Genetic Direction came to us with a requirement to generate 40-50 page PDF reports with lots graphics and dynamic content based on the given user profile data. And they wanted the solution in ruby as they are a ruby shop.
We did the initial analysis to find the feasibility of their requirements and were pleasantly surprised by HexaPDF and Prawn ruby gems.
Based on our findings, we built the PDFEngine as a ruby gem with 99.7% unit test coverage
To make sure the generated PDFs are pixel perfect, We built a small snapshot testing tool (using ImageMagick) to create a snapshot of the generated pdf and compares with the baseline version during each integration test run. This helped us to move fast with confidence to enhance / add more reports