feat: improved typings

Author: Romanchuk

src/I18NextCapPipe.ts

@@ -3,6 +3,7 @@ import { Inject, Injectable, Pipe, PipeTransform } from '@angular/core';
 import { I18NEXT_NAMESPACE, I18NEXT_SCOPE, I18NEXT_SERVICE } from './I18NEXT_TOKENS';
 import { I18NextPipe } from './I18NextPipe';
 import { ITranslationService } from './ITranslationService';
+import { PipeOptions } from './models';
 
 @Injectable()
 @Pipe({
@@ -17,7 +18,7 @@ export class I18NextCapPipe extends I18NextPipe implements PipeTransform {
     super(translateI18Next, ns, scope);
   }
 
-  public transform(key: string | string[], options?: any): string {
+  public transform(key: string | string[], options?: PipeOptions): string {
     options = options || {};
     options.format = 'cap';
     return super.transform(key, options);

src/I18NextEagerPipe.ts

@@ -4,6 +4,7 @@ import { Subject } from 'rxjs';
 import { takeUntil } from 'rxjs/operators';
 import { I18NEXT_NAMESPACE, I18NEXT_SCOPE, I18NEXT_SERVICE } from './I18NEXT_TOKENS';
 import { ITranslationService } from './ITranslationService';
+import { PipeOptions } from './models';
 
 @Pipe({
   name: 'i18nextEager',
@@ -32,7 +33,7 @@ constructor(
       });
   }
 
-  public transform(key: string | string[], options?: any): string {
+  public transform(key: string | string[], options?: PipeOptions): string {
     const newKey = this.translateI18Next.language + '|' + JSON.stringify(key);
     if (!this.lastKey || this.lastKey !== newKey) {
       this.lastKey = newKey;

src/I18NextFormatPipe.ts

@@ -2,6 +2,7 @@ import { Inject, Injectable, Pipe, PipeTransform } from '@angular/core';
 
 import { I18NEXT_SERVICE } from './I18NEXT_TOKENS';
 import { ITranslationService } from './ITranslationService';
+import { FormatPipeOptions } from './models';
 
 @Injectable()
 @Pipe({
@@ -13,8 +14,8 @@ export class I18NextFormatPipe implements PipeTransform {
       @Inject(I18NEXT_SERVICE) private translateI18Next: ITranslationService
   ) {}
 
-  public transform(value: any, options: Object | string): string {
-    let opts: any = typeof(options) === 'string' ? { format: options } : options;
+  public transform(value: any, options: FormatPipeOptions | string): string {
+    let opts: FormatPipeOptions = typeof(options) === 'string' ? { format: options } : options;
     return this.translateI18Next.format(value, opts.format, opts.lng);
   }
 }

src/I18NextPipe.ts

@@ -1,7 +1,9 @@
 import { Inject, Injectable, Pipe, PipeTransform } from '@angular/core';
+import * as i18n from 'i18next';
 
 import { I18NEXT_NAMESPACE, I18NEXT_SCOPE, I18NEXT_SERVICE } from './I18NEXT_TOKENS';
 import { ITranslationService } from './ITranslationService';
+import { PipeOptions } from './models';
 @Injectable()
 @Pipe({
     name: 'i18next'
@@ -13,10 +15,10 @@ export class I18NextPipe implements PipeTransform {
       @Inject(I18NEXT_NAMESPACE) protected ns: string | string[],
       @Inject(I18NEXT_SCOPE) protected scope: string | string[]) {}
 
-  public transform(key: string | string[], options?: any): string {
+  public transform(key: string | string[], options?: PipeOptions): string {
     options = this.prepareOptions(options);
 
-    let i18nOpts = this.translateI18Next.options;
+    let i18nOpts: i18n.TOptions = this.translateI18Next.options;
     if (options.prependScope === undefined || options.prependScope === true) {
       if (this.scope) {
         key = this.prependScope(key, this.scope, i18nOpts.keySeparator, i18nOpts.nsSeparator);
@@ -28,12 +30,8 @@ export class I18NextPipe implements PipeTransform {
       }
     }
 
-    let result: string;
-    if (options.defaultValue) {
-      result = this.translateI18Next.t(key, options.defaultValue, options);
-    } else {
-      result = this.translateI18Next.t(key, options);
-    }
+    let result: string = this.translateI18Next.t(key, options);
+
     if (options.format) {
       if (result) {
         result = this.translateI18Next
@@ -87,7 +85,7 @@ export class I18NextPipe implements PipeTransform {
     return key.indexOf(nsSeparator) !== -1;
   }
 
-  private prepareOptions(options: any) {
+  private prepareOptions(options: PipeOptions) {
     options = options || {};
     if (options.context != null)
       options.context = options.context.toString();

src/I18NextService.ts

@@ -24,12 +24,12 @@ export class I18NextService implements ITranslationService {
 
   constructor(@Inject(I18NEXT_ERROR_HANDLING_STRATEGY) private errorHandlingStrategy: I18NextErrorHandlingStrategy) {}
 
-  public use(plugin: any) {
-    i18next.use.call(i18next, plugin);
+  public use<T extends i18n.Module>(module: T | i18n.Newable<T> | i18n.ThirdPartyModule[] | i18n.Newable<i18n.ThirdPartyModule>[]) {
+    i18next.use.call(i18next, module);
     return this;
   }
 
-  public init(options?: any): Promise<any> {
+  public init(options?: i18n.InitOptions): Promise<any> {
     options = options || {};
 
     this.subscribeEvents();
@@ -45,13 +45,16 @@ export class I18NextService implements ITranslationService {
 
   }
 
-  public t(key: string | string[], options?: any): string;
-  public t(key: string | string[], defaultValue?: any, options?: any): string {
-    options = options || {};
-    return i18next.t.call(i18next, <any>key, defaultValue, options);
+  t(key: string | string[], optionsOrDefault?: string | i18n.TOptions, options?: i18n.TOptions): string {
+    const hasDefault = optionsOrDefault && typeof(optionsOrDefault) === 'string';
+    if (hasDefault) {
+      return i18next.t.call(i18next, <any>key, optionsOrDefault, options);
+    } else {
+      return i18next.t.call(i18next, <any>key, options);
+    }
   }
 
-  public format(value: any, format: string, lng: string): string {
+  public format(value: any, format?: string, lng?: string): string {
     return i18next.format.call(i18next, value, format, lng);
   }
 

src/ITranslationService.ts

@@ -1,3 +1,4 @@
+import * as i18n from 'i18next';
 import { ITranslationEvents } from './ITranslationEvents';
 
 export interface ITranslationService {
@@ -8,14 +9,13 @@ export interface ITranslationService {
 
   options: any;
 
-  use(plugin: any);
+  use<T extends i18n.Module>(module: T | i18n.Newable<T> | i18n.ThirdPartyModule[] | i18n.Newable<i18n.ThirdPartyModule>[]);
 
-  init(options?: any): Promise<any>;
+  init(options?: i18n.InitOptions): Promise<any>;
 
-  t(key: string | string[], options?: any): string;
-  t(key: string | string[], defaultValue?: any, options?: any): string;
+  t(key: string | string[], optionsOrDefault?: string | i18n.TOptions, options?: i18n.TOptions): string;
 
-  format(value: any, format: string, lng: string): string;
+  format: i18n.FormatFunction;
 
   exists(key, options);
 

src/models.ts

@@ -0,0 +1,5 @@
+import * as i18n from 'i18next';
+
+export type FormatPipeOptions = { format?: string, lng?: string };
+export type PrependPipeOptions = { prependScope?: boolean, prependNamespace?: boolean };
+export type PipeOptions = i18n.TOptions & FormatPipeOptions & PrependPipeOptions;