source: node_modules/d3-transition/src/transition/attr.js@ a762898

import {interpolateTransformSvg as interpolateTransform} from "d3-interpolate";
import {namespace} from "d3-selection";
import {tweenValue} from "./tween.js";
import interpolate from "./interpolate.js";

function attrRemove(name) {
  return function() {
    this.removeAttribute(name);
  };
}

function attrRemoveNS(fullname) {
  return function() {
    this.removeAttributeNS(fullname.space, fullname.local);
  };
}

function attrConstant(name, interpolate, value1) {
  var string00,
      string1 = value1 + "",
      interpolate0;
  return function() {
    var string0 = this.getAttribute(name);
    return string0 === string1 ? null
        : string0 === string00 ? interpolate0
        : interpolate0 = interpolate(string00 = string0, value1);
  };
}

function attrConstantNS(fullname, interpolate, value1) {
  var string00,
      string1 = value1 + "",
      interpolate0;
  return function() {
    var string0 = this.getAttributeNS(fullname.space, fullname.local);
    return string0 === string1 ? null
        : string0 === string00 ? interpolate0
        : interpolate0 = interpolate(string00 = string0, value1);
  };
}

function attrFunction(name, interpolate, value) {
  var string00,
      string10,
      interpolate0;
  return function() {
    var string0, value1 = value(this), string1;
    if (value1 == null) return void this.removeAttribute(name);
    string0 = this.getAttribute(name);
    string1 = value1 + "";
    return string0 === string1 ? null
        : string0 === string00 && string1 === string10 ? interpolate0
        : (string10 = string1, interpolate0 = interpolate(string00 = string0, value1));
  };
}

function attrFunctionNS(fullname, interpolate, value) {
  var string00,
      string10,
      interpolate0;
  return function() {
    var string0, value1 = value(this), string1;
    if (value1 == null) return void this.removeAttributeNS(fullname.space, fullname.local);
    string0 = this.getAttributeNS(fullname.space, fullname.local);
    string1 = value1 + "";
    return string0 === string1 ? null
        : string0 === string00 && string1 === string10 ? interpolate0
        : (string10 = string1, interpolate0 = interpolate(string00 = string0, value1));
  };
}

export default function(name, value) {
  var fullname = namespace(name), i = fullname === "transform" ? interpolateTransform : interpolate;
  return this.attrTween(name, typeof value === "function"
      ? (fullname.local ? attrFunctionNS : attrFunction)(fullname, i, tweenValue(this, "attr." + name, value))
      : value == null ? (fullname.local ? attrRemoveNS : attrRemove)(fullname)
      : (fullname.local ? attrConstantNS : attrConstant)(fullname, i, value));
}