assume toPosition is opposite to fromPosition

src/components/ConnectionLine/index.tsx

@@ -82,8 +82,6 @@ export default ({
     targetY: number,
     targetPosition: Position | undefined;
 
-  let toCurvature: 'sourceCurvature' | 'targetCurvature';
-
   switch (connectionHandleType) {
     case 'source':
       {
@@ -93,7 +91,6 @@ export default ({
         targetX = toX;
         targetY = toY;
         targetPosition = toPosition;
-        toCurvature = 'targetCurvature';
       }
       break;
     case 'target':
@@ -104,7 +101,6 @@ export default ({
         targetX = fromX;
         targetY = fromY;
         targetPosition = fromPosition;
-        toCurvature = 'sourceCurvature';
       }
       break;
   }
@@ -143,10 +139,8 @@ export default ({
   };
 
   if (connectionLineType === ConnectionLineType.Bezier) {
-    // we don't know the destination position, so we can zero the to curvature
-    dAttr = getBezierPath({ ...pathParams, [toCurvature]: 0 });
-    // or we assume the destination position is opposite to the source position
-    // dAttr = getBezierPath(pathParams);
+    // we assume the destination position is opposite to the source position
+    dAttr = getBezierPath(pathParams);
   } else if (connectionLineType === ConnectionLineType.Step) {
     dAttr = getSmoothStepPath({
       ...pathParams,

src/components/Edges/BezierEdge.tsx

@@ -11,8 +11,6 @@ export interface GetBezierPathParams {
   targetY: number;
   targetPosition?: Position;
   curvature?: number;
-  sourceCurvature?: number;
-  targetCurvature?: number;
   centerX?: number;
   centerY?: number;
 }
@@ -91,8 +89,6 @@ export function getBezierPath({
   targetY,
   targetPosition = Position.Top,
   curvature = 0.25,
-  sourceCurvature = curvature,
-  targetCurvature = curvature,
   centerX,
   centerY,
 }: GetBezierPathParams): string {
@@ -107,7 +103,7 @@ export function getBezierPath({
     y2: targetY,
     cX: centerX,
     cY: centerY,
-    c: sourceCurvature,
+    c: curvature,
   });
   const [targetControlX, targetControlY] = getControlWithCurvature({
     pos: targetPosition,
@@ -117,7 +113,7 @@ export function getBezierPath({
     y2: sourceY,
     cX: centerX,
     cY: centerY,
-    c: targetCurvature,
+    c: curvature,
   });
   return `M${sourceX},${sourceY} C${sourceControlX},${sourceControlY} ${targetControlX},${targetControlY} ${targetX},${targetY}`;
 }