feat(vscode): support custom rstest package path (#679)

Author: njzydark

packages/vscode/package.json

@@ -48,6 +48,11 @@
             "debug"
           ],
           "default": "default"
+        },
+        "rstest.rstestPackagePath": {
+          "markdownDescription": "The path to a `package.json` file of a Rstest executable (it's usually inside `node_modules`) in case the extension cannot find it. It will be used to resolve Rstest API paths. This should be used as a last resort fix. Supports `${workspaceFolder}` placeholder.",
+          "scope": "resource",
+          "type": "string"
         }
       }
     }

packages/vscode/src/config.ts

@@ -10,6 +10,9 @@ export type ExtensionConfig = {
   testFileGlobPattern: string[];
   // Controls verbosity of extension logging routed to the Output channel.
   logLevel: LogLevel;
+  // The path to a package.json file of a Rstest executable.
+  // Used as a last resort if the extension cannot auto-detect @rstest/core.
+  rstestPackagePath?: string;
 };
 
 export const defaultConfig: ExtensionConfig = {
@@ -44,6 +47,13 @@ export function getConfigValue<K extends keyof ExtensionConfig>(
     return (isLogLevel(v) ? v : defaultConfig[key]) as ExtensionConfig[K];
   }
 
+  if (key === 'rstestPackagePath') {
+    const v = value as unknown;
+    return (
+      typeof v === 'string' && v.trim().length > 0 ? v : undefined
+    ) as ExtensionConfig[K];
+  }
+
   return value as ExtensionConfig[K];
 }
 
@@ -60,5 +70,6 @@ export function getConfig(folder?: vscode.WorkspaceFolder): ExtensionConfig {
   return {
     testFileGlobPattern: getConfigValue('testFileGlobPattern', folder),
     logLevel: getConfigValue('logLevel', folder),
+    rstestPackagePath: getConfigValue('rstestPackagePath', folder),
   } satisfies ExtensionConfig;
 }

packages/vscode/src/master.ts

@@ -1,10 +1,11 @@
 import { spawn } from 'node:child_process';
 import { createServer } from 'node:http';
-import path from 'node:path';
+import path, { dirname } from 'node:path';
 import getPort from 'get-port';
 import vscode from 'vscode';
 import type { WebSocket } from 'ws';
 import { WebSocketServer } from 'ws';
+import { getConfigValue } from './config';
 import { logger } from './logger';
 import type {
   WorkerEvent,
@@ -26,17 +27,54 @@ export class RstestApi {
       // TODO: use 0 temporarily.
       const workspace = vscode.workspace.workspaceFolders?.[0];
       if (!workspace) {
-        vscode.window.showErrorMessage('No workspace found');
         throw new Error('No workspace found');
       }
-      const nodeExport = require.resolve('@rstest/core', {
-        paths: [workspace.uri.fsPath],
-      });
+
+      // Check if user configured a custom package path (last resort fix)
+      let configuredPackagePath = getConfigValue(
+        'rstestPackagePath',
+        workspace,
+      );
+
+      if (configuredPackagePath) {
+        // Support ${workspaceFolder} placeholder
+        configuredPackagePath = configuredPackagePath.replace(
+          // biome-ignore lint: This is a VS Code config placeholder string
+          '${workspaceFolder}',
+          workspace.uri.fsPath,
+        );
+        // Validate that the path points to package.json
+        if (!configuredPackagePath.endsWith('package.json')) {
+          const errorMessage = `"rstest.rstestPackagePath" must point to a package.json file, instead got: ${configuredPackagePath}`;
+          throw new Error(errorMessage);
+        }
+
+        // User provided a custom path to package.json
+        configuredPackagePath = path.isAbsolute(configuredPackagePath)
+          ? configuredPackagePath
+          : path.resolve(workspace.uri.fsPath, configuredPackagePath);
+
+        logger.debug(
+          'Using configured rstestPackagePath:',
+          configuredPackagePath,
+        );
+      }
+
+      const nodeExport = require.resolve(
+        configuredPackagePath ? dirname(configuredPackagePath) : '@rstest/core',
+        {
+          paths: [workspace.uri.fsPath],
+        },
+      );
+
       let corePackageJsonPath: string;
       try {
-        corePackageJsonPath = require.resolve('@rstest/core/package.json', {
-          paths: [workspace.uri.fsPath],
-        });
+        corePackageJsonPath = require.resolve(
+          configuredPackagePath || '@rstest/core/package.json',
+          {
+            paths: [workspace.uri.fsPath],
+          },
+        );
       } catch (e) {
         vscode.window.showErrorMessage(
           'Failed to resolve @rstest/core/package.json. Please upgrade @rstest/core to the latest version.',