Add support for browser only mode

[MathiasWP]

First of all, great library, love it!

But, I just spent a lot of hours debugging why our application failed, and it's because iconv-lite, a dependency of this library uses require('buffer').Buffer, which ended up in our web application JS code.

Could this library have an export version that does not use include any node specific modules?

[kenjiuno]

As you have noticed, buffer and string_decoder packages need to be polyfilled in some ways.

For now, I have no good idea to get rid of them from the msgreader dependency.

But msgreader may run on a web app environment built with a bundler like webpack.

demo: msgreader_demo
repo: HiraokaHyperTools/msgreader_demo

The important part is that the demo includes buffer - npm npm package, which has some compatibility with Node.js Buffer | Node.js v25.7.0 Documentation.

Also string_decoder - npm needs to be included as well.

{
  "name": "msgreader_demo",
  "version": "0.1.0",
  "main": "src/index.ts",
  "author": "kenjiuno",
  "license": "MIT",
  "private": true,
  "devDependencies": {
    "@kenjiuno/decompressrtf": "^0.1.4",
    "@kenjiuno/msgreader": "1.28.0-alpha.1",
    "@popperjs/core": "^2.11.6",
    "@types/jsoneditor": "^9.9.0",
    "bootstrap": "5.2.3",
    "buffer": "^6.0.3",
    "css-loader": "^6.7.2",
    "jquery": "^3.6.1",
    "jsoneditor": "^9.9.2",
    "rxjs": "^7.5.7",
    "string_decoder": "^1.3.0",
    "style-loader": "^3.3.1",
    "ts-loader": "^9.4.1",
    "typescript": "^4.9.3",
    "webpack": "^5.75.0",
    "webpack-cli": "^5.0.0"
  },
  "scripts": {
    "dev": "webpack --mode development --watch",
    "build": "webpack --mode production",
    "u": "yarn upgrade && yarn build"
  }
}

[MathiasWP]

Would it be a possibility to replace these dependencies with the browser-equivalents of them? So that they work both in NodeJS and in the browser?

[kenjiuno]

I have posted a very early experimental version of msgreader msgreader-web-ng, which removes iconv-lite. I'm not sure whether this works well. Anyway, unit tests are passed for now.

• HiraokaHyperTools/msgreader-web-ng
• @kenjiuno/msgreader-web-ng - npm

[MathiasWP]

I have posted a very early experimental version of msgreader msgreader-web-ng, which removes iconv-lite. I'm not sure whether this works well. Anyway, unit tests are passed for now.

• HiraokaHyperTools/msgreader-web-ng
• @kenjiuno/msgreader-web-ng - npm

Awesome! If all unit tests pass, won't that be sufficient enough? What exactly is iconv-lite's role in this library anyways?

[kenjiuno]

What exactly is iconv-lite's role in this library anyways?

iconv-lite is invoked:

• When the msg file contains ANSI string properties.
• When decoding UTF-16 LE.

msg (also pst) has a version:

• ANSI
• Unicode (it is always UTF-16 LE encoding)

ANSI version of the msg file is exported whenever Use Unicode format is unchecked in Microsoft Office Outlook. This occurs often for the non-Asian versions of Windows:

---

You can test the functionality of ansiEncoding. Try it with ansiEncoding ms932:

• https://github.com/HiraokaHyperTools/msgreader/blob/master/test/nonUnicodeCP932.json
• https://github.com/HiraokaHyperTools/msgreader/blob/master/test/nonUnicodeCP932.msg

---

@kenjiuno/msgreader-web-ng@0.2.0-alpha1 will work for use with web apps.

• demo: hiraokahypertools.github.io/msgreader-web-ng_demo/
• repo: HiraokaHyperTools/msgreader-web-ng_demo

[MathiasWP]

Could this help to make this library fully browser compatible? pillarjs/iconv-lite#384

[kenjiuno]

Could this help to make this library fully browser compatible? pillarjs/iconv-lite#384

I'm not sure for now.

I have searched the browser-related issues around this repository. These are hits:

• Migrated from Angular 19 to Angular v20 - now getting an error related to your library #62
• Module "stream" has been externalized for browser compatibility. Cannot access "stream.Transform" in client code #47

It is said that runtime errors (not build-time errors) are raised when msgreader is used on their web-based apps.
So I need to assume how the frontend app is composed. To verify that the known issues are gone.

Is it enough to start a new web project with npx sv create? like HiraokaHyperTools/msgreader-web-ng_demo