Reformat project into workspaces

api/src/category.repository.ts

@@ -0,0 +1,30 @@
+// structural interface to the test table
+export interface CatetoryNode {
+    id: number;
+    name: string;
+    path: string; // ltree field
+}
+
+export class CategoryRepository {
+    // simulate generating a SQL query targeting child paths
+    generateDescendantsQuery(parentPath: string): { sql: string; values: string[] } {
+        return {
+            sql: 'SELECT id, name, path FROM categories WHERE path <@ $1::ltree',
+            values: [parentPath]
+        };
+    }
+
+    generateWildcardQuery(pattern: string): { sql: string, values: string[] } {
+        // Simulate genrating a SQL query using ltree wildcards
+        return {
+            sql: 'SELECT id, name, path FROM categories WHERE path ~ $1::lquery',
+            values: [pattern]
+        };
+    }
+
+    // helper utility to validate a string as an ltree value
+    isValidLtreePath(path: string): boolean {
+        const ltreeRegex = /^[A-Za-z0-9_]+(\.[A-Za-z0-9_]+)*$/;
+        return ltreeRegex.test(path);
+    }
+}