From e9e46464c27e5155dd404888ebbd1452fc37541b Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Tue, 13 Mar 2018 21:54:54 -0400
Subject: [PATCH] Add `SchemaVersion` type

---
 js/modules/types/schema_version.js        |  5 +++++
 test/modules/types/schema_version_test.js | 25 +++++++++++++++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 js/modules/types/schema_version.js
 create mode 100644 test/modules/types/schema_version_test.js

diff --git a/js/modules/types/schema_version.js b/js/modules/types/schema_version.js
new file mode 100644
index 000000000..3a0d08980
--- /dev/null
+++ b/js/modules/types/schema_version.js
@@ -0,0 +1,5 @@
+const isNumber = require('lodash/isNumber');
+
+
+exports.isValid = value =>
+  isNumber(value) && value >= 0;
diff --git a/test/modules/types/schema_version_test.js b/test/modules/types/schema_version_test.js
new file mode 100644
index 000000000..a3205c485
--- /dev/null
+++ b/test/modules/types/schema_version_test.js
@@ -0,0 +1,25 @@
+require('mocha-testcheck').install();
+const { assert } = require('chai');
+
+const SchemaVersion = require('../../../js/modules/types/schema_version');
+
+
+describe('SchemaVersion', () => {
+  describe('isValid', () => {
+    check.it(
+      'should return true for positive integers',
+      gen.posInt,
+      (input) => {
+        assert.isTrue(SchemaVersion.isValid(input));
+      }
+    );
+
+    check.it(
+      'should return false for any other value',
+      gen.primitive.suchThat(value => typeof value !== 'number' || value < 0),
+      (input) => {
+        assert.isFalse(SchemaVersion.isValid(input));
+      }
+    );
+  });
+});