use TypeScript in JSDoc

.gitignore

@@ -3,6 +3,7 @@ node_modules
 pnpm-lock.yaml
 package-lock.json
 coverage
+**/*.d.ts
 *~
 
 # For misc scripts and experiments:

lib/encryption.js

@@ -3,10 +3,23 @@ const b4a = require('b4a')
 const MsgV3 = require('./msg-v3')
 
 /**
- * @typedef {import('./index').Rec} Rec
+ * @typedef {import('./index').RecPresent} RecPresent
  * @typedef {import('ppppp-keypair').Keypair} Keypair
+ *
+ * @typedef {Buffer | Uint8Array} B4A
+ *
+ * @typedef {{
+ *   name: string;
+ *   setup?: (config: any, cb: any) => void;
+ *   onReady?: (cb: any) => void;
+ *   encrypt: (plaintext: B4A, opts: any) => B4A;
+ *   decrypt: (ciphertext: B4A, opts: any) => B4A | null;
+ * }} EncryptionFormat
  */
 
+/**
+ * @param {string} str
+ */
 function ciphertextStrToBuffer(str) {
   const dot = str.indexOf('.')
   return b4a.from(str.slice(0, dot), 'base64')
@@ -17,21 +30,21 @@ function ciphertextStrToBuffer(str) {
  * @param {Keypair} keypair
  */
 function keypairToSSBKeys(keypair) {
-  const public = b4a.from(base58.decode(keypair.public)).toString('base64')
+  const _public = b4a.from(base58.decode(keypair.public)).toString('base64')
-  const private = b4a.from(base58.decode(keypair.private)).toString('base64')
+  const _private = b4a.from(base58.decode(keypair.private)).toString('base64')
   return {
-    id: `@${public}.ed25519`,
+    id: `@${_public}.ed25519`,
     curve: keypair.curve,
-    public,
+    public: _public,
-    private,
+    private: _private,
   }
 }
 
 /**
- * @param {Rec} rec
+ * @param {RecPresent} rec
  * @param {any} peer
  * @param {any} config
- * @returns {Rec}
+ * @returns {RecPresent}
  */
 function decrypt(rec, peer, config) {
   const msgEncrypted = rec.msg
@@ -63,6 +76,9 @@ function decrypt(rec, peer, config) {
   }
 }
 
+/**
+ * @param {RecPresent} rec
+ */
 function reEncrypt(rec) {
   return {
     hash: rec.hash,

lib/index.js

@@ -1,47 +1,63 @@
 const path = require('node:path')
+// @ts-ignore
 const push = require('push-stream')
+// @ts-ignore
 const AAOL = require('async-append-only-log')
 const promisify = require('promisify-4loc')
 const b4a = require('b4a')
 const base58 = require('bs58')
+// @ts-ignore
 const Obz = require('obz')
 const MsgV2 = require('./msg-v3')
 const { ReadyGate } = require('./utils')
 const { decrypt } = require('./encryption')
 
 /**
+ * @typedef {import('ppppp-keypair').Keypair} Keypair
  * @typedef {import('./msg-v3').Msg} Msg
+ * @typedef {import('./encryption').EncryptionFormat} EncryptionFormat
+ *
+ * @typedef {Buffer | Uint8Array} B4A
  */
 
 /**
- * @typedef {Object} RecDeleted
+ * @typedef {{
- * @property {never} hash
+ *   hash?: never;
- * @property {never} msg
+ *   msg?: never;
- * @property {never} received
+ *   received?: never;
- * @property {Object} misc
+ *   misc: {
- * @property {number} misc.offset
+ *     offset: number;
- * @property {number} misc.size
+ *     size: number;
- * @property {number} misc.seq
+ *     seq: number;
- */
+ *   };
-
+ * }} RecDeleted
-/**
+ *
- * @typedef {Object} RecPresent
+ * @typedef {{
- * @property {string} hash
+ *   hash: string;
- * @property {Msg} msg
+ *   msg: Msg;
- * @property {number} received
+ *   received: number;
- * @property {Object} misc
+ *   misc: {
- * @property {number} misc.offset
+ *     offset: number;
- * @property {number} misc.size
+ *     size: number;
- * @property {number} misc.seq
+ *     seq: number;
- * @property {boolean=} misc.private
+ *     private?: boolean;
- * @property {Object=} misc.originalData
+ *     originalData?: any;
- * @property {string=} misc.encryptionFormat
+ *     encryptionFormat?: string;
- */
+ *   }
-
+ * }} RecPresent
-/**
+ *
  * @typedef {RecPresent | RecDeleted} Rec
  */
 
+/**
+ * @template T
+ * @typedef {(...args: [Error] | [null, T]) => void} CB
+ */
+
+/**
+ * @typedef {(...args: [Error] | []) => void} CBVoid
+ */
+
 class DBTangle extends MsgV2.Tangle {
   /**
    * @param {string} rootHash
@@ -55,6 +71,9 @@ class DBTangle extends MsgV2.Tangle {
     }
   }
 
+  /**
+   * @param {string} msgHash
+   */
   getDeletablesAndErasables(msgHash) {
     const erasables = this.shortestPathToRoot(msgHash)
     const sorted = this.topoSort()
@@ -66,28 +85,42 @@ class DBTangle extends MsgV2.Tangle {
   }
 }
 
-exports.name = 'db'
+/**
-
+ * @param {any} peer
-exports.init = function initDB(peer, config) {
+ * @param {{ path: string; keypair: Keypair; }} config
+ */
+function initDB(peer, config) {
   /** @type {Array<Rec>} */
   const recs = []
+
+  /** @type {Map<string, EncryptionFormat>} */
   const encryptionFormats = new Map()
+
   const onRecordAdded = Obz()
 
   const log = AAOL(path.join(config.path, 'db.bin'), {
     cacheSize: 1,
     blockSize: 64 * 1024,
     codec: {
+      /**
+       * @param {Msg} msg
+       */
       encode(msg) {
         return b4a.from(JSON.stringify(msg), 'utf8')
       },
+      /**
+       * @param {B4A} buf
+       */
       decode(buf) {
-        return JSON.parse(buf.toString('utf8'))
+        return JSON.parse(b4a.toString(buf, 'utf8'))
       },
     },
+    /**
+     * @param {B4A} buf
+     */
     validateRecord(buf) {
       try {
-        JSON.parse(buf.toString('utf8'))
+        JSON.parse(b4a.toString(buf, 'utf8'))
         return true
       } catch {
         return false
@@ -95,8 +128,9 @@ exports.init = function initDB(peer, config) {
     },
   })
 
-  peer.close.hook(function (fn, args) {
+  peer.close.hook(function (/** @type {any} */ fn, /** @type {any} */ args) {
     log.close(() => {
+      // @ts-ignore
       fn.apply(this, args)
     })
   })
@@ -107,24 +141,27 @@ exports.init = function initDB(peer, config) {
     let i = -1
     log.stream({ offsets: true, values: true, sizes: true }).pipe(
       push.drain(
+        // @ts-ignore
         function drainEach({ offset, value, size }) {
           i += 1
           if (!value) {
             // deleted record
-            recs.push({ misc: { offset, size, seq: i } })
+            /** @type {RecDeleted} */
+            const rec = { misc: { offset, size, seq: i } }
+            recs.push(rec)
             return
           }
           // TODO: for performance, dont decrypt on startup, instead decrypt on
           // demand, or decrypt in the background. Or then store the log with
           // decrypted msgs and only encrypt when moving it to the network.
           const rec = decrypt(value, peer, config)
-          rec.misc ??= {}
+          rec.misc ??= /** @type {Rec['misc']} */ ({})
           rec.misc.offset = offset
           rec.misc.size = size
           rec.misc.seq = i
           recs.push(rec)
         },
-        function drainEnd(err) {
+        function drainEnd(/** @type {any} */ err) {
           // prettier-ignore
           if (err) throw new Error('Failed to initially scan the log', { cause: err });
           scannedLog.setReady()
@@ -133,13 +170,26 @@ exports.init = function initDB(peer, config) {
     )
   })
 
+  /**
+   * @param {string} hash
+   * @param {Msg} msg
+   * @param {CB<Rec>} cb
+   */
   function logAppend(hash, msg, cb) {
+    /** @type {RecPresent} */
     const rec = {
       hash,
       msg,
       received: Date.now(),
+      misc: {
+        offset: 0,
+        size: 0,
+        seq: 0,
+      },
     }
-    log.append(rec, (err, newOffset) => {
+    log.append(
+      rec,
+      (/** @type {any} */ err, /** @type {number} */ newOffset) => {
         if (err) return cb(new Error('logAppend failed', { cause: err }))
         const offset = newOffset // latestOffset
         const size = b4a.from(JSON.stringify(rec), 'utf8').length
@@ -148,13 +198,17 @@ exports.init = function initDB(peer, config) {
         rec.misc = recExposed.misc = { offset, size, seq }
         recs.push(recExposed)
         cb(null, rec)
-    })
+      }
+    )
   }
 
+  /**
+   * @param {EncryptionFormat} encryptionFormat
+   */
   function installEncryptionFormat(encryptionFormat) {
     if (encryptionFormat.setup) {
       const loaded = new ReadyGate()
-      encryptionFormat.setup(config, (err) => {
+      encryptionFormat.setup(config, (/** @type {any} */ err) => {
         // prettier-ignore
         if (err) throw new Error(`Failed to install encryption format "${encryptionFormat.name}"`, {cause: err});
         loaded.setReady()
@@ -164,15 +218,27 @@ exports.init = function initDB(peer, config) {
     encryptionFormats.set(encryptionFormat.name, encryptionFormat)
   }
 
+  /**
+   * @param {string} ciphertextJS
+   */
   function findEncryptionFormatFor(ciphertextJS) {
     if (!ciphertextJS) return null
     if (typeof ciphertextJS !== 'string') return null
     const suffix = ciphertextJS.split('.').pop()
+    if (!suffix) {
+      // prettier-ignore
+      console.warn('findEncryptionFormatFor() failed to find suffix\n\n' + ciphertextJS)
+      return null
+    }
     const encryptionFormat = encryptionFormats.get(suffix) ?? null
     return encryptionFormat
   }
 
+  /**
+   * @param {Array<string>} tangleIds
+   */
   function populateTangles(tangleIds) {
+    /** @type {Record<string, DBTangle>} */
     const tangles = {}
     for (const tangleId of tangleIds) {
       tangles[tangleId] ??= new DBTangle(tangleId, records())
@@ -180,11 +246,19 @@ exports.init = function initDB(peer, config) {
     return tangles
   }
 
+  /**
+   * @param {CB<void>} cb
+   */
   function loaded(cb) {
     if (cb === void 0) return promisify(loaded)()
     scannedLog.onReady(cb)
   }
 
+  /**
+   * @param {Msg} msg
+   * @param {string} tangleRootHash
+   * @param {CB<Rec>} cb
+   */
   function add(msg, tangleRootHash, cb) {
     const msgHash = MsgV2.getMsgHash(msg)
 
@@ -223,6 +297,10 @@ exports.init = function initDB(peer, config) {
     })
   }
 
+  /**
+   * @param {{ keypair?: any; identity: string; domain: string; }} opts
+   * @param {CB<string>} cb
+   */
   function initializeFeed(opts, cb) {
     const keypair = opts.keypair ?? config.keypair
     const { identity, domain } = opts
@@ -234,10 +312,15 @@ exports.init = function initDB(peer, config) {
     add(feedRoot, MsgV2.getMsgHash(feedRoot), (err, rec) => {
       // prettier-ignore
       if (err) return cb(new Error('initializeFeed() failed to add root', { cause: err }));
-      cb(null, rec.hash)
+      const recHash = /** @type {string} */ (rec.hash)
+      cb(null, recHash)
     })
   }
 
+  /**
+   * @param {{keypair?: Keypair, _nonce?: string} | null} opts
+   * @param {CB<Rec>} cb
+   */
   function createIdentity(opts, cb) {
     const keypair = opts?.keypair ?? config.keypair
 
@@ -257,9 +340,15 @@ exports.init = function initDB(peer, config) {
     })
   }
 
+  /**
+   * @param {{ keypair: Keypair; identity: string; }} opts
+   * @param {CB<Rec>} cb
+   */
   function addToIdentity(opts, cb) {
-    if (!opts?.keypair) return cb(new Error('identity.add() requires a `keypair`'))
+    if (!opts?.keypair)
-    if (!opts?.identity) return cb(new Error('identity.add() requires a `identity`'))
+      return cb(new Error('identity.add() requires a `keypair`'))
+    if (!opts?.identity)
+      return cb(new Error('identity.add() requires a `identity`'))
     const addedKeypair = opts.keypair
     const signingKeypair = config.keypair
 
@@ -291,20 +380,31 @@ exports.init = function initDB(peer, config) {
     })
   }
 
+  /**
+   * @param {{
+   *   keypair?: Keypair;
+   *   encryptionFormat?: string;
+   *   data: any;
+   *   domain: string;
+   *   identity: string;
+   *   tangles?: Array<string>;
+   * }} opts
+   * @param {CB<Rec>} cb
+   */
   function publishToFeed(opts, cb) {
     if (!opts) return cb(new Error('feed.publish() requires an `opts`'))
     const keypair = opts.keypair ?? config.keypair
 
-    const encryptionFormat = encryptionFormats.get(opts.encryptionFormat)
     if (opts.data.recps) {
-      if (!encryptionFormat) {
+      if (!encryptionFormats.has(opts.encryptionFormat ?? '')) {
         // prettier-ignore
         return cb(new Error(`feed.publish() does not support encryption format "${opts.encryptionFormat}"`))
       }
     }
     if (!opts.data) return cb(new Error('feed.publish() requires a `data`'))
     if (!opts.domain) return cb(new Error('feed.publish() requires a `domain`'))
-    if (!opts.identity) return cb(new Error('feed.publish() requires a `identity`'))
+    if (!opts.identity)
+      return cb(new Error('feed.publish() requires a `identity`'))
 
     initializeFeed(opts, (err, feedRootHash) => {
       // prettier-ignore
@@ -330,6 +430,9 @@ exports.init = function initDB(peer, config) {
               `@${b4a.from(base58.decode(recp)).toString('base64')}.ed25519`
           ),
         }
+        const encryptionFormat = /** @type {EncryptionFormat} */ (
+          encryptionFormats.get(opts.encryptionFormat ?? '')
+        )
         let ciphertextBuf
         try {
           ciphertextBuf = encryptionFormat.encrypt(plaintext, encryptOpts)
@@ -367,31 +470,47 @@ exports.init = function initDB(peer, config) {
     })
   }
 
+  /**
+   * @param {string} id
+   * @param {string} findDomain
+   */
   function getFeedId(id, findDomain) {
     const findIdentity = MsgV2.stripIdentity(id)
     for (const rec of records()) {
-      if (MsgV2.isFeedRoot(rec.msg, findIdentity, findDomain)) return rec.hash
+      if (rec.msg && MsgV2.isFeedRoot(rec.msg, findIdentity, findDomain)) {
+        return rec.hash
+      }
     }
     return null
   }
 
-  // TODO: improve performance of this when getting many messages, the argument
+  /**
-  // could be an array of hashes, so we can do a single pass over the records.
+   * @param {string} msgId
+   */
   function getRecord(msgId) {
+    // TODO: improve performance of this when getting many messages, the arg
+    // could be an array of hashes, so we can do a single pass over the records.
     const isUri = msgId.startsWith('ppppp:')
     for (let i = 0; i < recs.length; i++) {
       const rec = recs[i]
       if (!rec) continue
-      if (isUri && msgId.endsWith(rec.hash)) return rec
+      if (isUri && rec.hash && msgId.endsWith(rec.hash)) return rec
       else if (!isUri && rec.hash === msgId) return rec
     }
     return null
   }
 
+  /**
+   * @param {string} msgId
+   */
   function get(msgId) {
     return getRecord(msgId)?.msg
   }
 
+  /**
+   * @param {string} msgId
+   * @param {CBVoid} cb
+   */
   function del(msgId, cb) {
     const rec = getRecord(msgId)
     if (!rec) return cb()
@@ -403,6 +522,10 @@ exports.init = function initDB(peer, config) {
     })
   }
 
+  /**
+   * @param {string} msgId
+   * @param {CBVoid} cb
+   */
   function erase(msgId, cb) {
     const rec = getRecord(msgId)
     if (!rec) return cb()
@@ -413,6 +536,10 @@ exports.init = function initDB(peer, config) {
     cb()
   }
 
+  /**
+   * @param {string} tangleId
+   * @returns {DBTangle}
+   */
   function getTangle(tangleId) {
     return new DBTangle(tangleId, records())
   }
@@ -460,3 +587,6 @@ exports.init = function initDB(peer, config) {
     _getLog: () => log,
   }
 }
+
+exports.name = 'db'
+exports.init = initDB

lib/msg-v3/get-msg-id.js

@@ -1,6 +1,7 @@
 const b4a = require('b4a')
 const blake3 = require('blake3')
 const base58 = require('bs58')
+// @ts-ignore
 const stringify = require('json-canon')
 
 /**
@@ -14,7 +15,8 @@ const stringify = require('json-canon')
  */
 function getMsgHashBuf(msg) {
   const metadataBuf = b4a.from(stringify(msg.metadata), 'utf8')
-  return blake3.hash(metadataBuf).subarray(0, 16)
+  const longHash = b4a.from(blake3.hash(metadataBuf))
+  return longHash.subarray(0, 16)
 }
 
 /**

lib/msg-v3/index.js

@@ -1,8 +1,10 @@
 const crypto = require('node:crypto')
 const base58 = require('bs58')
 const b4a = require('b4a')
+// @ts-ignore
 const stringify = require('json-canon')
 const Keypair = require('ppppp-keypair')
+// @ts-ignore
 const union = require('set.prototype.union')
 const { stripIdentity } = require('./strip')
 const isFeedRoot = require('./is-feed-root')
@@ -12,7 +14,6 @@ const {
   validateDomain,
   validateData,
   validate,
-  validateBatch,
   validateMsgHash,
 } = require('./validation')
 const Tangle = require('./tangle')
@@ -56,6 +57,11 @@ const Tangle = require('./tangle')
  * }} CreateOpts
  */
 
+/**
+ * @param {string} id
+ * @param {string} domain
+ * @returns {string}
+ */
 function getFeedRootHash(id, domain) {
   /** @type {Msg} */
   const msg = {
@@ -76,6 +82,10 @@ function getFeedRootHash(id, domain) {
   return getMsgHash(msg)
 }
 
+/**
+ * @param {Pick<CreateOpts, 'data'>} opts
+ * @returns {B4A}
+ */
 function toPlaintextBuffer(opts) {
   return b4a.from(stringify(opts.data), 'utf8')
 }
@@ -93,7 +103,7 @@ function create(opts) {
   const identity = opts.identity ? stripIdentity(opts.identity) : null
   const identityTips = opts.identityTips ? opts.identityTips.sort() : null
 
-  const tangles = {}
+  const tangles = /** @type {Msg['metadata']['tangles']} */ ({})
   if (opts.tangles) {
     for (const rootId in opts.tangles) {
       if ((err = validateMsgHash(rootId))) throw err
@@ -168,7 +178,7 @@ function createRoot(id, domain, keypair) {
 
 /**
  * @param {Keypair} keypair
- * @param {string} nonce
+ * @param {string | (() => string)} nonce
  * @returns {Msg}
  */
 function createIdentity(
@@ -217,5 +227,4 @@ module.exports = {
   fromPlaintextBuffer,
   Tangle,
   validate,
-  validateBatch,
 }

lib/msg-v3/is-feed-root.js

@@ -1,5 +1,12 @@
 const { stripIdentity } = require('./strip')
 
+/**
+ * @typedef {import('.').Msg} Msg
+ */
+
+/**
+ * @param {any} obj
+ */
 function isEmptyObject(obj) {
   for (const _key in obj) {
     return false
@@ -7,6 +14,11 @@ function isEmptyObject(obj) {
   return true
 }
 
+/**
+ * @param {Msg} msg
+ * @param {string | 0} id
+ * @param {string | 0} findDomain
+ */
 function isFeedRoot(msg, id = 0, findDomain = 0) {
   const { dataHash, dataSize, identity, identityTips, tangles, domain } = msg.metadata
   if (dataHash !== null) return false

lib/msg-v3/represent-data.js

@@ -1,15 +1,21 @@
 const blake3 = require('blake3')
 const b4a = require('b4a')
 const base58 = require('bs58')
+// @ts-ignore
 const stringify = require('json-canon')
 
+/**
+ * @typedef {Buffer | Uint8Array} B4A
+ */
+
 /**
  * @param {any} data
  * @returns {[string, number]}
  */
 function representData(data) {
   const dataBuf = b4a.from(stringify(data), 'utf8')
-  const dataHash = base58.encode(blake3.hash(dataBuf).subarray(0, 16))
+  const fullHash = /** @type {B4A} */ (blake3.hash(dataBuf))
+  const dataHash = base58.encode(fullHash.subarray(0, 16))
   const dataSize = dataBuf.length
   return [dataHash, dataSize]
 }

lib/msg-v3/strip.js

@@ -1,5 +1,12 @@
 const { getMsgHash } = require('./get-msg-id')
 
+/**
+ * @typedef {import('.').Msg} Msg
+ */
+
+/**
+ * @param {any} msgKey
+ */
 function stripMsgKey(msgKey) {
   if (typeof msgKey === 'object') {
     if (msgKey.key) return stripMsgKey(msgKey.key)

lib/msg-v3/tangle.js

@@ -2,6 +2,9 @@
  * @typedef {import("./index").Msg} Msg
  */
 
+/**
+ * @param {number} n
+ */
 function lipmaa(n) {
   let m = 1
   let po3 = 3
@@ -46,7 +49,7 @@ class Tangle {
   #rootHash
 
   /**
-   * @type {Msg}
+   * @type {Msg | undefined}
    */
   #rootMsg
 
@@ -77,13 +80,16 @@ class Tangle {
 
   /**
    * @param {string} rootHash
-   * @param {Iterable<Msg>} msgsIter
    */
   constructor(rootHash) {
     this.#rootHash = rootHash
     this.#maxDepth = 0
   }
 
+  /**
+   * @param {string} msgHash
+   * @param {Msg} msg
+   */
   add(msgHash, msg) {
     if (msgHash === this.#rootHash && !this.#rootMsg) {
       this.#tips.add(msgHash)
@@ -195,10 +201,17 @@ class Tangle {
 
   getFeed() {
     if (!this.isFeed()) return null
+    if (!this.#rootMsg) {
+      console.trace('Tangle is missing root message')
+      return null
+    }
     const { identity, domain } = this.#rootMsg.metadata
     return { identity, domain }
   }
 
+  /**
+   * @param {string} msgHash
+   */
   shortestPathToRoot(msgHash) {
     if (!this.#rootMsg) {
       console.trace('Tangle is missing root message')
@@ -209,10 +222,10 @@ class Tangle {
     while (true) {
       const prev = this.#prev.get(current)
       if (!prev) break
-      let minDepth = this.#depth.get(current)
+      let minDepth = /** @type {number} */ (this.#depth.get(current))
       let min = current
       for (const p of prev) {
-        const d = this.#depth.get(p)
+        const d = /** @type {number} */ (this.#depth.get(p))
         if (d < minDepth) {
           minDepth = d
           min = p
@@ -226,18 +239,22 @@ class Tangle {
     return path
   }
 
-  precedes(a, b) {
+  /**
+   * @param {string} msgHashA
+   * @param {string} msgHashB
+   */
+  precedes(msgHashA, msgHashB) {
     if (!this.#rootMsg) {
       console.trace('Tangle is missing root message')
       return false
     }
-    if (a === b) return false
+    if (msgHashA === msgHashB) return false
-    if (b === this.#rootHash) return false
+    if (msgHashB === this.#rootHash) return false
-    let toCheck = [b]
+    let toCheck = [msgHashB]
     while (toCheck.length > 0) {
-      const prev = this.#prev.get(toCheck.shift())
+      const prev = this.#prev.get(/** @type {string} */ (toCheck.shift()))
       if (!prev) continue
-      if (prev.includes(a)) return true
+      if (prev.includes(msgHashA)) return true
       toCheck.push(...prev)
     }
     return false

lib/msg-v3/validation.js

@@ -1,11 +1,20 @@
 const b4a = require('b4a')
 const base58 = require('bs58')
 const Keypair = require('ppppp-keypair')
+// @ts-ignore
 const stringify = require('json-canon')
 const Tangle = require('./tangle')
 const representData = require('./represent-data')
 const isFeedRoot = require('./is-feed-root')
 
+/**
+ * @typedef {import('.').Msg} Msg
+ */
+
+/**
+ * @param {Msg} msg
+ * @returns {string | undefined}
+ */
 function validateShape(msg) {
   if (!msg || typeof msg !== 'object') {
     return 'invalid message: not an object\n' + JSON.stringify(msg)
@@ -25,7 +34,9 @@ function validateShape(msg) {
     return 'invalid message: must have metadata.dataSize\n' + JSON.stringify(msg)
   }
   if (!('identity' in msg.metadata)) {
-    return 'invalid message: must have metadata.identity\n' + JSON.stringify(msg)
+    return (
+      'invalid message: must have metadata.identity\n' + JSON.stringify(msg)
+    )
   }
   if (!('identityTips' in msg.metadata)) {
     // prettier-ignore
@@ -45,6 +56,10 @@ function validateShape(msg) {
   }
 }
 
+/**
+ * @param {Msg} msg
+ * @returns {string | undefined}
+ */
 function validatePubkey(msg) {
   const { pubkey } = msg
   if (typeof pubkey !== 'string') {
@@ -63,6 +78,12 @@ function validatePubkey(msg) {
   }
 }
 
+/**
+ *
+ * @param {Msg} msg
+ * @param {Set<string>} pubkeys
+ * @returns {string | undefined}
+ */
 function validateIdentityPubkey(msg, pubkeys) {
   // Unusual case: if the msg is a feed root, ignore the identity and pubkey
   if (isFeedRoot(msg)) return
@@ -73,6 +94,10 @@ function validateIdentityPubkey(msg, pubkeys) {
   }
 }
 
+/**
+ * @param {string} str
+ * @returns {string | undefined}
+ */
 function validateMsgHash(str) {
   try {
     const hashBuf = b4a.from(base58.decode(str))
@@ -85,6 +110,10 @@ function validateMsgHash(str) {
   }
 }
 
+/**
+ * @param {Msg} msg
+ * @returns {string | undefined}
+ */
 function validateDataSize(msg) {
   const { dataSize } = msg.metadata
   if (!Number.isSafeInteger(dataSize) || dataSize < 0) {
@@ -93,6 +122,10 @@ function validateDataSize(msg) {
   }
 }
 
+/**
+ * @param {Msg} msg
+ * @returns {string | undefined}
+ */
 function validateSignature(msg) {
   const { sig } = msg
   if (typeof sig !== 'string') {
@@ -122,10 +155,13 @@ function validateSignature(msg) {
 }
 
 /**
- *
+ * @typedef {NonNullable<ReturnType<Tangle['getFeed']>>} FeedDetails
- * @param {any} msg
+ */
+
+/**
+ * @param {Msg} msg
  * @param {Tangle} tangle
- * @param {*} tangleId
+ * @param {string} tangleId
  * @returns
  */
 function validateTangle(msg, tangle, tangleId) {
@@ -143,7 +179,7 @@ function validateTangle(msg, tangle, tangleId) {
     return `invalid message: depth "${depth}" should have been a positive integer\n` + JSON.stringify(msg)
   }
   if (tangle.isFeed()) {
-    const { identity, domain } = tangle.getFeed()
+    const { identity, domain } = /** @type {FeedDetails} */ (tangle.getFeed())
     if (domain !== msg.metadata.domain) {
       // prettier-ignore
       return `invalid message: domain "${msg.metadata.domain}" should have been feed domain "${domain}"\n` + JSON.stringify(msg)
@@ -202,6 +238,11 @@ function validateTangle(msg, tangle, tangleId) {
   }
 }
 
+/**
+ * @param {Msg} msg
+ * @param {string} msgHash
+ * @param {string} tangleId
+ */
 function validateTangleRoot(msg, msgHash, tangleId) {
   if (msgHash !== tangleId) {
     // prettier-ignore
@@ -213,6 +254,9 @@ function validateTangleRoot(msg, msgHash, tangleId) {
   }
 }
 
+/**
+ * @param {string} domain
+ */
 function validateDomain(domain) {
   if (!domain || typeof domain !== 'string') {
     // prettier-ignore
@@ -232,6 +276,9 @@ function validateDomain(domain) {
   }
 }
 
+/**
+ * @param {Msg} msg
+ */
 function validateData(msg) {
   const { data } = msg
   if (data === null) {
@@ -260,6 +307,13 @@ function validateData(msg) {
   }
 }
 
+/**
+ * @param {Msg} msg
+ * @param {Tangle} tangle
+ * @param {Set<string>} pubkeys
+ * @param {string} msgHash
+ * @param {string} rootHash
+ */
 function validate(msg, tangle, pubkeys, msgHash, rootHash) {
   let err
   if ((err = validateShape(msg))) return err

lib/utils.js

@@ -6,6 +6,9 @@ class ReadyGate {
     this.#ready = false
   }
 
+  /**
+   * @param {() => void} cb
+   */
   onReady(cb) {
     if (this.#ready) cb()
     else this.#waiting.add(cb)

package.json

@@ -14,6 +14,7 @@
   "files": [
     "lib/**/*"
   ],
+  "types": "types/index.d.ts",
   "engines": {
     "node": ">=16"
   },
@@ -46,9 +47,11 @@
     "pretty-quick": "^3.1.3",
     "rimraf": "^4.4.0",
     "secret-stack": "^6.4.2",
-    "ssb-box": "^1.0.1"
+    "ssb-box": "^1.0.1",
+    "typescript": "^5.1.3"
   },
   "scripts": {
+    "build": "tsc --build --clean && tsc --build",
     "test": "node --test",
     "format-code": "prettier --write \"(lib|test)/**/*.js\"",
     "format-code-staged": "pretty-quick --staged --pattern \"(lib|test)/**/*.js\"",

tsconfig.json

@@ -0,0 +1,16 @@
+{
+  "include": ["lib/**/*.js"],
+  "exclude": ["coverage/", "node_modules/", "test/"],
+  "compilerOptions": {
+    "checkJs": true,
+    "declaration": true,
+    "emitDeclarationOnly": true,
+    "exactOptionalPropertyTypes": true,
+    "forceConsistentCasingInFileNames": true,
+    "lib": ["es2022", "dom"],
+    "module": "node16",
+    "skipLibCheck": true,
+    "strict": true,
+    "target": "es2021"
+  }
+}