Handle NaN in obligated amount input properly

- there is some hackiness to the text input portion

js/components/text_input.js

@@ -103,7 +103,8 @@ export default {
       this.value = e.target.value.trim()
 
       if (this.validation === 'dollars') {
-        this.value = formatDollars(this._rawValue(e.target.value))
+        let value = Number.isNaN(e.target.value) ? '0' : e.target.value
+        this.value = formatDollars(this._rawValue(value))
       }
     },
 

js/components/totals_box.js

@@ -11,10 +11,16 @@ export default {
 
   computed: {
     formattedObligated: function() {
-      return formatDollars(this.obligated)
+      return formatDollars(this._filterNaN(this.obligated))
     },
     formattedContractAmount: function() {
-      return formatDollars(this.contractAmount)
+      return formatDollars(this._filterNaN(this.contractAmount))
+    },
+  },
+
+  methods: {
+    _filterNaN: function(value) {
+      return Number.isNaN(value) ? 0 : value
     },
   },
 }