#4199 split screen diff error fix

Author: Mnehmos

src/integrations/editor/DiffViewProvider.ts

@@ -432,31 +432,90 @@ export class DiffViewProvider {
 
 		// Open new diff editor.
 		return new Promise<vscode.TextEditor>((resolve, reject) => {
-			const fileName = path.basename(uri.fsPath)
-			const fileExists = this.editType === "modify"
-
-			const disposable = vscode.window.onDidChangeActiveTextEditor((editor) => {
-				if (editor && arePathsEqual(editor.document.uri.fsPath, uri.fsPath)) {
-					disposable.dispose()
-					resolve(editor)
+			;(async () => {
+				const fileName = path.basename(uri.fsPath)
+				const fileExists = this.editType === "modify"
+				let timeoutId: NodeJS.Timeout | undefined
+
+				console.log(`[DiffViewProvider] Attempting to open diff editor for: ${uri.fsPath}`)
+
+				const checkAndResolve = () => {
+					for (const group of vscode.window.tabGroups.all) {
+						for (const tab of group.tabs) {
+							if (
+								tab.input instanceof vscode.TabInputTextDiff &&
+								tab.input?.original?.scheme === DIFF_VIEW_URI_SCHEME &&
+								arePathsEqual(tab.input.modified.fsPath, uri.fsPath)
+							) {
+								// Found the diff editor, now try to show it to get the TextEditor instance
+								vscode.window.showTextDocument(tab.input.modified, { preserveFocus: true }).then(
+									(editor) => {
+										console.log(
+											`[DiffViewProvider] Diff editor found and activated via tabGroups: ${editor.document.uri.fsPath}`,
+										)
+										if (timeoutId) clearTimeout(timeoutId)
+										disposableTabGroup.dispose()
+										resolve(editor)
+									},
+									(err) => {
+										console.error(
+											`[DiffViewProvider] Error showing text document after finding tab: ${err}`,
+										)
+										if (timeoutId) clearTimeout(timeoutId)
+										disposableTabGroup.dispose()
+										reject(
+											new Error(`Failed to show diff editor after finding tab: ${err.message}`),
+										)
+									},
+								)
+								return true
+							}
+						}
+					}
+					return false
 				}
-			})
-
-			vscode.commands.executeCommand(
-				"vscode.diff",
-				vscode.Uri.parse(`${DIFF_VIEW_URI_SCHEME}:${fileName}`).with({
-					query: Buffer.from(this.originalContent ?? "").toString("base64"),
-				}),
-				uri,
-				`${fileName}: ${fileExists ? "Original ↔ Roo's Changes" : "New File"} (Editable)`,
-				{ preserveFocus: true },
-			)
 
-			// This may happen on very slow machines i.e. project idx.
-			setTimeout(() => {
-				disposable.dispose()
-				reject(new Error("Failed to open diff editor, please try again..."))
-			}, 10_000)
+				// Listen for changes in tab groups, which includes tabs moving between windows
+				const disposableTabGroup = vscode.window.tabGroups.onDidChangeTabGroups(() => {
+					console.log(`[DiffViewProvider] onDidChangeTabGroups fired. Checking for diff editor.`)
+					checkAndResolve()
+				})
+
+				vscode.commands
+					.executeCommand(
+						"vscode.diff",
+						vscode.Uri.parse(`${DIFF_VIEW_URI_SCHEME}:${fileName}`).with({
+							query: Buffer.from(this.originalContent ?? "").toString("base64"),
+						}),
+						uri,
+						`${fileName}: ${fileExists ? "Original ↔ Roo's Changes" : "New File"} (Editable)`,
+						{ preserveFocus: true },
+					)
+					.then(
+						async () => {
+							console.log(`[DiffViewProvider] vscode.diff command executed for: ${uri.fsPath}`)
+							// Give a brief moment for the editor to appear in tab groups
+							await new Promise((r) => setTimeout(r, 100))
+							if (!checkAndResolve()) {
+								console.log(
+									`[DiffViewProvider] Diff editor not immediately found after command. Waiting for tab group changes.`,
+								)
+							}
+						},
+						(err) => {
+							console.error(`[DiffViewProvider] Error executing vscode.diff command: ${err}`)
+							if (timeoutId) clearTimeout(timeoutId)
+							disposableTabGroup.dispose()
+							reject(new Error(`Failed to open diff editor command: ${err.message}`))
+						},
+					)
+
+				timeoutId = setTimeout(() => {
+					console.log(`[DiffViewProvider] Diff editor open timeout triggered for: ${uri.fsPath}`)
+					disposableTabGroup.dispose()
+					reject(new Error("Failed to open diff editor, please try again..."))
+				}, 10_000)
+			})()
 		})
 	}