Add flow type annotations.

.aegir.js

@@ -0,0 +1,17 @@
+"use strict"
+
+module.exports = {
+  // Have not used webpack so just copied proposed setup from
+  // https://babeljs.io/docs/setup/#installation
+  webpack: {
+    module: {
+      rules: [
+        {
+          test: /\.js$/,
+          exclude: /node_modules/,
+          loader: "babel-loader"
+        }
+      ]
+    }
+  }
+}

.babelrc

@@ -0,0 +1,34 @@
+{
+  "env": {
+    "development": {
+      "sourceMaps": "inline",
+      "comments": false,
+      "presets": [
+        [
+          "env",
+          {
+            "targets": {
+              "node": "current"
+            }
+          }
+        ],
+        "flow-node"
+      ]
+    },
+    "umd": {
+      "comments": false,
+      "presets": [
+        [
+          "env",
+          {
+            "modules": false,
+            "targets": {
+              "browsers": "last 2 versions"
+            }
+          }
+        ],
+        "flow-node"
+      ]
+    }
+  }
+}

.flowconfig

@@ -0,0 +1,9 @@
+[ignore]
+.*/node_modules/documentation/*
+
+[libs]
+
+[include]
+
+[options]
+suppress_comment= \\(.\\|\n\\)*\\@FlowIgnore

.gitignore

@@ -35,3 +35,4 @@ node_modules
 
 dist
 docs
+lib

.vscode/settings.json

@@ -0,0 +1,4 @@
+{
+  "editor.formatOnSave": false,
+  "json.format.enable": false
+}

appveyor.yml

@@ -24,6 +24,7 @@ install:
   - npm install
 
 test_script:
+  - npm run build:node
   - npm run test:node
 
 build: off

package.json

@@ -2,19 +2,30 @@
   "name": "multihashes",
   "version": "0.4.13",
   "description": "multihash implementation",
-  "main": "src/index.js",
+  "main": "lib/index.js",
   "scripts": {
-    "lint": "aegir lint",
+    "lint": "lint-staged && npm run type-check",
     "test:browser": "aegir test --target browser",
     "test:node": "aegir test --target node",
-    "build": "aegir build",
-    "test": "aegir test",
+    "type-check": "flow check",
+    "build": "npm run build:node && BABEL_ENV=umd aegir build",
+    "test": "npm run build:node && aegir test",
     "docs": "aegir docs",
     "release": "aegir release --docs",
     "release-minor": "aegir release --type minor --docs",
     "release-major": "aegir release --type major --docs",
     "coverage": "aegir coverage",
-    "coverage-publish": "aegir coverage --provider coveralls"
+    "coverage-publish": "aegir coverage --provider coveralls",
+    "build:types": "flow-copy-source --verbose src lib",
+    "build:lib": "babel --out-dir lib src",
+    "build:node": "npm run build:types && npm run build:lib",
+    "start": "flow-copy-source --watch --verbose src lib & babel --watch --out-dir lib src"
+  },
+  "lint-staged": {
+    "*.js": [
+      "prettier --no-semi --write",
+      "git add"
+    ]
   },
   "pre-commit": [
     "lint",
@@ -43,10 +54,21 @@
   },
   "devDependencies": {
     "aegir": "^12.3.0",
+    "babel-cli": "6.26.0",
+    "babel-core": "6.26.0",
+    "babel-loader": "7.1.2",
+    "babel-preset-flow-node": "2.0.1",
     "buffer-equal": "1.0.0",
     "chai": "^4.1.2",
     "dirty-chai": "^2.0.1",
-    "pre-commit": "^1.2.2"
+    "flow-bin": "^0.66.0",
+    "flow-copy-source": "^1.2.0",
+    "lint-staged": "^6.0.0",
+    "pre-commit": "^1.2.2",
+    "prettier": "1.10.2",
+    "rollup": "0.56.1",
+    "rollup.config.flow": "1.0.0",
+    "source-map-support": "0.5.3"
   },
   "contributors": [
     "Alan Shaw <alan@tableflip.io>",

src/index.js

@@ -1,27 +1,38 @@
+// @flow
+
 /**
  * Multihash implementation in JavaScript.
  *
  * @module multihash
  */
 'use strict'
 
-const bs58 = require('bs58')
+import bs58 from 'bs58'
+import varint from 'varint'
+import {names, codes, defaultLengths, type Name, type Code} from "./constants"
+
 
-const cs = require('./constants')
+export {names, codes, defaultLengths}
 
-exports.names = cs.names
-exports.codes = cs.codes
-exports.defaultLengths = cs.defaultLengths
 
-const varint = require('varint')
+export type Multihash = Buffer
+export type MultihashPrefix = Buffer
+export type B58Buffer = Buffer
+export type HexString = string
+export type MultihashData = {
+  code: Code,
+  name: Name,
+  length: number,
+  digest: Buffer
+}
 
 /**
  * Convert the given multihash to a hex encoded string.
  *
  * @param {Buffer} hash
  * @returns {string}
  */
-exports.toHexString = function toHexString (hash) {
+export function toHexString (hash:Multihash):HexString {
   if (!Buffer.isBuffer(hash)) {
     throw new Error('must be passed a buffer')
   }
@@ -35,17 +46,18 @@ exports.toHexString = function toHexString (hash) {
  * @param {string} hash
  * @returns {Buffer}
  */
-exports.fromHexString = function fromHexString (hash) {
+export function fromHexString (hash:HexString):Multihash {
   return Buffer.from(hash, 'hex')
 }
 
+export type B58String = string
 /**
  * Convert the given multihash to a base58 encoded string.
  *
  * @param {Buffer} hash
  * @returns {string}
  */
-exports.toB58String = function toB58String (hash) {
+export function toB58String (hash:Multihash):B58String {
   if (!Buffer.isBuffer(hash)) {
     throw new Error('must be passed a buffer')
   }
@@ -59,7 +71,7 @@ exports.toB58String = function toB58String (hash) {
  * @param {string|Buffer} hash
  * @returns {Buffer}
  */
-exports.fromB58String = function fromB58String (hash) {
+export function fromB58String (hash:B58String|B58Buffer):Multihash {
   let encoded = hash
   if (Buffer.isBuffer(hash)) {
     encoded = hash.toString()
@@ -74,7 +86,7 @@ exports.fromB58String = function fromB58String (hash) {
  * @param {Buffer} buf
  * @returns {{code: number, name: string, length: number, digest: Buffer}} result
  */
-exports.decode = function decode (buf) {
+export function decode (buf:Multihash):MultihashData {
   if (!(Buffer.isBuffer(buf))) {
     throw new Error('multihash must be a Buffer')
   }
@@ -84,7 +96,7 @@ exports.decode = function decode (buf) {
   }
 
   let code = varint.decode(buf)
-  if (!exports.isValidCode(code)) {
+  if (!isValidCode(code)) {
     throw new Error(`multihash unknown function code: 0x${code.toString(16)}`)
   }
   buf = buf.slice(varint.decode.bytes)
@@ -101,7 +113,7 @@ exports.decode = function decode (buf) {
 
   return {
     code: code,
-    name: cs.codes[code],
+    name: codes[code],
     length: len,
     digest: buf
   }
@@ -117,13 +129,13 @@ exports.decode = function decode (buf) {
  * @param {number} [length]
  * @returns {Buffer}
  */
-exports.encode = function encode (digest, code, length) {
+export function encode (digest:Buffer, code:Code, length:number):Multihash {
   if (!digest || !code) {
     throw new Error('multihash encode requires at least two args: digest, code')
   }
 
   // ensure it's a hashfunction code.
-  const hashfn = exports.coerceCode(code)
+  const hashfn = coerceCode(code)
 
   if (!(Buffer.isBuffer(digest))) {
     throw new Error('digest should be a Buffer')
@@ -150,21 +162,22 @@ exports.encode = function encode (digest, code, length) {
  * @param {string|number} name
  * @returns {number}
  */
-exports.coerceCode = function coerceCode (name) {
+// TODO: Sholud we just allow Name here instead ?
+export function coerceCode (name:Name|Code):Code {
   let code = name
 
   if (typeof name === 'string') {
-    if (!cs.names[name]) {
+    if (!names[name]) {
       throw new Error(`Unrecognized hash function named: ${name}`)
     }
-    code = cs.names[name]
+    code = names[name]
   }
 
   if (typeof code !== 'number') {
     throw new Error(`Hash function code should be a number. Got: ${code}`)
   }
 
-  if (!cs.codes[code] && !exports.isAppCode(code)) {
+  if (!codes[code] && !exports.isAppCode(code)) {
     throw new Error(`Unrecognized function code: ${code}`)
   }
 
@@ -177,7 +190,7 @@ exports.coerceCode = function coerceCode (name) {
  * @param {number} code
  * @returns {boolean}
  */
-exports.isAppCode = function appCode (code) {
+export function isAppCode (code:number):boolean {
   return code > 0 && code < 0x10
 }
 
@@ -187,12 +200,12 @@ exports.isAppCode = function appCode (code) {
  * @param {number} code
  * @returns {boolean}
  */
-exports.isValidCode = function validCode (code) {
-  if (exports.isAppCode(code)) {
+export function isValidCode(code:number):boolean {
+  if (isAppCode(code)) {
     return true
   }
 
-  if (cs.codes[code]) {
+  if (codes[(code:any)]) {
     return true
   }
 
@@ -206,19 +219,18 @@ exports.isValidCode = function validCode (code) {
  * @returns {undefined}
  * @throws {Error}
  */
-function validate (multihash) {
-  exports.decode(multihash) // throws if bad.
+export function validate (multihash:Buffer) {
+  decode(multihash) // throws if bad.
 }
-exports.validate = validate
 
 /**
  * Returns a prefix from a valid multihash. Throws an error if it is not valid.
  *
  * @param {Buffer} multihash
- * @returns {undefined}
+ * @returns {Buffer}
  * @throws {Error}
  */
-exports.prefix = function prefix (multihash) {
+export function prefix (multihash:Multihash):MultihashPrefix {
   validate(multihash)
 
   return multihash.slice(0, 2)

test/index.spec.js

@@ -9,8 +9,8 @@ const expect = chai.expect
 const bufeq = require('buffer-equal')
 const bs58 = require('bs58')
 
-const mh = require('../src')
-const constants = require('../src/constants')
+const mh = require('../lib')
+const constants = require('../lib/constants')
 const validCases = require('./fixtures/valid')
 const invalidCases = require('./fixtures/invalid')
 

test/node.js

@@ -0,0 +1,4 @@
+// TODO: Instead mocha should be passed additional arg
+// `--require source-map-support/register` but as things stand now there is
+// no way to do it without changes to aegir so we do this instead for now.
+require("source-map-support/register")