preinstall.js

   1 "use strict";
   2
   3 const fs = require("fs");
   4 const path = require("path");
   5
   6 const { https } = require("follow-redirects");
   7 const semver = require("semver");
   8 const tar = require("tar");
   9 const unbz2 = require("unbzip2-stream");
  10 const unzipper = require("unzipper");
  11
  12 const pkg = require("./package.json");
  13 const bindir = path.join(__dirname, "bin");
  14
  15 const trim = str => str && String(str).trim();
  16
  17 const dhallVersion = trim(pkg["dhall-version"] || process.env.DHALL_VERSION);
  18 if (!dhallVersion) throw new Error("Missing DHALL_VERSION environment variable.");
  19
  20 const dhallJsonVersion = trim(pkg["dhall-json-version"] || process.env.DHALL_JSON_VERSION);
  21 if (!dhallJsonVersion) throw new Error("Missing DHALL_JSON_VERSION environment variable.");
  22 if (semver.valid(dhallJsonVersion) && semver.lt(dhallJsonVersion, "1.2.8")) {
  23   throw new Error(`This release of the \`${pkg.name}\` npm package installs \`json-to-dhall\`, which isn’t provided by \`dhall-json@<1.2.8\`.`);
  24 }
  25
  26 const release = `https://github.com/dhall-lang/dhall-haskell/releases/download/${dhallVersion}/dhall-json-${dhallJsonVersion}`;
  27
  28 const get = (archive, callback) => {
  29   const url = `${release}-${archive}`;
  30   return https.get(url, res => {
  31     if (res.statusCode >= 400) throw new Error(`Error fetching ${url}: ${res.statusMessage}`);
  32     return callback(res);
  33   });
  34 };
  35
  36 if (process.platform === "win32") {
  37   get("x86_64-windows.zip", res =>
  38     res.pipe(unzipper.Extract({ path: bindir }))
  39   );
  40 } else {
  41   get("x86_64-linux.tar.bz2", res =>
  42     res.pipe(unbz2()).pipe(tar.x({ C: __dirname }).on("finish", () => {
  43       fs.readdir(bindir, (err, names) => {
  44         if (err) throw err;
  45         for (const name of names) {
  46           fs.rename(path.join(bindir, name), path.join(bindir, name + ".exe"), err => {
  47             if (err) throw err;
  48           });
  49         }
  50       });
  51     }))
  52   );
  53 }