refactor: share path-root query predicate (WealthLedger/frontend#142) (#154)

src/shared/api/index.ts

@@ -13,6 +13,7 @@ export {
 	isApiErrorCode,
 	isBrokerageAccessLoss,
 } from "./problem-details";
+export { isGetUnder } from "./query-predicate";
 export { isReadFailureExhausted, readRetry } from "./read-failure";
 
 export {

src/shared/api/query-predicate.test.ts

@@ -0,0 +1,26 @@
+import { describe, expect, it } from "vitest";
+
+import { isGetUnder } from "./query-predicate";
+
+describe("isGetUnder", () => {
+	it("matches the root itself and nested paths for get queries only", () => {
+		const predicate = isGetUnder(["/api/v1/bank-cards"]);
+
+		expect(predicate(["get", "/api/v1/bank-cards"])).toBe(true);
+		expect(predicate(["get", "/api/v1/bank-cards/{id}"])).toBe(true);
+		expect(predicate(["get", "/api/v1/bank-cards"])).toBe(true);
+		expect(predicate(["get", "/api/v1/bank-cardsx"])).toBe(false);
+		expect(predicate(["post", "/api/v1/bank-cards"])).toBe(false);
+		expect(predicate(["get", "/api/v1/other"])).toBe(false);
+	});
+
+	it("checks every root and tolerates init and non-string parts", () => {
+		const predicate = isGetUnder(["/api/v1/stocks", "/api/v1/bonds"]);
+
+		expect(predicate(["get", "/api/v1/stocks/{uid}/quote", { params: {} }]))
+			.toBe(true);
+		expect(predicate(["get", "/api/v1/bonds"])).toBe(true);
+		expect(predicate([undefined, "/api/v1/stocks"])).toBe(false);
+		expect(predicate(["get", undefined])).toBe(false);
+	});
+});

src/shared/api/query-predicate.ts

@@ -0,0 +1,18 @@
+import type { QueryKey } from "@tanstack/react-query";
+
+// openapi-react-query shapes query keys as [method, path, init].
+function isGetUnder(roots: readonly string[]) {
+	const predicate = (queryKey: QueryKey) => {
+		const [method, path] = queryKey as readonly [unknown, unknown];
+
+		return (
+			method === "get"
+			&& typeof path === "string"
+			&& roots.some(root => path === root || path.startsWith(`${root}/`))
+		);
+	};
+
+	return predicate;
+}
+
+export { isGetUnder };