add test for validateNumber

package-lock.json

@@ -1323,6 +1323,7 @@
       "version": "1.7.1",
       "resolved": "https://registry.npmjs.org/clipboard/-/clipboard-1.7.1.tgz",
       "integrity": "sha1-Ng1taUbpmnof7zleQrqStem1oWs=",
+      "dev": true,
       "optional": true,
       "requires": {
         "good-listener": "1.2.2",
@@ -1601,6 +1602,7 @@
       "version": "3.2.0",
       "resolved": "https://registry.npmjs.org/delegate/-/delegate-3.2.0.tgz",
       "integrity": "sha512-IofjkYBZaZivn0V8nnsMJGBr4jVLxHDheKSW88PyxS5QC4Vo9ZbZVvhzlSxY87fVq3STR6r+4cGepyHkcWOQSw==",
+      "dev": true,
       "optional": true
     },
     "delegates": {
@@ -2388,6 +2390,7 @@
       "version": "1.2.2",
       "resolved": "https://registry.npmjs.org/good-listener/-/good-listener-1.2.2.tgz",
       "integrity": "sha1-1TswzfkxPf+33JoNR3CWqm0UXFA=",
+      "dev": true,
       "optional": true,
       "requires": {
         "delegate": "3.2.0"
@@ -3700,6 +3703,7 @@
       "version": "1.9.0",
       "resolved": "https://registry.npmjs.org/prismjs/-/prismjs-1.9.0.tgz",
       "integrity": "sha1-+j4tntw8OIfB8fMJXUHx+bQgDw8=",
+      "dev": true,
       "requires": {
         "clipboard": "1.7.1"
       }
@@ -4113,6 +4117,7 @@
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/select/-/select-1.1.2.tgz",
       "integrity": "sha1-DnNQrN7ICxEIUoeG7B1EGNEbOW0=",
+      "dev": true,
       "optional": true
     },
     "semistandard": {
@@ -4570,6 +4575,7 @@
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/tiny-emitter/-/tiny-emitter-2.0.2.tgz",
       "integrity": "sha512-2NM0auVBGft5tee/OxP4PI3d8WItkDM+fPnaRAVo6xTDI2knbz9eC5ArWGqtGlYqiH3RU5yMpdyTTO7MguC4ow==",
+      "dev": true,
       "optional": true
     },
     "to-fast-properties": {