Merge pull request #352 from wbkd/develop

Develop

README.md

@@ -542,6 +542,7 @@ You can find all examples in the [example](example) folder or check out the live
 - [interaction](https://reactflow.dev/interaction)
 - [provider](https://reactflow.dev/provider)
 - [hidden](https://reactflow.dev/hidden)
+- [edge types](https://reactflow.dev/edge-types)
 
 # Development
 

cypress/integration/flow/basic.spec.js

@@ -1,7 +1,9 @@
 describe('Basic Flow Rendering', () => {
-  it('renders a flow with three nodes', () => {
+  before(() => {
     cy.visit('/basic');
+  });
 
+  it('renders a flow with three nodes', () => {
     cy.get('.react-flow__renderer');
     cy.get('.react-flow-basic-example'); // check if className prop works
     cy.get('.react-flow__node').should('have.length', 4);
@@ -115,16 +117,10 @@ describe('Basic Flow Rendering', () => {
   });
 
   it('drags the pane', () => {
-    // for d3 we have to pass the window to the event
-    // https://github.com/cypress-io/cypress/issues/3441
-
-    const newPosition = {
-      clientX: Cypress.config('viewportWidth') * 0.6,
-      clientY: Cypress.config('viewportHeight') * 0.7,
-    };
-
     const styleBeforeDrag = Cypress.$('.react-flow__nodes').css('transform');
 
+    // for d3 we have to pass the window to the event
+    // https://github.com/cypress-io/cypress/issues/3441
     cy.window().then((win) => {
       cy.get('.react-flow__zoompane')
         .trigger('mousedown', 'topLeft', { which: 1, view: win })

cypress/integration/flow/controls.spec.js

@@ -0,0 +1,80 @@
+describe('Controls Testing', () => {
+  before(() => {
+    cy.visit('/');
+  });
+
+  it('renders the control panel', () => {
+    cy.get('.react-flow__controls');
+  });
+
+  it('zooms in', () => {
+    const styleBeforeZoom = Cypress.$('.react-flow__nodes').css('transform');
+
+    cy.get('.react-flow__controls-zoomin')
+      .click()
+      .then(() => {
+        const styleAfterZoom = Cypress.$('.react-flow__nodes').css('transform');
+        expect(styleBeforeZoom).to.not.equal(styleAfterZoom);
+      });
+  });
+
+  it('zooms out', () => {
+    const styleBeforeZoom = Cypress.$('.react-flow__nodes').css('transform');
+
+    cy.get('.react-flow__controls-zoomout')
+      .click()
+      .then(() => {
+        const styleAfterZoom = Cypress.$('.react-flow__nodes').css('transform');
+        expect(styleBeforeZoom).to.not.equal(styleAfterZoom);
+      });
+  });
+
+  // view is already fitted so we drag the pane to un-fit it
+  it('drags the pane', () => {
+    const styleBeforeDrag = Cypress.$('.react-flow__nodes').css('transform');
+
+    // for d3 we have to pass the window to the event
+    // https://github.com/cypress-io/cypress/issues/3441
+    cy.window().then((win) => {
+      cy.get('.react-flow__zoompane')
+        .trigger('mousedown', 'topLeft', { which: 1, view: win })
+        .trigger('mousemove', 'bottomLeft')
+        .trigger('mouseup', { force: true, view: win })
+        .then(() => {
+          const styleAfterDrag = Cypress.$('.react-flow__nodes').css('transform');
+          expect(styleBeforeDrag).to.not.equal(styleAfterDrag);
+        });
+    });
+  });
+
+  it('fits view', () => {
+    const styleBeforeZoom = Cypress.$('.react-flow__nodes').css('transform');
+
+    cy.get('.react-flow__controls-fitview')
+      .click()
+      .then(() => {
+        const styleAfterZoom = Cypress.$('.react-flow__nodes').css('transform');
+        expect(styleBeforeZoom).to.not.equal(styleAfterZoom);
+      });
+  });
+
+  it('uses interactive control - not interactive', () => {
+    cy.get('.react-flow__node:first').click().should('have.class', 'selected');
+    cy.get('.react-flow__renderer').click('bottomRight');
+    cy.get('.react-flow__node:first').should('not.have.class', 'selected');
+
+    cy.get('.react-flow__controls-interactive')
+      .click()
+      .then(() => {
+        cy.get('.react-flow__node:first').should('not.have.class', 'selected');
+      });
+  });
+
+  it('uses interactive control - interactive', () => {
+    cy.get('.react-flow__controls-interactive')
+      .click()
+      .then(() => {
+        cy.get('.react-flow__node:first').click().should('have.class', 'selected');
+      });
+  });
+});

cypress/integration/flow/custom-node.js

@@ -1,10 +0,0 @@
-describe('Custom Node Flow Rendering', () => {
-  it('renders a flow', () => {
-    cy.visit('/custom-node');
-
-    cy.get('.react-flow__renderer');
-
-    cy.get('.react-flow__node').should('have.length', 4);
-    cy.get('.react-flow__edge').should('have.length', 3);
-  });
-});

cypress/integration/flow/empty.spec.js

@@ -1,7 +1,9 @@
 describe('Empty Flow Rendering', () => {
-  it('renders an empty flow', () => {
+  before(() => {
     cy.visit('/empty');
+  });
 
+  it('renders an empty flow', () => {
     cy.get('.react-flow__renderer');
     cy.get('.react-flow__node').should('not.exist');
     cy.get('.react-flow__edge').should('not.exist');
@@ -16,26 +18,6 @@ describe('Empty Flow Rendering', () => {
       .trigger('mouseup', 'bottomRight', { force: true });
   });
 
-  it('renders a control panel', () => {
-    cy.get('.react-flow__controls');
-  });
-
-  it('uses zoom in control', () => {
-    cy.get('.react-flow__controls-zoomin').click();
-  });
-
-  it('uses zoom out control', () => {
-    cy.get('.react-flow__controls-zoomout').click();
-  });
-
-  it('uses fit view control', () => {
-    cy.get('.react-flow__controls-fitview').click();
-  });
-
-  it('uses lock view control', () => {
-    cy.get('.react-flow__controls-interactive');
-  });
-
   it('renders an empty mini map', () => {
     cy.get('.react-flow__minimap');
     cy.get('.react-flow__minimap-node').should('not.exist');

cypress/integration/flow/graph-utils.spec.js

@@ -0,0 +1,130 @@
+import { isNode, isEdge, getOutgoers, removeElements, addEdge } from '../../../src/utils/graph.ts';
+
+const nodes = [
+  { id: '1', type: 'input', data: { label: 'Node 1' }, position: { x: 250, y: 5 } },
+  { id: '2', data: { label: 'Node 2' }, position: { x: 100, y: 100 } },
+  { id: '3', data: { label: 'Node 3' }, position: { x: 400, y: 100 } },
+  { id: '4', data: { label: 'Node 4' }, position: { x: 400, y: 200 } },
+];
+
+const edges = [
+  { id: 'e1-2', source: '1', target: '2', animated: true },
+  { id: 'e1-3', source: '1', target: '3' },
+];
+
+const elements = [...nodes, ...edges];
+
+describe('Graph Utils Testing', () => {
+  it('tests isNode function', () => {
+    expect(isNode(nodes[0])).to.be.true;
+    expect(isNode(edges[0])).to.be.false;
+  });
+
+  it('tests isEdge function', () => {
+    expect(isEdge(edges[0])).to.be.true;
+    expect(isEdge(nodes[0])).to.be.false;
+  });
+
+  it('tests getOutgoers function', () => {
+    const outgoers = getOutgoers(nodes[0], elements);
+    expect(outgoers.length).to.be.equal(2);
+
+    const noOutgoers = getOutgoers(nodes[1], elements);
+    expect(noOutgoers.length).to.be.equal(0);
+  });
+
+  describe('tests addEdge function', () => {
+    it('adds edge', () => {
+      const newEdge = { source: '2', target: '3' };
+      const nextElements = addEdge(newEdge, elements);
+
+      expect(nextElements.length).to.be.equal(elements.length + 1);
+    });
+
+    it('tries to add invalid edge', () => {
+      const newEdge = { nosource: '1', notarget: '3' };
+
+      try {
+        addEdge(newEdge, elements);
+      } catch (e) {
+        console.log(e.message);
+
+        expect(e.message).to.be.equal("Can't create edge. An edge needs a source and a target.");
+      }
+    });
+
+    it('tries to add edge with id that does not exist', () => {
+      const notExistingId = 'does-not-exist';
+      const newEdge = { source: notExistingId, target: '3' };
+
+      try {
+        addEdge(newEdge, elements);
+      } catch (e) {
+        console.log(e.message);
+        expect(e.message).to.be.equal(`Can't create edge. Node with id=${notExistingId} does not exist.`);
+      }
+    });
+  });
+
+  describe('tests removeElements function', () => {
+    it('removes a node', () => {
+      const nextElements = removeElements([nodes[0]], elements);
+
+      const nextNodes = nextElements.filter((e) => isNode(e));
+      const nextEdges = nextElements.filter((e) => isEdge(e));
+
+      expect(nextNodes.length).to.be.equal(nodes.length - 1);
+      expect(nextEdges.length).to.be.equal(edges.length - 2);
+    });
+
+    it('removes multiple nodes', () => {
+      const elementsToRemove = [nodes[0], nodes[1]];
+      const nextElements = removeElements(elementsToRemove, elements);
+      const nextNodes = nextElements.filter((e) => isNode(e));
+      const nextEdges = nextElements.filter((e) => isEdge(e));
+
+      expect(nextNodes.length).to.be.equal(nodes.length - 2);
+      expect(nextEdges.length).to.be.equal(0);
+    });
+
+    it('removes no node', () => {
+      const nextElementsNoRemove = removeElements([], elements);
+      expect(nextElementsNoRemove.length).to.be.equal(elements.length);
+    });
+
+    it('tries to removes node that does not exist', () => {
+      const nextElementsNoRemove = removeElements([{ id: 'id-that-does-not-exist' }], elements);
+      expect(nextElementsNoRemove.length).to.be.equal(elements.length);
+    });
+
+    it('removes an edge', () => {
+      const nextElements = removeElements([edges[0]], elements);
+
+      const nextNodes = nextElements.filter((e) => isNode(e));
+      const nextEdges = nextElements.filter((e) => isEdge(e));
+
+      expect(nextNodes.length).to.be.equal(nodes.length);
+      expect(nextEdges.length).to.be.equal(edges.length - 1);
+    });
+
+    it('removes multiple edges', () => {
+      const nextElements = removeElements([edges[0], edges[1]], elements);
+
+      const nextNodes = nextElements.filter((e) => isNode(e));
+      const nextEdges = nextElements.filter((e) => isEdge(e));
+
+      expect(nextNodes.length).to.be.equal(nodes.length);
+      expect(nextEdges.length).to.be.equal(edges.length - 2);
+    });
+
+    it('removes node and edge', () => {
+      const nextElements = removeElements([nodes[0], edges[0]], elements);
+
+      const nextNodes = nextElements.filter((e) => isNode(e));
+      const nextEdges = nextElements.filter((e) => isEdge(e));
+
+      expect(nextNodes.length).to.be.equal(nodes.length - 1);
+      expect(nextEdges.length).to.be.equal(edges.length - 2);
+    });
+  });
+});

cypress/integration/flow/hidden.spec.js

@@ -1,7 +1,9 @@
 describe('Hidden Flow Rendering', () => {
-  it('renders the initial flow', () => {
+  before(() => {
     cy.visit('/hidden');
+  });
 
+  it('renders initial flow', () => {
     cy.get('.react-flow__renderer');
     cy.get('.react-flow__node').should('have.length', 4);
     cy.get('.react-flow__edge').should('have.length', 3);

cypress/integration/flow/interaction.spec.js

@@ -1,7 +1,9 @@
 describe('Interaction Flow Rendering', () => {
-  it('renders initial flow', () => {
+  before(() => {
     cy.visit('/interaction');
+  });
 
+  it('renders initial flow', () => {
     cy.get('.react-flow__renderer');
     cy.get('.react-flow__node').should('have.length', 4);
     cy.get('.react-flow__edge').should('have.length', 2);
@@ -23,6 +25,38 @@ describe('Interaction Flow Rendering', () => {
     cy.get('body').type('{shift}', { release: true });
   });
 
+  it('tries to connect to nodes', () => {
+    cy.get('.react-flow__node')
+      .contains('Node 3')
+      .find('.react-flow__handle.source')
+      .then(($el) => {
+        const pointerEvents = $el.css('pointer-events');
+        expect(pointerEvents).to.equal('none');
+      });
+  });
+
+  it('tries to zoom by scroll', () => {
+    const styleBeforeZoom = Cypress.$('.react-flow__nodes').css('transform');
+
+    cy.get('.react-flow__zoompane')
+      .dblclick()
+      .then(() => {
+        const styleAfterZoom = Cypress.$('.react-flow__nodes').css('transform');
+        expect(styleBeforeZoom).to.equal(styleAfterZoom);
+      });
+  });
+
+  it('tries to zoom by double click', () => {
+    const styleBeforeZoom = Cypress.$('.react-flow__nodes').css('transform');
+
+    cy.get('.react-flow__zoompane')
+      .trigger('wheel', 'topLeft', { deltaY: -200 })
+      .then(() => {
+        const styleAfterZoom = Cypress.$('.react-flow__nodes').css('transform');
+        expect(styleBeforeZoom).to.equal(styleAfterZoom);
+      });
+  });
+
   it('toggles draggable mode', () => {
     cy.get('.react-flow__draggable').click();
   });
@@ -47,4 +81,53 @@ describe('Interaction Flow Rendering', () => {
   it('selects an edge by click', () => {
     cy.get('.react-flow__edge:first').click().should('have.class', 'selected');
   });
+
+  it('toggles connectable mode', () => {
+    cy.get('.react-flow__connectable').click();
+  });
+
+  it('connects two nodes', () => {
+    cy.get('.react-flow__node')
+      .contains('Node 3')
+      .find('.react-flow__handle.source')
+      .trigger('mousedown', { which: 1 });
+
+    cy.get('.react-flow__node')
+      .contains('Node 4')
+      .find('.react-flow__handle.target')
+      .trigger('mousemove')
+      .trigger('mouseup', { force: true });
+
+    cy.get('.react-flow__edge').should('have.length', 3);
+  });
+
+  it('toggles zoom on scroll', () => {
+    cy.get('.react-flow__zoomonscroll').click();
+  });
+
+  it('zooms by scroll', () => {
+    const styleBeforeZoom = Cypress.$('.react-flow__nodes').css('transform');
+
+    cy.get('.react-flow__zoompane')
+      .trigger('wheel', 'topLeft', { deltaY: 200 })
+      .then(() => {
+        const styleAfterZoom = Cypress.$('.react-flow__nodes').css('transform');
+        expect(styleBeforeZoom).not.to.equal(styleAfterZoom);
+      });
+  });
+
+  it('toggles zoom on double click', () => {
+    cy.get('.react-flow__zoomondbl').click();
+  });
+
+  it('zooms by double click', () => {
+    const styleBeforeZoom = Cypress.$('.react-flow__nodes').css('transform');
+
+    cy.get('.react-flow__zoompane')
+      .dblclick()
+      .then(() => {
+        const styleAfterZoom = Cypress.$('.react-flow__nodes').css('transform');
+        expect(styleBeforeZoom).not.to.equal(styleAfterZoom);
+      });
+  });
 });

cypress/integration/flow/minimap.spec.js

@@ -0,0 +1,69 @@
+describe('Minimap Testing', () => {
+  before(() => {
+    cy.visit('/');
+  });
+
+  it('renders the mini map', () => {
+    cy.get('.react-flow__minimap');
+    cy.get('.react-flow__minimap-mask');
+  });
+
+  it('has same number of nodes as the pane', () => {
+    const paneNodes = Cypress.$('.react-flow__node').length;
+    const minimapNodes = Cypress.$('.react-flow__minimap-node').length;
+
+    expect(paneNodes).equal(minimapNodes);
+  });
+
+  it('changes zoom level', () => {
+    const viewBoxBeforeZoom = Cypress.$('.react-flow__minimap').attr('viewBox');
+    const maskPathBeforeZoom = Cypress.$('.react-flow__minimap-mask').attr('d');
+
+    cy.get('.react-flow__zoompane')
+      .trigger('wheel', 'topLeft', { deltaY: -200 })
+      .then(() => {
+        const viewBoxAfterZoom = Cypress.$('.react-flow__minimap').attr('viewBox');
+        const maskPathAfterZoom = Cypress.$('.react-flow__minimap-mask').attr('d');
+
+        expect(viewBoxBeforeZoom).to.not.equal(viewBoxAfterZoom);
+        expect(maskPathBeforeZoom).to.not.equal(maskPathAfterZoom);
+      });
+  });
+
+  it('changes node position', () => {
+    const xPosBeforeDrag = Cypress.$('.react-flow__minimap-node:first').attr('x');
+    const yPosBeforeDrag = Cypress.$('.react-flow__minimap-node:first').attr('y');
+    const maskPathBeforeDrag = Cypress.$('.react-flow__minimap-mask').attr('d');
+
+    cy.drag('.react-flow__node:first', { x: 500, y: 25 }).then(($el) => {
+      const xPosAfterDrag = Cypress.$('.react-flow__minimap-node:first').attr('x');
+      const yPosAfterDrag = Cypress.$('.react-flow__minimap-node:first').attr('y');
+      const maskPathAfterDrag = Cypress.$('.react-flow__minimap-mask').attr('d');
+
+      expect(xPosBeforeDrag).to.not.equal(xPosAfterDrag);
+      expect(yPosBeforeDrag).to.not.equal(yPosAfterDrag);
+      expect(maskPathBeforeDrag).to.not.equal(maskPathAfterDrag);
+    });
+  });
+
+  it('changes node positions via pane drag', () => {
+    const viewBoxBeforeDrag = Cypress.$('.react-flow__minimap').attr('viewBox');
+    const maskPathBeforeDrag = Cypress.$('.react-flow__minimap-mask').attr('d');
+
+    // for d3 we have to pass the window to the event
+    // https://github.com/cypress-io/cypress/issues/3441
+    cy.window().then((win) => {
+      cy.get('.react-flow__zoompane')
+        .trigger('mousedown', 'topLeft', { which: 1, view: win })
+        .trigger('mousemove', 'bottomLeft')
+        .trigger('mouseup', { force: true, view: win })
+        .then(() => {
+          const viewBoxAfterDrag = Cypress.$('.react-flow__minimap').attr('viewBox');
+          const maskPathAfterDrag = Cypress.$('.react-flow__minimap-mask').attr('d');
+
+          expect(viewBoxBeforeDrag).to.not.equal(viewBoxAfterDrag);
+          expect(maskPathBeforeDrag).to.not.equal(maskPathAfterDrag);
+        });
+    });
+  });
+});

cypress/integration/flow/overview.spec.js

@@ -1,17 +0,0 @@
-describe('Overview Flow Rendering', () => {
-  it('renders a flow', () => {
-    cy.visit('/');
-
-    cy.get('.react-flow__renderer');
-
-    cy.get('.react-flow__node').should('have.length', 7);
-    cy.get('.react-flow__edge').should('have.length', 6);
-  });
-
-  it('renders a grid', () => {
-    cy.get('.react-flow__background');
-
-    const gridStroke = Cypress.$('.react-flow__background path').attr('fill');
-    expect(gridStroke).to.equal('#888');
-  });
-});

cypress/integration/flow/stress.spec.js

@@ -1,10 +0,0 @@
-describe('Stress Flow Rendering', () => {
-  it('renders initial flow', () => {
-    cy.visit('/stress');
-
-    cy.get('.react-flow__renderer');
-
-    cy.get('.react-flow__node').should('have.length', 100);
-    cy.get('.react-flow__edge').should('have.length', 99);
-  });
-});

example/src/CustomNode/index.js

@@ -70,7 +70,7 @@ const CustomNodeFlow = () => {
       nodeTypes={{
         selectorNode: ColorSelectorNode,
       }}
-      connectionLineStyle={{ stroke: '#ddd', strokeWidth: 2 }}
+      connectionLineStyle={{ stroke: '#ddd' }}
       snapToGrid={true}
       snapGrid={[16, 16]}
     >

example/src/EdgeTypes/index.js

@@ -0,0 +1,36 @@
+/**
+ * Example for checking the different edge types and source and target positions
+ */
+import React, { useState } from 'react';
+
+import ReactFlow, { removeElements, addEdge, MiniMap, Controls, Background } from 'react-flow-renderer';
+import { getElements } from './utils';
+
+const onLoad = (reactFlowInstance) => {
+  reactFlowInstance.fitView();
+  console.log(reactFlowInstance.getElements());
+};
+
+const initialElements = getElements();
+
+const EdgeTypesFlow = () => {
+  const [elements, setElements] = useState(initialElements);
+  const onElementsRemove = (elementsToRemove) => setElements((els) => removeElements(elementsToRemove, els));
+  const onConnect = (params) => setElements((els) => addEdge(params, els));
+
+  return (
+    <ReactFlow
+      elements={elements}
+      onLoad={onLoad}
+      onElementsRemove={onElementsRemove}
+      onConnect={onConnect}
+      minZoom={0.2}
+    >
+      <MiniMap />
+      <Controls />
+      <Background />
+    </ReactFlow>
+  );
+};
+
+export default EdgeTypesFlow;

example/src/EdgeTypes/utils.js

@@ -0,0 +1,104 @@
+const nodeWidth = 80;
+const nodeGapWidth = nodeWidth * 2;
+const nodeStyle = { width: nodeWidth, fontSize: 11, color: 'white' };
+
+const sourceTargetPositions = [
+  { source: 'bottom', target: 'top' },
+  { source: 'right', target: 'left' },
+];
+const nodeColors = [
+  ['#1e9e99', '#4cb3ac', '#6ec9c0', '#8ddfd4'],
+  ['#0f4c75', '#1b5d8b', '#276fa1', '#3282b8'],
+];
+const edgeTypes = ['default', 'step', 'smoothstep', 'straight'];
+const offsets = [
+  {
+    x: 0,
+    y: -nodeGapWidth,
+  },
+  {
+    x: nodeGapWidth,
+    y: -nodeGapWidth,
+  },
+  {
+    x: nodeGapWidth,
+    y: 0,
+  },
+  {
+    x: nodeGapWidth,
+    y: nodeGapWidth,
+  },
+  {
+    x: 0,
+    y: nodeGapWidth,
+  },
+  {
+    x: -nodeGapWidth,
+    y: nodeGapWidth,
+  },
+  {
+    x: -nodeGapWidth,
+    y: 0,
+  },
+  {
+    x: -nodeGapWidth,
+    y: -nodeGapWidth,
+  },
+];
+
+let id = 0;
+const getNodeId = () => (id++).toString();
+
+export function getElements() {
+  const initialElements = [];
+
+  for (let sourceTargetIndex = 0; sourceTargetIndex < sourceTargetPositions.length; sourceTargetIndex++) {
+    const currSourceTargetPos = sourceTargetPositions[sourceTargetIndex];
+
+    for (let edgeTypeIndex = 0; edgeTypeIndex < edgeTypes.length; edgeTypeIndex++) {
+      const currEdgeType = edgeTypes[edgeTypeIndex];
+
+      for (let offsetIndex = 0; offsetIndex < offsets.length; offsetIndex++) {
+        const currOffset = offsets[offsetIndex];
+
+        const style = { ...nodeStyle, background: nodeColors[sourceTargetIndex][edgeTypeIndex] };
+        const sourcePosition = {
+          x: offsetIndex * nodeWidth * 4,
+          y: edgeTypeIndex * 300 + sourceTargetIndex * edgeTypes.length * 300,
+        };
+        const sourceId = getNodeId();
+        const sourceData = { label: `Source ${sourceId}` };
+        const sourceNode = {
+          id: sourceId,
+          style,
+          data: sourceData,
+          position: sourcePosition,
+          sourcePosition: currSourceTargetPos.source,
+          targetPosition: currSourceTargetPos.target,
+        };
+
+        const targetId = getNodeId();
+        const targetData = { label: `Target ${targetId}` };
+        const targetPosition = {
+          x: sourcePosition.x + currOffset.x,
+          y: sourcePosition.y + currOffset.y,
+        };
+        const targetNode = {
+          id: targetId,
+          style,
+          data: targetData,
+          position: targetPosition,
+          sourcePosition: currSourceTargetPos.source,
+          targetPosition: currSourceTargetPos.target,
+        };
+
+        initialElements.push(sourceNode);
+        initialElements.push(targetNode);
+
+        initialElements.push({ id: `${sourceId}-${targetId}`, source: sourceId, target: targetId, type: currEdgeType });
+      }
+    }
+  }
+
+  return initialElements;
+}

example/src/Interaction/index.js

@@ -22,8 +22,8 @@ const InteractionFlow = () => {
   const [isSelectable, setIsSelectable] = useState(false);
   const [isDraggable, setIsDraggable] = useState(false);
   const [isConnectable, setIsConnectable] = useState(false);
-  const [zoomOnScroll, setZoomOnScroll] = useState(true);
-  const [zoomOnDoubleClick, setZoomOnDoubleClick] = useState(true);
+  const [zoomOnScroll, setZoomOnScroll] = useState(false);
+  const [zoomOnDoubleClick, setZoomOnDoubleClick] = useState(false);
 
   return (
     <ReactFlow

example/src/Overview/index.js

@@ -95,8 +95,10 @@ const initialElements = [
     source: '5',
     target: '7',
     type: 'step',
+    style: { stroke: '#f6ab6c' },
     label: 'a step edge',
-    labelStyle: { fill: 'red', fontWeight: 700 },
+    animated: true,
+    labelStyle: { fill: '#f6ab6c', fontWeight: 700 },
   },
 ];
 
@@ -126,17 +128,18 @@ const OverviewFlow = () => {
       onSelectionChange={onSelectionChange}
       style={{ width: '100%', height: '100%' }}
       onLoad={onLoad}
-      connectionLineStyle={{ stroke: '#ddd', strokeWidth: 2 }}
+      connectionLineStyle={{ stroke: '#ddd' }}
       snapToGrid={true}
       snapGrid={[16, 16]}
     >
       <MiniMap
         nodeColor={(n) => {
-          if (n.type === 'input') return 'blue';
-          if (n.type === 'output') return 'green';
-          if (n.type === 'default') return 'red';
+          if (n.style?.background) return n.style.background;
+          if (n.type === 'input') return '#9999ff';
+          if (n.type === 'output') return '#79c9b7';
+          if (n.type === 'default') return '#ff6060';
 
-          return '#FFCC00';
+          return '#eee';
         }}
       />
       <Controls />

example/src/index.js

@@ -13,6 +13,7 @@ import Validation from './Validation';
 import Horizontal from './Horizontal';
 import Provider from './Provider';
 import Hidden from './Hidden';
+import EdgeTypes from './EdgeTypes';
 
 import './index.css';
 
@@ -69,6 +70,10 @@ const routes = [
     path: '/hidden',
     component: Hidden,
   },
+  {
+    path: '/edge-types',
+    component: EdgeTypes,
+  },
 ];
 
 const navLinks = routes.filter((route) => route.label);

package.json

@@ -16,10 +16,12 @@
     "start:examples": "npm run build && cd example && npm start",
     "dev:wait": "start-server-and-test start:examples http-get://localhost:3000",
     "build:example": "npm install && npm run build && cd example && npm install && npm run build",
-    "cy:run": "cypress run",
     "cy:open": "cypress open",
     "cypress": "npm run dev:wait cy:open",
-    "test": "npm run dev:wait cy:run",
+    "test:chrome": "cypress run --browser chrome",
+    "test:firefox": "cypress run --browser firefox",
+    "test:all": "npm run test:chrome && npm run test:firefox",
+    "test": "npm run dev:wait test:chrome",
     "release": "release-it"
   },
   "dependencies": {

src/additional-components/MiniMap/MiniMapNode.tsx

@@ -15,7 +15,7 @@ const MiniMapNode = ({ node, color, borderRadius }: MiniMapNodeProps) => {
     height,
   } = node.__rf;
   const { background, backgroundColor } = node.style || {};
-  const fill = (background || backgroundColor || color) as string;
+  const fill = (color || background || backgroundColor) as string;
 
   return (
     <rect

src/components/ConnectionLine/index.tsx

@@ -2,7 +2,6 @@ import React, { useEffect, useState, CSSProperties } from 'react';
 import cc from 'classcat';
 
 import { getBezierPath } from '../Edges/BezierEdge';
-import { getStepPath } from '../Edges/StepEdge';
 import { getSmoothStepPath } from '../Edges/SmoothStepEdge';
 import { ElementId, Node, Transform, HandleElement, Position, ConnectionLineType, HandleType } from '../../types';
 
@@ -80,12 +79,18 @@ export default ({
       targetPosition,
     });
   } else if (connectionLineType === ConnectionLineType.Step) {
-    dAttr = getStepPath({
+    dAttr = getSmoothStepPath({
+      xOffset,
+      yOffset,
+      centerX,
       centerY,
       sourceX,
       sourceY,
+      sourcePosition: sourceHandle?.position,
       targetX,
       targetY,
+      targetPosition,
+      borderRadius: 0,
     });
   } else if (connectionLineType === ConnectionLineType.SmoothStep) {
     dAttr = getSmoothStepPath({

src/components/Edges/SmoothStepEdge.tsx

@@ -2,7 +2,7 @@ import React, { memo } from 'react';
 
 import EdgeText from './EdgeText';
 import { getMarkerEnd } from './utils';
-import { EdgeBezierProps, Position } from '../../types';
+import { EdgeSmoothStepProps, Position } from '../../types';
 
 // These are some helper methods for drawing the round corners
 // The name indicates the direction of the path. "bottomLeftCorner" goes
@@ -44,6 +44,7 @@ interface GetSmoothStepPathParams {
   targetX: number;
   targetY: number;
   targetPosition?: Position;
+  borderRadius?: number;
 }
 
 export function getSmoothStepPath({
@@ -57,9 +58,10 @@ export function getSmoothStepPath({
   targetX,
   targetY,
   targetPosition = Position.Top,
+  borderRadius = 5,
 }: GetSmoothStepPathParams): string {
-  const cornerWidth = Math.min(5, Math.abs(targetX - sourceX));
-  const cornerHeight = Math.min(5, Math.abs(targetY - sourceY));
+  const cornerWidth = Math.min(borderRadius, Math.abs(targetX - sourceX));
+  const cornerHeight = Math.min(borderRadius, Math.abs(targetY - sourceY));
   const cornerSize = Math.min(cornerWidth, cornerHeight, xOffset, yOffset);
 
   const leftAndRight = [Position.Left, Position.Right];
@@ -141,7 +143,8 @@ export default memo(
     targetPosition = Position.Top,
     arrowHeadType,
     markerEndId,
-  }: EdgeBezierProps) => {
+    borderRadius = 5,
+  }: EdgeSmoothStepProps) => {
     const yOffset = Math.abs(targetY - sourceY) / 2;
     const centerY = targetY < sourceY ? targetY + yOffset : targetY - yOffset;
 
@@ -159,6 +162,7 @@ export default memo(
       targetX,
       targetY,
       targetPosition,
+      borderRadius,
     });
 
     const markerEnd = getMarkerEnd(arrowHeadType, markerEndId);

src/components/Edges/StepEdge.tsx

@@ -1,61 +1,8 @@
 import React, { memo } from 'react';
 
-import EdgeText from './EdgeText';
-import { getMarkerEnd } from './utils';
-import { EdgeProps } from '../../types';
+import { EdgeSmoothStepProps } from '../../types';
+import SmoothStepEdge from './SmoothStepEdge';
 
-interface GetStepPathParams {
-  centerY: number;
-  sourceX: number;
-  sourceY: number;
-  targetX: number;
-  targetY: number;
-}
-
-export function getStepPath({ centerY, sourceX, sourceY, targetX, targetY }: GetStepPathParams): string {
-  return `M ${sourceX},${sourceY}L ${sourceX},${centerY}L ${targetX},${centerY}L ${targetX},${targetY}`;
-}
-
-export default memo(
-  ({
-    sourceX,
-    sourceY,
-    targetX,
-    targetY,
-    label,
-    labelStyle,
-    labelShowBg,
-    labelBgStyle,
-    style,
-    arrowHeadType,
-    markerEndId,
-  }: EdgeProps) => {
-    const yOffset = Math.abs(targetY - sourceY) / 2;
-    const centerY = targetY < sourceY ? targetY + yOffset : targetY - yOffset;
-
-    const xOffset = Math.abs(targetX - sourceX) / 2;
-    const centerX = targetX < sourceX ? targetX + xOffset : targetX - xOffset;
-
-    const path = getStepPath({ centerY, sourceX, sourceY, targetX, targetY });
-
-    const markerEnd = getMarkerEnd(arrowHeadType, markerEndId);
-
-    const text = label ? (
-      <EdgeText
-        x={centerX}
-        y={centerY}
-        label={label}
-        labelStyle={labelStyle}
-        labelShowBg={labelShowBg}
-        labelBgStyle={labelBgStyle}
-      />
-    ) : null;
-
-    return (
-      <>
-        <path style={style} className="react-flow__edge-path" d={path} markerEnd={markerEnd} />
-        {text}
-      </>
-    );
-  }
-);
+export default memo((props: EdgeSmoothStepProps) => {
+  return <SmoothStepEdge {...props} borderRadius={0} />;
+});

src/style.css

@@ -63,7 +63,7 @@
 .react-flow__edge-path {
   fill: none;
   stroke: #bbb;
-  stroke-width: 2;
+  stroke-width: 1.5;
 }
 
 .react-flow__edge-text {
@@ -83,7 +83,7 @@
 .react-flow__connection-path {
   fill: none;
   stroke: #ddd;
-  stroke-width: 2;
+  stroke-width: 1.5;
 }
 
 .react-flow__nodes {
@@ -107,7 +107,7 @@
 .react-flow__node-input,
 .react-flow__node-output {
   padding: 10px;
-  border-radius: 5px;
+  border-radius: 3px;
   width: 150px;
   font-size: 12px;
   color: #222;
@@ -127,16 +127,16 @@
   }
 }
 
-.react-flow__node-default {
-  background: #ff6060;
-}
-
 .react-flow__node-input {
   background: #9999ff;
 }
 
+.react-flow__node-default {
+  background: #ff6060;
+}
+
 .react-flow__node-output {
-  background: #55dd99;
+  background: #79c9b7;
 }
 
 .react-flow__nodesselection {

src/types/index.ts

@@ -99,6 +99,10 @@ export interface EdgeBezierProps extends EdgeProps {
   targetPosition: Position;
 }
 
+export interface EdgeSmoothStepProps extends EdgeBezierProps {
+  borderRadius?: number;
+}
+
 export interface NodeProps {
   id: ElementId;
   type: string;

src/utils/graph.ts

@@ -33,9 +33,16 @@ const getEdgeId = ({ source, target }: Connection): ElementId => `reactflow__edg
 
 export const addEdge = (edgeParams: Edge | Connection, elements: Elements): Elements => {
   if (!edgeParams.source || !edgeParams.target) {
-    throw new Error('Can not create edge. An edge needs a source and a target');
+    throw new Error("Can't create edge. An edge needs a source and a target.");
   }
 
+  // make sure that there is node with the target and one with the source id
+  [edgeParams.source, edgeParams.target].forEach((id) => {
+    if (!elements.find((e) => isNode(e) && e.id === id)) {
+      throw new Error(`Can't create edge. Node with id=${id} does not exist.`);
+    }
+  });
+
   if (isEdge(edgeParams)) {
     return elements.concat({ ...edgeParams });
   }