In the introduction, we saw that a file with a name ending in _test.go would automatically be run as part of the test phase. Go uses this naming convention for additional compiler features to provide the ability to include code for a specific platform or computer architecture. For example, a file named main_windows.go will only be included in the compilation if you are building for Microsoft Windows, and the main_darwin.go file would only be compiled for macOS (darwin is the name of the underlying operating system). Similarly, the computer architecture can be used to conditionally include source code, and so a file named main_arm.go would only be part of the build for a 32-bit ARM-based processor.
Go also supports the conditional compilation of arbitrary files through the use of build constraints (also known as build...