There are a number of test suites for 6502, each with their own intentions and peculiarities.
For the most part they aim to test emulators, which are subject to different bugs than CPU implementations, and therefore the effective coverage may not be as good as expected. Such tests are generally self-checking - there is no golden results file of bus activity - and generally assume some specific platform's I/O facilities.
- AllSuiteA.asm from the hcm-6502 (verilog) project. ROM available.