Integration with Razorcat TESSY

TESSY, the unit test tool from Razorcat, merges its unit-level coverage with integration-level coverage from the trace port - one picture, not two.

TESSY is the established unit test tool of Razorcat, qualified by TÜV SÜD for use in safety-related software development under ISO 26262 within the certificate’s stated scope. Hyper Coverage is the feature that lets it consume coverage from outside itself.

The integration transfers named coverage obligations and their Accemic result status into the TESSY Hyper Coverage workflow - what travels, and how, is described under How it connects.

Coverage from an integration test and from a unit test, merged into one Hyper Coverage view - drawn after TESSY's code and flow-graph views. Each edge keeps its execution count, and the merged view keeps both levels visible.

The problem it solves

Unit testing produces excellent structural coverage of code paths that unit tests can reach. Integration and system testing exercises the paths that unit tests cannot construct - but historically produced no structural coverage at all, because you could not instrument the integrated build.

The result was two incomparable artifacts and an argument in the middle. Hyper Coverage merges them: TESSY holds the unit-level data, CEDARtools^® supplies the integration-level data from the trace port, and the report shows what is covered at which level.

Why the level matters

A line covered by a unit test and a line covered by a system test are not equivalent evidence, and a merged report that hides the difference is worse than two separate ones. The point of the merge is not a bigger percentage - it is being able to say which level each piece of evidence came from.

Unit and integration results may be viewed together, but their provenance and test level remain distinguishable. A combined percentage must not conceal which obligations were established at unit level, integration level, through passive trace or through CEDARtools.Anchor supplementation.

How it connects

CEDARtools^® writes its results as a TESSY export - a coverage format that TESSY reads directly. One transfer carries the line and branch results together with the additional metadata required for condition and MC/DC evidence.

From sources to a combined report: TESSY builds the binary, the test environment executes it while CEDARtools^® records coverage from the trace port, and the per-test coverage is imported into TESSY next to the unit-test results.

In TESSY, the transfer is one action: Import on a test collection reads the CEDARtools^® results, and the integration-level coverage appears alongside the unit-test collections.

Transfer checks

The integration verifies the producer and receiver versions, project identity, executable or build identity, obligation-set identity, unique obligation mapping, count consistency and the handling of unresolved or excluded obligations. A transfer is rejected if required identifiers are missing, duplicated or refer to a different analyzed build.

Documented jointly

The approach was presented at Embedded World Conference 2026 in a joint paper by Accemic and Razorcat - Weiss, Schulz and Wittner. A revised version is openly available as Integration-First Structural Coverage for Embedded Software (arXiv preprint, August 2026). Both are on the publications page, and they describe the real pipeline rather than an intended one.

TESSY is a product of Razorcat Development GmbH. Razorcat and Accemic are not corporately affiliated; neither the integration nor the joint publication transfers certification or assurance status between the products.