feat: add unit pipe (#11)

Author: json-derulo

Diff for: README.md

@@ -170,17 +170,38 @@ their [docs](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/G
 
 With the `INTL_COUNTRY_PIPE_DEFAULT_OPTIONS` injection token you can specify default options.
 
+### Unit pipe
+
+Use the unit pipe like the following:
+
+```
+{{1.2 | intlUnit: 'hour': options}}
+```
+
+The input can be one of the following:
+
+* number
+* string (must be parseable as number)
+* null
+* undefined
+
+The unit parameter is required, see
+the [specification](https://tc39.es/proposal-unified-intl-numberformat/section6/locales-currencies-tz_proposed_out.html#sec-issanctionedsimpleunitidentifier)
+for a full list of possible values. If you want to transform a decimal number instead, use the `intlDecimal` pipe.
+
+The options are the same as the options for `new Intl.NumberFormat()`. For a list of the options, see
+their [docs](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat).
+
+With the `INTL_UNIT_PIPE_DEFAULT_OPTIONS` injection token you can specify default options.
+
 ## Background
 
 For more context, see the following [GitHub issue](https://github.com/angular/angular/issues/49143)
 
 ## Feature Roadmap
 
 * Performance: Prepare Intl.* object with default options, only construct new object when necessary
-* Relative time
+* Limit options to only what is allowed by Intl API
+* List pipe
+* Relative time pipe
 * Migration Schematics for usages of Angular pipes
-
-## Chore Roadmap
-
-* Automatic npm publishing
-* Automatic changelog generation

Diff for: projects/angular-ecmascript-intl/src/lib/intl.module.ts

@@ -5,6 +5,7 @@ import {IntlDecimalPipe} from "./decimal/intl-decimal.pipe";
 import {IntlPercentPipe} from "./percent/intl-percent.pipe";
 import {IntlCurrencyPipe} from "./currency/intl-currency.pipe";
 import {IntlCountryPipe} from "./country/intl-country.pipe";
+import {IntlUnitPipe} from "./unit/intl-unit.pipe";
 
 @NgModule({
   imports: [
@@ -14,6 +15,7 @@ import {IntlCountryPipe} from "./country/intl-country.pipe";
     IntlPercentPipe,
     IntlCurrencyPipe,
     IntlCountryPipe,
+    IntlUnitPipe,
   ],
   exports: [
     IntlDatePipe,
@@ -22,6 +24,7 @@ import {IntlCountryPipe} from "./country/intl-country.pipe";
     IntlPercentPipe,
     IntlCurrencyPipe,
     IntlCountryPipe,
+    IntlUnitPipe,
   ],
 })
 export class IntlModule {

Diff for: projects/angular-ecmascript-intl/src/lib/unit/intl-unit-pipe-default-options.ts

@@ -0,0 +1,3 @@
+import {InjectionToken} from "@angular/core";
+
+export const INTL_UNIT_PIPE_DEFAULT_OPTIONS = new InjectionToken<Partial<Intl.NumberFormatOptions>>('IntlUnitPipeDefaultOptions');

Diff for: projects/angular-ecmascript-intl/src/lib/unit/intl-unit.pipe.spec.ts

@@ -0,0 +1,158 @@
+import {IntlUnitPipe} from './intl-unit.pipe';
+import {TestBed} from "@angular/core/testing";
+import {INTL_LOCALES} from "../locale";
+import {INTL_UNIT_PIPE_DEFAULT_OPTIONS} from "./intl-unit-pipe-default-options";
+
+describe('IntlUnitPipe', () => {
+  let testUnit: IntlUnitPipe;
+
+  describe('parsing', () => {
+    beforeEach(() => {
+      testUnit = new IntlUnitPipe('en-US');
+    });
+
+    it('should create an instance', () => {
+      expect(testUnit).toBeTruthy();
+    });
+
+    it('should handle null values', () => {
+      expect(testUnit.transform(null, undefined)).toBeNull();
+    });
+
+    it('should handle undefined values', () => {
+      expect(testUnit.transform(undefined, undefined)).toBeNull();
+    });
+
+    it('should handle empty strings', () => {
+      expect(testUnit.transform('', undefined)).toBeNull();
+    });
+
+    it('should transform numbers', () => {
+      expect(testUnit.transform(1, 'hour')).toEqual('1 hr');
+    });
+
+    it('should transform strings', () => {
+      expect(testUnit.transform('2', 'hour')).toEqual('2 hr');
+    });
+
+    it('should handle invalid strings', () => {
+      expect(() => testUnit.transform('invalid number', undefined)).toThrow();
+    });
+
+    it('should handle missing Intl.NumberFormat browser API', () => {
+      // @ts-expect-error Intl APIs are not expected to be undefined
+      spyOn(Intl, 'NumberFormat').and.returnValue(undefined);
+      const consoleError = spyOn(console, 'error');
+      expect(testUnit.transform('1', 'hour')).toBeNull();
+
+      expect(consoleError).toHaveBeenCalledTimes(1);
+    });
+  });
+
+  describe('internationalization', () => {
+    it('should respect the set locale', () => {
+      TestBed.configureTestingModule({
+        providers: [
+          IntlUnitPipe,
+          {
+            provide: INTL_LOCALES,
+            useValue: 'de-DE',
+          },
+        ],
+      });
+      testUnit = TestBed.inject(IntlUnitPipe);
+
+      expect(testUnit.transform(1, 'hour')).toEqual('1 Std.');
+    });
+
+    it('should fall back to the browser default locale', () => {
+      TestBed.configureTestingModule({providers: [IntlUnitPipe]});
+
+      const result1 = TestBed.inject(IntlUnitPipe).transform(1, 'hour');
+      const result2 = new IntlUnitPipe(navigator.language).transform(1, 'hour');
+
+      expect(result1).toEqual(result2);
+    });
+  });
+
+  describe('options', () => {
+    it('should respect the setting from default config', () => {
+      TestBed.configureTestingModule({
+        providers: [
+          IntlUnitPipe,
+          {
+            provide: INTL_LOCALES,
+            useValue: 'en-US',
+          },
+          {
+            provide: INTL_UNIT_PIPE_DEFAULT_OPTIONS,
+            useValue: {
+              unitDisplay: 'narrow',
+            },
+          },
+        ],
+      });
+      testUnit = TestBed.inject(IntlUnitPipe);
+
+      expect(testUnit.transform(1, 'liter')).toEqual('1L');
+
+    });
+
+    it('should give the user options a higher priority', () => {
+      TestBed.configureTestingModule({
+        providers: [
+          IntlUnitPipe,
+          {
+            provide: INTL_LOCALES,
+            useValue: 'en-US',
+          },
+          {
+            provide: INTL_UNIT_PIPE_DEFAULT_OPTIONS,
+            useValue: {
+              unitDisplay: 'short',
+            },
+          },
+        ],
+      });
+      testUnit = TestBed.inject(IntlUnitPipe);
+
+      expect(testUnit.transform(1, 'liter', {unitDisplay: 'narrow'})).toEqual('1L');
+    });
+  });
+
+  it('should respect locale option', () => {
+    TestBed.configureTestingModule({
+      providers: [
+        IntlUnitPipe,
+        {
+          provide: INTL_LOCALES,
+          useValue: 'en-US',
+        },
+      ],
+    });
+    testUnit = TestBed.inject(IntlUnitPipe);
+
+    expect(testUnit.transform(1, 'hour', {locale: 'de-DE'})).toEqual('1 Std.');
+  });
+
+  it('should not override the style option', () => {
+    TestBed.configureTestingModule({
+      providers: [
+        IntlUnitPipe,
+        {
+          provide: INTL_LOCALES,
+          useValue: 'en-US',
+        },
+        {
+          provide: INTL_UNIT_PIPE_DEFAULT_OPTIONS,
+          useValue: {
+            style: 'decimal',
+          },
+        },
+      ],
+    });
+    testUnit = TestBed.inject(IntlUnitPipe);
+
+    expect(testUnit.transform(1, 'hour', {style: 'decimal'})).toEqual('1 hr');
+  });
+});

Diff for: projects/angular-ecmascript-intl/src/lib/unit/intl-unit.pipe.ts

@@ -0,0 +1,39 @@
+import {Inject, Optional, Pipe, PipeTransform} from '@angular/core';
+import {IntlPipeOptions} from "../intl-pipe-options";
+import {INTL_LOCALES} from "../locale";
+import {getNumericValue} from "../utils/number-utils";
+import {INTL_UNIT_PIPE_DEFAULT_OPTIONS} from "./intl-unit-pipe-default-options";
+
+export type IntlUnitPipeOptions = Partial<Intl.NumberFormatOptions> & IntlPipeOptions;
+
+@Pipe({
+  name: 'intlUnit',
+  standalone: true,
+})
+export class IntlUnitPipe implements PipeTransform {
+
+  constructor(@Optional() @Inject(INTL_LOCALES) readonly locale?: string | string[] | null,
+              @Optional() @Inject(INTL_UNIT_PIPE_DEFAULT_OPTIONS) readonly defaultOptions?: Partial<Intl.NumberFormatOptions> | null) {
+  }
+
+  transform(value: number | string | null | undefined, unit: string | undefined, options?: IntlUnitPipeOptions): string | null {
+    if (typeof value !== 'number' && !value) {
+      return null;
+    }
+
+    const numericValue = getNumericValue(value);
+
+    const {locale, ...intlOptions} = options ?? {};
+
+    try {
+      return new Intl.NumberFormat(
+        locale ?? this.locale ?? undefined,
+        {...this.defaultOptions, ...intlOptions, unit, style: 'unit'},
+      ).format(numericValue);
+    } catch (e) {
+      console.error('Error while transforming the percent value', e);
+      return null;
+    }
+  }
+
+}

Diff for: projects/angular-ecmascript-intl/src/public-api.ts

@@ -16,3 +16,5 @@ export * from './lib/language/intl-language-pipe-default-options';
 export * from './lib/locale';
 export * from './lib/percent/intl-percent.pipe';
 export * from './lib/percent/intl-percent-pipe-default-options';
+export * from './lib/unit/intl-unit.pipe';
+export * from './lib/unit/intl-unit-pipe-default-options';

Diff for: projects/angular-intl-demo/src/app/pipes/pipes-routing.module.ts

@@ -7,6 +7,7 @@ import {PercentComponent} from "./percent/percent.component";
 import {CurrencyComponent} from "./currency/currency.component";
 import {LanguageComponent} from "./language/language.component";
 import {CountryComponent} from "./country/country.component";
+import {UnitComponent} from "./unit/unit.component";
 
 const routes: Routes = [
   {
@@ -29,6 +30,10 @@ const routes: Routes = [
         path: 'currency',
         component: CurrencyComponent,
       },
+      {
+        path: 'unit',
+        component: UnitComponent,
+      },
       {
         path: 'language',
         component: LanguageComponent,

Diff for: projects/angular-intl-demo/src/app/pipes/pipes.component.html

@@ -7,6 +7,8 @@
      routerLinkActive>Percent</a>
   <a #currencyActive="routerLinkActive" [active]="currencyActive.isActive" mat-tab-link routerLink="currency"
      routerLinkActive>Currency</a>
+  <a #unitActive="routerLinkActive" [active]="unitActive.isActive" mat-tab-link routerLink="unit"
+     routerLinkActive>Unit</a>
   <a #languageActive="routerLinkActive" [active]="languageActive.isActive" mat-tab-link routerLink="language"
      routerLinkActive>Language</a>
   <a #countryActive="routerLinkActive" [active]="countryActive.isActive" mat-tab-link routerLink="country"

Diff for: projects/angular-intl-demo/src/app/pipes/pipes.module.ts

@@ -15,6 +15,7 @@ import {PipesRoutingModule} from "./pipes-routing.module";
 import {CountryComponent} from "./country/country.component";
 import {NgxMatDatetimePickerModule, NgxMatNativeDateModule} from "@angular-material-components/datetime-picker";
 import {MatDatepickerModule} from "@angular/material/datepicker";
+import {UnitComponent} from "./unit/unit.component";
 
 @NgModule({
   declarations: [
@@ -25,6 +26,7 @@ import {MatDatepickerModule} from "@angular/material/datepicker";
     CurrencyComponent,
     PipesComponent,
     CountryComponent,
+    UnitComponent,
   ],
   imports: [
     CommonModule,