Implement backendClient object to unify calls to the portal api

1 files changed, 59 insertions, 0 deletions

diff --git a/packages/website/ts/utils/backend_client.ts b/packages/website/ts/utils/backend_client.ts
new file mode 100644
index 000000000..366519856
--- /dev/null
+++ b/packages/website/ts/utils/backend_client.ts
@@ -0,0 +1,59 @@
+import { BigNumber, logUtils } from '@0xproject/utils';
+import * as _ from 'lodash';
+import * as queryString from 'query-string';
+
+import { ArticlesBySection, ItemByAddress, WebsiteBackendGasInfo, WebsiteBackendPriceInfo } from 'ts/types';
+import { configs } from 'ts/utils/configs';
+import { errorReporter } from 'ts/utils/error_reporter';
+
+const ETH_GAS_STATION_ENDPOINT = '/eth_gas_station';
+const PRICES_ENDPOINT = '/prices';
+const WIKI_ENDPOINT = '/wiki';
+
+export const backendClient = {
+    async getGasInfoAsync(): Promise<WebsiteBackendGasInfo> {
+        const result = await requestAsync(ETH_GAS_STATION_ENDPOINT);
+        return result;
+    },
+    async getPriceInfosAsync(tokenAddresses: string[]): Promise<WebsiteBackendPriceInfo[]> {
+        if (_.isEmpty(tokenAddresses)) {
+            return [];
+        }
+        const joinedTokenAddresses = tokenAddresses.join(',');
+        const queryParams = {
+            tokens: joinedTokenAddresses,
+        };
+        const result = await requestAsync(PRICES_ENDPOINT, queryParams);
+        return result;
+    },
+    async getWikiArticlesBySectionAsync(): Promise<ArticlesBySection> {
+        const result = await requestAsync(WIKI_ENDPOINT);
+        return result;
+    },
+};
+
+async function requestAsync(endpoint: string, queryParams?: object): Promise<any> {
+    const query = queryStringFromQueryParams(queryParams);
+    const url = `${configs.BACKEND_BASE_URL}${endpoint}${query}`;
+    const response = await fetch(url);
+    if (response.status !== 200) {
+        const errorText = `Error requesting url: ${url}, ${response.status}: ${response.statusText}`;
+        logUtils.log(errorText);
+        const error = Error(errorText);
+        // tslint:disable-next-line:no-floating-promises
+        errorReporter.reportAsync(error);
+        throw error;
+    }
+    const result = await response.json();
+    return result;
+}
+
+function queryStringFromQueryParams(queryParams?: object): string {
+    // if params are undefined or empty, return an empty string
+    if (_.isUndefined(queryParams) || _.isEmpty(queryParams)) {
+        return '';
+    }
+    // stringify the formatted object
+    const stringifiedParams = queryString.stringify(queryParams);
+    return `?${stringifiedParams}`;
+}