Merge pull request #188 from sasjs/special-missings

Added isSpecialMissing function to be used in Adapter and DataController

src/input/index.ts

@@ -8,3 +8,5 @@ export {
   InputValidator,
   Choice
 } from './readAndValidateInput'
+
+export { isSpecialMissing } from './validators'

src/input/validators.spec.ts

@@ -1,6 +1,7 @@
 import {
   choiceValidator,
   confirmationValidator,
+  isSpecialMissing,
   urlValidator
 } from './validators'
 
@@ -100,3 +101,23 @@ describe('choiceValidator', () => {
     )
   })
 })
+
+describe('Special Missing check', () => {
+  it('should accept special missings', () => {
+    expect(isSpecialMissing('s')).toBeTrue()
+    expect(isSpecialMissing('.')).toBeTrue()
+    expect(isSpecialMissing('.s')).toBeTrue()
+    expect(isSpecialMissing('_')).toBeTrue()
+    expect(isSpecialMissing('._')).toBeTrue()
+  })
+
+  it('should reject non special missings', () => {
+    expect(isSpecialMissing('ss')).toBeFalse()
+    expect(isSpecialMissing('..')).toBeFalse()
+    expect(isSpecialMissing('__')).toBeFalse()
+    expect(isSpecialMissing('23')).toBeFalse()
+    expect(isSpecialMissing(23)).toBeFalse()
+    expect(isSpecialMissing(null)).toBeFalse()
+    expect(isSpecialMissing(undefined)).toBeFalse()
+  })
+})

src/input/validators.ts

@@ -14,3 +14,13 @@ export const choiceValidator = (
   numberOfChoices: number,
   errorMessage: string
 ) => (value > 0 && value <= numberOfChoices) || errorMessage
+
+// This regex will match special missing
+// `a-z` or `_` or `.` or '.[a-z]'
+export const isSpecialMissing = (value: any) => {
+  // This regex can't cover the case with `..` two dots, so if we receive it that is false special missing
+  if (typeof value === 'string' && value.includes('..')) return false
+
+  const regex = new RegExp('^(\\.)?[a-z_.]{1}$', 'i')
+  return regex.test(value)
+}