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

src/utils/parseSkipSegments.ts

@@ -2,42 +2,7 @@ import { Request } from "express";
 import { ActionType, SegmentUUID, Category, Service } from "../types/segments.model";
 import { getService } from "./getService";
 
-type fn = (req: Request) => any[];
-
-const syntaxErrorWrapper = (fn: fn, req: Request) => {
-    try { return fn(req); }
-    catch (e) { return undefined; }
-};
-
-// Default to sponsor
-const getCategories = (req: Request): 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]
-            : ["sponsor"];
-
-// Default to skip
-const getActionTypes = (req: Request): 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]
-            : [ActionType.Skip];
-
-// Default 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]
-            : [];
+import { parseCategories, parseActionTypes, parseRequiredSegments } from "./parseParams";
 
 const errorMessage = (parameter: string) => `${parameter} parameter does not match format requirements.`;
 
@@ -48,20 +13,14 @@ export function parseSkipSegments(req: Request): {
     service: Service;
     errors: string[];
 } {
-    let categories: Category[] = syntaxErrorWrapper(getCategories, req);
-    const actionTypes: ActionType[] = syntaxErrorWrapper(getActionTypes, req);
-    const requiredSegments: SegmentUUID[] = syntaxErrorWrapper(getRequiredSegments, req);
+    const categories: Category[] = parseCategories(req, [ "sponsor" as Category ]);
+    const actionTypes: ActionType[] = parseActionTypes(req, [ActionType.Skip]);
+    const requiredSegments: SegmentUUID[] = parseRequiredSegments(req);
     const service: Service = getService(req.query.service, req.body.services);
     const errors: string[] = [];
     if (!Array.isArray(categories)) errors.push(errorMessage("categories"));
-    else {
-        // check category names for invalid characters
-        // and none string elements
-        categories = categories
-            .filter((item: any) => typeof item === "string")
-            .filter((category) => !(/[^a-z|_|-]/.test(category)));
-        if (categories.length === 0) errors.push("No valid categories provided.");
-    }
+    else if (categories.length === 0) errors.push("No valid categories provided.");
+
     if (!Array.isArray(actionTypes)) errors.push(errorMessage("actionTypes"));
     if (!Array.isArray(requiredSegments)) errors.push(errorMessage("requiredSegments"));
     // finished parsing