Introduce command to set default Code Tour database

extensions/ql-vscode/src/databases-ui.ts

@@ -12,6 +12,7 @@ import {
   CancellationToken,
   ThemeIcon,
   ThemeColor,
+  workspace,
 } from "vscode";
 import { pathExists, stat, readdir, remove } from "fs-extra";
 
@@ -218,6 +219,15 @@ export class DatabaseUI extends DisposableObject {
         },
       ),
     );
+    this.push(
+      commandRunnerWithProgress(
+        "codeQL.setDefaultTourDatabase",
+        this.handleSetDefaultTourDatabase,
+        {
+          title: "Set Default Database for Codespace CodeQL Tour",
+        },
+      ),
+    );
     this.push(
       commandRunnerWithProgress(
         "codeQL.upgradeCurrentDatabase",
@@ -348,6 +358,40 @@ export class DatabaseUI extends DisposableObject {
     }
   };
 
+  private handleSetDefaultTourDatabase = async (
+    progress: ProgressCallback,
+    token: CancellationToken,
+  ): Promise<void> => {
+    try {
+      if (!workspace.workspaceFolders?.length) {
+        throw new Error("No workspace folder is open.");
+      } else {
+        // This specifically refers to the database folder in
+        // https://github.com/github/codespaces-codeql
+        const uri = Uri.parse(
+          `${workspace.workspaceFolders[0].uri}/codeql-tutorial-database`,
+        );
+
+        let databaseItem = this.databaseManager.findDatabaseItem(uri);
+        if (databaseItem === undefined) {
+          databaseItem = await this.databaseManager.openDatabase(
+            progress,
+            token,
+            uri,
+          );
+        }
+        await this.databaseManager.setCurrentDatabaseItem(databaseItem);
+      }
+    } catch (e) {
+      // rethrow and let this be handled by default error handling.
+      throw new Error(
+        `Could not set the database for the Code Tour. Please make sure you are using the default workspace in your codespace: ${getErrorMessage(
+          e,
+        )}`,
+      );
+    }
+  };
+
   handleRemoveOrphanedDatabases = async (): Promise<void> => {
     void extLogger.log("Removing orphaned databases from workspace storage.");
     let dbDirs = undefined;