Fix crash in codeql.debugQuery when run from command palette

Author: Dave Bartolomeo

extensions/ql-vscode/src/common/commands.ts

@@ -150,7 +150,7 @@ export type LocalQueryCommands = {
 
 // Debugger commands
 export type DebuggerCommands = {
-  "codeQL.debugQuery": (uri: Uri) => Promise<void>;
+  "codeQL.debugQuery": (uri: Uri | undefined) => Promise<void>;
   "codeQL.debugQueryContextEditor": (uri: Uri) => Promise<void>;
   "codeQL.startDebuggingSelection": () => Promise<void>;
   "codeQL.startDebuggingSelectionContextEditor": () => Promise<void>;

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

@@ -185,8 +185,11 @@ export class DebuggerUI
     this.sessions.delete(session.id);
   }
 
-  private async debugQuery(uri: Uri): Promise<void> {
-    const queryPath = validateQueryUri(uri, false);
+  private async debugQuery(uri: Uri | undefined): Promise<void> {
+    const queryPath =
+      uri !== undefined
+        ? validateQueryUri(uri, false)
+        : await this.localQueries.getCurrentQuery(false);
 
     // Start debugging with a default configuration that just specifies the query path.
     await debug.startDebugging(undefined, {

extensions/ql-vscode/src/local-queries.ts

@@ -412,7 +412,7 @@ export class LocalQueries extends DisposableObject {
    * For now, the "active query" is just whatever query is in the active text editor. Once we have a
    * propery "queries" panel, we can provide a way to select the current query there.
    */
-  private async getCurrentQuery(allowLibraryFiles: boolean): Promise<string> {
+  public async getCurrentQuery(allowLibraryFiles: boolean): Promise<string> {
     const editor = window.activeTextEditor;
     if (editor === undefined) {
       throw new Error(