fix issues with circular imports

Parts of this commit are from a patch by sebasjm.  The circular imports
caused an issue with webpack.  While we don't use webpack in the wallet,
the wallet should still be importable by webpack.

Some packages were importing their dependencies via "index.js", which
re-exports public exports of the package.  This resulted in circular
dependencies which were resolved correctly by rollup, but not by
webpack.

1 files changed, 21 insertions, 5 deletions

diff --git a/packages/taler-wallet-core/src/headless/helpers.ts b/packages/taler-wallet-core/src/headless/helpers.ts
index 5007a65ac..1ae556b39 100644
--- a/packages/taler-wallet-core/src/headless/helpers.ts
+++ b/packages/taler-wallet-core/src/headless/helpers.ts
@@ -30,7 +30,6 @@ import {
 } from "@gnu-taler/idb-bridge";
 import { openTalerDatabase } from "../db";
 import { HttpRequestLibrary } from "../util/http";
-import fs from "fs";
 import { NodeThreadCryptoWorkerFactory } from "../crypto/workers/nodeThreadWorker";
 import { NodeHttpLib } from "./NodeHttpLib";
 import { Logger } from "../util/logging";
@@ -40,6 +39,21 @@ import { WalletNotification } from "@gnu-taler/taler-util";
 
 const logger = new Logger("headless/helpers.ts");
 
+const nodejs_fs = (function () {
+  let fs: typeof import("fs");
+  return function() {
+    if (!fs) {
+      /**
+       * need to use an expression when doing a require if we want
+       * webpack not to find out about the requirement
+       */
+      const _r = "require"
+      fs = module[_r]("fs") 
+    }
+    return fs
+  }
+})()
+
 export interface DefaultNodeWalletArgs {
   /**
    * Location of the wallet database.
@@ -87,7 +101,7 @@ export async function getDefaultNodeWallet(
   const storagePath = args.persistentStoragePath;
   if (storagePath) {
     try {
-      const dbContentStr: string = fs.readFileSync(storagePath, {
+      const dbContentStr: string = nodejs_fs().readFileSync(storagePath, {
         encoding: "utf-8",
       });
       const dbContent = JSON.parse(dbContentStr);
@@ -109,11 +123,11 @@ export async function getDefaultNodeWallet(
       }
       const tmpPath = `${args.persistentStoragePath}-${makeId(5)}.tmp`;
       const dbContent = myBackend.exportDump();
-      fs.writeFileSync(tmpPath, JSON.stringify(dbContent, undefined, 2), {
+      nodejs_fs().writeFileSync(tmpPath, JSON.stringify(dbContent, undefined, 2), {
         encoding: "utf-8",
       });
       // Atomically move the temporary file onto the DB path.
-      fs.renameSync(tmpPath, args.persistentStoragePath);
+      nodejs_fs().renameSync(tmpPath, args.persistentStoragePath);
     };
   }
 
@@ -143,7 +157,9 @@ export async function getDefaultNodeWallet(
   let workerFactory;
   try {
     // Try if we have worker threads available, fails in older node versions.
-    require("worker_threads");
+    const _r = "require"
+    const worker_threads = module[_r]("worker_threads");
+    // require("worker_threads");
     workerFactory = new NodeThreadCryptoWorkerFactory();
   } catch (e) {
     logger.warn(