use shared parseParams helper

src/utils/parseParams.ts

@@ -0,0 +1,75 @@
+import { Request } from "express";
+import { ActionType, SegmentUUID, Category } from "../types/segments.model";
+import { config } from "../config";
+
+type fn = (req: Request, fallback: any) => any[];
+
+const syntaxErrorWrapper = (fn: fn, req: Request, fallback: any) => {
+    try { return fn(req, fallback); }
+    catch (e) {
+        return undefined;
+    }
+};
+
+const getCategories = (req: Request, fallback: Category[] ): string[] | Category[] =>
+    req.query.categories
+        ? JSON.parse(req.query.categories as string)
+        : req.query.category
+            ? Array.isArray(req.query.category)
+                ? req.query.category
+                : [req.query.category]
+            : fallback;
+
+const validateString = (array: any[]): any[] => {
+    if (!Array.isArray(array)) return undefined;
+    return array
+        .filter((item: any) => typeof item === "string")
+        .filter((item: string) => !(/[^a-z|_|-]/.test(item)));
+};
+
+const filterActionType = (actionTypes: ActionType[]) => {
+    const filterCategories = new Set();
+    for (const [key, value] of Object.entries(config.categorySupport)) {
+        for (const type of actionTypes) {
+            if (value.includes(type)) {
+                filterCategories.add(key as Category);
+            }
+        }
+    }
+    return [...filterCategories];
+};
+
+export const filterInvalidCategoryActionType = (categories: Category[], actionTypes: ActionType[]): Category[] =>
+    categories.filter((category: Category) => filterActionType(actionTypes).includes(category));
+
+const getActionTypes = (req: Request, fallback: ActionType[]): ActionType[] =>
+    req.query.actionTypes
+        ? JSON.parse(req.query.actionTypes as string)
+        : req.query.actionType
+            ? Array.isArray(req.query.actionType)
+                ? req.query.actionType
+                : [req.query.actionType]
+            : fallback;
+
+// fallback to empty array
+const getRequiredSegments = (req: Request): SegmentUUID[] =>
+    req.query.requiredSegments
+        ? JSON.parse(req.query.requiredSegments as string)
+        : req.query.requiredSegment
+            ? Array.isArray(req.query.requiredSegment)
+                ? req.query.requiredSegment
+                : [req.query.requiredSegment]
+            : [];
+
+export const parseCategories = (req: Request, fallback: Category[]): Category[] => {
+    const categories = syntaxErrorWrapper(getCategories, req, fallback);
+    return categories ? validateString(categories) : undefined;
+};
+
+export const parseActionTypes = (req: Request, fallback: ActionType[]): ActionType[] => {
+    const actionTypes = syntaxErrorWrapper(getActionTypes, req, fallback);
+    return actionTypes ? validateString(actionTypes) : undefined;
+};
+
+export const parseRequiredSegments = (req: Request): SegmentUUID[] | undefined =>
+    syntaxErrorWrapper(getRequiredSegments, req, []); // never fall back