fadedOverlayController?.clear()
+			this.activeLineController?.clear()
 		}
 	}
 
-	async saveChanges(diagnosticsEnabled: boolean = true, writeDelayMs: number = DEFAULT_WRITE_DELAY_MS): Promise<{
+	async saveChanges(
+		diagnosticsEnabled: boolean = true,
+		writeDelayMs: number = DEFAULT_WRITE_DELAY_MS,
+	): Promise<{
 		newProblemsMessage: string | undefined
 		userEdits: string | undefined
 		finalContent: string | undefined
@@ -216,22 +235,22 @@ export class DiffViewProvider {
 		// and can address them accordingly. If problems don't change immediately after
 		// applying a fix, won't be notified, which is generally fine since the
 		// initial fix is usually correct and it may just take time for linters to catch up.
-		
+
 		let newProblemsMessage = ""
-		
+
 		if (diagnosticsEnabled) {
 			// Add configurable delay to allow linters time to process and clean up issues
 			// like unused imports (especially important for Go and other languages)
 			// Ensure delay is non-negative
 			const safeDelayMs = Math.max(0, writeDelayMs)
-			
+
 			try {
 				await delay(safeDelayMs)
 			} catch (error) {
 				// Log error but continue - delay failure shouldn't break the save operation
 				console.warn(`Failed to apply write delay: ${error}`)
 			}
-			
+
 			const postDiagnostics = vscode.languages.getDiagnostics()
 
 			const newProblems = await diagnosticsToProblemsString(
@@ -549,13 +568,19 @@ export class DiffViewProvider {
 	}
 
 	private scrollEditorToLine(line: number) {
-		if (this.activeDiffEditor) {
-			const scrollLine = line + 4
+		if (!this.activeDiffEditor) {
+			return
+		}
 
+		try {
+			const scrollLine = line + 4
 			this.activeDiffEditor.revealRange(
 				new vscode.Range(scrollLine, 0, scrollLine, 0),
 				vscode.TextEditorRevealType.InCenter,
 			)
+		} catch (error) {
+			// Editor might be disposed
+			console.debug("DiffViewProvider: Failed to scroll editor", error)
 		}
 	}
 
@@ -564,25 +589,30 @@ export class DiffViewProvider {
 			return
 		}
 
-		const currentContent = this.activeDiffEditor.document.getText()
-		const diffs = diff.diffLines(this.originalContent || "", currentContent)
+		try {
+			const currentContent = this.activeDiffEditor.document.getText()
+			const diffs = diff.diffLines(this.originalContent || "", currentContent)
 
-		let lineCount = 0
+			let lineCount = 0
 
-		for (const part of diffs) {
-			if (part.added || part.removed) {
-				// Found the first diff, scroll to it without stealing focus.
-				this.activeDiffEditor.revealRange(
-					new vscode.Range(lineCount, 0, lineCount, 0),
-					vscode.TextEditorRevealType.InCenter,
-				)
+			for (const part of diffs) {
+				if (part.added || part.removed) {
+					// Found the first diff, scroll to it without stealing focus.
+					this.activeDiffEditor.revealRange(
+						new vscode.Range(lineCount, 0, lineCount, 0),
+						vscode.TextEditorRevealType.InCenter,
+					)
 
-				return
-			}
+					return
+				}
 
-			if (!part.removed) {
-				lineCount += part.count || 0
+				if (!part.removed) {
+					lineCount += part.count || 0
+				}
 			}
+		} catch (error) {
+			// Editor might be disposed
+			console.debug("DiffViewProvider: Failed to scroll to first diff", error)
 		}
 	}
 
@@ -599,15 +629,23 @@ export class DiffViewProvider {
 	}
 
 	async reset(): Promise<void> {
+		// Dispose decoration controllers before clearing references
+		if (this.fadedOverlayController) {
+			this.fadedOverlayController.dispose()
+			this.fadedOverlayController = undefined
+		}
+		if (this.activeLineController) {
+			this.activeLineController.dispose()
+			this.activeLineController = undefined
+		}
+
 		await this.closeAllDiffViews()
 		this.editType = undefined
 		this.isEditing = false
 		this.originalContent = undefined
 		this.createdDirs = []
 		this.documentWasOpen = false
 		this.activeDiffEditor = undefined
-		this.fadedOverlayController = undefined
-		this.activeLineController = undefined
 		this.streamedLines = []
 		this.preDiagnostics = []
 	}