[BUG] Rects do not accept string formatted numbers without units (e.g. "42")for `x` and `y` parameters.

[jdthorpe]

1. Read the FAQs 👇

2. Describe the bug

If either of the x or y attributes of a <rect>'s animate parameter is a string without units (like "42") then neither x or y position is included in the DOM.

3. IMPORTANT: Provide a CodeSandbox reproduction of the bug

See This Sandbox
4. Steps to reproduce

Steps to reproduce the behavior:

Open the sandbox, and notice that the 3 rects are not staggered. The x value is a string formatted number ("15") and the y value is a number (15). To get this to work correctly, convert the x value to either a number (15) or add units to the string (e.g. "15px")

5. Expected behavior

The x and y parameters of an SVG <rect> should accept string numbers without units.

6. Video or screenshots

See the sandbox example

7. Environment details

Chrome and Edge for Mac