buildBindings.ts

import fs from "fs";
import path from "path";
import { exec } from "./exec";
import { testBindings } from "./testBindings";
import { assertSupportedSwigVersion } from "./swig";
import {
  ensureDirFromFilepath,
  findBindingsFile,
  BINDINGS_DIR,
  BLST_WRAP_CPP_PREBUILD,
} from "./paths";

export async function buildBindings(binaryPath: string) {
  if (
    process.env.BLST_WRAP_CPP_FORCE_BUILD &&
    fs.existsSync(BLST_WRAP_CPP_PREBUILD)
  ) {
    console.log(
      `BLST_WRAP_CPP_FORCE_BUILD=true, cleaning existing BLST_WRAP_CPP_PREBUILD ${BLST_WRAP_CPP_PREBUILD}`
    );
    fs.unlinkSync(BLST_WRAP_CPP_PREBUILD);
  }

  // Make sure SWIG generated bindings are available or download from release assets
  if (fs.existsSync(BLST_WRAP_CPP_PREBUILD)) {
    console.log(
      `BLST_WRAP_CPP_PREBUILD ${BLST_WRAP_CPP_PREBUILD} exists, SWIG will be skipped`
    );
  } else {
    if (process.env.SWIG_SKIP_RUN) {
      throw Error(`Prebuild SWIG not found ${BLST_WRAP_CPP_PREBUILD}`);
    } else {
      await assertSupportedSwigVersion();
      console.log("Building bindings from src");
    }
  }

  // From https://github.com/sass/node-sass/blob/769f3a6f5a3949bd8e69c6b0a5d385a9c07924b4/scripts/build.js#L59
  const nodeJsExec = process.execPath;
  const nodeGypExec = require.resolve(
    path.join("node-gyp", "bin", "node-gyp.js")
  );

  console.log("Launching node-gyp", {
    nodeJsExec,
    nodeGypExec,
    cwd: BINDINGS_DIR,
    BLST_WRAP_CPP_PREBUILD,
  });

  await exec(nodeJsExec, [nodeGypExec, "rebuild"], {
    cwd: BINDINGS_DIR,
    env: { ...process.env, BLST_WRAP_CPP_PREBUILD },
  });

  // The output of node-gyp is not at a predictable path but various
  // depending on the OS.
  const bindingsFileOutput = findBindingsFile(BINDINGS_DIR);

  // Copy built .node file to expected path
  ensureDirFromFilepath(binaryPath);
  fs.copyFileSync(bindingsFileOutput, binaryPath);

  // Make sure downloaded bindings work
  await testBindings(binaryPath);
}