Testing And Benchmarking in Chapel

Here’s the translation of the Go testing and benchmarking example to Chapel:

use UnitTest;

// We'll be testing this simple implementation of an
// integer minimum. Typically, the code we're testing
// would be in a source file named something like
// `intutils.chpl`, and the test file for it would then
// be named `test_intutils.chpl`.

proc IntMin(a: int, b: int): int {
    if a < b {
        return a;
    }
    return b;
}

// A test is created by writing a procedure with a name
// beginning with `test_`.

proc test_IntMinBasic() {
    var ans = IntMin(2, -2);
    assertEqual(ans, -2, "IntMin(2, -2) = {ans}; want -2");
}

// Writing tests can be repetitive, so it's idiomatic to
// use a table-driven style, where test inputs and
// expected outputs are listed in a table and a single loop
// walks over them and performs the test logic.

proc test_IntMinTableDriven() {
    var tests = [
        (a: 0, b: 1, want: 0),
        (a: 1, b: 0, want: 0),
        (a: 2, b: -2, want: -2),
        (a: 0, b: -1, want: -1),
        (a: -1, b: 0, want: -1)
    ];

    for test in tests {
        var ans = IntMin(test.a, test.b);
        assertEqual(ans, test.want, "IntMin({test.a}, {test.b}) = {ans}; want {test.want}");
    }
}

// Benchmark tests in Chapel are typically created using
// the `Timer` module and running the function multiple times.

use Time;

proc benchmark_IntMin() {
    var timer: Timer;
    const iterations = 1000000;

    timer.start();
    for i in 1..iterations {
        IntMin(1, 2);
    }
    timer.stop();

    writeln("BenchmarkIntMin: ", iterations, " iterations in ", timer.elapsed(), " seconds");
}

// Run all tests and benchmarks
UnitTest.main();
benchmark_IntMin();

To run the tests and benchmark in Chapel, you would typically save this code in a file (e.g., test_intutils.chpl) and then use the Chapel compiler (chpl) to compile and run it:

$ chpl test_intutils.chpl -o test_intutils
$ ./test_intutils

This will run all the tests defined with the test_ prefix and then run the benchmark. The output will show which tests passed or failed, and the benchmark results.

Chapel’s testing framework is different from Go’s, but we’ve replicated the basic structure and concepts. The UnitTest module provides assertion functions like assertEqual that are similar to Go’s testing package.

For benchmarking, Chapel doesn’t have a built-in benchmarking tool like Go’s, so we’ve created a simple benchmark using the Timer module. This gives us a basic way to measure performance, though it’s not as sophisticated as Go’s benchmarking tools.

Remember that in a real Chapel project, you might split your code into multiple files and use Chapel’s module system to organize your code and tests.

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Testing And Benchmarking in Chapel