guard against exceptions when updating configuration

src/zigProvider.ts

@@ -2,7 +2,7 @@ import vscode from "vscode";
 
 import semver from "semver";
 
-import { resolveExePathAndVersion } from "./zigUtil";
+import { resolveExePathAndVersion, workspaceConfigUpdateNoThrow } from "./zigUtil";
 
 interface ExeWithVersion {
     exe: string;
@@ -50,13 +50,14 @@ export class ZigProvider implements vscode.Disposable {
      * @param zigPath The path to the zig executable. If `null`, the `zig.path` config option will be removed.
      */
     public async setAndSave(zigPath: string | null) {
+        const zigConfig = vscode.workspace.getConfiguration("zig");
         if (!zigPath) {
-            await vscode.workspace.getConfiguration("zig").update("path", undefined, true);
+            await workspaceConfigUpdateNoThrow(zigConfig, "path", undefined, true);
             return;
         }
         const newValue = this.resolveZigPathConfigOption(zigPath);
         if (!newValue) return;
-        await vscode.workspace.getConfiguration("zig").update("path", newValue.exe, true);
+        await workspaceConfigUpdateNoThrow(zigConfig, "path", newValue.exe, true);
         this.set(newValue);
     }
 

src/zigSetup.ts

@@ -7,7 +7,14 @@ import semver from "semver";
 
 import * as minisign from "./minisign";
 import * as versionManager from "./versionManager";
-import { VersionIndex, ZigVersion, asyncDebounce, getHostZigName, resolveExePathAndVersion } from "./zigUtil";
+import {
+    VersionIndex,
+    ZigVersion,
+    asyncDebounce,
+    getHostZigName,
+    resolveExePathAndVersion,
+    workspaceConfigUpdateNoThrow,
+} from "./zigUtil";
 import { ZigProvider } from "./zigProvider";
 
 let statusItem: vscode.StatusBarItem;
@@ -52,7 +59,8 @@ async function installZig(context: vscode.ExtensionContext, temporaryVersion?: s
 
     try {
         const exePath = await versionManager.install(versionManagerConfig, version);
-        await vscode.workspace.getConfiguration("zig").update("path", undefined, true);
+        const zigConfig = vscode.workspace.getConfiguration("zig");
+        await workspaceConfigUpdateNoThrow(zigConfig, "path", undefined, true);
         zigProvider.set({ exe: exePath, version: version });
     } catch (err) {
         zigProvider.set(null);
@@ -272,7 +280,8 @@ async function selectVersionAndInstall(context: vscode.ExtensionContext) {
             await installZig(context);
             break;
         case "Use Zig in PATH":
-            await vscode.workspace.getConfiguration("zig").update("path", "zig", true);
+            const zigConfig = vscode.workspace.getConfiguration("zig");
+            await workspaceConfigUpdateNoThrow(zigConfig, "path", "zig", true);
             break;
         case "Manually Specify Path":
             const uris = await vscode.window.showOpenDialog({
@@ -573,10 +582,10 @@ export async function setupZig(context: vscode.ExtensionContext) {
         const zigConfig = vscode.workspace.getConfiguration("zig");
         const zigPath = zigConfig.get<string>("path", "");
         if (zigPath.startsWith(context.globalStorageUri.fsPath)) {
-            await zigConfig.update("path", undefined, true);
+            await workspaceConfigUpdateNoThrow(zigConfig, "path", undefined, true);
         }
 
-        await zigConfig.update("initialSetupDone", undefined, true);
+        await workspaceConfigUpdateNoThrow(zigConfig, "initialSetupDone", undefined, true);
 
         await context.workspaceState.update("zig-version", undefined);
     }

src/zigUtil.ts

@@ -121,6 +121,28 @@ export function asyncDebounce<T extends (...args: unknown[]) => Promise<Awaited<
         });
 }
 
+/**
+ * Wrapper around `vscode.WorkspaceConfiguration.update` that doesn't throw an exception.
+ * A common cause of an exception is when the `settings.json` file is read-only.
+ */
+export async function workspaceConfigUpdateNoThrow(
+    config: vscode.WorkspaceConfiguration,
+    section: string,
+    value: unknown,
+    configurationTarget?: vscode.ConfigurationTarget | boolean | null,
+    overrideInLanguage?: boolean,
+): Promise<void> {
+    try {
+        await config.update(section, value, configurationTarget, overrideInLanguage);
+    } catch (err) {
+        if (err instanceof Error) {
+            void vscode.window.showErrorMessage(err.message);
+        } else {
+            void vscode.window.showErrorMessage("failed to update settings.json");
+        }
+    }
+}
+
 // Check timestamp `key` to avoid automatically checking for updates
 // more than once in an hour.
 export async function shouldCheckUpdate(context: vscode.ExtensionContext, key: string): Promise<boolean> {

src/zls.ts

@@ -17,7 +17,7 @@ import semver from "semver";
 
 import * as minisign from "./minisign";
 import * as versionManager from "./versionManager";
-import { getHostZigName, handleConfigOption, resolveExePathAndVersion } from "./zigUtil";
+import { getHostZigName, handleConfigOption, resolveExePathAndVersion, workspaceConfigUpdateNoThrow } from "./zigUtil";
 import { zigProvider } from "./zigSetup";
 
 const ZIG_MODE: DocumentSelector = [
@@ -201,8 +201,13 @@ async function configurationMiddleware(
             switch (response) {
                 case `Use ${optionName} instead`:
                     const { [optionName]: newValue, ...updatedAdditionalOptions } = additionalOptions;
-                    await configuration.update("additionalOptions", updatedAdditionalOptions, true);
-                    await configuration.update(section, newValue, true);
+                    await workspaceConfigUpdateNoThrow(
+                        configuration,
+                        "additionalOptions",
+                        updatedAdditionalOptions,
+                        true,
+                    );
+                    await workspaceConfigUpdateNoThrow(configuration, section, newValue, true);
                     break;
                 case "Show zig.zls.additionalOptions":
                     await vscode.commands.executeCommand("workbench.action.openSettingsJson", {
@@ -337,10 +342,10 @@ async function isEnabled(): Promise<boolean> {
             );
             switch (response) {
                 case "Yes":
-                    await zlsConfig.update("enabled", "on", true);
+                    await workspaceConfigUpdateNoThrow(zlsConfig, "enabled", "on", true);
                     return true;
                 case "No":
-                    await zlsConfig.update("enabled", "off", true);
+                    await workspaceConfigUpdateNoThrow(zlsConfig, "enabled", "off", true);
                     return false;
                 case undefined:
                     return false;
@@ -391,8 +396,8 @@ export async function activate(context: vscode.ExtensionContext) {
         const zlsConfig = vscode.workspace.getConfiguration("zig.zls");
         const zlsPath = zlsConfig.get<string>("path", "");
         if (zlsPath.startsWith(context.globalStorageUri.fsPath)) {
-            await zlsConfig.update("enabled", "on", true);
-            await zlsConfig.update("path", undefined, true);
+            await workspaceConfigUpdateNoThrow(zlsConfig, "enabled", "on", true);
+            await workspaceConfigUpdateNoThrow(zlsConfig, "path", undefined, true);
         }
     }
 
@@ -421,14 +426,14 @@ export async function activate(context: vscode.ExtensionContext) {
         statusItem,
         vscode.commands.registerCommand("zig.zls.enable", async () => {
             const zlsConfig = vscode.workspace.getConfiguration("zig.zls");
-            await zlsConfig.update("enabled", "on", true);
+            await workspaceConfigUpdateNoThrow(zlsConfig, "enabled", "on", true);
         }),
         vscode.commands.registerCommand("zig.zls.stop", async () => {
             await stopClient();
         }),
         vscode.commands.registerCommand("zig.zls.startRestart", async () => {
             const zlsConfig = vscode.workspace.getConfiguration("zig.zls");
-            await zlsConfig.update("enabled", "on", true);
+            await workspaceConfigUpdateNoThrow(zlsConfig, "enabled", "on", true);
             await restartClient(context);
         }),
         vscode.commands.registerCommand("zig.zls.openOutput", () => {