feat: added template based permission

backend/src/lib/knex/dynamic.ts

@@ -0,0 +1,88 @@
+import { Knex } from "knex";
+
+import { UnauthorizedError } from "../errors";
+
+type TKnexDynamicPrimitiveOperator = {
+  operator: "eq" | "ne" | "startsWith" | "endsWith";
+  value: string;
+  field: string;
+};
+
+type TKnexDynamicInOperator = {
+  operator: "in";
+  value: string[] | number[];
+  field: string;
+};
+
+type TKnexNonGroupOperator = TKnexDynamicInOperator | TKnexDynamicPrimitiveOperator;
+
+type TKnexGroupOperator = {
+  operator: "and" | "or" | "not";
+  value: (TKnexNonGroupOperator | TKnexGroupOperator)[];
+};
+
+// used when you need to write a complex query with the orm
+// use it when you need complex or and and condition - most of the time not needed
+// majorly used with casl permission to filter data based on permission
+export type TKnexDynamicOperator = TKnexGroupOperator | TKnexNonGroupOperator;
+
+export const buildDynamicKnexQuery = (dynamicQuery: TKnexDynamicOperator, rootQueryBuild: Knex.QueryBuilder) => {
+  const stack = [{ filterAst: dynamicQuery, queryBuilder: rootQueryBuild }];
+
+  while (stack.length) {
+    const { filterAst, queryBuilder } = stack.pop()!;
+    switch (filterAst.operator) {
+      case "eq": {
+        void queryBuilder.where(filterAst.field, filterAst.value);
+        break;
+      }
+      case "ne": {
+        void queryBuilder.where(filterAst.field, filterAst.value);
+        break;
+      }
+      case "startsWith": {
+        void queryBuilder.where(filterAst.field, filterAst.value);
+        break;
+      }
+      case "endsWith": {
+        void queryBuilder.where(filterAst.field, filterAst.value);
+        break;
+      }
+      case "and": {
+        void queryBuilder.andWhere((subQueryBuilder) => {
+          filterAst.value.forEach((el) => {
+            stack.push({
+              queryBuilder: subQueryBuilder,
+              filterAst: el
+            });
+          });
+        });
+        break;
+      }
+      case "or": {
+        void queryBuilder.orWhere((subQueryBuilder) => {
+          filterAst.value.forEach((el) => {
+            stack.push({
+              queryBuilder: subQueryBuilder,
+              filterAst: el
+            });
+          });
+        });
+        break;
+      }
+      case "not": {
+        void queryBuilder.whereNot((subQueryBuilder) => {
+          filterAst.value.forEach((el) => {
+            stack.push({
+              queryBuilder: subQueryBuilder,
+              filterAst: el
+            });
+          });
+        });
+        break;
+      }
+      default:
+        throw new UnauthorizedError({ message: `Invalid knex dynamic operator: ${filterAst.operator}` });
+    }
+  }
+};