Merge pull request #66 from libsql/custom-fetch

Allow the user to provide custom fetch() function

package.json

@@ -93,7 +93,7 @@
         "typescript": "^4.9.4"
     },
     "dependencies": {
-        "@libsql/hrana-client": "^0.4.2",
+        "@libsql/hrana-client": "^0.4.3",
         "better-sqlite3": "^8.0.1",
         "js-base64": "^3.7.5"
     }

src/__tests__/client.test.ts

@@ -1,5 +1,6 @@
 import { expect } from "@jest/globals";
 import type { MatcherFunction } from "expect";
+import { fetch, Request, Response } from "@libsql/isomorphic-fetch";
 
 import "./helpers.js";
 
@@ -874,3 +875,21 @@ const hasNetworkErrors = isWs && (server == "test_v1" || server == "test_v2");
         }));
     }
 });
+
+(isHttp ? test : test.skip)("custom fetch", async () => {
+    let fetchCalledCount = 0;
+    function customFetch(request: Request): Promise<Response> {
+        expect(request).toBeInstanceOf(Request);
+        fetchCalledCount += 1;
+        return fetch(request);
+    }
+
+    const c = createClient({...config, fetch: customFetch});
+    try {
+        const rs = await c.execute("SELECT 42");
+        expect(rs.rows[0][0]).toStrictEqual(42);
+        expect(fetchCalledCount).toStrictEqual(1);
+    } finally {
+        c.close();
+    }
+});

src/api.ts

@@ -28,6 +28,15 @@ export interface Config {
      * - `"string"`: returns SQLite integers as strings.
      */
     intMode?: IntMode;
+
+    /** Custom `fetch` function to use for the HTTP client.
+     *
+     * By default, the HTTP client uses `fetch` from the `@libsql/isomorphic-fetch` package, but you can pass
+     * your own function here. The argument to this function will be `Request` from
+     * `@libsql/isomorphic-fetch`, and it must return a promise that resolves to an object that is compatible
+     * with the Web `Response`.
+     */
+    fetch?: Function;
 }
 
 /** Representation of integers from database as JavaScript values. See {@link Config.intMode}. */

src/config.ts

@@ -11,6 +11,7 @@ export interface ExpandedConfig {
     path: string;
     authToken: string | undefined;
     intMode: IntMode;
+    fetch: Function | undefined;
 }
 
 export type ExpandedScheme = "wss" | "ws" | "https" | "http" | "file";
@@ -99,5 +100,6 @@ export function expandConfig(config: Config, preferHttp: boolean): ExpandedConfi
         path: uri.path,
         authToken,
         intMode,
+        fetch: config.fetch,
     };
 }

src/http.ts

@@ -36,7 +36,7 @@ export function _createClient(config: ExpandedConfig): Client {
     }
 
     const url = encodeBaseUrl(config.scheme, config.authority, config.path);
-    return new HttpClient(url, config.authToken, config.intMode);
+    return new HttpClient(url, config.authToken, config.intMode, config.fetch);
 }
 
 const sqlCacheCapacity = 30;
@@ -46,8 +46,13 @@ export class HttpClient implements Client {
     protocol: "http";
 
     /** @private */
-    constructor(url: URL, authToken: string | undefined, intMode: IntMode) {
-        this.#client = hrana.openHttp(url, authToken);
+    constructor(
+        url: URL,
+        authToken: string | undefined,
+        intMode: IntMode,
+        customFetch: Function | undefined,
+    ) {
+        this.#client = hrana.openHttp(url, authToken, customFetch);
         this.#client.intMode = intMode;
         this.protocol = "http";
     }