From 880c340f332bf801321bcf927c60ebbb7f384d31 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20B=C3=B6lsche?= <regular.gonzales@googlemail.com>
Date: Sun, 29 Sep 2019 16:53:58 +0200
Subject: [PATCH 1/2] Add canonicalize function, add ipv6 option to host() (now
 returns v4 by default), add tests

---
 index.js     | 33 ++++++++++++++++++++++-----------
 package.json |  3 +++
 test.js      | 25 +++++++++++++++++++++++++
 3 files changed, 50 insertions(+), 11 deletions(-)
 create mode 100644 test.js

diff --git a/index.js b/index.js
index 8aa3504..5ff36d9 100644
--- a/index.js
+++ b/index.js
@@ -1,14 +1,25 @@
 var ip = require('non-private-ip')
 
-module.exports = {
-  host: function(scope) {
-    var f = {
-      device: function () {return 'localhost'},
-      local: ip.private,
-      private: ip.private,
-      public: ip
-    }[scope]
-    if (!f) throw new Error('invalid scope: ' + scope)
-    return f()
-  }
+function canonicalize(scope) {
+  var canonicalized = {
+    device: 'device',
+    local: 'private',
+    private: 'private',
+    public: 'public'
+  }[scope]
+  if (!canonicalized) throw new Error('invalid scope: ' + scope)
+  return canonicalized
 }
+
+function host(scope, opts) {
+  opts = opts || {}
+  var family = opts.ipv6 ? 'v6' : 'v4'
+  return {
+    device: {v4: '127.0.0.1', v6: '::1'}[family],
+    private: ip.private[family],
+    public: ip[family]
+  }[canonicalize(scope)]
+}
+
+module.exports.canonicalize = canonicalize
+module.exports.host = host
diff --git a/package.json b/package.json
index 703761f..c9ffc6b 100644
--- a/package.json
+++ b/package.json
@@ -11,5 +11,8 @@
   "license": "MIT",
   "dependencies": {
     "non-private-ip": "^1.4.4"
+  },
+  "devDependencies": {
+    "tape": "^4.11.0"
   }
 }
diff --git a/test.js b/test.js
new file mode 100644
index 0000000..19d2970
--- /dev/null
+++ b/test.js
@@ -0,0 +1,25 @@
+var test = require('tape')
+var scopes = require('.')
+
+test('canonicalize', function(t) {
+  var allScopes = 'device local private public'.split(' ')
+  t.deepEqual(
+    allScopes.map(scopes.canonicalize), 
+    'device private private public'.split(' ')
+  )
+  t.end()
+})
+
+test('throw if scope is invalid', function(t) {
+  t.throws(function() {
+    scopes.canonicalize('this')
+  })
+  t.end()
+})
+
+test('host("device") returns ipv4 or ipv6 representation of localhost', function(t) {
+  t.equal(scopes.host('device'), '127.0.0.1')
+  t.equal(scopes.host('device', {ipv6: true}), '::1')
+  t.equal(scopes.host('device', {ipv6: false}), '127.0.0.1')
+  t.end()
+})

From 0243f1ed9a0fba46f674aa5ac9521326de208379 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20B=C3=B6lsche?= <regular.gonzales@googlemail.com>
Date: Sun, 29 Sep 2019 17:11:43 +0200
Subject: [PATCH 2/2] readme

---
 README.md | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index ff98cda..8fb1fec 100644
--- a/README.md
+++ b/README.md
@@ -8,9 +8,22 @@ This module should become the definition of what scopes mean in ssb.
 
 ## API
 
-## `host(scope)`
-
-returns default host for a given scope
+## `canonicalize(scope)`
+
+There are two names used in the scuttlebutt codebase for the LAN scope: `local` and `private`.
+`canonocalize()` deals with this (and possible other aliases) by mapping both names to 'private'.
+
+The complete mapping is:
+
+```
+- device  -> device
+- local   -> private
+- private -> private
+- public  -> public
+```
+## `host(scope, opts)`
+ 
+returns default host for a given scope. Returns an IPv4 address unless opts.ipv6 is truthy.
 
 - `device` -> 'localhost'
 - `local` -> private/non-routable IP (e.g. 192.168 ...)