feat: vendor permission system source

pi-permission-system/test/helpers/fake-ts-node.ts

@@ -0,0 +1,28 @@
+import type { TSNode } from "#src/access-intent/bash/parser";
+
+/**
+ * Build a fake {@link TSNode} for testing the pure AST helpers without paying
+ * for a real tree-sitter parse.
+ *
+ * Fills only the fields those helpers read; `children` drives both `childCount`
+ * and `child(i)`, so a node's structural shape (delimiters plus a
+ * `variable_name`, a quoted string's inner content) can be expressed directly.
+ *
+ * Prefer a real parse (`getParser()`) when the test's subject is the AST shape
+ * tree-sitter actually produces; use this when the subject is the helper's
+ * behavior given a shape.
+ */
+export function makeTSNode(
+  type: string,
+  text: string,
+  children: TSNode[] = [],
+): TSNode {
+  return {
+    type,
+    text,
+    startIndex: 0,
+    childCount: children.length,
+    isNamed: true,
+    child: (i) => children[i] ?? null,
+  };
+}