Warn users about lack of symlink privileges on Windows (#888)

* warn users about lack of symlink privileges on Windows

* fix spelling of privilege

Co-authored-by: award999 <[email protected]>

* move notification code into its own file under src/ui

---------

Co-authored-by: award999 <[email protected]>

Author: matthewbastien

package.json

@@ -357,6 +357,13 @@
               "Show the Swift build status as a progress notification."
             ],
             "order": 17
+          },
+          "swift.warnAboutSymlinkCreation": {
+            "type": "boolean",
+            "default": true,
+            "description": "Controls whether or not the extension will warn about being unable to create symlinks. (Windows only)",
+            "scope": "application",
+            "order": 18
           }
         }
       },
@@ -1187,4 +1194,4 @@
     "vscode-languageclient": "^9.0.1",
     "xml2js": "^0.6.2"
   }
-}
+}

src/configuration.ts

@@ -272,6 +272,17 @@ const configuration = {
             .getConfiguration("swift")
             .get<OpenAfterCreateNewProjectOptions>("openAfterCreateNewProject", "prompt");
     },
+    /** Whether or not the extension should warn about being unable to create symlinks on Windows */
+    get warnAboutSymlinkCreation(): boolean {
+        return vscode.workspace
+            .getConfiguration("swift")
+            .get<boolean>("warnAboutSymlinkCreation", true);
+    },
+    set warnAboutSymlinkCreation(value: boolean) {
+        vscode.workspace
+            .getConfiguration("swift")
+            .update("warnAboutSymlinkCreation", value, vscode.ConfigurationTarget.Global);
+    },
 };
 
 export default configuration;

src/extension.ts

@@ -34,6 +34,7 @@ import { showToolchainError } from "./ui/ToolchainSelection";
 import { SwiftToolchain } from "./toolchain/toolchain";
 import { SwiftOutputChannel } from "./ui/SwiftOutputChannel";
 import { showReloadExtensionNotification } from "./ui/ReloadExtension";
+import { checkAndWarnAboutWindowsSymlinks } from "./ui/win32";
 
 /**
  * External API as exposed by the extension. Can be queried by other extensions
@@ -49,8 +50,10 @@ export interface Api {
 export async function activate(context: vscode.ExtensionContext): Promise<Api | undefined> {
     try {
         console.debug("Activating Swift for Visual Studio Code...");
-
         const outputChannel = new SwiftOutputChannel();
+
+        checkAndWarnAboutWindowsSymlinks(outputChannel);
+
         const toolchain: SwiftToolchain | undefined = await SwiftToolchain.create()
             .then(toolchain => {
                 outputChannel.log(toolchain.swiftVersionString);

src/ui/win32.ts

@@ -0,0 +1,69 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the VS Code Swift open source project
+//
+// Copyright (c) 2024 the VS Code Swift project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of VS Code Swift project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import * as fs from "fs/promises";
+import { SwiftOutputChannel } from "./SwiftOutputChannel";
+import { TemporaryFolder } from "../utilities/tempFolder";
+import configuration from "../configuration";
+import * as vscode from "vscode";
+
+/**
+ * Warns the user about lack of symbolic link support on Windows. Performs the
+ * check in the background to avoid extending extension startup times.
+ *
+ * @param outputChannel The Swift output channel to log any errors to
+ */
+export function checkAndWarnAboutWindowsSymlinks(outputChannel: SwiftOutputChannel) {
+    if (process.platform === "win32" && configuration.warnAboutSymlinkCreation) {
+        isSymlinkAllowed(outputChannel).then(async canCreateSymlink => {
+            if (canCreateSymlink) {
+                return;
+            }
+            const selected = await vscode.window.showWarningMessage(
+                "The Swift extension is unable to create symbolic links on your system and some features may not work correctly. Please either enable Developer Mode or allow symlink creation via Windows privileges.",
+                "Learn More",
+                "Don't Show Again"
+            );
+            if (selected === "Learn More") {
+                return vscode.env.openExternal(
+                    vscode.Uri.parse(
+                        "https://learn.microsoft.com/en-us/windows/apps/get-started/enable-your-device-for-development"
+                    )
+                );
+            } else if (selected === "Don't Show Again") {
+                configuration.warnAboutSymlinkCreation = false;
+            }
+        });
+    }
+}
+
+/**
+ * Checks to see if the platform allows creating symlinks.
+ *
+ * @returns whether or not a symlink can be created
+ */
+export async function isSymlinkAllowed(outputChannel?: SwiftOutputChannel): Promise<boolean> {
+    const temporaryFolder = await TemporaryFolder.create();
+    return await temporaryFolder.withTemporaryFile("", async testFilePath => {
+        const testSymlinkPath = temporaryFolder.filename("symlink-");
+        try {
+            await fs.symlink(testFilePath, testSymlinkPath, "file");
+            await fs.unlink(testSymlinkPath);
+            return true;
+        } catch (error) {
+            outputChannel?.log(`${error}`);
+            return false;
+        }
+    });
+}