README.adoc

Fillmore Labs C++ Sample

Experiment in setting up a C++ build pipeline.

Table of Contents

• Purpose
• Running
  • Prerequisites
  • Tests
  • Main App
  • Dependency Inversion Principle

Purpose

This code is a simple FizzBuzz implementation, to play around with a C++17 build pipeline.

Running

Prerequisites

You need Bazelisk installed, with HomeBrew just use brew install bazelisk.

Tests

To run all tests, use

bazel test //test/...

Main App

Run the app with

bazel run //main:cpp-sample

or, for the alternate strategy (same result):

bazel run //main:cpp-sample-alt

Dependency Inversion Principle

This code demonstrates the application of the dependency inversion principle. Naively, one would simply make the main programm dependent on the concrete implementation of the transformation strategy. Here, we simply let the main programm own the interface, making it independent of the implementation and therefore the strategy exchangable.

Dependencies of //main:main

bazel query 'filter("^//", kind("source file", deps(//main:main)))'
//main:fizzbuzz.h
//main:main.cc

Then, to put everything together, cpp-sample.cc or cpp-sample-alt.cc pull in the concrete implementaion making a runnable application:

Dependencies of //main:cpp-sample

bazel query 'filter("^//", kind("source file", deps(//main:cpp-sample)))'
//lib:fizzbuzz.cc
//main:fizzbuzz.h
//main:main.cc

Dependencies of //main:cpp-sample-alt

bazel query 'filter("^//", kind("source file", deps(//main:cpp-sample-alt)))'
//lib_alt:fizzbuzz.cc
//main:fizzbuzz.h
//main:main.cc

The tests work the same way:

Dependencies of //test:fizzbuzz-test

bazel query 'filter("^//", kind("source file", deps(//test:fizzbuzz-test)))'
//lib:fizzbuzz.cc
//main:fizzbuzz.h
//test:fizzbuzz-test.cc

Dependencies of //test:fizzbuzz-test-alt

bazel query 'filter("^//", kind("source file", deps(//test:fizzbuzz-test-alt)))'
//lib_alt:fizzbuzz.cc
//main:fizzbuzz.h
//test:fizzbuzz-test.cc