Merge pull request #1013 from tradingstrategy-ai/fetch-schema-validate

Add optional schema validation to fetchPublicApi

Author: kenkunz

package.json

@@ -26,6 +26,7 @@
     "@eslint/compat": "^1.3.1",
     "@eslint/js": "^9.31.0",
     "@playwright/test": "^1.54.1",
+    "@standard-schema/spec": "^1.0.0",
     "@sveltejs/adapter-node": "^5.2.13",
     "@sveltejs/enhanced-img": "^0.7.0",
     "@sveltejs/kit": "^2.26.1",

pnpm-lock.yaml

@@ -1,4 +1,5 @@
 import 'unplugin-icons/types/svelte';
+import type { StandardSchemaV1 } from '@standard-schema/spec';
 import type { CountryCode } from '$lib/helpers/geo';
 import type { TimeBucket } from '$lib/schemas/utility';
 
@@ -10,6 +11,7 @@ declare global {
 			message: string;
 			chainName?: string;
 			stack?: string[];
+			issues?: readonly StandardSchemaV1.Issue[] | undefined;
 			eventId?: string;
 		}
 

src/app.d.ts

@@ -6,7 +6,7 @@
 	import Series from './Series.svelte';
 	import { tsToUnixTimestamp } from './candle-data-feed.svelte';
 	import { fetchPublicApi } from '$lib/helpers/public-api';
-	import { dateToTs, tsToDate } from './helpers';
+	import { dateToTs } from './helpers';
 
 	type Props = {
 		token: BenchmarkToken;
@@ -39,7 +39,7 @@
 		token.loading = true;
 		benchmarkData = [];
 
-		const pairCandles = await fetchPublicApi(fetch, 'candles', {
+		const pairCandles = await fetchPublicApi<Record<string, ApiCandle[]>>(fetch, 'candles', {
 			pair_id: token.pairId,
 			exchange_type: token.exchangeType,
 			candle_type: 'price',
@@ -48,7 +48,7 @@
 			end: range[1].toISOString().slice(0, 19)
 		});
 
-		const candles = (pairCandles[token.pairId] ?? []) as ApiCandle[];
+		const candles = pairCandles[token.pairId] ?? [];
 
 		const initialBenchmarkValue = candles[0]?.c ?? 0;
 

src/lib/charts/BenchmarkSeries.svelte

@@ -1,13 +1,14 @@
 import type { TimeInterval } from 'd3-time';
-import type { UTCTimestamp } from 'lightweight-charts';
 import type { TimeBucket } from '$lib/schemas/utility';
 import type { ApiCandle, CandleDataItem, DataFeed } from './types';
 import { timeBucketToInterval } from './helpers';
 import { isHttpError } from '@sveltejs/kit';
 import { fetchPublicApi } from '$lib/helpers/public-api';
+import { parseDate } from '$lib/helpers/date';
+import { dateToTs } from './helpers';
 
 export function tsToUnixTimestamp(ts: string) {
-	return (new Date(`${ts}Z`).valueOf() / 1000) as UTCTimestamp;
+	return dateToTs(parseDate(ts)!);
 }
 
 export function apiCandleToDataItem(c: ApiCandle): CandleDataItem {
@@ -20,7 +21,7 @@ export function apiCandleToDataItem(c: ApiCandle): CandleDataItem {
 	};
 }
 
-export type ApiDataTransformer = (data: any) => CandleDataItem[];
+export type ApiDataTransformer = (data: unknown) => CandleDataItem[];
 
 export class CandleDataFeed implements DataFeed<CandleDataItem> {
 	interval: TimeInterval;
@@ -37,6 +38,7 @@ export class CandleDataFeed implements DataFeed<CandleDataItem> {
 		readonly transformApiData: ApiDataTransformer
 	) {
 		this.interval = timeBucketToInterval(timeBucket);
+		// eslint-disable-next-line svelte/prefer-svelte-reactivity
 		this.endDate = this.interval.floor(new Date());
 	}
 

src/lib/charts/candle-data-feed.svelte.ts

@@ -39,6 +39,11 @@ export type LendingReserveIndexParams = Partial<{
 
 type LendingReserveSearchKey = keyof LendingReserveIndexParams;
 
+type LendingReserveApiResponse = {
+	results: LendingReserve[];
+	total: number;
+};
+
 export type LendingReserveIndexResponse = {
 	rows: LendingReserve[];
 	totalRowCount: number;
@@ -53,18 +58,25 @@ const defaultParams: LendingReserveIndexParams = {
 
 const allKeys: LendingReserveSearchKey[] = ['page_size', 'page', 'sort', 'direction', 'protocol_slug', 'chain_slug'];
 
-export async function fetchLendingReserves(fetch: Fetch, params: LendingReserveIndexParams) {
+export async function fetchLendingReserves(
+	fetch: Fetch,
+	params: LendingReserveIndexParams
+): Promise<LendingReserveIndexResponse | undefined> {
 	const apiParams: Record<string, string> = {};
 
 	for (const key of allKeys) {
 		const value = params[key] || defaultParams[key];
 		if (value) apiParams[key] = String(value);
 	}
 
-	const data = await fetchPublicApi(fetch, 'lending-reserves', apiParams, true);
+	const data = await fetchPublicApi<LendingReserveApiResponse>(fetch, 'lending-reserves', apiParams, {
+		abortPrevious: true
+	});
+
+	if (!data) return;
 
 	return {
 		rows: data.results,
 		totalRowCount: data.total
-	} as LendingReserveIndexResponse;
+	};
 }

src/lib/explorer/lending-reserve-client.ts

@@ -14,8 +14,21 @@ export type PairIndexParams = Partial<{
 
 type PairSearchKey = keyof PairIndexParams;
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+type PairInfo = Record<string, any>;
+
+export type PairDetails = {
+	summary: PairInfo;
+	additional_details: PairInfo;
+};
+
+type PairApiResponse = {
+	results: PairInfo[];
+	total: number;
+};
+
 export type PairIndexResponse = {
-	rows: Record<string, any>[];
+	rows: PairInfo[];
 	totalRowCount: number;
 };
 
@@ -36,22 +49,22 @@ const allKeys: PairSearchKey[] = [
 	'token_addresses'
 ];
 
-export async function fetchPairs(fetch: Fetch, params: PairIndexParams) {
+export async function fetchPairs(fetch: Fetch, params: PairIndexParams): Promise<PairIndexResponse | undefined> {
 	const apiParams: Record<string, string> = {};
 
 	for (const key of allKeys) {
 		const value = params[key] || defaultParams[key];
 		if (value) apiParams[key] = String(value);
 	}
 
-	const data = await fetchPublicApi(fetch, 'pairs', apiParams, true);
+	const data = await fetchPublicApi<PairApiResponse>(fetch, 'pairs', apiParams, { abortPrevious: true });
 
 	if (!data) return;
 
 	return {
 		rows: data.results,
 		totalRowCount: data.total
-	} as PairIndexResponse;
+	};
 }
 
 export type PairIndexData = PairIndexResponse & {

src/lib/explorer/pair-client.ts

@@ -10,8 +10,16 @@ export type TokenIndexParams = Partial<{
 
 type TokenSearchKey = keyof TokenIndexParams;
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type TokenDetails = Record<string, any>;
+
+type TokenApiResponse = {
+	results: TokenDetails[];
+	total: number;
+};
+
 export type TokenIndexResponse = {
-	rows: Record<string, any>[];
+	rows: TokenDetails[];
 	totalRowCount: number;
 };
 
@@ -24,20 +32,20 @@ const defaultParams: TokenIndexParams = {
 
 const allKeys: TokenSearchKey[] = ['page_size', 'page', 'sort', 'direction', 'chain_slug'];
 
-export async function fetchTokens(fetch: Fetch, params: TokenIndexParams) {
+export async function fetchTokens(fetch: Fetch, params: TokenIndexParams): Promise<TokenIndexResponse | undefined> {
 	const apiParams: Record<string, string> = {};
 
 	for (const key of allKeys) {
 		const value = params[key] || defaultParams[key];
 		if (value) apiParams[key] = String(value);
 	}
 
-	const data = await fetchPublicApi(fetch, 'tokens', apiParams, true);
+	const data = await fetchPublicApi<TokenApiResponse>(fetch, 'tokens', apiParams, { abortPrevious: true });
 
 	if (!data) return;
 
 	return {
 		rows: data.results,
 		totalRowCount: data.total
-	} as TokenIndexResponse;
+	};
 }

src/lib/explorer/token-client.ts

@@ -2,6 +2,10 @@
  * Misc exchange data helpers.
  */
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type ExchangeDetails = Record<string, any>;
+export type ExchangeIndexResponse = { exchanges: ExchangeDetails[] };
+
 export type ExchangeNameInfo = {
 	name: string;
 	version: number;

src/lib/helpers/exchange.ts

@@ -1,5 +1,6 @@
 // Helpers for working with Trading Strategy public APIs
 import { type NumericRange, error } from '@sveltejs/kit';
+import type { StandardSchemaV1 } from '@standard-schema/spec';
 import { backendUrl } from '$lib/config';
 
 type Params = Record<string, string>;
@@ -12,10 +13,22 @@ const controllers: Record<string, AbortController> = {};
  * @param fetch SvelteKit's fetch function
  * @param endpoint final path segment of endpoint, e.g.: 'chains', 'pairs'
  * @param params URL paramaters as a record of string values
- * @param abortPrevious set to true to abort pending requets to the same endpoint
- * @returns the deserialised JSON payload
+ * @param options optional configuration
+ * @param options.abortPrevious abort any pending requests to the same endpoint
+ * @param options.schema Standard Schema for response validation (e.g., `z.object({ ... })`)
+ * @returns the deserialized and optionally validated JSON payload
  */
-export async function fetchPublicApi(fetch: Fetch, endpoint: string, params: Params = {}, abortPrevious = false) {
+export async function fetchPublicApi<T = unknown>(
+	fetch: Fetch,
+	endpoint: string,
+	params: Params = {},
+	options?: {
+		abortPrevious?: boolean;
+		schema?: StandardSchemaV1<unknown, T>;
+	}
+): Promise<T> {
+	const { abortPrevious = false, schema } = options ?? {};
+
 	let signal: AbortSignal | undefined = undefined;
 
 	if (abortPrevious) {
@@ -26,16 +39,28 @@ export async function fetchPublicApi(fetch: Fetch, endpoint: string, params: Par
 
 	const searchParams = new URLSearchParams(params);
 
+	let data: unknown;
+
 	try {
 		const resp = await fetch(`${backendUrl}/${endpoint}?${searchParams}`, { signal });
 		if (!resp.ok) throw await publicApiError(resp);
-		return resp.json();
+		data = await resp.json();
 	} catch (e) {
-		if (e.name === 'AbortError') return;
+		if ((e as Error).name === 'AbortError') return undefined as T;
 		throw e;
 	} finally {
 		if (!signal?.aborted) delete controllers[endpoint];
 	}
+
+	// return raw response payload if no validation schema was provided
+	if (!schema) return data as T;
+
+	// validate response and return validated/typed payload if successful
+	const result = await schema['~standard'].validate(data);
+	if (result.issues) {
+		error(500, { message: 'API response validation failed', ...result });
+	}
+	return result.value;
 }
 
 /**
@@ -82,5 +107,6 @@ export function optionalDataError(dataType?: string) {
 	return (err: Error) => {
 		console.error(`${errorIntro}; rendering page without data.`);
 		console.error(err);
+		return undefined;
 	};
 }