The application is a map onto which GeoJSON files (among other formats) can be dropped and viewed.
Recently we added a feature to print the current map view to PDF. The two parameters I need to test are size (A4, A3 etc) and DPI (which is fixed at 300DPI).
It’s easy to design a test for the first parameter but I am not so sure about the second (DPI). My strategy is so far:
Drag two GeoJSONs onto the map, ((!): GeoJSONs contain vector graphics)
a. each coloured differently (eg. one red, one blue) and
b. each with 300 equally-spaced parallel lines
c. displace one file by half the spacing so that the two sets of lines are interlocking, like a zipper.
Set zoom level accordingly, to measure one Inch across the stack of parallel lines (that’s logical because I want 300 lines per inch)
Export the PDF.
At this point, I’m not sure what the result should be. I see a block, that’s for sure. But what colour will it be?! Colour of either GeoJSON or a mix? (Eg. red OR blue for the whole block, or purple)?
And the key question... is this a valid test for proving 300DPI?