Path to asset is treated as url not local file

[bfialkoff]

I am trying to create a rect object and set its fill using a pattern. So I create a defs element, create a pattern, set an image and in the fill property of the rect object set it fill using the css url. Like so: 

this.imageRect = this.svg
                .append('rect')
                .classed('engine-rect', true);

            let defs = this.svg
                .append('defs');
            
            defs.append('pattern')
                .attr({
                    id: 'image',
                    height: '100%',
                    width: '100%',
                    patternContentUnits: 'objectBoundingBox'
                })
                .append('image')
                .attr({
                    height: 1,
                    width: 1,
                    preserveAspectRatio: 'none',
                    'xlink:href': "../assets/engine_part.png"
                })

this.imageRect
                .attr({
                    x: 50,
                    y: 50,
                    width: 50,
                    height: 50,
                    fill: 'url(#image)'
                })

This doesn't work. When I inspect the defs element in the browser I see the following:

I can see that PowerBI is treating the path to the image as a link and not a local file. How can I fix this?