Quick start guide npm error

Developers
1

Hello, I am trying to get the quick start “Hello World” Dapp working and so far have got the canisters built and deployed locally (I have also deployed to the IC a different frontend only Dapp to the IC). I can see the frontend canister is working by putting http://127.0.0.1:8000/?canisterId=hozae-racaq-aaaaa-aaaaa-c into my browser but when I try to run npm start I am hit with errors. The output from the terminal is:

explore_hello_frontend@0.1.0 prestart /mnt/d/Videos/Documents/test/explore_hello
npm run copy:types

explore_hello_frontend@0.1.0 copy:types /mnt/d/Videos/Documents/test/explore_hello
rsync -avr .dfx/$(echo ${DFX_NETWORK:-‘'})/canisters/ --exclude=‘assets/’ --exclude=‘idl/’ --exclude=’.wasm’
–exclude='.most’ --delete src/declarations

sending incremental file listexplore_hello_backend/
explore_hello_backend/explore_hello_backend.old.did
explore_hello_frontend/
explore_hello_frontend/assetstorage.old.did

sent 4,352 bytes received 62 bytes 8,828.00 bytes/sec
total size is 23,469 speedup is 5.32

explore_hello_frontend@0.1.0 start /mnt/d/Videos/Documents/test/explore_hello
webpack serve --mode development --env development

No production canister_ids.json found. Continuing with local
[webpack-cli] /mnt/d/Videos/Documents/test/explore_hello/node_modules/webpack-dev-server/lib/getPort.js:13
const maxPort = 65_535;
^^

SyntaxError: Invalid or unexpected token
at Module._compile (internal/modules/cjs/loader.js:723:23)
at Object.Module._extensions…js (internal/modules/cjs/loader.js:789:10)
at Module.load (internal/modules/cjs/loader.js:653:32) at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
at Function.Module._load
(internal/modules/cjs/loader.js:585:3)
at Module.require (internal/modules/cjs/loader.js:692:17)
at require (internal/modules/cjs/helpers.js:25:18)
at Function.getFreePort (/mnt/d/Videos/Documents/test/explore_hello/node_modules/webpack-dev-server/lib/Server.js:397:21)
at Server.start (/mnt/d/Videos/Documents/test/explore_hello/node_modules/webpack-dev-server/lib/Server.js:3245:40)
at process._tickCallback
(internal/process/next_tick.js:68:7)
npm ERR! code ELIFECYCLE
npm ERR! errno 2
npm ERR! explore_hello_frontend@0.1.0 start: webpack serve --mode development --env development
npm ERR! Exit status 2
npm ERR!
npm ERR! Failed at the explore_hello_frontend@0.1.0 start
script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR! /home/milo_welch/.npm/_logs/2022-11-07T20_52_47_491Z-debug.log

Any ideas as to how to fix this? Thanks

2

It sounds like it’s the keyword const that is throwing the error? That’s wild. What version of Node are you running?

3

I am running v16.17.0

4

Could you provide more context by providing snippet of package.json and webpack configurations?

5

my webpack.configjs looks as follows

const path = require("path");
const webpack = require("webpack");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const TerserPlugin = require("terser-webpack-plugin");

function initCanisterEnv() {
  let localCanisters, prodCanisters;
  try {
    localCanisters = require(path.resolve(
      ".dfx",
      "local",
      "canister_ids.json"
    ));
  } catch (error) {
    console.log("No local canister_ids.json found. Continuing production");
  }
  try {
    prodCanisters = require(path.resolve("canister_ids.json"));
  } catch (error) {
    console.log("No production canister_ids.json found. Continuing with local");
  }

  const network =
    process.env.DFX_NETWORK ||
    (process.env.NODE_ENV === "production" ? "ic" : "local");

  const canisterConfig = network === "local" ? localCanisters : prodCanisters;

  return Object.entries(canisterConfig).reduce((prev, current) => {
    const [canisterName, canisterDetails] = current;
    prev[canisterName.toUpperCase() + "_CANISTER_ID"] =
      canisterDetails[network];
    return prev;
  }, {});
}
const canisterEnvVariables = initCanisterEnv();

const isDevelopment = process.env.NODE_ENV !== "production";

const frontendDirectory = "hello_frontend";

const frontend_entry = path.join("src", frontendDirectory, "src", "index.html");

module.exports = {
  target: "web",
  mode: isDevelopment ? "development" : "production",
  entry: {
    // The frontend.entrypoint points to the HTML file for this build, so we need
    // to replace the extension to `.js`.
    index: path.join(__dirname, frontend_entry).replace(/\.html$/, ".js"),
  },
  devtool: isDevelopment ? "source-map" : false,
  optimization: {
    minimize: !isDevelopment,
    minimizer: [new TerserPlugin()],
  },
  resolve: {
    extensions: [".js", ".ts", ".jsx", ".tsx"],
    fallback: {
      assert: require.resolve("assert/"),
      buffer: require.resolve("buffer/"),
      events: require.resolve("events/"),
      stream: require.resolve("stream-browserify/"),
      util: require.resolve("util/"),
    },
  },
  output: {
    filename: "index.js",
    path: path.join(__dirname, "dist", frontendDirectory),
  },

  // Depending in the language or framework you are using for
  // front-end development, add module loaders to the default
  // webpack configuration. For example, if you are using React
  // modules and CSS as described in the "Adding a stylesheet"
  // tutorial, uncomment the following lines:
  // module: {
  //  rules: [
  //    { test: /\.(ts|tsx|jsx)$/, loader: "ts-loader" },
  //    { test: /\.css$/, use: ['style-loader','css-loader'] }
  //  ]
  // },
  plugins: [
    new HtmlWebpackPlugin({
      template: path.join(__dirname, frontend_entry),
      cache: false,
    }),
    new webpack.EnvironmentPlugin({
      NODE_ENV: "development",
      ...canisterEnvVariables,
    }),
    new webpack.ProvidePlugin({
      Buffer: [require.resolve("buffer/"), "Buffer"],
      process: require.resolve("process/browser"),
    }),
  ],
  // proxy /api to port 8000 during development
  devServer: {
    proxy: {
      "/api": {
        target: "http://127.0.0.1:8000",
        changeOrigin: true,
        pathRewrite: {
          "^/api": "/api",
        },
      },
    },
    static: path.resolve(__dirname, "src", frontendDirectory, "assets"),
    hot: true,
    watchFiles: [path.resolve(__dirname, "src", frontendDirectory)],
    liveReload: true,
  },
};

and this is my package.json

{
  "name": "hello_frontend",
  "version": "0.1.0",
  "description": "Internet Computer starter application",
  "keywords": [
    "Internet Computer",
    "Motoko",
    "JavaScript",
    "Canister"
  ],
  "scripts": {
    "build": "webpack",
    "prebuild": "npm run copy:types",
    "start": "webpack serve --mode development --env development",
    "prestart": "npm run copy:types",
    "copy:types": "rsync -avr .dfx/$(echo ${DFX_NETWORK:-'**'})/canisters/** --exclude='assets/' --exclude='idl/' --exclude='*.wasm' --exclude='*.most' --delete src/declarations"
  },
  "devDependencies": {
    "@dfinity/agent": "0.14.1",
    "@dfinity/candid": "0.14.1",
    "@dfinity/principal": "0.14.1",
    "assert": "2.0.0",
    "buffer": "6.0.3",
    "events": "3.3.0",
    "html-webpack-plugin": "5.5.0",
    "process": "0.11.10",
    "stream-browserify": "3.0.0",
    "terser-webpack-plugin": "^5.3.3",
    "util": "0.12.4",
    "webpack": "^5.73.0",
    "webpack-cli": "^4.10.0",
    "webpack-dev-server": "^4.8.1"
  },
  "engines": {
    "node": "^12 || ^14 || ^16 || ^18"
  },
  "browserslist": [
    "last 2 chrome version",
    "last 2 firefox version",
    "last 2 safari version",
    "last 2 edge version"
  ]
}

This both were set up via >>dfx new hello
It should be noted that I have to run >> dfx start --emulator rather than dfx start because otherwise on >> dfx deploy I get this error

Error: Failed to get wallet canister caller for identity ‘default’ on network ‘local’.

But I found a work around to this in another post

1 Like
6

It should be noted that I have to run >> dfx start --emulator rather than dfx start because otherwise on >> dfx deploy I get this error
Error: Failed to get wallet canister caller for identity ‘default’ on network ‘local’.

When switching between dfx start and dfx start --emulator, it’s necessary to use --clean, otherwise this wallet canister lookup will fail.

1 Like