react-native-svg/lib/extract/extractStroke.js

import extractBrush from "./extractBrush";
import extractOpacity from "./extractOpacity";
import extractLengthList from "./extractLengthList";

const caps = {
  butt: 0,
  square: 2,
  round: 1,
};

const joins = {
  miter: 0,
  bevel: 2,
  round: 1,
};

const strokeProps = [
  "stroke",
  "strokeWidth",
  "strokeOpacity",
  "strokeDasharray",
  "strokeDashoffset",
  "strokeLinecap",
  "strokeLinejoin",
  "strokeMiterlimit",
];
const numStrokeProps = strokeProps.length;

export default function extractStroke(props, styleProperties) {
  for (let i = 0; i < numStrokeProps; i++) {
    const name = strokeProps[i];
    if (props.hasOwnProperty(name)) {
      styleProperties.push(name);
    }
  }

  const { stroke, strokeWidth = 1, strokeDasharray } = props;
  const strokeDash =
    !strokeDasharray || strokeDasharray === "none"
      ? null
      : extractLengthList(strokeDasharray);

  return {
    stroke: extractBrush(stroke),
    strokeOpacity: extractOpacity(props.strokeOpacity),
    strokeLinecap: caps[props.strokeLinecap] || 0,
    strokeLinejoin: joins[props.strokeLinejoin] || 0,
    strokeDasharray:
      strokeDash && strokeDash.length % 2 === 1
        ? strokeDash.concat(strokeDash)
        : strokeDash,
    strokeWidth,
    strokeDashoffset: strokeDasharray ? +props.strokeDashoffset || 0 : null,
    strokeMiterlimit: parseFloat(props.strokeMiterlimit) || 4,
  };
}