do not use empty string to indicate lookup in PATH

package.json

@@ -110,7 +110,7 @@
             "null"
           ],
           "default": null,
-          "description": "Set a custom path to the Zig binary. Empty string will lookup zig in PATH."
+          "description": "Set a custom path to the Zig binary. The string \"zig\" means lookup zig in PATH."
         },
         "zig.checkForUpdate": {
           "scope": "resource",
@@ -173,7 +173,7 @@
             "null"
           ],
           "default": null,
-          "description": "Path to `zls` executable. Example: `C:/zls/zig-cache/bin/zls.exe`. Empty string will lookup ZLS in PATH.",
+          "description": "Path to `zls` executable. Example: `C:/zls/zig-cache/bin/zls.exe`. The string \"zls\" means lookup ZLS in PATH.",
           "format": "path"
         },
         "zig.zls.enableSnippets": {

src/zigSetup.ts

@@ -187,12 +187,8 @@ async function checkUpdate(context: vscode.ExtensionContext) {
 async function getUpdatedVersion(context: vscode.ExtensionContext): Promise<ZigVersion | null> {
     const configuration = vscode.workspace.getConfiguration("zig");
     const zigPath = configuration.get<string | null>("path", null);
-    if (zigPath) {
-        const zigBinPath = vscode.Uri.joinPath(context.globalStorageUri, "zig_install", "zig").fsPath;
-        if (!zigPath.startsWith(zigBinPath)) return null;
-    } else {
-        return null;
-    }
+    const zigBinPath = vscode.Uri.joinPath(context.globalStorageUri, "zig_install", "zig").fsPath;
+    if (!zigPath?.startsWith(zigBinPath)) return null;
 
     const curVersion = getVersion(zigPath, "version");
     if (!curVersion) return null;
@@ -222,13 +218,29 @@ export async function setupZig(context: vscode.ExtensionContext) {
         await checkUpdate(context);
     });
 
+    {
+        // convert an empty string for `zig.path` and `zig.zls.path` to `zig` and `zls` respectively.
+        // This check can be removed once enough time has passed so that most users switched to the new value
+
+        const zigConfig = vscode.workspace.getConfiguration("zig");
+        const initialSetupDone = zigConfig.get<boolean>("initialSetupDone", false);
+        const zigPath = zigConfig.get<string | null>("path");
+        if (zigPath === "" || (initialSetupDone && zigPath === null)) {
+            await zigConfig.update("path", "zig", true);
+        }
+
+        const zlsConfig = vscode.workspace.getConfiguration("zig.zls");
+        const zlsPath = zlsConfig.get<string | null>("path");
+        if (zlsPath === "" || (initialSetupDone && zlsPath === null)) {
+            await zlsConfig.update("path", "zls", true);
+        }
+    }
+
     const configuration = vscode.workspace.getConfiguration("zig");
     if (!configuration.get<boolean>("initialSetupDone")) {
         await configuration.update("initialSetupDone", await initialSetup(context), true);
     }
 
-    // The `path` value may have changed after the initial setup is done but it will not need updating
-    if (!configuration.get<string | null>("path", null)) return; // also returns on ""
     if (!configuration.get<boolean>("checkForUpdate")) return;
     if (!(await shouldCheckUpdate(context, "zigUpdate"))) return;
     await checkUpdate(context);
@@ -269,7 +281,7 @@ async function initialSetup(context: vscode.ExtensionContext): Promise<boolean>
                 await zigConfig.update("path", uris[0].path, true);
                 break;
             case "Use Zig in PATH":
-                await zigConfig.update("path", "", true);
+                await zigConfig.update("path", "zig", true);
                 break;
             case undefined:
                 await zigConfig.update("path", undefined, true);
@@ -303,7 +315,7 @@ async function initialSetup(context: vscode.ExtensionContext): Promise<boolean>
 
                 await zlsConfig.update("path", uris[0].path, true);
             case "Use ZLS in PATH":
-                await zlsConfig.update("path", "", true);
+                await zlsConfig.update("path", "zls", true);
                 break;
             case undefined:
                 // explicitly set `zig.zls.path` to null so it is visible in the `settings.json`

src/zigUtil.ts

@@ -21,7 +21,7 @@ export function getExePath(exePath: string | null, exeName: string, optionName:
         }
     }
 
-    if (!exePath) {
+    if (exePath === null) {
         exePath = which.sync(exeName, { nothrow: true });
     } else if (exePath.startsWith("~")) {
         exePath = path.join(os.homedir(), exePath.substring(1));
@@ -30,7 +30,7 @@ export function getExePath(exePath: string | null, exeName: string, optionName:
     }
 
     let message;
-    if (!exePath) {
+    if (exePath === null) {
         message = `Could not find ${exeName} in PATH`;
     } else if (!fs.existsSync(exePath)) {
         message = `\`${optionName}\` ${exePath} does not exist`;
@@ -49,7 +49,8 @@ export function getExePath(exePath: string | null, exeName: string, optionName:
 export function getZigPath(): string {
     const configuration = vscode.workspace.getConfiguration("zig");
     const zigPath = configuration.get<string | null>("path", null);
-    return getExePath(zigPath, "zig", "zig.path");
+    const exePath = zigPath !== "zig" ? zigPath : null; // the string "zig" means lookup in PATH
+    return getExePath(exePath, "zig", "zig.path");
 }
 
 // Check timestamp `key` to avoid automatically checking for updates

src/zls.ts

@@ -94,7 +94,8 @@ export async function stopClient() {
 export function getZLSPath(): string {
     const configuration = vscode.workspace.getConfiguration("zig.zls");
     const zlsPath = configuration.get<string | null>("path", null);
-    return getExePath(zlsPath, "zls", "zig.zls.path");
+    const exePath = zlsPath !== "zls" ? zlsPath : null; // the string "zls" means lookup in PATH
+    return getExePath(exePath, "zls", "zig.zls.path");
 }
 
 const downloadsRoot = "https://zigtools-releases.nyc3.digitaloceanspaces.com/zls";