#530 Started adding some tests around how flowchart shapes are rendered in SVG

src/diagrams/flowchart/flowChartShapes.spec.js

@@ -0,0 +1,89 @@
+import { addToRender } from './flowChartShapes';
+
+describe('flowchart shapes', function() {
+  [
+    [
+      'question',
+      4,
+      function(w, h) {
+        return (w + h) * 0.9;
+      },
+      function(w, h) {
+        return (w + h) * 0.9;
+      }
+    ],
+    [
+      'hexagon',
+      6,
+      function(w, h) {
+        return w + h / 2;
+      },
+      function(w, h) {
+        return h;
+      }
+    ],
+    [
+      'rect_left_inv_arrow',
+      5,
+      function(w) {
+        return w;
+      },
+      function(w, h) {
+        return h;
+      }
+    ]
+  ].forEach(function([shapeType, expectedPointCount, getW, getH]) {
+    it(`should add a ${shapeType} shape that renders a properly translated polygon element`, function() {
+      const mockRender = MockRender();
+      const mockSvg = MockSvg();
+      addToRender(mockRender);
+
+      [[100, 100], [123, 45], [71, 300]].forEach(function([width, height]) {
+        const shape = mockRender.shapes()[shapeType](mockSvg, { width, height }, {});
+        const dx = -getW(width, height) / 2;
+        const dy = getH(width, height) / 2;
+        const points = shape.__attrs.points.split(' ');
+        expect(shape.__tag).toEqual('polygon');
+        expect(shape.__attrs).toHaveProperty('transform', `translate(${dx},${dy})`);
+        expect(points).toHaveLength(expectedPointCount);
+      });
+    });
+  });
+});
+
+function MockRender() {
+  const shapes = {};
+  return {
+    shapes() {
+      return shapes;
+    }
+  };
+}
+
+function MockSvg(tag, ...args) {
+  const children = [];
+  const attributes = {};
+  return {
+    get __args() {
+      return args;
+    },
+    get __tag() {
+      return tag;
+    },
+    get __children() {
+      return children;
+    },
+    get __attrs() {
+      return attributes;
+    },
+    insert: function(tag, ...args) {
+      const child = MockSvg(tag, ...args);
+      children.push(child);
+      return child;
+    },
+    attr(name, value) {
+      this.__attrs[name] = value;
+      return this;
+    }
+  };
+}