Feat: Add date type (elastic#271)

* feat: add a date type

* fix: date function doesn't pass input to moment

moment doesn't take generic string input anymore, this relies on the native Date type, unless format is provided

* fix: wrap formatdate's context input in Date type

moment doesn't allow passing arbitrary strings in

common/functions/date.js

@@ -1,25 +1,44 @@
 import moment from 'moment';
 
+const getInputDate = (input) => {
+  // return current date if no input
+  if (!input) return new Date();
+
+  // attempt to cast to a number
+  const numInput = Number(input);
+  if (!isNaN(numInput)) return numInput;
+
+  // return the input
+  return input;
+};
+
 export const date = {
   name: 'date',
-  type: 'number',
+  type: 'date',
   context: {
     types: ['null'],
   },
-  help: 'Returns the current time, or a time parsed from a string, as milliseconds since epoch',
+  help: 'Returns the current time, or a time parsed from a string, as milliseconds since epoch.',
   args: {
     _: {
       types: ['string', 'null'],
-      help: 'An optional date string to parse into milliseconds since epoch',
+      help: 'An optional date string to parse into milliseconds since epoch. ' +
+        'Can be either a valid Javascript Date input or a string to parse using the format argument. ',
     },
     format: {
       types: ['string', 'null'],
-      help: 'The momentJS format for parsing the optional date string (See https://momentjs.com/docs/#/displaying/)',
+      help: 'The momentJS format for parsing the optional date string (See https://momentjs.com/docs/#/displaying/).',
     },
   },
   fn: (context, args) => {
-    if (!args._) return moment().valueOf();
-    if (!args.format) return moment(args._).valueOf();
-    return moment(args._, args.format).valueOf();
+    const inputDate = getInputDate(args._);
+    const outputDate = (args._ && args.format) ? moment(inputDate, args.format).toDate() : new Date(inputDate);
+
+    if (isNaN(outputDate.getTime())) throw new Error(`Invalid date input: ${args._}`);
+
+    return {
+      type: 'date',
+      value: outputDate,
+    };
   },
 };

common/functions/formatdate.js

@@ -14,6 +14,6 @@ export const formatdate = {
     },
   },
   fn: (context, args) => {
-    return moment(context).format(args._);
+    return moment(new Date(context)).format(args._);
   },
 };

common/types/date.js

@@ -0,0 +1,38 @@
+export const date = {
+  name: 'date',
+  from: {
+    number: n => ({
+      type: 'date',
+      value: new Date(n),
+    }),
+    string: s => ({
+      type: 'date',
+      value: new Date(s),
+    }),
+  },
+  to: {
+    string: d => d.value.toISOString(),
+    number: d => d.value.getTime(),
+    render: d => {
+      return {
+        type: 'render',
+        as: 'markdown',
+        value: {
+          content: String(d.value.toISOString()),
+        },
+      };
+    },
+    datatable: (d) => {
+      return {
+        type: 'datatable',
+        columns: [
+          {
+            name: 'value',
+            type: 'date',
+          },
+        ],
+        rows: [{ value: d.value.getTime() }],
+      };
+    },
+  },
+};

common/types/index.js

@@ -1,6 +1,7 @@
 import { boolean } from './boolean';
 import { datatable } from './datatable';
 import { dataurl } from './dataurl';
+import { date } from './date';
 import { error } from './error';
 import { filter } from './filter';
 import { image } from './image';
@@ -16,6 +17,7 @@ export const typeSpecs = [
   boolean,
   datatable,
   dataurl,
+  date,
   error,
   filter,
   image,