Avoid AST Viewer for invalid selections

When a directory is selected or there are multiple selections, do not
show the command.

extensions/ql-vscode/CHANGELOG.md

@@ -2,12 +2,13 @@
 
 ## [UNRELEASED]
 
+- Fix a bug where invoking _View AST_ from the file explorer would not view the selected file. Instead it would view the active editor. Also, prevent the _View AST_ from appearing if the current selection includes a directory or multiple files. [#1113](https://github.com/github/vscode-codeql/pull/1113)
+
 ## 1.5.10 - 25 January 2022
 
 - Fix a bug where the results view moved column even when it was already visible. [#1070](https://github.com/github/vscode-codeql/pull/1070)
 - Add packaging-related commands. _CodeQL: Download Packs_ downloads query packs from the package registry that can be run locally, and _CodeQL: Install Pack Dependencies_ installs dependencies for packs in your workspace. [#1076](https://github.com/github/vscode-codeql/pull/1076)
 - Add query history items as soon as a query is run, including new icons for each history item. [#1094](https://github.com/github/vscode-codeql/pull/1094)
-- Fix a bug where invoking _View AST_ from the file explorer would not view the selected file. Instead it would view the active editor. [#1113](https://github.com/github/vscode-codeql/pull/1113)
 
 ## 1.5.9 - 17 December 2021
 

extensions/ql-vscode/package.json

@@ -735,7 +735,7 @@
         {
           "command": "codeQL.viewAst",
           "group": "9_qlCommands",
-          "when": "resourceScheme == codeql-zip-archive"
+          "when": "resourceScheme == codeql-zip-archive && !explorerResourceIsFolder && !listMultiSelection"
         },
         {
           "command": "codeQL.runQueries",

extensions/ql-vscode/src/extension.ts

@@ -1002,9 +1002,8 @@ async function activateWithInstalledDistribution(
   ctx.subscriptions.push(commandRunnerWithProgress('codeQL.viewAst', async (
     progress: ProgressCallback,
     token: CancellationToken,
-    selectedFile: Uri,
+    selectedFile: Uri
   ) => {
-
     const ast = await templateProvider.provideAst(
       progress,
       token,