Add string validator & tests for UUIDv4

ui/src/utils/stringValidators.js

@@ -0,0 +1,6 @@
+// uses Gajus' regex matcher from https://stackoverflow.com/questions/136505/searching-for-uuids-in-text-with-regex
+export const isUUIDv4 = str =>
+  str.length === 36 &&
+  !!str.match(
+    /[a-f0-9]{8}-[a-f0-9]{4}-4[a-f0-9]{3}-[89aAbB][a-f0-9]{3}-[a-f0-9]{12}/
+  )

ui/test/utils/stringValidators.test.js

@@ -0,0 +1,24 @@
+import uuid from 'uuid'
+
+import {isUUIDv4} from 'src/utils/stringValidators'
+
+describe('isUUIDv4', () => {
+  it('returns false for non-matches', () => {
+    const inputWrongLength = 'abcd'
+    expect(isUUIDv4(inputWrongLength)).toEqual(false)
+
+    const inputWrongFormat = 'abcdefghijklmnopqrstuvwxyz1234567890'
+    expect(isUUIDv4(inputWrongFormat)).toEqual(false)
+
+    const inputWrongCharRange = 'z47ac10b-58cc-4372-a567-0e02b2c3d479'
+    expect(isUUIDv4(inputWrongCharRange)).toEqual(false)
+  })
+
+  it('returns true for matches', () => {
+    const inputRight = 'a47ac10b-58cc-4372-a567-0e02b2c3d479'
+    expect(isUUIDv4(inputRight)).toEqual(true)
+
+    const inputRightFromLibrary = uuid.v4()
+    expect(isUUIDv4(inputRightFromLibrary)).toEqual(true)
+  })
+})