Modularly import only the D3.js modules you require

d3Importer.js

import { line, curve, curveCatmullRom } from "d3-shape";
import { scaleTime, scaleLinear } from "d3-scale";
import { axisBottom, axisLeft } from 'd3-axis';
import { timeParse, isoFormat } from "d3-time-format";
import { select } from "d3-selection";
import { extent, max, min } from "d3-array";

export default {
    line: line,
    scaleTime: scaleTime,
    scaleLinear: scaleLinear,
    axisBottom: axisBottom,
    axisLeft: axisLeft,
    timeParse: timeParse,
    isoFormat: isoFormat,
    select: select,
    extent: extent,
    min: min,
    max: max,
};

index.jsx

import d3 from './d3Importer.js';