feat: Replace external types with stub types

Previously, Typescript users had to install the optional dependencies for the types to be available. These have now been replaced with stub types so that the optional dependencies no longer need to be installed.

close #405

README.md

@@ -131,18 +131,6 @@ npm run browser-test
 It's [here](https://github.com/sebbo2002/ical-generator/blob/develop/CHANGELOG.md). If you need the changelog for
 `ical-generator` 1.x.x and older, you'll find it [here](https://github.com/sebbo2002/ical-generator/blob/25338b8bf98f9afd3c88849e735fa33fa45fb766/CHANGELOG.md).
 
-### I use Typescript and get `TS2307: Cannot find module` errors
-`ical-generator` supports some third-party libraries such as moment.js or Day.js. To enable Typescript to do something
-with these types, they must of course also be installed. Unfortunately, npm does not install optional `peerDependencies`.
-Because these modules are not necessary for JavaScript users, I have marked these modules as optional. So if you use
-Typescript, you need the following modules to build the code that uses `ical-calendar`:
-
-```bash
-npm i -D @types/node rrule moment-timezone moment dayjs @types/luxon
-```
-
-For JavaScript users they are not necessary.
-
 ### I get a `ReferenceError: TextEncoder is not defined` error (in some browsers)
 This library uses [`TextEncoder`](https://developer.mozilla.org/en-US/docs/Web/API/TextEncoder), which
 is available in node.js ≥ 11.0.0 and [all modern browsers](https://caniuse.com/?search=textencoder).

src/calendar.ts

@@ -1,6 +1,5 @@
 'use strict';
 
-import type {Duration} from 'moment-timezone';
 import {
     addOrGetCustomAttributes,
     checkEnum,
@@ -10,10 +9,9 @@ import {
     toDurationString
 } from './tools';
 import ICalEvent, {ICalEventData, ICalEventJSONData} from './event';
-import {writeFile, writeFileSync} from 'fs';
-import {promises as fsPromises} from 'fs';
+import {writeFile, writeFileSync, promises as fsPromises} from 'fs';
 import {ServerResponse} from 'http';
-import {ICalTimezone} from './types';
+import { ICalMomentDurationStub, ICalTimezone } from './types';
 
 
 export interface ICalCalendarData {
@@ -25,7 +23,7 @@ export interface ICalCalendarData {
     source?: string | null;
     url?: string | null;
     scale?: string | null;
-    ttl?: number | Duration | null;
+    ttl?: number | ICalMomentDurationStub | null;
     events?: (ICalEvent | ICalEventData)[];
     x?: {key: string, value: string}[] | [string, string][] | Record<string, string>;
 }
@@ -472,8 +470,8 @@ export default class ICalCalendar {
      *
      * @since 0.2.5
      */
-    ttl(ttl: number | Duration | null): this;
-    ttl(ttl?: number | Duration | null): this | number | null {
+    ttl(ttl: number | ICalMomentDurationStub | null): this;
+    ttl(ttl?: number | ICalMomentDurationStub | null): this | number | null {
         if (ttl === undefined) {
             return this.data.ttl;
         }

src/event.ts

@@ -1,6 +1,5 @@
 'use strict';
 
-import type {RRule} from 'rrule';
 import uuid from 'uuid-random';
 import {
     addOrGetCustomAttributes,
@@ -10,7 +9,8 @@ import {
     escape,
     formatDate,
     formatDateTZ,
-    generateCustomAttributes, isRRule,
+    generateCustomAttributes,
+    isRRule,
     toDate,
     toJSON
 } from './tools';
@@ -25,6 +25,7 @@ import {
     ICalLocation,
     ICalOrganizer,
     ICalRepeatingOptions,
+    ICalRRuleStub,
     ICalWeekday
 } from './types';
 
@@ -63,7 +64,7 @@ export interface ICalEventData {
     stamp?: ICalDateTimeValue,
     allDay?: boolean,
     floating?: boolean,
-    repeating?: ICalRepeatingOptions | RRule | string | null,
+    repeating?: ICalRepeatingOptions | ICalRRuleStub | string | null,
     summary?: string,
     location?: ICalLocation | string | null,
     description?: ICalDescription | string | null,
@@ -93,7 +94,7 @@ interface ICalEventInternalData {
     stamp: ICalDateTimeValue,
     allDay: boolean,
     floating: boolean,
-    repeating: ICalEventInternalRepeatingData | RRule | string | null,
+    repeating: ICalEventInternalRepeatingData | ICalRRuleStub | string | null,
     summary: string,
     location: ICalLocation | null,
     description: ICalDescription | null,
@@ -555,7 +556,7 @@ export default class ICalEvent {
      * Get the event's repeating options
      * @since 0.2.0
      */
-    repeating(): ICalEventInternalRepeatingData | RRule | string | null;
+    repeating(): ICalEventInternalRepeatingData | ICalRRuleStub | string | null;
 
     /**
      * Set the event's repeating options by passing an [[`ICalRepeatingOptions`]] object.
@@ -584,7 +585,7 @@ export default class ICalEvent {
      * Set the event's repeating options by passing an [RRule object](https://github.com/jakubroztocil/rrule).
      * @since 2.0.0-develop.5
      */
-    repeating(repeating: RRule | null): this;
+    repeating(repeating: ICalRRuleStub | null): this;
 
     /**
      * Set the events repeating options by passing a string which is inserted in the ical file.
@@ -595,8 +596,8 @@ export default class ICalEvent {
     /**
      * @internal
      */
-    repeating(repeating: ICalRepeatingOptions | RRule | string | null): this;
-    repeating(repeating?: ICalRepeatingOptions | RRule | string | null): this | ICalEventInternalRepeatingData | RRule | string | null {
+    repeating(repeating: ICalRepeatingOptions | ICalRRuleStub | string | null): this;
+    repeating(repeating?: ICalRepeatingOptions | ICalRRuleStub | string | null): this | ICalEventInternalRepeatingData | ICalRRuleStub | string | null {
         if (repeating === undefined) {
             return this.data.repeating;
         }

src/index.ts

@@ -96,7 +96,13 @@ export {
     ICalDescription,
     ICalEventRepeatingFreq,
     ICalWeekday,
-    ICalTimezone
+    ICalTimezone,
+    ICalMomentStub,
+    ICalMomentTimezoneStub,
+    ICalMomentDurationStub,
+    ICalLuxonDateTimeStub,
+    ICalDayJsStub,
+    ICalRRuleStub
 } from './types';
 
 export {

src/tools.ts

@@ -1,13 +1,12 @@
 'use strict';
 
-
-import type {Moment, Duration} from 'moment';
-import type {Moment as MomentTZ} from 'moment-timezone';
-import type {Dayjs} from 'dayjs';
-import type {DateTime as LuxonDateTime} from 'luxon';
-import type { RRule } from 'rrule';
-
-import {ICalDateTimeValue, ICalOrganizer} from './types';
+import {
+    ICalDateTimeValue, ICalDayJsStub, ICalLuxonDateTimeStub,
+    ICalMomentDurationStub,
+    ICalMomentStub,
+    ICalMomentTimezoneStub,
+    ICalOrganizer, ICalRRuleStub
+} from './types';
 
 /**
  * Converts a valid date/time object supported by this library to a string.
@@ -315,32 +314,32 @@ export function toDate(value: ICalDateTimeValue): Date {
     return value.toDate();
 }
 
-export function isMoment(value: ICalDateTimeValue): value is Moment {
+export function isMoment(value: ICalDateTimeValue): value is ICalMomentStub {
 
     // @ts-ignore
     return value != null && value._isAMomentObject != null;
 }
-export function isMomentTZ(value: ICalDateTimeValue): value is MomentTZ {
-    return isMoment(value) && typeof value.tz === 'function';
+export function isMomentTZ(value: ICalDateTimeValue): value is ICalMomentTimezoneStub {
+    return isMoment(value) && 'tz' in value && typeof value.tz === 'function';
 }
-export function isDayjs(value: ICalDateTimeValue): value is Dayjs {
+export function isDayjs(value: ICalDateTimeValue): value is ICalDayJsStub {
     return typeof value === 'object' &&
         value !== null &&
         !(value instanceof Date) &&
         !isMoment(value) &&
         !isLuxonDate(value);
 }
-export function isLuxonDate(value: ICalDateTimeValue): value is LuxonDateTime {
-    return typeof value === 'object' && value !== null && typeof (value as LuxonDateTime).toJSDate === 'function';
+export function isLuxonDate(value: ICalDateTimeValue): value is ICalLuxonDateTimeStub {
+    return typeof value === 'object' && value !== null && 'toJSDate' in value && typeof value.toJSDate === 'function';
 }
 
-export function isMomentDuration(value: unknown): value is Duration {
+export function isMomentDuration(value: unknown): value is ICalMomentDurationStub {
 
     // @ts-ignore
     return value !== null && typeof value === 'object' && typeof value.asSeconds === 'function';
 }
 
-export function isRRule(value: unknown): value is RRule {
+export function isRRule(value: unknown): value is ICalRRuleStub {
 
     // @ts-ignore
     return value !== null && typeof value === 'object' && typeof value.between === 'function' && typeof value.toString === 'function';

src/types.ts

@@ -1,16 +1,10 @@
-import type {Moment} from 'moment';
-import type {Moment as MomentTZ} from 'moment-timezone';
-import type {Dayjs} from 'dayjs';
-import type {DateTime as LuxonDateTime} from 'luxon';
-
-
 /**
  * ical-generator supports [native Date](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date),
  * [moment.js](https://momentjs.com/) (and [moment-timezone](https://momentjs.com/timezone/), [Day.js](https://day.js.org/en/) and
  * [Luxon](https://moment.github.io/luxon/)'s [DateTime](https://moment.github.io/luxon/docs/class/src/datetime.js~DateTime.html)
  * objects. You can also pass a string which is then passed to javascript's Date internally.
  */
-export type ICalDateTimeValue = Date | Moment | MomentTZ | Dayjs | LuxonDateTime | string;
+export type ICalDateTimeValue = Date | ICalMomentStub | ICalMomentTimezoneStub | ICalLuxonDateTimeStub | ICalDayJsStub | string;
 
 export interface ICalRepeatingOptions {
     freq: ICalEventRepeatingFreq;
@@ -54,6 +48,49 @@ export interface ICalTimezone {
     generator?: (timezone: string) => string|null;
 }
 
+export interface ICalMomentStub {
+    _isAMomentObject: true;
+    format(format?: string): string;
+    clone(): ICalMomentStub;
+    utc(): ICalMomentStub;
+    toDate(): Date;
+    isValid(): boolean;
+    toJSON(): string;
+}
+
+export interface ICalMomentTimezoneStub extends ICalMomentStub {
+    clone(): ICalMomentTimezoneStub;
+    utc(): ICalMomentTimezoneStub;
+    tz(): string | undefined;
+    tz(timezone: string): ICalMomentTimezoneStub;
+}
+
+export interface ICalMomentDurationStub {
+    asSeconds(): number;
+}
+
+export interface ICalLuxonDateTimeStub {
+    setZone(zone?: string): ICalLuxonDateTimeStub;
+    toFormat(fmt: string): string;
+    toJSDate(): Date;
+    get isValid(): boolean;
+    toJSON(): string;
+}
+
+export interface ICalDayJsStub {
+    tz(zone?: string): ICalDayJsStub;
+    utc(): ICalDayJsStub;
+    format(format?: string): string;
+    toDate(): Date;
+    isValid(): boolean;
+    toJSON(): string;
+}
+
+export interface ICalRRuleStub {
+    between(after: Date, before: Date, inc?: boolean, iterator?: (d: Date, len: number) => boolean): Date[];
+    toString(): string;
+}
+
 export enum ICalEventRepeatingFreq {
     SECONDLY = 'SECONDLY',
     MINUTELY = 'MINUTELY',