Merge branch 'more-error-handling'

vscode/package.json

@@ -1025,6 +1025,7 @@
         "@viz-js/viz": "^3.0.1",
         "@vscode/codicons": "^0.0.32",
         "@vscode/webview-ui-toolkit": "^1.4.0",
+        "axios": "^1.6.8",
         "cytoscape": "^3.28.1",
         "cytoscape-context-menus": "^4.1.0",
         "cytoscape-cose-bilkent": "^4.1.0",

vscode/src/main.ts

@@ -31,12 +31,20 @@ let lspClient: LanguageClient;
 export async function activate(context: vscode.ExtensionContext) {
     log = vscode.window.createOutputChannel("Auxon");
 
+    const apiUrl = await config.modalityUrl();
+    const modalitydIsAlive = await api.isModalitydReachable(apiUrl.toString());
+    if (!modalitydIsAlive) {
+        const msg =
+            `The Auxon Modality backend server cannot be reached at '${apiUrl}'. ` +
+            `If modalityd is not running locally, set the 'auxon.modalityUrl' configuration`;
+        throw new Error(msg);
+    }
+
     // If this is a fresh install, prompt for new first user creation
     await user.handleNewUserCreation();
 
     lspClient = await lsp.activateLspClient(context);
 
-    const apiUrl = await config.modalityUrl();
     const allowInsecure = await config.allowInsecureHttps();
     let token = await config.userAuthToken();
 

vscode/src/modalityApi.ts

@@ -1,5 +1,6 @@
 import * as gen from "./generated/src/modality-api";
 import createClient from "openapi-fetch";
+import axios from "axios";
 
 // See https://github.com/ajaishankar/openapi-typescript-fetch#server-side-usage
 import fetch, { Headers, Request, Response } from "node-fetch";
@@ -75,6 +76,19 @@ export type Experiment = gen.components["schemas"]["Experiment"];
 
 type InternalClient = ReturnType<typeof createClient<gen.paths>>;
 
+export async function isModalitydReachable(baseUrl: string): Promise<boolean> {
+    if (baseUrl.endsWith("/")) {
+        baseUrl = baseUrl.slice(0, -1);
+    }
+    const url = baseUrl + "/v1/alive";
+    try {
+        const _response = await axios.get(url);
+    } catch (_exception) {
+        return false;
+    }
+    return true;
+}
+
 export class Client {
     client: InternalClient;