refactor: extract diff view label separator as shared constant

- Add DIFF_VIEW_LABEL_SEPARATOR constant to prevent breaking logic if string changes
- Update all usages in DiffViewProvider.ts and test file
- Addresses PR review feedback for better maintainability

Author: daniel-lxs

src/integrations/editor/DiffViewProvider.ts

@@ -15,6 +15,7 @@ import { Task } from "../../core/task/Task"
 import { DecorationController } from "./DecorationController"
 
 export const DIFF_VIEW_URI_SCHEME = "cline-diff"
+export const DIFF_VIEW_LABEL_SEPARATOR = "↔ Roo's Changes"
 
 // TODO: https://github.com/cline/cline/pull/3354
 export class DiffViewProvider {
@@ -397,7 +398,7 @@ export class DiffViewProvider {
 				// Also check by tab label for our specific diff views
 				// This catches cases where the diff view might be created differently
 				// when files are pre-opened as text documents
-				if (tab.label.includes("↔ Roo's Changes") && !tab.isDirty) {
+				if (tab.label.includes(DIFF_VIEW_LABEL_SEPARATOR) && !tab.isDirty) {
 					return true
 				}
 
@@ -512,7 +513,7 @@ export class DiffViewProvider {
 							query: Buffer.from(this.originalContent ?? "").toString("base64"),
 						}),
 						uri,
-						`${fileName}: ${fileExists ? "Original ↔ Roo's Changes" : "New File"} (Editable)`,
+						`${fileName}: ${fileExists ? `Original ${DIFF_VIEW_LABEL_SEPARATOR}` : "New File"} (Editable)`,
 						{ preserveFocus: true },
 					)
 				})

src/integrations/editor/__tests__/DiffViewProvider.spec.ts

@@ -1,4 +1,4 @@
-import { DiffViewProvider, DIFF_VIEW_URI_SCHEME } from "../DiffViewProvider"
+import { DiffViewProvider, DIFF_VIEW_URI_SCHEME, DIFF_VIEW_LABEL_SEPARATOR } from "../DiffViewProvider"
 import * as vscode from "vscode"
 import * as path from "path"
 
@@ -219,7 +219,7 @@ describe("DiffViewProvider", () => {
 				"vscode.diff",
 				expect.any(Object),
 				expect.any(Object),
-				"test.md: Original ↔ Roo's Changes (Editable)",
+				`test.md: Original ${DIFF_VIEW_LABEL_SEPARATOR} (Editable)`,
 				{ preserveFocus: true },
 			)
 		})
@@ -255,7 +255,7 @@ describe("DiffViewProvider", () => {
 						original: { scheme: DIFF_VIEW_URI_SCHEME },
 						modified: { fsPath: "/test/file1.ts" },
 					},
-					label: "file1.ts: Original ↔ Roo's Changes (Editable)",
+					label: `file1.ts: Original ${DIFF_VIEW_LABEL_SEPARATOR} (Editable)`,
 					isDirty: false,
 				},
 				// Diff view identified by label (for pre-opened files)
@@ -265,7 +265,7 @@ describe("DiffViewProvider", () => {
 						original: { scheme: "file" }, // Different scheme due to pre-opening
 						modified: { fsPath: "/test/file2.md" },
 					},
-					label: "file2.md: Original ↔ Roo's Changes (Editable)",
+					label: `file2.md: Original ${DIFF_VIEW_LABEL_SEPARATOR} (Editable)`,
 					isDirty: false,
 				},
 				// Regular file tab (should not be closed)
@@ -284,7 +284,7 @@ describe("DiffViewProvider", () => {
 						original: { scheme: DIFF_VIEW_URI_SCHEME },
 						modified: { fsPath: "/test/file4.ts" },
 					},
-					label: "file4.ts: Original ↔ Roo's Changes (Editable)",
+					label: `file4.ts: Original ${DIFF_VIEW_LABEL_SEPARATOR} (Editable)`,
 					isDirty: true,
 				},
 			]
@@ -317,13 +317,15 @@ describe("DiffViewProvider", () => {
 
 			// Verify that only the appropriate tabs were closed
 			expect(closedTabs).toHaveLength(2)
-			expect(closedTabs[0].label).toBe("file1.ts: Original ↔ Roo's Changes (Editable)")
-			expect(closedTabs[1].label).toBe("file2.md: Original ↔ Roo's Changes (Editable)")
+			expect(closedTabs[0].label).toBe(`file1.ts: Original ${DIFF_VIEW_LABEL_SEPARATOR} (Editable)`)
+			expect(closedTabs[1].label).toBe(`file2.md: Original ${DIFF_VIEW_LABEL_SEPARATOR} (Editable)`)
 
 			// Verify that the regular file and dirty diff were not closed
 			expect(closedTabs.find((t) => t.label === "file3.js")).toBeUndefined()
 			expect(
-				closedTabs.find((t) => t.label === "file4.ts: Original ↔ Roo's Changes (Editable)" && t.isDirty),
+				closedTabs.find(
+					(t) => t.label === `file4.ts: Original ${DIFF_VIEW_LABEL_SEPARATOR} (Editable)` && t.isDirty,
+				),
 			).toBeUndefined()
 		})
 	})