preinstall.js

   1 "use strict";
   2
   3 const { https } = require("follow-redirects");
   4 const tar = require("tar");
   5 const unbz2 = require("unbzip2-stream");
   6
   7 const pkg = require("./package.json");
   8
   9 const trim = str => str && String(str).trim();
  10
  11 const dhallVersion = trim(pkg["dhall-version"] || process.env.DHALL_VERSION);
  12 if (!dhallVersion) throw new Error("Missing DHALL_VERSION environment variable.");
  13
  14 const dhallJsonVersion = trim(pkg["dhall-json-version"] || process.env.DHALL_JSON_VERSION);
  15 if (!dhallJsonVersion) throw new Error("Missing DHALL_JSON_VERSION environment variable.");
  16
  17 const release = `https://github.com/dhall-lang/dhall-haskell/releases/download/${dhallVersion}/dhall-json-${dhallJsonVersion}`;
  18
  19 const url = `${release}-x86_64-linux.tar.bz2`;
  20 https.get(url, res => {
  21   if (res.statusCode >= 400) throw new Error(`Error fetching ${url}: ${res.statusMessage}`);
  22   res.pipe(unbz2()).pipe(tar.x({ C: __dirname }));
  23 });