Convert makeArray to use NotArray

Author: robertbrignull

extensions/ql-vscode/src/common/helpers-pure.ts

@@ -7,6 +7,18 @@
 
 import { RedactableError } from "./errors";
 
+// Matches any type that is not an array. This is useful to help avoid
+// nested arrays, or for cases like createSingleSelectionCommand to avoid T
+// accidentally getting instantiated as DatabaseItem[] instead of DatabaseItem.
+export type NotArray =
+  | string
+  | bigint
+  | number
+  | boolean
+  | (object & {
+      length?: never;
+    });
+
 /**
  * This error is used to indicate a runtime failure of an exhaustivity check enforced at compile time.
  */

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

@@ -3,14 +3,10 @@ import type {
   TreeViewContextMultiSelectionCommandFunction,
   TreeViewContextSingleSelectionCommandFunction,
 } from "../commands";
+import type { NotArray } from "../helpers-pure";
 import type { NotificationLogger } from "../logging";
 import { showAndLogErrorMessage } from "../logging";
 
-// A hack to match types that are not an array, which is useful to help avoid
-// misusing createSingleSelectionCommand, e.g. where T accidentally gets instantiated
-// as DatabaseItem[] instead of DatabaseItem.
-type NotArray = object & { length?: never };
-
 // A way to get the type system to help assert that one type is a supertype of another.
 type CreateSupertypeOf<Super, Sub extends Super> = Sub;
 

extensions/ql-vscode/src/debugger/debug-configuration.ts

@@ -8,6 +8,7 @@ import { getOnDiskWorkspaceFolders } from "../common/vscode/workspace-folders";
 import type { LocalQueries } from "../local-queries";
 import { getQuickEvalContext, validateQueryPath } from "../run-queries-shared";
 import type { LaunchConfig } from "./debug-protocol";
+import type { NotArray } from "../common/helpers-pure";
 import { getErrorMessage } from "../common/helpers-pure";
 import { showAndLogErrorMessage } from "../common/logging";
 import { extLogger } from "../common/logging/vscode";
@@ -39,7 +40,7 @@ export type QLDebugConfiguration = DebugConfiguration & QLDebugArgs;
 export type QLResolvedDebugConfiguration = DebugConfiguration & LaunchConfig;
 
 /** If the specified value is a single element, then turn it into an array containing that element. */
-function makeArray<T extends Exclude<unknown, unknown[]>>(value: T | T[]): T[] {
+function makeArray<T extends NotArray>(value: T | T[]): T[] {
   if (Array.isArray(value)) {
     return value;
   } else {