Use file system path

On windows, the `Uri.path` will return an extra folder, as we can see in the tests:

```
ENOENT: no such file or directory, open 'D:\C:\Users\RUNNER~1\AppData\Local\Temp\tmp-4784XPDQPb5jM6IW\test-ql-pack-ruby\qlpack.yml'
```

Let's use `Uri.fsPath` instead.

Author: elenatanasoiu

extensions/ql-vscode/src/qlpack-generator.ts

@@ -64,7 +64,7 @@ export class QlPackGenerator {
   }
 
   private async createQlPackYaml() {
-    const qlPackFilePath = join(this.folderUri.path, this.qlpackFileName);
+    const qlPackFilePath = join(this.folderUri.fsPath, this.qlpackFileName);
 
     const qlPackYml = {
       name: this.qlpackName,
@@ -78,7 +78,7 @@ export class QlPackGenerator {
   }
 
   private async createExampleQlFile() {
-    const exampleQlFilePath = join(this.folderUri.path, "example.ql");
+    const exampleQlFilePath = join(this.folderUri.fsPath, "example.ql");
 
     const exampleQl = `
 /**
@@ -98,6 +98,6 @@ select "Hello, world!"
   }
 
   private async createCodeqlPackLockYaml() {
-    await this.cliServer.packAdd(this.folderUri.path, this.queryLanguage);
+    await this.cliServer.packAdd(this.folderUri.fsPath, this.queryLanguage);
   }
 }

extensions/ql-vscode/test/vscode-tests/minimal-workspace/qlpack-generator.test.ts

@@ -2,8 +2,7 @@ import { join } from "path";
 import { existsSync } from "fs";
 import { QlPackGenerator, QueryLanguage } from "../../../src/qlpack-generator";
 import { CodeQLCliServer } from "../../../src/cli";
-import { isFolderAlreadyInWorkspace } from "../../../src/helpers";
-import { workspace } from "vscode";
+import { Uri, workspace } from "vscode";
 import { getErrorMessage } from "../../../src/pure/helpers-pure";
 import * as tmp from "tmp";
 
@@ -22,7 +21,7 @@ describe("QlPackGenerator", () => {
 
     language = "ruby";
     packFolderName = `test-ql-pack-${language}`;
-    packFolderPath = join(dir.name, packFolderName);
+    packFolderPath = Uri.file(join(dir.name, packFolderName)).fsPath;
 
     qlPackYamlFilePath = join(packFolderPath, "qlpack.yml");
     exampleQlFilePath = join(packFolderPath, "example.ql");
@@ -60,15 +59,16 @@ describe("QlPackGenerator", () => {
   });
 
   it("should generate a QL pack", async () => {
-    expect(isFolderAlreadyInWorkspace(packFolderName)).toBe(false);
+    expect(existsSync(packFolderPath)).toBe(false);
     expect(existsSync(qlPackYamlFilePath)).toBe(false);
     expect(existsSync(exampleQlFilePath)).toBe(false);
 
     await generator.generate();
 
-    expect(isFolderAlreadyInWorkspace(packFolderName)).toBe(true);
+    expect(existsSync(packFolderPath)).toBe(true);
     expect(existsSync(qlPackYamlFilePath)).toBe(true);
     expect(existsSync(exampleQlFilePath)).toBe(true);
+
     expect(packAddSpy).toHaveBeenCalledWith(packFolderPath, language);
   });
 });