Parrot Testing Status ^

The primary goal of the Parrot testing effort is to provide complete coverage of the critical Parrot core subsystems on all targeted platforms. Secondary goals include testing of non-critical core subsystems, and non-core code. This document tracks the status of our effort.

Until we have an automated way of quantitatively tracking test coverage, coverage will be tracked quantitatively, using the scale described below:


Very little, or no coverage of a component. This status is completely unacceptable and should be remedied immediately.


Some coverage of basic component operation. Missing some subtests of basic operation, failure cases, and invalid input. Component functionality may only be tested on a subset of platforms that provide that functionality.


Full or nearly-full coverage of basic component operation, failure cases, and invalid input. Tests are run on all platforms which allow component operation. Hard-to-test code is not yet well-covered. Some missing functionality is partially tested with failing TODO and SKIP tests.


Full coverage of basic component operation, failure cases, and invalid input on all platforms. Hard-to-test code is well-covered. Missing component functionality, including basic operation, failure cases, and invalid input is tested with failing TODO and SKIP tests.

Parrot Core Subsystems ^

Below is a breakdown of the Parrot core subsystems, and a qualitative measure of testing status.


This module tokenizes the input.


Fair. There are tests for basic operation, however these tests are spread throughout the test suite, and are not comprehensive. We can assume basic operation is well-tested, otherwise the compiler, optimizer, and interpreter probably wouldn't work very well. Tests under t/compilers/imcc/syn/, and others.

Compilers: IMCC, PGE, TGE




This rearranges PASM code to make it run faster.


Good. Most optimizations are well-tested. Tests under t/compilers/imcc/imcpasm/.


This is the core of Parrot. It comprises the various runcores, input/output, threading, events, exceptions, objects, bytecode loader, etc. Test coverage of the Parrot Interpreter is critical.


Fair. A breakdown of Interpreter subsystems below lists individual status.


Fair. Each PMC file has a corresponding test file. Some PMCs are heavily undertested. Tests under t/pmc/.


Good. Most operators are well-tested. Tests under t/op/.


Fair. Tests exist, but do not run on all platforms, and do not test some important cases. Tests in t/pmc/io.t and t/src/io.t.

Dynamic PMCs

Poor. Some dynamic PMCs do not have test files. Coverage in existing test files is far from complete. Tests under t/dynpmc/.

Dynamic ops

Poor. Only a few tests exist, and coverage of important test cases is weak. Tests under t/dynops/.


Poor. All packfile tests have been skipped. Tests under t/native_pbc.

Runtime Libraries and Includes


Poor. Some runtime libraries are tested, while others are not. No tests exist for include files. Tests under t/library/.

Configure Libraries


Good. Tests exist, and the coverage is decent and improving. Tests under t/configure/.

Test Libraries


Poor. Few tests exist, and coverage is poor. However, the test suite seems to run fine, giving a false sense of security.



Fair. Opcode documentation is well-tested, and Pod files are checked for standards-conformance, but many documentation tests are missing. Tests under t/doc.

Coding standard


Good. Tests under t/codingstd/*.t.

Examples and Benchmarks


Fair. Tests exist, and cover basic functionality of nearly all examples and benchmarks. Extensive testing of failures is not a priority. Tests under t/examples/ and t/benchmark/.



Poor. Few tests exist, and coverage is sparse. Tests under t/tools/.