Fail hard on invalid axis

Author: EzraBrooks

src/urdf/UrdfJoint.ts

@@ -58,14 +58,17 @@ export default class UrdfJoint {
     const axis = xml.getElementsByTagName(UrdfAttrs.Axis);
     if (axis.length > 0) {
       const xyzValue = axis[0].getAttribute(UrdfAttrs.Xyz)?.split(" ");
-      if (xyzValue && xyzValue.length === 3) {
-        const [x, y, z] = xyzValue.map(parseFloat);
-        this.axis = new Vector3({
-          x,
-          y,
-          z,
-        });
+      if (!xyzValue || xyzValue.length !== 3) {
+        throw new Error(
+          "If specified, axis must have an xyz value composed of three numbers",
+        );
       }
+      const [x, y, z] = xyzValue.map(parseFloat);
+      this.axis = new Vector3({
+        x,
+        y,
+        z,
+      });
     }
   }
 }

test/urdfjoint.test.js

@@ -15,6 +15,9 @@ describe("UrdfJoint", () => {
       jointWithAxisUrdf,
       "text/xml",
     ).documentElement;
+    if (!xml) {
+      throw new Error("Failed to parse XML");
+    }
     const joint = new UrdfJoint({ xml });
     expect(joint.axis.x).toBe(0);
     expect(joint.axis.y).toBe(1);
@@ -33,13 +36,16 @@ describe("UrdfJoint", () => {
       jointNoAxisUrdf,
       "text/xml",
     ).documentElement;
+    if (!xml) {
+      throw new Error("Failed to parse XML");
+    }
     const joint = new UrdfJoint({ xml });
     expect(joint.axis.x).toBe(1);
     expect(joint.axis.y).toBe(0);
     expect(joint.axis.z).toBe(0);
   });
 
-  it("should default axis to (1,0,0) if axis xyz is malformed", () => {
+  it("should throw if axis xyz is malformed", () => {
     const jointMalformedAxisUrdf = `
         <joint name="test_joint" type="revolute">
             <parent link="link1"/>
@@ -52,9 +58,11 @@ describe("UrdfJoint", () => {
       jointMalformedAxisUrdf,
       "text/xml",
     ).documentElement;
-    const joint = new UrdfJoint({ xml });
-    expect(joint.axis.x).toBe(1);
-    expect(joint.axis.y).toBe(0);
-    expect(joint.axis.z).toBe(0);
+    if (!xml) {
+      throw new Error("Failed to parse XML");
+    }
+    expect(() => new UrdfJoint({ xml })).toThrowError(
+      "If specified, axis must have an xyz value composed of three numbers",
+    );
   });
 });