previously added assert was using wrong path (__dirname rather than _…

…_dirname/..)

fixed the assert and added comments indicating what is supposed to point what.

server/src/languageServerBase.ts

@@ -14,7 +14,6 @@ import {
 
 import { AnalyzerService } from './analyzer/service';
 import { CommandLineOptions } from './common/commandLineOptions';
-import * as debug from './common/debug'
 import { Diagnostic as AnalyzerDiagnostic, DiagnosticCategory } from './common/diagnostic';
 import './common/extensions';
 import { combinePaths, convertPathToUri, convertUriToPath, normalizePath } from './common/pathUtils';
@@ -61,7 +60,6 @@ export abstract class LanguageServerBase {
         // virtual file system to be used. initialized to real file system by default. but can't be overritten
         this.fs = createFromRealFileSystem(this.connection.console);
         // Stash the base directory into a global variable.
-        debug.assertDefined(rootDirectory);
         (global as any).__rootDirectory = rootDirectory;
         this.connection.console.log(`Server root directory: ${ rootDirectory }`);
 

server/src/server.ts

@@ -18,8 +18,18 @@ class Server extends LanguageServerBase {
     private _controller: CommandController;
 
     constructor() {
-        debug.assert(fs.existsSync(path.join(__dirname, 'typeshed-fallback')), 'Unable to locate typeshed fallback folder.');
-        super('Pyright', getDirectoryPath(__dirname));
+        // pyright has "typeshed-fallback" under "client" and __dirname points to "client/server"
+        // make sure root directory point to "client", one level up from "client/server" where we can discover
+        // "typeshed-fallback" folder. in release, root is "extension" instead of "client" but
+        // folder structure is same (extension/server).
+        //
+        // root directory will be used for 2 different purposes.
+        // 1. to find "typeshed-fallback" folder.
+        // 2. to set "cwd" to run python to find search path.
+        const rootDirectory = getDirectoryPath(__dirname);
+        debug.assert(fs.existsSync(path.join(rootDirectory, 'typeshed-fallback')), `Unable to locate typeshed fallback folder at '${ rootDirectory }'`);
+        super('Pyright', rootDirectory);
+
         this._controller = new CommandController(this);
     }
 

server/src/tests/testUtils.ts

@@ -19,8 +19,8 @@ import { TestWalker } from '../analyzer/testWalker';
 import { cloneDiagnosticSettings, ConfigOptions, ExecutionEnvironment } from '../common/configOptions';
 import { Diagnostic, DiagnosticCategory } from '../common/diagnostic';
 import { DiagnosticSink, TextRangeDiagnosticSink } from '../common/diagnosticSink';
-import { ParseOptions, Parser, ParseResults } from '../parser/parser';
 import { createFromRealFileSystem } from '../common/vfs';
+import { ParseOptions, Parser, ParseResults } from '../parser/parser';
 
 // This is a bit gross, but it's necessary to allow the fallback typeshed
 // directory to be located when running within the jest environment. This