Chicken-and-egg problem with node-gyp: Pointing to a header file in a dependency

Question

This is my first attempt at building an npm package that includes C++ code. I thought that I had everything set up properly because, while working in the project folder for the package itself, npm i or node-gyp rebuild was working just fine.

But now that I've published the package, and I'm trying to use that package as a dependency in another project, installation is failing during compilation, when trying to include an important C header file:

  CXX(target) Release/obj.target/ar_signal_monitor/ar-signal-monitor-node.o
../ar-signal-monitor-node.cpp:1:10: fatal error: 'napi.h' file not found
#include <napi.h>
         ^~~~~~~~
1 error generated.

The header file is inside one of the package's dependencies, node-addon-api. My binding.gyp file looks like this:

{
  "targets": [
    {
      "target_name": "ar_signal_monitor",
      "cflags!": ["-fno-exceptions"],
      "cflags_cc!": ["-fno-exceptions"],
      "cflags": ["-Wall", "-std=c++11", "-pthread"],
      "cflags_cc": ["-Wall", "-pthread"],
      "sources": [
        "ar-signal-monitor-node.cpp",
        "ar-signal-monitor-node.h",
        "ar-signal-monitor.cpp",
        "ar-signal-monitor.h"
      ],
      "include_dirs": [
        "<!(node -e \"require('node-addon-api').include\")",
        "node_modules/node-addon-api",
        "/usr/include/node",
        "/usr/local/include/node"
      ],
      "libraries": [
        "-lwiringPi"
      ],
      "defines": ["NAPI_CPP_EXCEPTIONS"],
      'conditions': [
        ["OS==\"mac\"", {
          "defines": ["USE_FAKE_WIRING_PI"],
          "libraries!": ["-lwiringPi"],
          "xcode_settings": {"GCC_ENABLE_CPP_EXCEPTIONS": "YES"}
        }],
        ["OS==\"win\"", {
          "defines": ["USE_FAKE_WIRING_PI"],
          "libraries!": ["-lwiringPi"]
        }],
      ],
    }
  ]
}

I'm trying to use "include_dirs" to tell the compiler where to find the <napi.h> header file. I think that perhaps the problem I have is that the installation process wants to compile my C++ code first, and only after that's successfully done then load the dependent npm packages where the header file I need for successful compilation lives.

Is there a way around this problem? Is it a different problem than I think it is? I tried first including node-addon-api in the client project, but that didn't help. (And even if it had worked, that wouldn't be any better than a temporary word-around.)

Full code for the project can be found here: https://github.com/kshetline/rpi-acu-rite-temperature

Answer 1

I'd been thinking I'd needed to do something different in my binding.gyp file, but the solution (or, at least, a solution) turned out to be something I could do in my package.json:

  "scripts": {
    "preinstall": "npm i node-addon-api",