[RAM] Remove third party RRule library, replace with own timezone-com…

…pliant lib (#152873)

## Summary

Closes #152630

~Adds a fix for the weird UTC-but-not-really expected inputs in
rrule.js~

This PR removes the third-party `rrule` package and replaces it with
`@kbn/rrule`.

The third party RRule library's functions produced different results
depending on what system timezone you ran it in. It would output local
timestamps in UTC, making it impossible to do reliable math on them.
It's now replaced with our own library that passes all of our own tests
for the limited cross-section of the RRule spec that we need to support.
It's possible that it wouldn't stand up to the rigor of more complex
RRule queries, but it supports the ones that our Recurrence Scheduler UI
supports just fine.

### Checklist

- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

.github/CODEOWNERS

@@ -552,6 +552,7 @@ examples/response_stream @elastic/ml-ui
 packages/kbn-rison @elastic/kibana-operations
 x-pack/plugins/rollup @elastic/platform-deployment-management
 examples/routing_example @elastic/kibana-core
+packages/kbn-rrule @elastic/response-ops
 packages/kbn-rule-data-utils @elastic/security-detections-response @elastic/actionable-observability @elastic/response-ops
 x-pack/plugins/rule_registry @elastic/response-ops @elastic/actionable-observability
 x-pack/plugins/runtime_fields @elastic/platform-deployment-management

package.json

@@ -555,6 +555,7 @@
     "@kbn/rison": "link:packages/kbn-rison",
     "@kbn/rollup-plugin": "link:x-pack/plugins/rollup",
     "@kbn/routing-example-plugin": "link:examples/routing_example",
+    "@kbn/rrule": "link:packages/kbn-rrule",
     "@kbn/rule-data-utils": "link:packages/kbn-rule-data-utils",
     "@kbn/rule-registry-plugin": "link:x-pack/plugins/rule_registry",
     "@kbn/runtime-fields-plugin": "link:x-pack/plugins/runtime_fields",
@@ -965,7 +966,6 @@
     "require-in-the-middle": "^6.0.0",
     "reselect": "^4.1.6",
     "rison-node": "1.0.2",
-    "rrule": "2.6.4",
     "rxjs": "^7.5.5",
     "safe-squel": "^5.12.5",
     "seedrandom": "^3.0.5",

packages/kbn-rrule/README.md

@@ -0,0 +1,70 @@
+# @kbn/rrule
+
+A rewrite of [rrule.js](https://github.com/jakubroztocil/rrule) using `moment-timezone` for timezone support. Ensures that we always get the same outputs no matter what local timezone the executing system is set to.
+
+Differences from library on Github:
+
+- It is **recommended** to generate input Dates from UTC timestamps, but not required. This implementation will perform calculations on inputted Dates accurate to their corresponding Unix timestamps.
+- Timezones IDs are required. They're very important for dealing with things like day-of-week changes or DST.
+- `inc` argument from `between`, `before`, `after` is removed, and is computed as if it were `true`
+- SECONDLY frequency is not implemented.
+- This implementation may not accurately support the entire [iCalendar RRULE RFC](https://www.rfc-editor.org/rfc/rfc5545). It is known to work for common scenarios configurable in the Recurrence Scheduler UI, plus some other more complicated ones. See `rrule.test.ts` for known working configurations.
+
+Known not to work are mostly edge cases:
+
+- Manually configuring `setpos` with any frequency besides `MONTHLY`
+- `wkst` doesn't seem to have an effect on anything (I was also unable to get it to affect anything in the original library though)
+- Setting `byyearday` on anything besides `Frequency.YEARLY`, setting `bymonthday` on anything besides `MONTHLY`, and other similar odd situations
+
+## Constructor
+
+Create an RRule with the following options:
+
+```ts
+new RRule({
+  dtstart: Date; // Recommended to generate this from a UTC timestamp, but this impl
+  tzid: string; // Takes a Moment.js timezone string. Recommended to use a country and city for DST accuracy, e.g. America/Phoenix and America/Denver are both in Mountain time but Phoenix doesn't observe DST
+  freq?: Frequency; // Defaults to YEARLY
+  interval?: number; // Every x freq, e.g. 1 and YEARLY is every 1 year, 2 and WEEKLY is every 2 weeks
+  until?: Date; // Recur until this date
+  count?: number; // Number of times this rule should recur until it stops
+  wkst?: Weekday | number; // Start of week, defaults to Monday
+  // The following, if not provided, will be automatically derived from the dtstart
+  byweekday?: Weekday[] | string[]; // Day(s) of the week to recur, OR nth-day-of-month strings, e.g. "+2TU" second Tuesday of month, "-1FR" last Friday of the month, which will get internally converted to a byweekday/bysetpos combination
+  bysetpos?: number[]; // Positive or negative integer affecting nth day of the month, eg -2 combined with byweekday of FR is 2nd to last Friday of the month. Best not to set this manually and just use byweekday.
+  byyearday?: number[]; // Day(s) of the year that this rule should recur, e.g. 32 is Feb 1. Respects leap years.
+  bymonth?: number[]; // Month(s) of the year that this rule should recur
+  bymonthday?: number[]; // Day(s) of the momth to recur
+  byhour?: number[]; // Hour(s) of the day to recur
+  byminute?: number[]; // Minute(s) of the hour to recur
+  bysecond?: number[]; // Seconds(s) of the day to recur
+});
+```
+
+## Methods
+
+### `RRule.prototype.all(limit?: number)`
+
+returns `Date[] & { hasMore?: boolean}`
+
+Returns an array all dates matching the rule. By default, limited to 10000 iterations. Pass something to `limit` to change this.
+
+If it hits the limit, the array will come back with the property `hasMore: true`.
+
+### `RRule.prototype.before(dt: Date)`
+
+returns `Date | null`
+
+Returns the last recurrence before `dt`, or `null` if there is none.
+
+### RRule.prototype.after(dt: Date)`
+
+returns `Date | null`
+
+Returns the last recurrence after `dt`, or `null` if there is none.
+
+### RRule.prototype.between(start: Date, end: Date)`
+
+returns `Date[]`
+
+Returns an array of all dates between `start` and `end`.

packages/kbn-rrule/index.ts

@@ -0,0 +1,11 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+export { RRule, Frequency, Weekday } from './rrule';
+export type { Options } from './rrule';
+export declare type WeekdayStr = 'MO' | 'TU' | 'WE' | 'TH' | 'FR' | 'SA' | 'SU';

packages/kbn-rrule/jest.config.js

@@ -0,0 +1,13 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+module.exports = {
+  preset: '@kbn/test',
+  rootDir: '../..',
+  roots: ['<rootDir>/packages/kbn-rrule'],
+};

packages/kbn-rrule/kibana.jsonc

@@ -0,0 +1,5 @@
+{
+  "type": "shared-common",
+  "id": "@kbn/rrule",
+  "owner": "@elastic/response-ops"
+}

packages/kbn-rrule/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "@kbn/rrule",
+  "private": true,
+  "version": "1.0.0",
+  "license": "SSPL-1.0 OR Elastic License 2.0"
+}