Npm: download the required binaries during installation (#188)

* Track .npm/bin/index.js

* Download the binaries inside postinstall

* fix: give proper permissions to the downloaded executables

* fix: use better error message in case downloading fails

* Use platform detection to determine extension of the downloaded binary

* Add the extension to eval lefthook

* Both output console error and wrap custom message

* It is matter of taste, but let it be install script, not postinstall

Co-authored-by: Andrey Novikov <envek@envek.name>

.gitignore

@@ -12,7 +12,9 @@ dist/
 .rubygems/pkg/
 .rubygems/libexec/
 .npm/bin/
+!.npm/bin/*.js
 package.json
+!.npm/package.json
 node_modules/
 yarn.lock
 package-lock.json

.npm/bin/index.js

@@ -1,12 +1,13 @@
 #!/usr/bin/env node
 
 var spawn = require('child_process').spawn;
-const { getExePath } = require('../get-exe');
+const path = require("path")
+const extension = ["win32", "cygwin"].includes(process.platform) ? ".exe" : ""
+const exePath = path.join(__dirname, `lefthook${extension}`)
 
 var command_args = process.argv.slice(2);
-
 var child = spawn(
-    getExePath(),
+    exePath,
     command_args,
     { stdio: "inherit" });
 

.npm/install.js

@@ -0,0 +1,81 @@
+const { spawnSync } = require("child_process")
+
+const iswin = ["win32", "cygwin"].includes(process.platform)
+
+async function install() {
+  if (process.env.CI) {
+    return
+  }
+  const exePath = await downloadBinary()
+  if (!iswin) {
+    const { chmodSync } = require("fs")
+    chmodSync(exePath, "755")
+  }
+  // run install
+  spawnSync(exePath, ["install", "-f"], {
+    cwd: process.env.INIT_CWD || process.cwd,
+    stdio: "inherit",
+  })
+}
+
+function getDownloadURL() {
+  // Detect OS
+  // https://nodejs.org/api/process.html#process_process_platform
+  let goOS = process.platform
+  let extension = ""
+  if (iswin) {
+    goOS = "windows"
+    extension = ".exe"
+  }
+
+  // Convert the goOS to the os name in the download URL
+  let downloadOS = goOS === "darwin" ? "macOS" : goOS
+  downloadOS = `${downloadOS.charAt(0).toUpperCase()}${downloadOS.slice(1)}`
+
+  // Detect architecture
+  // https://nodejs.org/api/process.html#process_process_arch
+  let arch = process.arch
+  switch (process.arch) {
+    case "x64": {
+      arch = "x86_64"
+      break
+    }
+    case "x32":
+    case "ia32": {
+      arch = "i386"
+      break
+    }
+  }
+  const version = require("./package.json").version
+
+  return `https://github.com/evilmartians/lefthook/releases/download/v${version}/lefthook_${version}_${downloadOS}_${arch}${extension}`
+}
+
+const { DownloaderHelper } = require("node-downloader-helper")
+const path = require("path")
+
+async function downloadBinary() {
+  // TODO zip the binaries to reduce the download size
+  const downloadURL = getDownloadURL()
+  const extension = iswin ? ".exe" : ""
+  const fileName = `lefthook${extension}`
+  const binDir = path.join(__dirname, "bin")
+  const dl = new DownloaderHelper(downloadURL, binDir, {
+    fileName,
+    retry: { maxRetries: 5, delay: 50 },
+  })
+  dl.on("end", () => console.log("lefthook binary was downloaded"))
+  try {
+    await dl.start()
+  } catch(e) {
+    const message = `Failed to download ${fileName}: ${e.message} while fetching ${downloadURL}`
+    console.error(message)
+    throw new Error(message)
+  }
+  return path.join(binDir, fileName)
+}
+
+// start:
+install().catch((e) => {
+  throw e
+})

.npm/package.json

@@ -29,6 +29,9 @@
     "ia32"
   ],
   "scripts": {
-    "postinstall": "node postinstall.js"
+    "install": "node install.js"
+  },
+  "dependencies": {
+    "node-downloader-helper": "^1.0.18"
   }
 }