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Contributing

Due to the precarious nature of the Open Specifications Promise, it is very important to ensure code is cleanroom.

The Contribution Notes should be perused before contributing code.

File organization (click to show)

Folders:

foldercontents
binserver-side bin scripts (xlsx.njs)
bitsraw source files that make up the final script
distdist files for web browsers and nonstandard JS environments
miscmiscellaneous supporting scripts
modulesTypeScript source files that generate some of the bits
packagesSupport libraries and tools
test_filestest files (pulled from the test artifacts distribution)
testsbrowser tests (run make ctest to rebuild)
typesTypeScript definitions and tests

After cloning the repo, running make help will display a list of commands.

Setup​

These instructions will cover system configuration, cloning the source repo, building, reproducing official releases, and running NodeJS and browser tests.

Tested Deployments

These instructions were tested on the following platforms:

PlatformArchitectureTest Date
Linux (Steam Deck Holo x64)linux-x642024-09-20
Linux (Arch Linux AArch64)linux-arm2024-05-10
MacOS 14.4 (x64)darwin-x642024-07-12
MacOS 15.1 (ARM64)darwin-arm2024-11-10
Windows 10 (x64) + WSL Ubuntuwin10-x642024-07-12
Windows 11 (x64) + WSL Ubuntuwin11-x642024-12-19
Windows 11 (ARM) + WSL Ubuntuwin11-arm2024-05-23

With some additional dependencies, the unminified scripts are reproducible and tests will pass in Windows XP with NodeJS 5.10.0.

Install dependencies​

OS-Specific Setup​

A) Ensure WSL ("WSL 2" in Windows 10) and the Ubuntu distribution are installed.

Installation Notes (click to hide)

In "Turn Windows features on or off", all available features from the following list should be enabled:

  • "Hyper-V" (including every sub-feature)
  • "Virtual Machine Platform"
  • "Windows Hypervisor Platform"
  • "Windows Subsystem for Linux"

The WSL requirements have changed over the years. To be safe, it is recommended to install every listed feature that is available for the Windows version.

The following command installs Ubuntu within WSL:

wsl --update
wsl --install Ubuntu

In some versions of wsl, the -d flag must be specified:

wsl --update
wsl --install -d Ubuntu

In some tests, the install failed with a WSL_E_DEFAULT_DISTRO_NOT_FOUND error.

The resolution is to switch to WSL1, install, and switch back to WSL2:

wsl --set-default-version 1
wsl --install Ubuntu
wsl --set-default-version 2
wsl --install Ubuntu

In Windows 11 24H2, the wsl commands may fail with the following message:

Class not registered
Error code: Wsl/CallMsi/Install/REGDB_E_CLASSNOTREG

WSL should be manually installed. Once installed, WSL2 should be activated:

wsl --set-default-version 2
wsl --install -d Ubuntu

WSL will not run in a Windows on ARM VM on computers with the M1 CPU

Apple Silicon M1 processors do not support nested virtualization.

M2 processors do support nested virtualization. SheetJS users have reported success with Windows on ARM running on computers with the M2 Max CPU.

B) Install NVM within WSL:

sudo apt-get install curl
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/master/install.sh | bash

C) Exit the WSL session and start a new session

D) Install NodeJS 16 using NVM:

nvm install 16
nvm use 16

E) Clone the js-crc32 repo

git clone https://git.sheetjs.com/sheetjs/js-crc32

On Windows 10, this clone may fail due to issues with core.filemode:

fatal: could not set 'core.filemode' to 'false'

The main drive must be remounted with the metadata option:

cd /
sudo umount /mnt/c
sudo mount -t drvfs C: /mnt/c -o metadata
cd -

If this clone fails with an error message that mentions SSL or secure connection or certificates, build and install a version of Git with proper SSL support:

: # Git does not support OpenSSL out of the box, must do this
curl -LO https://github.com/niko-dunixi/git-openssl-shellscript/raw/main/compile-git-with-openssl.sh
chmod +x compile-git-with-openssl.sh
./compile-git-with-openssl.sh

F) Set git config core.autocrlf setting to false. The following commands should be run twice, once within PowerShell (if Git for Windows is installed) and once within WSL bash:

git config --global --add core.autocrlf false
git config --global --unset core.autocrlf true

G) Run unzip. If the program is missing, install manually:

sudo apt-get install -y unzip

H) Run make. If the program is missing, install manually:

sudo apt-get install -y make

Build from source tree​

  1. Clone the project:
git clone https://git.sheetjs.com/sheetjs/sheetjs
cd sheetjs

On older platforms, the clone may fail due to SSL certificate problems:

fatal: unable to access 'https://git.sheetjs.com/sheetjs/sheetjs/': SSL certificate problem: certificate has expired

The simplest workaround is to disable SSL verification:

git config --global http.sslVerify false

It is strongly recommended to re-enable SSL verification after cloning:

git config --global http.sslVerify true
  1. Install NodeJS modules for building the scripts:
npm i
npm i -g [email protected] voc @sheetjs/uglify-js

If npm i -g fails with a permissions issue, run the command with sudo:

npm i
sudo npm i -g [email protected] voc @sheetjs/uglify-js
Older Versions of Dependencies

Some of the dependencies are wildly out of date. While SheetJS libraries aim to run in older versions of NodeJS and browsers, some libraries have opted to break backwards compatibility. The specific versions are used because they are known to work and known to produce consistent and reproducible results.

  1. Initialize the test files:
rmdir test_files
curl -LO https://test-files.sheetjs.com/test_files.zip
unzip test_files.zip
mkdir -p tmp

The rmdir command may fail if the folder is missing. The error can be ignored.

This step may take a few minutes as the current test snapshot is large.

  1. Run the esbuild tool once:
npx -y [email protected] --version

The command will print the version number 0.14.14.

  1. Run a build and verify with a short test:
: # Full Build
cd modules; make clean; make; cd ..
make
make dist

: # Short test
make test_misc

: # Reset repo
git checkout -- .

In some tests on older releases of macOS, the build failed with an error:

ReferenceError: n is not defined

The first error in the call stack points to dist/xlsx.zahl.js.

Older versions of macOS sed are known to misinterpret newline characters. The workaround is to upgrade to a newer version of sed. On macOS:

brew install gnu-sed
echo 'export PATH="/usr/local/opt/gnu-sed/libexec/gnubin:$PATH"' >> ~/.profile
. ~/.profile

Reproduce official builds​

  1. Run git log and search for the commit that matches a particular release version. For example, version 0.20.3 can be found with:
git log | grep -B4 "version bump 0.20.3"

The output should look like:

$ git log | grep -B4 "version bump 0.20.3"
commit 8a7cfd47bde8258c0d91df6a737bf0136699cdf8 <-- this is the commit hash
Author: SheetJS <[email protected]>
Date:   Fri Jul 12 11:47:14 2024 -0400

    version bump 0.20.3
  1. Switch to that commit:
git checkout 8a7cfd47bde8258c0d91df6a737bf0136699cdf8
  1. Run the full build sequence:
make clean; make
cd modules; make clean; make; cd ..
make
make dist
  1. Verify the scripts by computing the MD5 checksum.

The checksum for the generated xlsx.full.min.js script can be computed using the md5 command on macOS or the md5sum command on WSL and Linux.

md5sum dist/xlsx.full.min.js

The checksum for the equivalent script on the SheetJS CDN can be computed with:

curl -L https://cdn.sheetjs.com/xlsx-0.20.3/package/dist/xlsx.full.min.js | md5sum -

The following output was captured in win11-arm for SheetJS version 0.20.3:

$ md5sum dist/xlsx.full.min.js
6b3130af1ceadf07caa0ec08af7addff  dist/xlsx.full.min.js
$ curl -L https://cdn.sheetjs.com/xlsx-0.20.3/package/dist/xlsx.full.min.js | md5sum -
6b3130af1ceadf07caa0ec08af7addff  -

The two hashes should match.

  1. Return to the HEAD commit:
git checkout master

Test in web browsers​

  1. Start local server:
make ctestserv

The terminal will display a port number. For example:

Serving HTTP on 0.0.0.0 port 8000 (http://0.0.0.0:8000/)
  1. Open a browser window and access http://localhost:8000, replacing 8000 with the port number from the terminal window.

Development​

The xlsx.js and xlsx.mjs files are constructed from the files in the bits subfolder. The build script (run make) will concatenate the individual bits to produce the scripts.

When changing the .js scripts in bits, the following sequence rebuilds the xlsx.js and xlsx.mjs scripts:

make

When changing the .ts scripts in modules, the following sequence rebuilds the xlsx.js and xlsx.mjs scripts:

cd modules; make clean; make; cd ..

To produce the dist files, run make dist.

The various xlsx.* scripts in the base folder and the files in the dist folder are updated on each version release.

They should not be committed between versions!

Tests​

The test_misc target runs the targeted feature tests. It should take 5-10 seconds to perform feature tests without testing against the full test battery. New features should be accompanied with tests for the relevant file formats.

For tests involving the read side, an appropriate feature test would involve reading an existing file and checking the resulting workbook object. If a parameter is involved, files should be read with different values to verify that the feature is working as expected.

For tests involving a new write feature which can already be parsed, appropriate feature tests would involve writing a workbook with the feature and then opening and verifying that the feature is preserved.

For tests involving a new write feature without an existing read ability, please add a feature test to the kitchen sink tests/write.js.