Allow null value & v-model.number config + handle input of type number

- Dev should be allowed to set input to null and expect v-model to
  retain the null value. Requesting a reconsideration against returning
a string as in commit 95b7f83

- Handle v-model.number modifier correctly. Whether the input is string,
  number or null, the resulting emit() should return the same type or
null. Requesting this as an alternative to resolve vuetifyjs#2137.

- Handle input of type number. Likewise, the resulting emit() should
  return the same type. Requesting this as an alternative to resolve vuetifyjs#2136.

src/components/VTextField/VTextField.js

@@ -90,7 +90,8 @@ export default {
         // Inner unmaskText() strips off non-alphanum
         // maskText() masks and removes dirty alphanum
         // Outer unmaskText() provides a clean lazyValue
-        this.lazyValue = this.unmaskText(this.maskText(this.unmaskText(val)))
+        const value = this.unmaskText(this.maskText(this.unmaskText(val)))
+        this.lazyValue = typeof val === 'number' ? +value : value
         this.mask ? this.setSelectionRange()
           : this.$emit('input', this.returnMaskedValue
             ? this.$refs.input.value : this.lazyValue)
@@ -118,8 +119,9 @@ export default {
     value (val) {
       // Value was changed externally, update lazy
       const masked = this.maskText(this.unmaskText(val))
+      const value = this.unmaskText(masked)
 
-      this.lazyValue = this.unmaskText(masked)
+      this.lazyValue = typeof val === 'number' ? +value : value
       !this.validateOnBlur && this.validate()
       this.shouldAutoGrow && this.calculateInputHeight()
 

src/mixins/maskable.js

@@ -67,10 +67,12 @@ export default {
       }
 
       selection = 0
-      for (const char of newText) {
-        isMaskDelimiter(char) || position--
-        selection++
-        if (position <= 0) break
+      if (newText) {
+        for (const char of newText) {
+          isMaskDelimiter(char) || position--
+          selection++
+          if (position <= 0) break
+        }
       }
 
       this.$nextTick(() => {
@@ -94,10 +96,12 @@ export default {
       let selection = 0
 
       this.$refs.input.value = newValue
-      for (const char of newValue) {
-        if (this.lazySelection <= 0) break
-        isMaskDelimiter(char) || this.lazySelection--
-        selection++
+      if (newValue) {
+        for (const char of newValue) {
+          if (this.lazySelection <= 0) break
+          isMaskDelimiter(char) || this.lazySelection--
+          selection++
+        }
       }
 
       this.setCaretPosition(selection)

src/util/mask.js

@@ -90,14 +90,15 @@ const maskValidates = (mask, char) => {
  * @return {String}
  */
 export const maskText = (text, masked, dontFillMaskBlanks) => {
-  if (text == null) return ''
-  text = String(text)
-  if (!masked.length || !text.length) return text
+  if (!masked.length || !text) return text
   if (!Array.isArray(masked)) masked = masked.split('')
 
   let textIndex = 0
   let maskIndex = 0
   let newText = ''
+
+  text = String(text)
+
   while (maskIndex < masked.length) {
     const mask = masked[maskIndex]
 
@@ -134,5 +135,5 @@ export const maskText = (text, masked, dontFillMaskBlanks) => {
  * @return {String}
  */
 export const unmaskText = (text) => {
-  return text ? text.replace(new RegExp(defaultDelimiters, 'g'), '') : text
+  return text ? String(text).replace(new RegExp(defaultDelimiters, 'g'), '') : text
 }