estimating-trends/src/js/d3/grid.js

import * as d3 from 'd3';

// d3js module: add grid
export default (selection, scales, options) => {
  const addGridlinesX = () => d3.axisBottom(scales.xScale).ticks(5);
  const addGridlinesY = () => d3.axisLeft(scales.yScale).ticks(15);

  // add the X gridlines
  selection.append('g')
    .attr('class', 'grid  grid--x')
    .attr('transform', `translate(0, ${options.heightWithoutMargin})`)
    .call(
      addGridlinesX()
      .tickSize(-options.heightWithoutMargin)
      .tickFormat('')
    );

  // add the Y gridlines
  selection.append('g')
    .attr('class', `grid  grid--y  mod${options.module}__grid--y`)
    .call(
      addGridlinesY()
      .tickSize(-options.widthWithoutMargin)
      .tickFormat('')
    );

};