maxGraph · tbouffard · Feb 11, 2025 · Feb 8, 2025 · Feb 8, 2025 · Feb 11, 2025
diff --git a/packages/core/__tests__/view/geometry/node/StencilShapeRegistry.test.ts b/packages/core/__tests__/view/geometry/node/StencilShapeRegistry.test.ts
@@ -0,0 +1,24 @@
+/*
+Copyright 2025-present The maxGraph project Contributors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { describe, expect, test } from '@jest/globals';
+import { StencilShapeRegistry } from '../../../../src';
+
+describe('getStencil', () => {
+  test.each([null, undefined, 'unknown'])('pass %s, return undefined', (name) => {
+    expect(StencilShapeRegistry.getStencil(name)).toBeUndefined();
+  });
+});
diff --git a/packages/core/src/view/cell/CellRenderer.ts b/packages/core/src/view/cell/CellRenderer.ts
@@ -178,9 +178,8 @@ class CellRenderer {
   createShape(state: CellState) {
     let shape = null;
 
-    // Checks if there is a stencil for the name and creates
-    // a shape instance for the stencil if one exists
-    const stencil = StencilShapeRegistry.getStencil(<string>state.style.shape);
+    // Checks if there is a stencil for the name and creates a shape instance for the stencil if one exists
+    const stencil = StencilShapeRegistry.getStencil(state.style.shape);
 
     if (stencil) {
       shape = new Shape(stencil);

diff --git a/packages/core/src/view/geometry/node/StencilShape.ts b/packages/core/src/view/geometry/node/StencilShape.ts
@@ -558,9 +558,7 @@ class StencilShape extends Shape {
           );
         }
       } else if (name === 'include-shape') {
-        const stencil = StencilShapeRegistry.getStencil(
-          node.getAttribute('name') as string
-        );
+        const stencil = StencilShapeRegistry.getStencil(node.getAttribute('name'));
 
         if (stencil) {
           const x = x0 + Number(node.getAttribute('x')) * sx;

diff --git a/packages/core/src/view/geometry/node/StencilShapeRegistry.ts b/packages/core/src/view/geometry/node/StencilShapeRegistry.ts
@@ -23,48 +23,39 @@ type Stencils = {
 };
 
 /**
- * A singleton class that provides a registry for stencils and the methods
- * for painting those stencils onto a canvas or into a DOM.
+ * A singleton class that provides a registry for stencils and the methods for painting those stencils onto a canvas or into a DOM.
  *
  * Code to add stencils:
  * ```javascript
- * let req = mxUtils.load('test/stencils.xml');
- * let root = req.getDocumentElement();
+ * const response = load('test/stencils.xml');
+ * const root = response.getDocumentElement();
  * let shape = root.firstChild;
  *
- * while (shape != null)
- * {
- *   if (shape.nodeType === mxConstants.NODETYPE_ELEMENT)
- *  {
- *    mxStencilRegistry.addStencil(shape.getAttribute('name'), new mxStencil(shape));
+ * while (shape) {
+ *   if (shape.nodeType === mxConstants.NODETYPE_ELEMENT) {
+ *    StencilShapeRegistry.addStencil(shape.getAttribute('name'), new mxStencil(shape));
  *  }
  *
  *  shape = shape.nextSibling;
  * }
  * ```
- * @class StencilShapeRegistry
  */
 class StencilShapeRegistry {
   static stencils: Stencils = {};
 
   /**
-   * Adds the given {@link Stencil}.
-   * @static
-   * @param {string} name
-   * @param {StencilShape} stencil
+   * Adds the given {@link StencilShape}.
    */
-  static addStencil(name: string, stencil: StencilShape) {
+  static addStencil(name: string, stencil: StencilShape): void {
     StencilShapeRegistry.stencils[name] = stencil;
   }
 
   /**
-   * Returns the {@link Stencil} for the given name.
-   * @static
-   * @param {string} name
-   * @returns {StencilShape}
+   * Returns the {@link StencilShape} for the given name.
    */
-  static getStencil(name: string) {
-    return StencilShapeRegistry.stencils[name];
+  static getStencil(name?: string | null): StencilShape | undefined {
+    // Tests are validating that using the non-null assertion (!) is safe
+    return StencilShapeRegistry.stencils[name!];
   }
 }
 

diff --git a/packages/html/stories/Stencils.stories.ts b/packages/html/stories/Stencils.stories.ts
@@ -95,7 +95,7 @@ const Template = ({ label, ...args }: Record<string, string>) => {
 
     // Uses the shape for resize previews
     createSelectionShape(bounds: Rectangle) {
-      const stencil = StencilShapeRegistry.getStencil(this.state.style.shape ?? '');
+      const stencil = StencilShapeRegistry.getStencil(this.state.style.shape);
       let shape: Shape;
 
       if (stencil) {