add fetch retries configuration (#378)

Author: guybedford

src/common/fetch-common.ts

@@ -11,6 +11,12 @@ export type FetchFn = (
   ...args: any[]
 ) => Promise<Response | globalThis.Response>;
 
+let retryCount = 3;
+
+export function setRetryCount(count: number) {
+  retryCount = count;
+}
+
 /**
  * Wraps a fetch request with retry logic on exceptions, which is useful for
  * spotty connections that may fail intermittently.
@@ -22,7 +28,7 @@ export function wrapWithRetry(fetch: FetchFn): FetchFn {
       try {
         return await fetch(url, ...args);
       } catch (e) {
-        if (retries++ > 3) throw e;
+        if (retries++ >= retryCount) throw e;
       }
     }
   };

src/generator.ts

@@ -44,6 +44,7 @@ import { getDefaultProviderStrings, type Provider } from "./providers/index.js";
 import * as nodemodules from "./providers/nodemodules.js";
 import { Resolver } from "./trace/resolver.js";
 import { getMaybeWrapperUrl } from "./common/wrapper.js";
+import { setRetryCount } from "./common/fetch-common.js";
 
 // Utility exports for users:
 export { analyzeHtml };
@@ -308,6 +309,12 @@ export interface GeneratorOptions {
    * Whether to include "integrity" field in the import map
    */
   integrity?: boolean;
+
+  /**
+   * The number of fetch retries to attempt for request failures.
+   * Defaults to 3.
+   */
+  fetchRetries?: number;
 }
 
 export interface ModuleAnalysis {
@@ -400,6 +407,7 @@ export class Generator {
     commonJS = false,
     typeScript = false,
     integrity = false,
+    fetchRetries,
   }: GeneratorOptions = {}) {
     // Initialise the debug logger:
     const { log, logStream } = createLogger();
@@ -512,6 +520,10 @@ export class Generator {
     this.map = new ImportMap({ mapUrl: this.mapUrl, rootUrl: this.rootUrl });
     if (!integrity) this.map.integrity = {};
     if (inputMap) this.addMappings(inputMap);
+
+    // Set the fetch retry count
+    if (typeof fetchRetries === 'number')
+      setRetryCount(fetchRetries);
   }
 
   /**
@@ -1411,3 +1423,4 @@ function detectDefaultProvider(
 
   return defaultProvider || winner || "jspm.io";
 }
+

src/providers/deno.ts

@@ -8,7 +8,6 @@ import { SemverRange } from "sver";
 // @ts-ignore
 import { fetch } from "#fetch";
 import { Install } from "../generator.js";
-import { IImportMap, ImportMap } from "@jspm/import-map";
 
 const cdnUrl = "https://deno.land/x/";
 const stdlibUrl = "https://deno.land/std";

src/providers/nodemodules.ts

@@ -1,4 +1,4 @@
-import { ExactModule, LatestPackageTarget } from "../install/package.js";
+import { LatestPackageTarget } from "../install/package.js";
 import { ExactPackage } from "../install/package.js";
 import { Resolver } from "../trace/resolver.js";
 import { Provider } from "./index.js";