feat: download release binary in postinstall script

This implementation uses a local copy of binary-install to bring in
changes from
EverlastingBugstopper/binary-install#12.

Author: EricCrosson

README.md

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+## Supported Systems
+
+The following operating systems are supported
+
+- [x] GNU/Linux
+- [x] Mac OS
+- [ ] Windows
+
+The following package managers are supported
+
+- [x] npm
+- [ ] yarn

npm/binary-install.js

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+const { existsSync, mkdirSync } = require("fs");
+const { join } = require("path");
+const { spawnSync } = require("child_process");
+
+const axios = require("axios");
+const tar = require("tar");
+const rimraf = require("rimraf");
+
+const error = msg => {
+  console.error(msg);
+  process.exit(1);
+};
+
+class Binary {
+  constructor(name, url) {
+    let errors = [];
+    if (typeof url !== "string") {
+      errors.push("url must be a string");
+    } else {
+      try {
+        new URL(url);
+      } catch (e) {
+        errors.push(e);
+      }
+    }
+    if (name && typeof name !== "string") {
+      errors.push("name must be a string");
+    }
+
+    if (!name) {
+      errors.push("You must specify the name of your binary");
+    }
+    if (errors.length > 0) {
+      let errorMsg =
+        "One or more of the parameters you passed to the Binary constructor are invalid:\n";
+      errors.forEach(error => {
+        errorMsg += error;
+      });
+      errorMsg +=
+        '\n\nCorrect usage: new Binary("my-binary", "https://example.com/binary/download.tar.gz")';
+      error(errorMsg);
+    }
+    this.url = url;
+    this.name = name;
+    this.installDirectory = join(__dirname,  "../node_modules/binary-install/bin");
+
+    if (!existsSync(this.installDirectory)) {
+      mkdirSync(this.installDirectory, { recursive: true });
+    }
+
+    this.binaryPath = join(this.installDirectory, this.name);
+  }
+
+  install(fetchOptions) {
+    if (existsSync(this.installDirectory)) {
+      rimraf.sync(this.installDirectory);
+    }
+
+    mkdirSync(this.installDirectory, { recursive: true });
+
+    // console.log(`Downloading release from ${this.url}`);
+
+    return axios({ ...fetchOptions, url: this.url, responseType: "stream" })
+      .then(res => {
+        return new Promise((resolve, reject) => {
+          const sink = tar.x({ strip: 1, C: this.installDirectory });
+          res.data.pipe(sink);
+          sink.on('finish', () => resolve());
+          sink.on('error', err => reject(err));
+        });
+      })
+      .then(() => {
+        // console.log(`${this.name} has been installed!`);
+      })
+      .catch(e => {
+        error(`Error fetching release: ${e.message}`);
+      });
+  }
+
+  run() {
+    if (!existsSync(this.binaryPath)) {
+      error(`You must install ${this.name} before you can run it`);
+    }
+
+    const [, , ...args] = process.argv;
+
+    const options = { cwd: process.cwd(), stdio: "inherit" };
+
+    const result = spawnSync(this.binaryPath, args, options);
+
+    if (result.error) {
+      error(result.error);
+    }
+
+    process.exit(result.status);
+  }
+}
+
+module.exports.Binary = Binary;

npm/get-binary.js

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+const os = require('os')
+const { Binary } = require('./binary-install')
+
+const knownUnixLikePackages = {
+  'darwin x64 LE': 'x86_64-apple-darwin',
+  'linux x64 LE': 'x86_64-unknown-linux-gnu',
+}
+
+const binPathForCurrentPlatform = () => {
+  const platformKey = `${process.platform} ${os.arch()} ${os.endianness()}`
+  if (platformKey in knownUnixLikePackages) {
+    return knownUnixLikePackages[platformKey]
+  }
+
+  throw new Error('Unsupported platform: ${platformKey}')
+}
+
+const getBinary = () => {
+  const { version, repository } = require('../package.json')
+  const platform = binPathForCurrentPlatform()
+  const url = `${repository.url}/releases/download/v${version}/typescript-tools-${platform}.tar.gz`
+  const binaryName = 'monorepo'
+  return new Binary(binaryName, url)
+}
+
+module.exports = getBinary

npm/install.js

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+const fs = require('fs')
+const path = require('path')
+const getBinary = require('./get-binary')
+
+// Link the downloaded binary into the node_modules/.bin directory
+const linkBinaryIntoBin = () => {
+  const binaryName = 'monorepo'
+  const existingPath = path.resolve(__dirname, `../node_modules/binary-install/bin/${binaryName}`)
+  const desiredPath = path.resolve(__dirname, `../node_modules/.bin/${binaryName}`)
+
+  // Only symlink the path when it does not yet exist
+  if (!fs.existsSync(desiredPath)) {
+    fs.linkSync(existingPath, desiredPath)
+  }
+}
+
+// Downloaded binary to /node_modules/binary-install/bin/{ name }
+getBinary().install()
+  .then(linkBinaryIntoBin)

npm/uninstall.js

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+// When installing, the `preinstall` script is executed before any dependencies are
+// installed. Since this script `require`s a dependency, another developer who clones
+// the repository and runs `npm install` will get an error that dependencies are
+// missing.
+//
+// We guard against this with a try/catch to swallow the error: if the dependencies are
+// not found it means the package wasn't installed yet, and that means there's no binary
+// to uninstall in the first place.
+
+const getBinary = () => {
+  try {
+    const getBinary = require('./get-binary')
+    return getBinary()
+  } catch {
+
+  }
+}
+
+const binary = getBinary()
+console.log("Binary is", binary)
+if (binary) {
+  binary.uninstall()
+}