Just-one-space (from Emacs) implementation for Atom

init.js

"use babel";

atom.commands.add('atom-text-editor', 'hartmann:just-one-space', () => {
    const editor = atom.workspace.getActiveTextEditor();

    if (!editor) {
        return;
    }

    const changes = editor.getCursorBufferPositions().map((point) => {
        const line = editor.lineTextForBufferRow(point.row)
        const range = editor.getBuffer().rangeForRow(point.row, false)
        const leftOfCursor = line.substring(0, point.column)
        const rightOfCursor = line.substring(point.column)
        const leftOfCursorNoWhitespace = leftOfCursor.trimRight()
        const rightOfCursorNoWhitespace = rightOfCursor.trimLeft()
        const newPosition = [point.row, leftOfCursorNoWhitespace.length + 1]
        const newLine = `${leftOfCursorNoWhitespace} ${rightOfCursorNoWhitespace}`;
        return {
            range: range,
            line: newLine,
            position: newPosition,
        }
    });

    // This is a bit hacky, I use setCursorBufferPosition to reset all cursors
    // and then add the remaining cursors using addCursorAtBufferPosition.
    const [first, ...rest] = changes;

    editor.getBuffer().setTextInRange(first.range, first.line);
    editor.setCursorBufferPosition(first.position);

    rest.forEach( ({ range, line, position}) => {
        editor.getBuffer().setTextInRange(range, line);
        editor.addCursorAtBufferPosition(position);
    });

});