allow passing WeekdayStr to byweekday like the types suggest is possible

src/helpers.ts

@@ -2,6 +2,8 @@
 // Helper functions
 // =============================================================================
 
+import { ALL_WEEKDAYS, WeekdayStr } from './weekday'
+
 export const isPresent = function<T>(value?: T | null | undefined): value is T {
   return value !== null && value !== undefined
 }
@@ -10,6 +12,10 @@ export const isNumber = function (value?: any): value is number {
   return typeof value === 'number'
 }
 
+export const isWeekdayStr = function (value?: any): value is WeekdayStr {
+  return ALL_WEEKDAYS.indexOf(value) >= 0
+}
+
 export const isArray = Array.isArray
 
 /**

src/parseoptions.ts

@@ -1,8 +1,8 @@
 import { Options, ParsedOptions, freqIsDailyOrGreater } from './types'
-import { includes, notEmpty, isPresent, isNumber, isArray } from './helpers'
+import { includes, notEmpty, isPresent, isNumber, isArray, isWeekdayStr } from './helpers'
 import RRule, { defaultKeys, DEFAULT_OPTIONS } from './rrule'
 import dateutil from './dateutil'
-import { Weekday } from './weekday'
+import { ALL_WEEKDAYS, Weekday } from './weekday'
 import { Time } from './datetime'
 
 export function initializeOptions (options: Partial<Options>) {
@@ -139,6 +139,9 @@ export function parseOptions (options: Partial<Options>) {
   } else if (isNumber(opts.byweekday)) {
     opts.byweekday = [opts.byweekday]
     opts.bynweekday = null
+  } else if (isWeekdayStr(opts.byweekday)) {
+    opts.byweekday = [Weekday.fromStr(opts.byweekday).weekday]
+    opts.bynweekday = null
   } else if (opts.byweekday instanceof Weekday) {
     if (!opts.byweekday.n || opts.freq > RRule.MONTHLY) {
       opts.byweekday = [opts.byweekday.weekday]
@@ -148,7 +151,7 @@ export function parseOptions (options: Partial<Options>) {
       opts.byweekday = null
     }
   } else {
-    const byweekday = []
+    const byweekday: number[] = []
     const bynweekday = []
 
     for (let i = 0; i < opts.byweekday.length; i++) {
@@ -157,13 +160,15 @@ export function parseOptions (options: Partial<Options>) {
       if (isNumber(wday)) {
         byweekday.push(wday)
         continue
+      } else if (isWeekdayStr(wday)) {
+        byweekday.push(Weekday.fromStr(wday).weekday)
+        continue
       }
 
-      const wd = wday as Weekday
-      if (!wd.n || opts.freq > RRule.MONTHLY) {
-        byweekday.push(wd.weekday)
+      if (!wday.n || opts.freq > RRule.MONTHLY) {
+        byweekday.push(wday.weekday)
       } else {
-        bynweekday.push([wd.weekday, wd.n])
+        bynweekday.push([wday.weekday, wday.n])
       }
     }
     opts.byweekday = notEmpty(byweekday) ? byweekday : null

src/weekday.ts

@@ -3,7 +3,7 @@
 // =============================================================================
 
 export type WeekdayStr = 'MO' | 'TU' | 'WE' | 'TH' | 'FR' | 'SA' | 'SU'
-const WDAYS: WeekdayStr[] = ['MO', 'TU', 'WE', 'TH', 'FR', 'SA', 'SU']
+export const ALL_WEEKDAYS: WeekdayStr[] = ['MO', 'TU', 'WE', 'TH', 'FR', 'SA', 'SU']
 
 export class Weekday {
   public readonly weekday: number
@@ -15,6 +15,10 @@ export class Weekday {
     this.n = n
   }
 
+  static fromStr (str: WeekdayStr): Weekday {
+    return new Weekday(ALL_WEEKDAYS.indexOf(str))
+  }
+
   // __call__ - Cannot call the object directly, do it through
   // e.g. RRule.TH.nth(-1) instead,
   nth (n: number) {
@@ -28,7 +32,7 @@ export class Weekday {
 
   // __repr__
   toString () {
-    let s: string = WDAYS[this.weekday]
+    let s: string = ALL_WEEKDAYS[this.weekday]
     if (this.n) s = (this.n > 0 ? '+' : '') + String(this.n) + s
     return s
   }

test/parseoptions.test.ts

@@ -1,5 +1,6 @@
 import { parseOptions } from '../src/parseoptions'
 import { expect } from 'chai'
+import RRule from '../src'
 
 describe('TZID', () => {
   it('leaves null when null', () => {
@@ -13,3 +14,35 @@ describe('TZID', () => {
     expect(options.parsedOptions.tzid).to.equal('America/Los_Angeles')
   })
 })
+
+describe('byweekday', () => {
+  it('works with a single numeric day', () => {
+    const options = parseOptions({ byweekday: 1 })
+    expect(options.parsedOptions.byweekday).to.eql([1])
+  })
+
+  it('works with a single Weekday day', () => {
+    const options = parseOptions({ byweekday: RRule.TU })
+    expect(options.parsedOptions.byweekday).to.eql([1])
+  })
+
+  it('works with a single string day', () => {
+    const options = parseOptions({ byweekday: 'TU' })
+    expect(options.parsedOptions.byweekday).to.eql([1])
+  })
+
+  it('works with a multiple numeric days', () => {
+    const options = parseOptions({ byweekday: [1, 2] })
+    expect(options.parsedOptions.byweekday).to.eql([1, 2])
+  })
+
+  it('works with a multiple Weekday days', () => {
+    const options = parseOptions({ byweekday: [RRule.TU, RRule.WE] })
+    expect(options.parsedOptions.byweekday).to.eql([1, 2])
+  })
+
+  it('works with a multiple string days', () => {
+    const options = parseOptions({ byweekday: ['TU', 'WE'] })
+    expect(options.parsedOptions.byweekday).to.eql([1, 2])
+  })
+})