add types for CustomParseFormat plugin, and allow creating types fo…

…r static plugins

src/index.d.ts

@@ -14,7 +14,15 @@ declare namespace dayjs {
   type OpUnitTypeShort = 'w'
   type OpUnitType = UnitType | "week" | OpUnitTypeShort;
 
-  type PluginFunc<TPlugin> = (option: ConfigType, d1: Dayjs, d2: Dayjs) => void
+  type PluginFunc<TPlugin> = (option: ConfigType, dayjsClass: InstanceType<Dayjs>, dayjsFactory: dayjs) => void;
+
+  /**
+   * Branding for static plugins, to enable better type inference.
+   * `extend` from this to make the plugin static
+   */
+  interface StaticPlugin {
+    __staticPlugin: never;
+  }
 }
 
 interface dayjs<TPlugin = {}> {
@@ -25,7 +33,7 @@ interface dayjs<TPlugin = {}> {
   extend<UPlugin extends object>(
     plugin: dayjs.PluginFunc<UPlugin>,
     option?: dayjs.ConfigType
-  ): dayjs<TPlugin & UPlugin>;
+  ): UPlugin extends dayjs.StaticPlugin ? (dayjs<TPlugin> & UPlugin) : dayjs<TPlugin & UPlugin>;
   locale(arg1: any, arg2?: any): string;
   isDayjs(d: any): d is Dayjs;
   unix(t: number): Dayjs;
@@ -76,7 +84,7 @@ declare class Dayjs {
 
   format(template?: string): string;
 
-    diff(dayjs: ConfigType, unit: OpUnitType, float?: boolean): number
+  diff(dayjs: ConfigType, unit: OpUnitType, float?: boolean): number
 
   valueOf(): number;
 
@@ -96,11 +104,11 @@ declare class Dayjs {
 
   toString(): string;
 
-    isBefore(dayjs: ConfigType, unit?: OpUnitType): boolean
+  isBefore(dayjs: ConfigType, unit?: OpUnitType): boolean
 
-    isSame(dayjs: ConfigType, unit?: OpUnitType): boolean
+  isSame(dayjs: ConfigType, unit?: OpUnitType): boolean
 
-    isAfter(dayjs: ConfigType, unit?: OpUnitType): boolean
+  isAfter(dayjs: ConfigType, unit?: OpUnitType): boolean
 
   locale(arg1: any, arg2?: any): Dayjs;
 }

src/plugin/customParseFormat/index.d.ts

@@ -0,0 +1,8 @@
+import { ConfigType, PluginFunc, StaticPlugin } from '../../index'
+
+interface CustomParseFormatPlugin extends StaticPlugin {
+  (input: string, format: string): this;
+}
+
+declare const pluginFn: PluginFunc<CustomParseFormatPlugin>;
+export default pluginFn

test/index.d.test.ts → test/index.test.d.ts

@@ -4,6 +4,7 @@ import advancedFormat from '../src/plugin/advancedFormat'
 import buddhistEra from '../src/plugin/buddhistEra'
 import isLeapYear from '../src/plugin/isLeapYear'
 import isBetween from '../src/plugin/isBetween'
+import customParseFormat from '../src/plugin/customParseFormat'
 
 dayjs()
 
@@ -90,3 +91,6 @@ dayjs.extend(isBetween)('2010-10-20').isBetween('2010-10-19', dayjs('2010-10-25'
 const multiplePluginsDayjs = dayjs.extend(relativeTime).extend(isLeapYear)()
 multiplePluginsDayjs.toNow()
 multiplePluginsDayjs.isLeapYear()
+
+const dayjsWithCustomParseFormat = dayjs.extend(customParseFormat);
+dayjsWithCustomParseFormat('05/02/69 1:02:03 PM -05:00', 'MM/DD/YY H:mm:ss A Z');