Add parsing logic

api/update/index.js

@@ -1,6 +1,93 @@
+/*
+Should download the version JSON file from the VSCodium repo
+the JSON file should conform to this schema:
+{
+  "url": "<url to release download>",
+  "name": "1.33.1", // the version number
+  "version": "51b0b28134d51361cf996d2f0a1c698247aeabd8", // the latest commit hash
+  "productVersion": "1.33.1", // the version number
+  "hash": "cb4109f196d23b9d1e8646ce43145c5bb62f55a8", // sha1 of the release download
+  "timestamp": 1554971059007,
+  "sha256hash": "ac2a1c8772501732cd5ff539a04bb4dc566b58b8528609d2b34bbf970d08cf01" // sha256 of the release download
+}
+The hashes can be ignored by this api/lambda -- we are only concerned with whether
+the commit hash in the url parameter matches the "version" identifier in the above payload
+*/
+
+
 const { parse } = require('url')
 
-module.exports = (req, res) => {
-  const parsed = parse(req.url, true)
-  res.end(JSON.stringify(parsed, null, 2))
+const STABLE = 'stable'
+
+const DARWIN = 'darwin'
+const WINDOWS = 'win32'
+const LINUX = 'linux'
+
+const IA32 = 'ia32'
+const X64 = 'x64'
+
+const ARCHIVE = 'archive'
+const USER = 'user'
+
+const QUALITIES = new Set([STABLE])
+const OS = new Set([DARWIN, WINDOWS, LINUX])
+const TYPES = new Set([ARCHIVE, USER])
+const ARCH = new Set([IA32, X64])
+
+function getJSON ({ os, arch, type }) {
+  // TODO get os/arch/type specific JSON file from a repo where these files will be stored
+  return {
+    "url": "https://github.com/release/something.zip",
+    "name": "1.33.1", // the version number
+    "version": "51b0b28134d51361cf996d2f0a1c698247aeabd8", // the latest commit hash
+    "productVersion": "1.33.1", // the version number
+    "hash": "cb4109f196d23b9d1e8646ce43145c5bb62f55a8", // sha1 of the release download
+    "timestamp": 1554971059007,
+    "sha256hash": "ac2a1c8772501732cd5ff539a04bb4dc566b58b8528609d2b34bbf970d08cf01" // sha256 of the release download
+  }
+}
+
+// returns false if invalid, or an object of os, arch, type if valid
+function validateInput (platform, quality) {
+  // a bunch of validation rules for the different permutations
+  if (!QUALITIES.has(quality)) return false
+
+  let [os, arch, type] = platform.split('-')
+  if (!OS.has(os)) return false
+
+  if (os === WINDOWS && !type) {
+    type = arch
+    arch = IA32
+  }
+
+  if (os === WINDOWS || os === LINUX) {
+    if (!ARCH.has(arch)) return false
+  }
+
+  if (os === WINDOWS && !TYPES.has(type)) return false
+
+  return { os, arch, type }
+}
+
+module.exports = (req, res) => {
+  const { query } = parse(req.url, true)
+  const { platform, quality, commit } = query
+  const input = validateInput(platform, quality)
+  if (!input) {
+    res.writeHead(404)
+    res.end()
+    return
+  }
+
+  const { os, arch, type } = input
+  const latest = getJSON({ os, arch, type })
+
+  if (commit === latest.version) {
+    res.writeHead(204)
+    res.end()
+    return
+  }
+  res.setHeader('Content-Type', 'application/json')
+  res.write(JSON.stringify(latest))
+  res.end()
 }

now.json

@@ -6,5 +6,5 @@
       "dest": "/api/update?platform=$platform&quality=$quality&commit=$commit"
     }
   ],
-  "builds": [{ "src": "index.js", "use": "@now/node" }]
+  "builds": [{ "src": "api/update/index.js", "use": "@now/node" }]
 }