anastasis-core: provide reducer CLI, refactor state machine

package.json

@@ -8,8 +8,8 @@
     "check": "pnpm run --filter '{packages}' --if-present test"
   },
   "devDependencies": {
-    "@linaria/esbuild": "^3.0.0-beta.7",
-    "@linaria/shaker": "^3.0.0-beta.7",
-    "esbuild": "^0.12.21"
+    "@linaria/esbuild": "^3.0.0-beta.13",
+    "@linaria/shaker": "^3.0.0-beta.13",
+    "esbuild": "^0.12.29"
   }
 }

packages/anastasis-core/bin/anastasis-ts-reducer.js

@@ -0,0 +1,14 @@
+#!/usr/bin/env node
+
+async function r() {
+  try {
+    (await import("source-map-support")).install();
+  } catch (e) {
+    console.warn("can't load souremaps");
+    // Do nothing.
+  }
+
+  (await import("../dist/anastasis-cli.js")).reducerCliMain();
+}
+
+r();

packages/anastasis-core/package.json

@@ -6,8 +6,8 @@
   "module": "./lib/index.js",
   "types": "./lib/index.d.ts",
   "scripts": {
-    "prepare": "tsc",
-    "compile": "tsc",
+    "prepare": "tsc && rollup -c",
+    "compile": "tsc && rollup -c",
     "pretty": "prettier --write src",
     "test": "tsc && ava",
     "coverage": "tsc && nyc ava",
@@ -17,15 +17,23 @@
   "license": "AGPL-3-or-later",
   "type": "module",
   "devDependencies": {
+    "@rollup/plugin-commonjs": "^21.0.1",
+    "@rollup/plugin-json": "^4.1.0",
+    "@rollup/plugin-node-resolve": "^13.0.6",
     "ava": "^3.15.0",
-    "typescript": "^4.4.3"
+    "rimraf": "^3.0.2",
+    "rollup": "^2.59.0",
+    "rollup-plugin-sourcemaps": "^0.6.3",
+    "source-map-support": "^0.5.19",
+    "typescript": "^4.4.4"
   },
   "dependencies": {
     "@gnu-taler/taler-util": "workspace:^0.8.3",
     "fetch-ponyfill": "^7.1.0",
     "fflate": "^0.6.0",
     "hash-wasm": "^4.9.0",
-    "node-fetch": "^3.0.0"
+    "node-fetch": "^3.0.0",
+    "tslib": "^2.1.0"
   },
   "ava": {
     "files": [

packages/anastasis-core/rollup.config.js

@@ -0,0 +1,30 @@
+// rollup.config.js
+import commonjs from "@rollup/plugin-commonjs";
+import nodeResolve from "@rollup/plugin-node-resolve";
+import json from "@rollup/plugin-json";
+import builtins from "builtin-modules";
+import sourcemaps from "rollup-plugin-sourcemaps";
+
+export default {
+  input: "lib/index.node.js",
+  output: {
+    file: "dist/anastasis-cli.js",
+    format: "es",
+    sourcemap: true,
+  },
+  external: builtins,
+  plugins: [
+    nodeResolve({
+      preferBuiltins: true,
+    }),
+
+    sourcemaps(),
+
+    commonjs({
+      sourceMap: true,
+      transformMixedEsModules: true,
+    }),
+
+    json(),
+  ],
+};

packages/anastasis-core/src/cli.ts

@@ -0,0 +1,64 @@
+import { clk } from "@gnu-taler/taler-util";
+import {
+  getBackupStartState,
+  getRecoveryStartState,
+  reduceAction,
+} from "./index.js";
+import fs from "fs";
+
+export const reducerCli = clk
+  .program("reducer", {
+    help: "Command line interface for the GNU Taler wallet.",
+  })
+  .flag("initBackup", ["-b", "--backup"])
+  .flag("initRecovery", ["-r", "--restore"])
+  .maybeOption("argumentsJson", ["-a", "--arguments"], clk.STRING)
+  .maybeArgument("action", clk.STRING)
+  .maybeArgument("stateFile", clk.STRING);
+
+async function read(stream: NodeJS.ReadStream): Promise<string> {
+  const chunks = [];
+  for await (const chunk of stream) {
+    chunks.push(chunk);
+  }
+  return Buffer.concat(chunks).toString("utf8");
+}
+
+reducerCli.action(async (x) => {
+  if (x.reducer.initBackup) {
+    console.log(JSON.stringify(await getBackupStartState()));
+    return;
+  } else if (x.reducer.initRecovery) {
+    console.log(JSON.stringify(await getRecoveryStartState()));
+    return;
+  }
+
+  const action = x.reducer.action;
+  if (!action) {
+    console.log("action required");
+    return;
+  }
+
+  let lastState: any;
+  if (x.reducer.stateFile) {
+    const s = fs.readFileSync(x.reducer.stateFile, { encoding: "utf-8" });
+    lastState = JSON.parse(s);
+  } else {
+    const s = await read(process.stdin);
+    lastState = JSON.parse(s);
+  }
+
+  let args: any;
+  if (x.reducer.argumentsJson) {
+    args = JSON.parse(x.reducer.argumentsJson);
+  } else {
+    args = {};
+  }
+
+  const nextState = await reduceAction(lastState, action, args);
+  console.log(JSON.stringify(nextState));
+});
+
+export function reducerCliMain() {
+  reducerCli.run();
+}

packages/anastasis-core/src/index.node.ts

@@ -0,0 +1,2 @@
+export * from "./index.js";
+export { reducerCliMain } from "./cli.js";

packages/anastasis-core/src/reducer-types.ts

@@ -1,4 +1,14 @@
-import { Duration, Timestamp } from "@gnu-taler/taler-util";
+import {
+  AmountString,
+  buildCodecForObject,
+  codecForAny,
+  codecForList,
+  codecForNumber,
+  codecForString,
+  codecForTimestamp,
+  Duration,
+  Timestamp,
+} from "@gnu-taler/taler-util";
 import { KeyShare } from "./crypto.js";
 import { RecoveryDocument } from "./recovery-document-types.js";
 
@@ -23,7 +33,7 @@ export interface Policy {
     authentication_method: number;
     provider: string;
   }[];
-} 
+}
 
 export interface PolicyProvider {
   provider_url: string;
@@ -70,7 +80,9 @@ export interface ReducerStateBackup {
 
   core_secret?: CoreSecret;
 
-  expiration?: Duration;
+  expiration?: Timestamp;
+
+  upload_fees?: AmountString[];
 }
 
 export interface AuthMethod {
@@ -94,8 +106,8 @@ export interface UserAttributeSpec {
   uuid: string;
   widget: string;
   optional?: boolean;
-  'validation-regex': string | undefined;
-  'validation-logic': string | undefined;
+  "validation-regex": string | undefined;
+  "validation-logic": string | undefined;
 }
 
 export interface RecoveryInternalData {
@@ -244,6 +256,11 @@ export interface ActionArgEnterUserAttributes {
   identity_attributes: Record<string, string>;
 }
 
+export const codecForActionArgEnterUserAttributes = () =>
+  buildCodecForObject<ActionArgEnterUserAttributes>()
+    .property("identity_attributes", codecForAny())
+    .build("ActionArgEnterUserAttributes");
+
 export interface ActionArgAddAuthentication {
   authentication_method: {
     type: string;
@@ -270,15 +287,69 @@ export interface ActionArgEnterSecret {
     value: string;
     mime?: string;
   };
-  expiration: Duration;
+  expiration: Timestamp;
 }
 
+export interface ActionArgSelectContinent {
+  continent: string;
+}
+
+export const codecForActionArgSelectContinent = () =>
+  buildCodecForObject<ActionArgSelectContinent>()
+    .property("continent", codecForString())
+    .build("ActionArgSelectContinent");
+
+export interface ActionArgSelectCountry {
+  country_code: string;
+  currencies: string[];
+}
+
+export const codecForActionArgSelectCountry = () =>
+  buildCodecForObject<ActionArgSelectCountry>()
+    .property("country_code", codecForString())
+    .property("currencies", codecForList(codecForString()))
+    .build("ActionArgSelectCountry");
+
 export interface ActionArgsSelectChallenge {
   uuid: string;
 }
 
+export const codecForActionArgSelectChallenge = () =>
+  buildCodecForObject<ActionArgsSelectChallenge>()
+    .property("uuid", codecForString())
+    .build("ActionArgSelectChallenge");
+
 export type ActionArgsSolveChallengeRequest = SolveChallengeAnswerRequest;
 
 export interface SolveChallengeAnswerRequest {
   answer: string;
 }
+
+export interface PolicyMember {
+  authentication_method: number;
+  provider: string;
+}
+
+export interface ActionArgsAddPolicy {
+  policy: PolicyMember[];
+}
+
+export const codecForPolicyMember = () =>
+  buildCodecForObject<PolicyMember>()
+    .property("authentication_method", codecForNumber())
+    .property("provider", codecForString())
+    .build("PolicyMember");
+
+export const codecForActionArgsAddPolicy = () =>
+  buildCodecForObject<ActionArgsAddPolicy>()
+    .property("policy", codecForList(codecForPolicyMember()))
+    .build("ActionArgsAddPolicy");
+
+export interface ActionArgsUpdateExpiration {
+  expiration: Timestamp;
+}
+
+export const codecForActionArgsUpdateExpiration = () =>
+  buildCodecForObject<ActionArgsUpdateExpiration>()
+    .property("expiration", codecForTimestamp)
+    .build("ActionArgsUpdateExpiration");

packages/taler-util/src/clk.ts

@@ -0,0 +1,620 @@
+/*
+ This file is part of GNU Taler
+ (C) 2019 GNUnet e.V.
+
+ GNU Taler is free software; you can redistribute it and/or modify it under the
+ terms of the GNU General Public License as published by the Free Software
+ Foundation; either version 3, or (at your option) any later version.
+
+ GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+/**
+ * Imports.
+ */
+import process from "process";
+import path from "path";
+import readline from "readline";
+
+export namespace clk {
+  class Converter<T> {}
+
+  export const INT = new Converter<number>();
+  export const STRING: Converter<string> = new Converter<string>();
+
+  export interface OptionArgs<T> {
+    help?: string;
+    default?: T;
+    onPresentHandler?: (v: T) => void;
+  }
+
+  export interface ArgumentArgs<T> {
+    metavar?: string;
+    help?: string;
+    default?: T;
+  }
+
+  export interface SubcommandArgs {
+    help?: string;
+  }
+
+  export interface FlagArgs {
+    help?: string;
+  }
+
+  export interface ProgramArgs {
+    help?: string;
+  }
+
+  interface ArgumentDef {
+    name: string;
+    conv: Converter<any>;
+    args: ArgumentArgs<any>;
+    required: boolean;
+  }
+
+  interface SubcommandDef {
+    commandGroup: CommandGroup<any, any>;
+    name: string;
+    args: SubcommandArgs;
+  }
+
+  type ActionFn<TG> = (x: TG) => void;
+
+  type SubRecord<S extends keyof any, N extends keyof any, V> = {
+    [Y in S]: { [X in N]: V };
+  };
+
+  interface OptionDef {
+    name: string;
+    flagspec: string[];
+    /**
+     * Converter, only present for options, not for flags.
+     */
+    conv?: Converter<any>;
+    args: OptionArgs<any>;
+    isFlag: boolean;
+    required: boolean;
+  }
+
+  function splitOpt(opt: string): { key: string; value?: string } {
+    const idx = opt.indexOf("=");
+    if (idx == -1) {
+      return { key: opt };
+    }
+    return { key: opt.substring(0, idx), value: opt.substring(idx + 1) };
+  }
+
+  function formatListing(key: string, value?: string): string {
+    const res = "  " + key;
+    if (!value) {
+      return res;
+    }
+    if (res.length >= 25) {
+      return res + "\n" + "    " + value;
+    } else {
+      return res.padEnd(24) + " " + value;
+    }
+  }
+
+  export class CommandGroup<GN extends keyof any, TG> {
+    private shortOptions: { [name: string]: OptionDef } = {};
+    private longOptions: { [name: string]: OptionDef } = {};
+    private subcommandMap: { [name: string]: SubcommandDef } = {};
+    private subcommands: SubcommandDef[] = [];
+    private options: OptionDef[] = [];
+    private arguments: ArgumentDef[] = [];
+
+    private myAction?: ActionFn<TG>;
+
+    constructor(
+      private argKey: string,
+      private name: string | null,
+      private scArgs: SubcommandArgs,
+    ) {}
+
+    action(f: ActionFn<TG>): void {
+      if (this.myAction) {
+        throw Error("only one action supported per command");
+      }
+      this.myAction = f;
+    }
+
+    requiredOption<N extends keyof any, V>(
+      name: N,
+      flagspec: string[],
+      conv: Converter<V>,
+      args: OptionArgs<V> = {},
+    ): CommandGroup<GN, TG & SubRecord<GN, N, V>> {
+      const def: OptionDef = {
+        args: args,
+        conv: conv,
+        flagspec: flagspec,
+        isFlag: false,
+        required: true,
+        name: name as string,
+      };
+      this.options.push(def);
+      for (const flag of flagspec) {
+        if (flag.startsWith("--")) {
+          const flagname = flag.substring(2);
+          this.longOptions[flagname] = def;
+        } else if (flag.startsWith("-")) {
+          const flagname = flag.substring(1);
+          this.shortOptions[flagname] = def;
+        } else {
+          throw Error("option must start with '-' or '--'");
+        }
+      }
+      return this as any;
+    }
+
+    maybeOption<N extends keyof any, V>(
+      name: N,
+      flagspec: string[],
+      conv: Converter<V>,
+      args: OptionArgs<V> = {},
+    ): CommandGroup<GN, TG & SubRecord<GN, N, V | undefined>> {
+      const def: OptionDef = {
+        args: args,
+        conv: conv,
+        flagspec: flagspec,
+        isFlag: false,
+        required: false,
+        name: name as string,
+      };
+      this.options.push(def);
+      for (const flag of flagspec) {
+        if (flag.startsWith("--")) {
+          const flagname = flag.substring(2);
+          this.longOptions[flagname] = def;
+        } else if (flag.startsWith("-")) {
+          const flagname = flag.substring(1);
+          this.shortOptions[flagname] = def;
+        } else {
+          throw Error("option must start with '-' or '--'");
+        }
+      }
+      return this as any;
+    }
+
+    requiredArgument<N extends keyof any, V>(
+      name: N,
+      conv: Converter<V>,
+      args: ArgumentArgs<V> = {},
+    ): CommandGroup<GN, TG & SubRecord<GN, N, V>> {
+      const argDef: ArgumentDef = {
+        args: args,
+        conv: conv,
+        name: name as string,
+        required: true,
+      };
+      this.arguments.push(argDef);
+      return this as any;
+    }
+
+    maybeArgument<N extends keyof any, V>(
+      name: N,
+      conv: Converter<V>,
+      args: ArgumentArgs<V> = {},
+    ): CommandGroup<GN, TG & SubRecord<GN, N, V | undefined>> {
+      const argDef: ArgumentDef = {
+        args: args,
+        conv: conv,
+        name: name as string,
+        required: false,
+      };
+      this.arguments.push(argDef);
+      return this as any;
+    }
+
+    flag<N extends string, V>(
+      name: N,
+      flagspec: string[],
+      args: OptionArgs<V> = {},
+    ): CommandGroup<GN, TG & SubRecord<GN, N, boolean>> {
+      const def: OptionDef = {
+        args: args,
+        flagspec: flagspec,
+        isFlag: true,
+        required: false,
+        name: name as string,
+      };
+      this.options.push(def);
+      for (const flag of flagspec) {
+        if (flag.startsWith("--")) {
+          const flagname = flag.substring(2);
+          this.longOptions[flagname] = def;
+        } else if (flag.startsWith("-")) {
+          const flagname = flag.substring(1);
+          this.shortOptions[flagname] = def;
+        } else {
+          throw Error("option must start with '-' or '--'");
+        }
+      }
+      return this as any;
+    }
+
+    subcommand<GN extends keyof any>(
+      argKey: GN,
+      name: string,
+      args: SubcommandArgs = {},
+    ): CommandGroup<GN, TG> {
+      const cg = new CommandGroup<GN, {}>(argKey as string, name, args);
+      const def: SubcommandDef = {
+        commandGroup: cg,
+        name: name as string,
+        args: args,
+      };
+      cg.flag("help", ["-h", "--help"], {
+        help: "Show this message and exit.",
+      });
+      this.subcommandMap[name as string] = def;
+      this.subcommands.push(def);
+      this.subcommands = this.subcommands.sort((x1, x2) => {
+        const a = x1.name;
+        const b = x2.name;
+        if (a === b) {
+          return 0;
+        } else if (a < b) {
+          return -1;
+        } else {
+          return 1;
+        }
+      });
+      return cg as any;
+    }
+
+    printHelp(progName: string, parents: CommandGroup<any, any>[]): void {
+      let usageSpec = "";
+      for (const p of parents) {
+        usageSpec += (p.name ?? progName) + " ";
+        if (p.arguments.length >= 1) {
+          usageSpec += "<ARGS...> ";
+        }
+      }
+      usageSpec += (this.name ?? progName) + " ";
+      if (this.subcommands.length != 0) {
+        usageSpec += "COMMAND ";
+      }
+      for (const a of this.arguments) {
+        const argName = a.args.metavar ?? a.name;
+        usageSpec += `<${argName}> `;
+      }
+      usageSpec = usageSpec.trimRight();
+      console.log(`Usage: ${usageSpec}`);
+      if (this.scArgs.help) {
+        console.log();
+        console.log(this.scArgs.help);
+      }
+      if (this.options.length != 0) {
+        console.log();
+        console.log("Options:");
+        for (const opt of this.options) {
+          let optSpec = opt.flagspec.join(", ");
+          if (!opt.isFlag) {
+            optSpec = optSpec + "=VALUE";
+          }
+          console.log(formatListing(optSpec, opt.args.help));
+        }
+      }
+
+      if (this.subcommands.length != 0) {
+        console.log();
+        console.log("Commands:");
+        for (const subcmd of this.subcommands) {
+          console.log(formatListing(subcmd.name, subcmd.args.help));
+        }
+      }
+    }
+
+    /**
+     * Run the (sub-)command with the given command line parameters.
+     */
+    run(
+      progname: string,
+      parents: CommandGroup<any, any>[],
+      unparsedArgs: string[],
+      parsedArgs: any,
+    ): void {
+      let posArgIndex = 0;
+      let argsTerminated = false;
+      let i;
+      let foundSubcommand: CommandGroup<any, any> | undefined = undefined;
+      const myArgs: any = (parsedArgs[this.argKey] = {});
+      const foundOptions: { [name: string]: boolean } = {};
+      const currentName = this.name ?? progname;
+      for (i = 0; i < unparsedArgs.length; i++) {
+        const argVal = unparsedArgs[i];
+        if (argsTerminated == false) {
+          if (argVal === "--") {
+            argsTerminated = true;
+            continue;
+          }
+          if (argVal.startsWith("--")) {
+            const opt = argVal.substring(2);
+            const r = splitOpt(opt);
+            const d = this.longOptions[r.key];
+            if (!d) {
+              console.error(
+                `error: unknown option '--${r.key}' for ${currentName}`,
+              );
+              process.exit(-1);
+              throw Error("not reached");
+            }
+            if (d.isFlag) {
+              if (r.value !== undefined) {
+                console.error(`error: flag '--${r.key}' does not take a value`);
+                process.exit(-1);
+                throw Error("not reached");
+              }
+              foundOptions[d.name] = true;
+              myArgs[d.name] = true;
+            } else {
+              if (r.value === undefined) {
+                if (i === unparsedArgs.length - 1) {
+                  console.error(`error: option '--${r.key}' needs an argument`);
+                  process.exit(-1);
+                  throw Error("not reached");
+                }
+                myArgs[d.name] = unparsedArgs[i + 1];
+                i++;
+              } else {
+                myArgs[d.name] = r.value;
+              }
+              foundOptions[d.name] = true;
+            }
+            continue;
+          }
+          if (argVal.startsWith("-") && argVal != "-") {
+            const optShort = argVal.substring(1);
+            for (let si = 0; si < optShort.length; si++) {
+              const chr = optShort[si];
+              const opt = this.shortOptions[chr];
+              if (!opt) {
+                console.error(`error: option '-${chr}' not known`);
+                process.exit(-1);
+              }
+              if (opt.isFlag) {
+                myArgs[opt.name] = true;
+                foundOptions[opt.name] = true;
+              } else {
+                if (si == optShort.length - 1) {
+                  if (i === unparsedArgs.length - 1) {
+                    console.error(`error: option '-${chr}' needs an argument`);
+                    process.exit(-1);
+                    throw Error("not reached");
+                  } else {
+                    myArgs[opt.name] = unparsedArgs[i + 1];
+                    i++;
+                  }
+                } else {
+                  myArgs[opt.name] = optShort.substring(si + 1);
+                }
+                foundOptions[opt.name] = true;
+                break;
+              }
+            }
+            continue;
+          }
+        }
+        if (this.subcommands.length != 0) {
+          const subcmd = this.subcommandMap[argVal];
+          if (!subcmd) {
+            console.error(`error: unknown command '${argVal}'`);
+            process.exit(-1);
+            throw Error("not reached");
+          }
+          foundSubcommand = subcmd.commandGroup;
+          break;
+        } else {
+          const d = this.arguments[posArgIndex];
+          if (!d) {
+            console.error(`error: too many arguments for ${currentName}`);
+            process.exit(-1);
+            throw Error("not reached");
+          }
+          myArgs[d.name] = unparsedArgs[i];
+          posArgIndex++;
+        }
+      }
+
+      if (parsedArgs[this.argKey].help) {
+        this.printHelp(progname, parents);
+        process.exit(0);
+        throw Error("not reached");
+      }
+
+      for (let i = posArgIndex; i < this.arguments.length; i++) {
+        const d = this.arguments[i];
+        if (d.required) {
+          if (d.args.default !== undefined) {
+            myArgs[d.name] = d.args.default;
+          } else {
+            console.error(
+              `error: missing positional argument '${d.name}' for ${currentName}`,
+            );
+            process.exit(-1);
+            throw Error("not reached");
+          }
+        }
+      }
+
+      for (const option of this.options) {
+        if (option.isFlag == false && option.required == true) {
+          if (!foundOptions[option.name]) {
+            if (option.args.default !== undefined) {
+              myArgs[option.name] = option.args.default;
+            } else {
+              const name = option.flagspec.join(",");
+              console.error(`error: missing option '${name}'`);
+              process.exit(-1);
+              throw Error("not reached");
+            }
+          }
+        }
+      }
+
+      for (const option of this.options) {
+        const ph = option.args.onPresentHandler;
+        if (ph && foundOptions[option.name]) {
+          ph(myArgs[option.name]);
+        }
+      }
+
+      if (foundSubcommand) {
+        foundSubcommand.run(
+          progname,
+          Array.prototype.concat(parents, [this]),
+          unparsedArgs.slice(i + 1),
+          parsedArgs,
+        );
+      } else if (this.myAction) {
+        let r;
+        try {
+          r = this.myAction(parsedArgs);
+        } catch (e) {
+          console.error(`An error occurred while running ${currentName}`);
+          console.error(e);
+          process.exit(1);
+        }
+        Promise.resolve(r).catch((e) => {
+          console.error(`An error occurred while running ${currentName}`);
+          console.error(e);
+          process.exit(1);
+        });
+      } else {
+        this.printHelp(progname, parents);
+        process.exit(-1);
+        throw Error("not reached");
+      }
+    }
+  }
+
+  export class Program<PN extends keyof any, T> {
+    private mainCommand: CommandGroup<any, any>;
+
+    constructor(argKey: string, args: ProgramArgs = {}) {
+      this.mainCommand = new CommandGroup<any, any>(argKey, null, {
+        help: args.help,
+      });
+      this.mainCommand.flag("help", ["-h", "--help"], {
+        help: "Show this message and exit.",
+      });
+    }
+
+    run(): void {
+      const args = process.argv;
+      if (args.length < 2) {
+        console.error(
+          "Error while parsing command line arguments: not enough arguments",
+        );
+        process.exit(-1);
+      }
+      const progname = path.basename(args[1]);
+      const rest = args.slice(2);
+
+      this.mainCommand.run(progname, [], rest, {});
+    }
+
+    subcommand<GN extends keyof any>(
+      argKey: GN,
+      name: string,
+      args: SubcommandArgs = {},
+    ): CommandGroup<GN, T> {
+      const cmd = this.mainCommand.subcommand(argKey, name as string, args);
+      return cmd as any;
+    }
+
+    requiredOption<N extends keyof any, V>(
+      name: N,
+      flagspec: string[],
+      conv: Converter<V>,
+      args: OptionArgs<V> = {},
+    ): Program<PN, T & SubRecord<PN, N, V>> {
+      this.mainCommand.requiredOption(name, flagspec, conv, args);
+      return this as any;
+    }
+
+    maybeOption<N extends keyof any, V>(
+      name: N,
+      flagspec: string[],
+      conv: Converter<V>,
+      args: OptionArgs<V> = {},
+    ): Program<PN, T & SubRecord<PN, N, V | undefined>> {
+      this.mainCommand.maybeOption(name, flagspec, conv, args);
+      return this as any;
+    }
+
+    /**
+     * Add a flag (option without value) to the program.
+     */
+    flag<N extends string>(
+      name: N,
+      flagspec: string[],
+      args: OptionArgs<boolean> = {},
+    ): Program<PN, T & SubRecord<PN, N, boolean>> {
+      this.mainCommand.flag(name, flagspec, args);
+      return this as any;
+    }
+
+    /**
+     * Add a required positional argument to the program.
+     */
+    requiredArgument<N extends keyof any, V>(
+      name: N,
+      conv: Converter<V>,
+      args: ArgumentArgs<V> = {},
+    ): Program<PN, T & SubRecord<PN, N, V>> {
+      this.mainCommand.requiredArgument(name, conv, args);
+      return this as any;
+    }
+
+    /**
+     * Add an optional argument to the program.
+     */
+    maybeArgument<N extends keyof any, V>(
+      name: N,
+      conv: Converter<V>,
+      args: ArgumentArgs<V> = {},
+    ): Program<PN, T & SubRecord<PN, N, V | undefined>> {
+      this.mainCommand.maybeArgument(name, conv, args);
+      return this as any;
+    }
+
+    action(f: ActionFn<T>): void {
+      this.mainCommand.action(f);
+    }
+  }
+
+  export type GetArgType<T> = T extends Program<any, infer AT>
+    ? AT
+    : T extends CommandGroup<any, infer AT>
+    ? AT
+    : any;
+
+  export function program<PN extends keyof any>(
+    argKey: PN,
+    args: ProgramArgs = {},
+  ): Program<PN, {}> {
+    return new Program(argKey as string, args);
+  }
+
+  export function prompt(question: string): Promise<string> {
+    const stdinReadline = readline.createInterface({
+      input: process.stdin,
+      output: process.stdout,
+    });
+    return new Promise<string>((resolve, reject) => {
+      stdinReadline.question(question, (res) => {
+        resolve(res);
+        stdinReadline.close();
+      });
+    });
+  }
+}

packages/taler-util/src/index.node.ts

@@ -21,3 +21,4 @@ initNodePrng();
 export * from "./index.js";
 export * from "./talerconfig.js";
 export * from "./globbing/minimatch.js";
+export { clk } from "./clk.js";