[@kbn/datemath] improve types (#24671)

* [kbn-datemath][parseEsInterval] improve types slightly

* [kbn-datemath][vis/leastCommonInterval] make types more precise

* [ui/leastCommonInterval] fix bug in finding same types

* add back valid test

packages/kbn-datemath/src/index.d.ts

@@ -17,13 +17,29 @@
  * under the License.
  */
 
-declare module '@kbn/datemath' {
-  const dateMath: {
-    parse: any;
-    unitsMap: any;
-    units: string[];
-    unitsAsc: string[];
-    unitsDesc: string[];
+import moment from 'moment';
+export type Unit = 'ms' | 's' | 'm' | 'h' | 'd' | 'w' | 'M' | 'y';
+
+declare const datemath: {
+  unitsMap: {
+    [k in Unit]: {
+      weight: number;
+      type: 'calendar' | 'fixed' | 'mixed';
+      base: number;
+    }
   };
-  export default dateMath;
-}
+  units: Unit[];
+  unitsAsc: Unit[];
+  unitsDesc: Unit[];
+
+  parse(
+    input: string,
+    options?: {
+      roundUp?: boolean;
+      forceNow?: boolean;
+      momentInstance?: typeof moment;
+    }
+  ): moment.Moment | undefined;
+};
+
+export default datemath;

packages/kbn-datemath/src/index.js

@@ -25,10 +25,10 @@ const unitsMap = {
   m: { weight: 3, type: 'mixed', base: 1000 * 60 },
   h: { weight: 4, type: 'mixed', base: 1000 * 60 * 60 },
   d: { weight: 5, type: 'mixed', base: 1000 * 60 * 60 * 24 },
-  w: { weight: 6, type: 'calendar' },
-  M: { weight: 7, type: 'calendar' },
+  w: { weight: 6, type: 'calendar', base: NaN },
+  M: { weight: 7, type: 'calendar', base: NaN },
   // q: { weight: 8, type: 'calendar' }, // TODO: moment duration does not support quarter
-  y: { weight: 9, type: 'calendar' },
+  y: { weight: 9, type: 'calendar', base: NaN },
 };
 const units = Object.keys(unitsMap).sort((a, b) => unitsMap[b].weight - unitsMap[a].weight);
 const unitsDesc = [...units];

src/ui/public/utils/parse_es_interval/index.ts

@@ -17,6 +17,6 @@
  * under the License.
  */
 
-export { parseEsInterval } from './parse_es_interval';
+export { parseEsInterval, ParsedInterval } from './parse_es_interval';
 export { InvalidEsCalendarIntervalError } from './invalid_es_calendar_interval_error';
 export { InvalidEsIntervalFormatError } from './invalid_es_interval_format_error';

src/ui/public/utils/parse_es_interval/invalid_es_calendar_interval_error.ts

@@ -17,11 +17,13 @@
  * under the License.
  */
 
+import { Unit } from '@kbn/datemath';
+
 export class InvalidEsCalendarIntervalError extends Error {
   constructor(
     public readonly interval: string,
     public readonly value: number,
-    public readonly unit: string,
+    public readonly unit: Unit,
     public readonly type: string
   ) {
     super(`Invalid calendar interval: ${interval}, value must be 1`);

src/ui/public/utils/parse_es_interval/parse_es_interval.ts

@@ -17,7 +17,7 @@
  * under the License.
  */
 
-import dateMath from '@kbn/datemath';
+import dateMath, { Unit } from '@kbn/datemath';
 
 import { InvalidEsCalendarIntervalError } from './invalid_es_calendar_interval_error';
 import { InvalidEsIntervalFormatError } from './invalid_es_interval_format_error';
@@ -26,6 +26,8 @@ const ES_INTERVAL_STRING_REGEX = new RegExp(
   '^([1-9][0-9]*)\\s*(' + dateMath.units.join('|') + ')$'
 );
 
+export type ParsedInterval = ReturnType<typeof parseEsInterval>;
+
 /**
  * Extracts interval properties from an ES interval string. Disallows unrecognized interval formats
  * and fractional values. Converts some intervals from "calendar" to "fixed" when the number of
@@ -37,7 +39,7 @@ const ES_INTERVAL_STRING_REGEX = new RegExp(
  * | -------- | ---------------- | ------------------- |
  * | ms       | fixed            | fixed               |
  * | s        | fixed            | fixed               |
- * | m        | fixed            | fixed               |
+ * | m        | calendar         | fixed               |
  * | h        | calendar         | fixed               |
  * | d        | calendar         | fixed               |
  * | w        | calendar         | N/A - disallowed    |
@@ -45,7 +47,7 @@ const ES_INTERVAL_STRING_REGEX = new RegExp(
  * | y        | calendar         | N/A - disallowed    |
  *
  */
-export function parseEsInterval(interval: string): { value: number; unit: string; type: string } {
+export function parseEsInterval(interval: string) {
   const matches = String(interval)
     .trim()
     .match(ES_INTERVAL_STRING_REGEX);
@@ -54,9 +56,9 @@ export function parseEsInterval(interval: string): { value: number; unit: string
     throw new InvalidEsIntervalFormatError(interval);
   }
 
-  const value = matches && parseFloat(matches[1]);
-  const unit = matches && matches[2];
-  const type = unit && dateMath.unitsMap[unit].type;
+  const value = parseFloat(matches[1]);
+  const unit = matches[2] as Unit;
+  const type = dateMath.unitsMap[unit].type;
 
   if (type === 'calendar' && value !== 1) {
     throw new InvalidEsCalendarIntervalError(interval, value, unit, type);
@@ -65,6 +67,9 @@ export function parseEsInterval(interval: string): { value: number; unit: string
   return {
     value,
     unit,
-    type: (type === 'mixed' && value === 1) || type === 'calendar' ? 'calendar' : 'fixed',
+    type:
+      (type === 'mixed' && value === 1) || type === 'calendar'
+        ? ('calendar' as 'calendar')
+        : ('fixed' as 'fixed'),
   };
 }

src/ui/public/vis/lib/least_common_interval.test.ts

@@ -48,6 +48,12 @@ describe('leastCommonInterval', () => {
     expect(() => {
       leastCommonInterval('60 s', '1m');
     }).toThrowError();
+    expect(() => {
+      leastCommonInterval('1m', '2m');
+    }).toThrowError();
+    expect(() => {
+      leastCommonInterval('1h', '2h');
+    }).toThrowError();
     expect(() => {
       leastCommonInterval('1d', '7d');
     }).toThrowError();

src/ui/public/vis/lib/least_common_interval.ts

@@ -25,8 +25,8 @@ import { parseEsInterval } from '../../utils/parse_es_interval';
  * Finds the lowest common interval between two given ES date histogram intervals
  * in the format of (value)(unit)
  *
- *  - `ms, s` units are fixed-length intervals
- *  - `m, h, d` units are fixed-length intervals when value > 1 (i.e. 2m, 24h, 7d),
+ *  - `ms` units are fixed-length intervals
+ *  - `s, m, h, d` units are fixed-length intervals when value > 1 (i.e. 2m, 24h, 7d),
  *    but calendar interval when value === 1
  *  - `w, M, q, y` units are calendar intervals and do not support multiple, aka
  *    value must === 1
@@ -51,7 +51,7 @@ export function leastCommonInterval(a: string, b: string): string {
   }
 
   // If intervals are calendar units, pick the larger one (calendar value is always 1)
-  if (aInt.type === 'calendar') {
+  if (aInt.type === 'calendar' || bInt.type === 'calendar') {
     return aUnit.weight > bUnit.weight ? `${aInt.value}${aInt.unit}` : `${bInt.value}${bInt.unit}`;
   }
 
@@ -68,8 +68,11 @@ export function leastCommonInterval(a: string, b: string): string {
     return a.replace(/\s/g, '');
   }
 
-  // Otherwise find the biggest unit that divides evenly
-  const lcmUnit = unitsDesc.find(unit => unitsMap[unit].base && lcmMs % unitsMap[unit].base === 0);
+  // Otherwise find the biggest non-calendar unit that divides evenly
+  const lcmUnit = unitsDesc.find(unit => {
+    const unitInfo = unitsMap[unit];
+    return !!(unitInfo.type !== 'calendar' && lcmMs % unitInfo.base === 0);
+  });
 
   // Throw error in case we couldn't divide evenly, theoretically we never get here as everything is
   // divisible by 1 millisecond