How do I specify the shell executable for child_process.exec?

Question

I'm using GitBash in windows 10 and want to execute git commands within a child_process.exec call. I think that since I installed git through "Git For Windows", I just need specify the shell as the GitBash executable. I've tried every variation of the path to GitBash executable that I could think of and it always fails. What is the path that node is looking for?

Example of paths that do not work c:/program files/git/usr/bin/bash c:/program\ files/git/usr/bin/bash /c/program\ files/git/usr/bin/bash c:\\program files\\git\\usr\\bin\\bash

const { expect } = require('chai');
const { exec } = require('child_process');

describe.only('exec', function(){
    it('should work', function(done){
        let shellPath = "c:\\program files\\git\\usr\\bin\\bash";
        expect(exec(`cat <<< "abc"`, { shell: shellPath }, (err, stdout) => {
            expect(err).to.be.null;
            expect(stdout.trim()).to.be.equal("abc");
            done();
        }));
    });
});

The first assertion fails with:

expected [Error: Command failed: cat <<< "abc" << was unexpected at this time.] to be null

Answer 1

There are some problems with this approach.

As the reference states, exec automatically uses Windows-specific shell arguments that won't work for Bash.

Another problem is that PATH may not be set to GitBash binaries path.

This should likely work:

delete process.platform;
process.platform = 'linux';

exec(`cat <<< "abc"`, {
  env: { PATH: 'C:\\Program Files\\git\\usr\\bin' },
  shell: 'C:\\Program Files\\git\\usr\\bin\\bash.exe'
}, (err, stdout) => {
  ...
});

process.platform = 'win32';

The workability of this solution may depend on bash.exe implementation.

The use of custom shell isn't needed to run git in Node; this is handled by Git executable.