From 91af69ffec3b267c6d5a68529672340d7788ec95 Mon Sep 17 00:00:00 2001
From: Arman Ozak <arman@armanozak.com>
Date: Mon, 18 May 2020 21:03:42 +0300
Subject: [PATCH 1/7] feat: add localization methods with fallbacks

---
 .../src/lib/services/localization.service.ts  |  52 +++---
 .../lib/tests/localization.service.spec.ts    | 172 +++++++++++++++++-
 .../core/src/lib/utils/localization-utils.ts  |  34 ++++
 3 files changed, 233 insertions(+), 25 deletions(-)
 create mode 100644 npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts

diff --git a/npm/ng-packs/packages/core/src/lib/services/localization.service.ts b/npm/ng-packs/packages/core/src/lib/services/localization.service.ts
index 8adef08f46..5fea751b14 100644
--- a/npm/ng-packs/packages/core/src/lib/services/localization.service.ts
+++ b/npm/ng-packs/packages/core/src/lib/services/localization.service.ts
@@ -2,11 +2,12 @@ import { Injectable, NgZone, Optional, SkipSelf } from '@angular/core';
 import { ActivatedRouteSnapshot, Router } from '@angular/router';
 import { Actions, ofActionSuccessful, Store } from '@ngxs/store';
 import { noop, Observable } from 'rxjs';
+import { map } from 'rxjs/operators';
 import { SetLanguage } from '../actions/session.actions';
-import { ApplicationConfiguration } from '../models/application-configuration';
 import { Config } from '../models/config';
 import { ConfigState } from '../states/config.state';
 import { registerLocale } from '../utils/initial-utils';
+import { localize, localizeWithFallback } from '../utils/localization-utils';
 
 type ShouldReuseRoute = (future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot) => boolean;
 
@@ -77,30 +78,35 @@ export class LocalizationService {
     return this.store.selectSnapshot(ConfigState.getLocalization(key, ...interpolateParams));
   }
 
-  isLocalized(key, sourceName) {
-    if (sourceName === '_') {
-      // A convention to suppress the localization
-      return true;
-    }
-
-    const localization = this.store.selectSnapshot(
-      ConfigState.getOne('localization'),
-    ) as ApplicationConfiguration.Localization;
-    sourceName = sourceName || localization.defaultResourceName;
-    if (!sourceName) {
-      return false;
-    }
+  localize(resourceName: string, key: string, defaultValue: string): Observable<string> {
+    return this.store
+      .select(ConfigState.getOne('localization'))
+      .pipe(map(localize(resourceName, key, defaultValue)));
+  }
 
-    const source = localization.values[sourceName];
-    if (!source) {
-      return false;
-    }
+  localizeSync(resourceName: string, key: string, defaultValue: string): string {
+    return localize(
+      resourceName,
+      key,
+      defaultValue,
+    )(this.store.selectSnapshot(ConfigState.getOne('localization')));
+  }
 
-    const value = source[key];
-    if (value === undefined) {
-      return false;
-    }
+  localizeWithFallback(
+    resourceNames: string[],
+    keys: string[],
+    defaultValue: string,
+  ): Observable<string> {
+    return this.store
+      .select(ConfigState.getOne('localization'))
+      .pipe(map(localizeWithFallback(resourceNames, keys, defaultValue)));
+  }
 
-    return true;
+  localizeWithFallbackSync(resourceNames: string[], keys: string[], defaultValue: string): string {
+    return localizeWithFallback(
+      resourceNames,
+      keys,
+      defaultValue,
+    )(this.store.selectSnapshot(ConfigState.getOne('localization')));
   }
 }
diff --git a/npm/ng-packs/packages/core/src/lib/tests/localization.service.spec.ts b/npm/ng-packs/packages/core/src/lib/tests/localization.service.spec.ts
index 8c5b859f9f..e17d53e463 100644
--- a/npm/ng-packs/packages/core/src/lib/tests/localization.service.spec.ts
+++ b/npm/ng-packs/packages/core/src/lib/tests/localization.service.spec.ts
@@ -1,7 +1,7 @@
 import { Router } from '@angular/router';
 import { createServiceFactory, SpectatorService, SpyObject } from '@ngneat/spectator/jest';
-import { Store, Actions } from '@ngxs/store';
-import { Observable, of, Subject } from 'rxjs';
+import { Actions, Store } from '@ngxs/store';
+import { of, Subject } from 'rxjs';
 import { LocalizationService } from '../services/localization.service';
 
 describe('LocalizationService', () => {
@@ -75,4 +75,172 @@ describe('LocalizationService', () => {
       }
     });
   });
+
+  describe('#localize', () => {
+    test.each`
+      resource     | key          | defaultValue | expected
+      ${'foo'}     | ${'bar'}     | ${'DEFAULT'} | ${'baz'}
+      ${'x'}       | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'a'}       | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
+      ${''}        | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
+      ${undefined} | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'foo'}     | ${'y'}       | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'x'}       | ${'y'}       | ${'DEFAULT'} | ${'z'}
+      ${'a'}       | ${'y'}       | ${'DEFAULT'} | ${'DEFAULT'}
+      ${''}        | ${'y'}       | ${'DEFAULT'} | ${'DEFAULT'}
+      ${undefined} | ${'y'}       | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'foo'}     | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'x'}       | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'a'}       | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${''}        | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${undefined} | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'foo'}     | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'x'}       | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'a'}       | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+      ${''}        | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+      ${undefined} | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+    `(
+      'should return observable $expected when resource name is $resource and key is $key',
+      async ({ resource, key, defaultValue, expected }) => {
+        store.select.andReturn(
+          of({
+            values: { foo: { bar: 'baz' }, x: { y: 'z' } },
+            defaultResourceName: 'x',
+          }),
+        );
+
+        const result = await service.localize(resource, key, defaultValue).toPromise();
+
+        expect(result).toBe(expected);
+      },
+    );
+  });
+
+  describe('#localizeSync', () => {
+    test.each`
+      resource     | key          | defaultValue | expected
+      ${'foo'}     | ${'bar'}     | ${'DEFAULT'} | ${'baz'}
+      ${'x'}       | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'a'}       | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
+      ${''}        | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
+      ${undefined} | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'foo'}     | ${'y'}       | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'x'}       | ${'y'}       | ${'DEFAULT'} | ${'z'}
+      ${'a'}       | ${'y'}       | ${'DEFAULT'} | ${'DEFAULT'}
+      ${''}        | ${'y'}       | ${'DEFAULT'} | ${'DEFAULT'}
+      ${undefined} | ${'y'}       | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'foo'}     | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'x'}       | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'a'}       | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${''}        | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${undefined} | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'foo'}     | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'x'}       | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'a'}       | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+      ${''}        | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+      ${undefined} | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+    `(
+      'should return $expected when resource name is $resource and key is $key',
+      ({ resource, key, defaultValue, expected }) => {
+        store.selectSnapshot.andReturn({
+          values: { foo: { bar: 'baz' }, x: { y: 'z' } },
+          defaultResourceName: 'x',
+        });
+
+        const result = service.localizeSync(resource, key, defaultValue);
+
+        expect(result).toBe(expected);
+      },
+    );
+  });
+
+  describe('#localizeWithFallback', () => {
+    test.each`
+      resources          | keys            | defaultValue | expected
+      ${['foo']}         | ${['bar']}      | ${'DEFAULT'} | ${'baz'}
+      ${['x']}           | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['foo']}         | ${['y']}        | ${'DEFAULT'} | ${'z'}
+      ${['x']}           | ${['y']}        | ${'DEFAULT'} | ${'z'}
+      ${['a', 'b', 'c']} | ${['y']}        | ${'DEFAULT'} | ${'z'}
+      ${['']}            | ${['y']}        | ${'DEFAULT'} | ${'z'}
+      ${[]}              | ${['y']}        | ${'DEFAULT'} | ${'z'}
+      ${['foo']}         | ${['bar', 'y']} | ${'DEFAULT'} | ${'baz'}
+      ${['x']}           | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
+      ${['a', 'b', 'c']} | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
+      ${['']}            | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
+      ${[]}              | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
+      ${['foo']}         | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['x']}           | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['foo']}         | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['x']}           | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
+    `(
+      'should return observable $expected when resource names are $resources and keys are $keys',
+      async ({ resources, keys, defaultValue, expected }) => {
+        store.select.andReturn(
+          of({
+            values: { foo: { bar: 'baz' }, x: { y: 'z' } },
+            defaultResourceName: 'x',
+          }),
+        );
+
+        const result = await service
+          .localizeWithFallback(resources, keys, defaultValue)
+          .toPromise();
+
+        expect(result).toBe(expected);
+      },
+    );
+  });
+
+  describe('#localizeWithFallbackSync', () => {
+    test.each`
+      resources          | keys            | defaultValue | expected
+      ${['foo']}         | ${['bar']}      | ${'DEFAULT'} | ${'baz'}
+      ${['x']}           | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['foo']}         | ${['y']}        | ${'DEFAULT'} | ${'z'}
+      ${['x']}           | ${['y']}        | ${'DEFAULT'} | ${'z'}
+      ${['a', 'b', 'c']} | ${['y']}        | ${'DEFAULT'} | ${'z'}
+      ${['']}            | ${['y']}        | ${'DEFAULT'} | ${'z'}
+      ${[]}              | ${['y']}        | ${'DEFAULT'} | ${'z'}
+      ${['foo']}         | ${['bar', 'y']} | ${'DEFAULT'} | ${'baz'}
+      ${['x']}           | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
+      ${['a', 'b', 'c']} | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
+      ${['']}            | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
+      ${[]}              | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
+      ${['foo']}         | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['x']}           | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['foo']}         | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['x']}           | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
+    `(
+      'should return $expected when resource names are $resources and keys are $keys',
+      ({ resources, keys, defaultValue, expected }) => {
+        store.selectSnapshot.andReturn({
+          values: { foo: { bar: 'baz' }, x: { y: 'z' } },
+          defaultResourceName: 'x',
+        });
+
+        const result = service.localizeWithFallbackSync(resources, keys, defaultValue);
+
+        expect(result).toBe(expected);
+      },
+    );
+  });
 });
diff --git a/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts b/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
new file mode 100644
index 0000000000..7d5a2c9e70
--- /dev/null
+++ b/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
@@ -0,0 +1,34 @@
+import { ApplicationConfiguration } from '../models/application-configuration';
+
+export function localize(resourceName: string, key: string, defaultValue: string) {
+  return function(localization: ApplicationConfiguration.Localization) {
+    if (resourceName === '_') return key;
+
+    const resource = localization.values[resourceName];
+
+    if (!resource) return defaultValue;
+
+    return resource[key] || defaultValue;
+  };
+}
+
+export function localizeWithFallback(
+  resourceNames: string[],
+  keys: string[],
+  defaultValue: string,
+) {
+  return function(localization: ApplicationConfiguration.Localization) {
+    resourceNames = resourceNames.concat(localization.defaultResourceName).filter(Boolean);
+
+    for (let i = 0; i < resourceNames.length; i++) {
+      const resourceName = resourceNames[i];
+
+      for (let j = 0; j < keys.length; j++) {
+        const localized = localize(resourceName, keys[j], null)(localization);
+        if (localized) return localized;
+      }
+    }
+
+    return defaultValue;
+  };
+}

From 3ebbb709f6ad1d9777457b6e794378ba88bbb74d Mon Sep 17 00:00:00 2001
From: Arman Ozak <arman@armanozak.com>
Date: Mon, 18 May 2020 21:08:12 +0300
Subject: [PATCH 2/7] fix: avoid lint errors

---
 .../packages/core/src/lib/utils/localization-utils.ts     | 2 ++
 .../src/lib/components/loader-bar/loader-bar.component.ts | 8 ++++----
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts b/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
index 7d5a2c9e70..530adc0621 100644
--- a/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
+++ b/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
@@ -1,6 +1,7 @@
 import { ApplicationConfiguration } from '../models/application-configuration';
 
 export function localize(resourceName: string, key: string, defaultValue: string) {
+  /* tslint:disable-next-line:only-arrow-functions */
   return function(localization: ApplicationConfiguration.Localization) {
     if (resourceName === '_') return key;
 
@@ -17,6 +18,7 @@ export function localizeWithFallback(
   keys: string[],
   defaultValue: string,
 ) {
+  /* tslint:disable-next-line:only-arrow-functions */
   return function(localization: ApplicationConfiguration.Localization) {
     resourceNames = resourceNames.concat(localization.defaultResourceName).filter(Boolean);
 
diff --git a/npm/ng-packs/packages/theme-shared/src/lib/components/loader-bar/loader-bar.component.ts b/npm/ng-packs/packages/theme-shared/src/lib/components/loader-bar/loader-bar.component.ts
index 41a5850131..512d959c5f 100644
--- a/npm/ng-packs/packages/theme-shared/src/lib/components/loader-bar/loader-bar.component.ts
+++ b/npm/ng-packs/packages/theme-shared/src/lib/components/loader-bar/loader-bar.component.ts
@@ -30,10 +30,6 @@ export class LoaderBarComponent implements OnDestroy, OnInit {
   @Input()
   color = '#77b6ff';
 
-  @Input()
-  filter = (action: StartLoader | StopLoader) =>
-    action.payload.url.indexOf('openid-configuration') < 0;
-
   @Input()
   isLoading = false;
 
@@ -47,6 +43,10 @@ export class LoaderBarComponent implements OnDestroy, OnInit {
 
   stopDelay = 800;
 
+  @Input()
+  filter = (action: StartLoader | StopLoader) =>
+    action.payload.url.indexOf('openid-configuration') < 0;
+
   private readonly clearProgress = () => {
     this.progressLevel = 0;
     this.cdRef.detectChanges();

From 20bfd29a5c6250a6e095bd776a6959001e97b59d Mon Sep 17 00:00:00 2001
From: Arman Ozak <arman@armanozak.com>
Date: Mon, 18 May 2020 23:09:09 +0300
Subject: [PATCH 3/7] refactor: set array lengths before loops

---
 .../packages/core/src/lib/utils/localization-utils.ts      | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts b/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
index 530adc0621..2a14b8d014 100644
--- a/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
+++ b/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
@@ -22,10 +22,13 @@ export function localizeWithFallback(
   return function(localization: ApplicationConfiguration.Localization) {
     resourceNames = resourceNames.concat(localization.defaultResourceName).filter(Boolean);
 
-    for (let i = 0; i < resourceNames.length; i++) {
+    const resourceCount = resourceNames.length;
+    const keyCount = keys.length;
+
+    for (let i = 0; i < resourceCount; i++) {
       const resourceName = resourceNames[i];
 
-      for (let j = 0; j < keys.length; j++) {
+      for (let j = 0; j < keyCount; j++) {
         const localized = localize(resourceName, keys[j], null)(localization);
         if (localized) return localized;
       }

From 6eb28e35c92a49acf7659d22fb25efafe5704580 Mon Sep 17 00:00:00 2001
From: Arman Ozak <arman@armanozak.com>
Date: Tue, 19 May 2020 17:34:17 +0300
Subject: [PATCH 4/7] refactor: reverse the higher-order functions

---
 .../src/lib/services/localization.service.ts  |  30 +++--
 .../src/lib/tests/localization-utils.spec.ts  |  90 +++++++++++++++
 .../lib/tests/localization.service.spec.ts    | 108 +++++++++---------
 .../packages/core/src/lib/utils/index.ts      |   1 +
 .../core/src/lib/utils/localization-utils.ts  |  30 +++--
 5 files changed, 179 insertions(+), 80 deletions(-)
 create mode 100644 npm/ng-packs/packages/core/src/lib/tests/localization-utils.spec.ts

diff --git a/npm/ng-packs/packages/core/src/lib/services/localization.service.ts b/npm/ng-packs/packages/core/src/lib/services/localization.service.ts
index 5fea751b14..8708eecfdb 100644
--- a/npm/ng-packs/packages/core/src/lib/services/localization.service.ts
+++ b/npm/ng-packs/packages/core/src/lib/services/localization.service.ts
@@ -7,7 +7,7 @@ import { SetLanguage } from '../actions/session.actions';
 import { Config } from '../models/config';
 import { ConfigState } from '../states/config.state';
 import { registerLocale } from '../utils/initial-utils';
-import { localize, localizeWithFallback } from '../utils/localization-utils';
+import { createLocalizer, createLocalizerWithFallback } from '../utils/localization-utils';
 
 type ShouldReuseRoute = (future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot) => boolean;
 
@@ -79,17 +79,15 @@ export class LocalizationService {
   }
 
   localize(resourceName: string, key: string, defaultValue: string): Observable<string> {
-    return this.store
-      .select(ConfigState.getOne('localization'))
-      .pipe(map(localize(resourceName, key, defaultValue)));
+    return this.store.select(ConfigState.getOne('localization')).pipe(
+      map(createLocalizer),
+      map(localize => localize(resourceName, key, defaultValue)),
+    );
   }
 
   localizeSync(resourceName: string, key: string, defaultValue: string): string {
-    return localize(
-      resourceName,
-      key,
-      defaultValue,
-    )(this.store.selectSnapshot(ConfigState.getOne('localization')));
+    const localization = this.store.selectSnapshot(ConfigState.getOne('localization'));
+    return createLocalizer(localization)(resourceName, key, defaultValue);
   }
 
   localizeWithFallback(
@@ -97,16 +95,14 @@ export class LocalizationService {
     keys: string[],
     defaultValue: string,
   ): Observable<string> {
-    return this.store
-      .select(ConfigState.getOne('localization'))
-      .pipe(map(localizeWithFallback(resourceNames, keys, defaultValue)));
+    return this.store.select(ConfigState.getOne('localization')).pipe(
+      map(createLocalizerWithFallback),
+      map(localizeWithFallback => localizeWithFallback(resourceNames, keys, defaultValue)),
+    );
   }
 
   localizeWithFallbackSync(resourceNames: string[], keys: string[], defaultValue: string): string {
-    return localizeWithFallback(
-      resourceNames,
-      keys,
-      defaultValue,
-    )(this.store.selectSnapshot(ConfigState.getOne('localization')));
+    const localization = this.store.selectSnapshot(ConfigState.getOne('localization'));
+    return createLocalizerWithFallback(localization)(resourceNames, keys, defaultValue);
   }
 }
diff --git a/npm/ng-packs/packages/core/src/lib/tests/localization-utils.spec.ts b/npm/ng-packs/packages/core/src/lib/tests/localization-utils.spec.ts
new file mode 100644
index 0000000000..f8bead7eda
--- /dev/null
+++ b/npm/ng-packs/packages/core/src/lib/tests/localization-utils.spec.ts
@@ -0,0 +1,90 @@
+import { createLocalizer, createLocalizerWithFallback } from '../utils/localization-utils';
+
+describe('Localization Utils', () => {
+  describe('#createLocalizer', () => {
+    const localize = createLocalizer({
+      values: { foo: { bar: 'baz' }, x: { y: 'z' } },
+      defaultResourceName: 'x',
+      currentCulture: null,
+      languages: [],
+    });
+
+    test.each`
+      resource     | key          | defaultValue | expected
+      ${'_'}       | ${'TEST'}    | ${'DEFAULT'} | ${'TEST'}
+      ${'foo'}     | ${'bar'}     | ${'DEFAULT'} | ${'baz'}
+      ${'x'}       | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'a'}       | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
+      ${''}        | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
+      ${undefined} | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'foo'}     | ${'y'}       | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'x'}       | ${'y'}       | ${'DEFAULT'} | ${'z'}
+      ${'a'}       | ${'y'}       | ${'DEFAULT'} | ${'DEFAULT'}
+      ${''}        | ${'y'}       | ${'DEFAULT'} | ${'DEFAULT'}
+      ${undefined} | ${'y'}       | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'foo'}     | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'x'}       | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'a'}       | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${''}        | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${undefined} | ${''}        | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'foo'}     | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'x'}       | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+      ${'a'}       | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+      ${''}        | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+      ${undefined} | ${undefined} | ${'DEFAULT'} | ${'DEFAULT'}
+    `(
+      'should return $expected when resource name is $resource and key is $key',
+      ({ resource, key, defaultValue, expected }) => {
+        const result = localize(resource, key, defaultValue);
+
+        expect(result).toBe(expected);
+      },
+    );
+  });
+
+  describe('#createLocalizerWithFallback', () => {
+    const localizeWithFallback = createLocalizerWithFallback({
+      values: { foo: { bar: 'baz' }, x: { y: 'z' } },
+      defaultResourceName: 'x',
+      currentCulture: null,
+      languages: [],
+    });
+
+    test.each`
+      resources          | keys                 | defaultValue | expected
+      ${['', '_']}       | ${['TEST', 'OTHER']} | ${'DEFAULT'} | ${'TEST'}
+      ${['foo']}         | ${['bar']}           | ${'DEFAULT'} | ${'baz'}
+      ${['x']}           | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['foo']}         | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${['x']}           | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${['a', 'b', 'c']} | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${['']}            | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${[]}              | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${['foo']}         | ${['bar', 'y']}      | ${'DEFAULT'} | ${'baz'}
+      ${['x']}           | ${['bar', 'y']}      | ${'DEFAULT'} | ${'z'}
+      ${['a', 'b', 'c']} | ${['bar', 'y']}      | ${'DEFAULT'} | ${'z'}
+      ${['']}            | ${['bar', 'y']}      | ${'DEFAULT'} | ${'z'}
+      ${[]}              | ${['bar', 'y']}      | ${'DEFAULT'} | ${'z'}
+      ${['foo']}         | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['x']}           | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['foo']}         | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['x']}           | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+    `(
+      'should return $expected when resource names are $resources and keys are $keys',
+      ({ resources, keys, defaultValue, expected }) => {
+        const result = localizeWithFallback(resources, keys, defaultValue);
+
+        expect(result).toBe(expected);
+      },
+    );
+  });
+});
diff --git a/npm/ng-packs/packages/core/src/lib/tests/localization.service.spec.ts b/npm/ng-packs/packages/core/src/lib/tests/localization.service.spec.ts
index e17d53e463..9d6f6ba3bf 100644
--- a/npm/ng-packs/packages/core/src/lib/tests/localization.service.spec.ts
+++ b/npm/ng-packs/packages/core/src/lib/tests/localization.service.spec.ts
@@ -79,6 +79,7 @@ describe('LocalizationService', () => {
   describe('#localize', () => {
     test.each`
       resource     | key          | defaultValue | expected
+      ${'_'}       | ${'TEST'}    | ${'DEFAULT'} | ${'TEST'}
       ${'foo'}     | ${'bar'}     | ${'DEFAULT'} | ${'baz'}
       ${'x'}       | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
       ${'a'}       | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
@@ -119,6 +120,7 @@ describe('LocalizationService', () => {
   describe('#localizeSync', () => {
     test.each`
       resource     | key          | defaultValue | expected
+      ${'_'}       | ${'TEST'}    | ${'DEFAULT'} | ${'TEST'}
       ${'foo'}     | ${'bar'}     | ${'DEFAULT'} | ${'baz'}
       ${'x'}       | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
       ${'a'}       | ${'bar'}     | ${'DEFAULT'} | ${'DEFAULT'}
@@ -156,32 +158,33 @@ describe('LocalizationService', () => {
 
   describe('#localizeWithFallback', () => {
     test.each`
-      resources          | keys            | defaultValue | expected
-      ${['foo']}         | ${['bar']}      | ${'DEFAULT'} | ${'baz'}
-      ${['x']}           | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['a', 'b', 'c']} | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['']}            | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
-      ${[]}              | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['foo']}         | ${['y']}        | ${'DEFAULT'} | ${'z'}
-      ${['x']}           | ${['y']}        | ${'DEFAULT'} | ${'z'}
-      ${['a', 'b', 'c']} | ${['y']}        | ${'DEFAULT'} | ${'z'}
-      ${['']}            | ${['y']}        | ${'DEFAULT'} | ${'z'}
-      ${[]}              | ${['y']}        | ${'DEFAULT'} | ${'z'}
-      ${['foo']}         | ${['bar', 'y']} | ${'DEFAULT'} | ${'baz'}
-      ${['x']}           | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
-      ${['a', 'b', 'c']} | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
-      ${['']}            | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
-      ${[]}              | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
-      ${['foo']}         | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['x']}           | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['a', 'b', 'c']} | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['']}            | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
-      ${[]}              | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['foo']}         | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['x']}           | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['a', 'b', 'c']} | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['']}            | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
-      ${[]}              | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
+      resources          | keys                 | defaultValue | expected
+      ${['', '_']}       | ${['TEST', 'OTHER']} | ${'DEFAULT'} | ${'TEST'}
+      ${['foo']}         | ${['bar']}           | ${'DEFAULT'} | ${'baz'}
+      ${['x']}           | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['foo']}         | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${['x']}           | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${['a', 'b', 'c']} | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${['']}            | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${[]}              | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${['foo']}         | ${['bar', 'y']}      | ${'DEFAULT'} | ${'baz'}
+      ${['x']}           | ${['bar', 'y']}      | ${'DEFAULT'} | ${'z'}
+      ${['a', 'b', 'c']} | ${['bar', 'y']}      | ${'DEFAULT'} | ${'z'}
+      ${['']}            | ${['bar', 'y']}      | ${'DEFAULT'} | ${'z'}
+      ${[]}              | ${['bar', 'y']}      | ${'DEFAULT'} | ${'z'}
+      ${['foo']}         | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['x']}           | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['foo']}         | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['x']}           | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
     `(
       'should return observable $expected when resource names are $resources and keys are $keys',
       async ({ resources, keys, defaultValue, expected }) => {
@@ -203,32 +206,33 @@ describe('LocalizationService', () => {
 
   describe('#localizeWithFallbackSync', () => {
     test.each`
-      resources          | keys            | defaultValue | expected
-      ${['foo']}         | ${['bar']}      | ${'DEFAULT'} | ${'baz'}
-      ${['x']}           | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['a', 'b', 'c']} | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['']}            | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
-      ${[]}              | ${['bar']}      | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['foo']}         | ${['y']}        | ${'DEFAULT'} | ${'z'}
-      ${['x']}           | ${['y']}        | ${'DEFAULT'} | ${'z'}
-      ${['a', 'b', 'c']} | ${['y']}        | ${'DEFAULT'} | ${'z'}
-      ${['']}            | ${['y']}        | ${'DEFAULT'} | ${'z'}
-      ${[]}              | ${['y']}        | ${'DEFAULT'} | ${'z'}
-      ${['foo']}         | ${['bar', 'y']} | ${'DEFAULT'} | ${'baz'}
-      ${['x']}           | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
-      ${['a', 'b', 'c']} | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
-      ${['']}            | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
-      ${[]}              | ${['bar', 'y']} | ${'DEFAULT'} | ${'z'}
-      ${['foo']}         | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['x']}           | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['a', 'b', 'c']} | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['']}            | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
-      ${[]}              | ${['']}         | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['foo']}         | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['x']}           | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['a', 'b', 'c']} | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
-      ${['']}            | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
-      ${[]}              | ${[]}           | ${'DEFAULT'} | ${'DEFAULT'}
+      resources          | keys                 | defaultValue | expected
+      ${['', '_']}       | ${['TEST', 'OTHER']} | ${'DEFAULT'} | ${'TEST'}
+      ${['foo']}         | ${['bar']}           | ${'DEFAULT'} | ${'baz'}
+      ${['x']}           | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['foo']}         | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${['x']}           | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${['a', 'b', 'c']} | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${['']}            | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${[]}              | ${['y']}             | ${'DEFAULT'} | ${'z'}
+      ${['foo']}         | ${['bar', 'y']}      | ${'DEFAULT'} | ${'baz'}
+      ${['x']}           | ${['bar', 'y']}      | ${'DEFAULT'} | ${'z'}
+      ${['a', 'b', 'c']} | ${['bar', 'y']}      | ${'DEFAULT'} | ${'z'}
+      ${['']}            | ${['bar', 'y']}      | ${'DEFAULT'} | ${'z'}
+      ${[]}              | ${['bar', 'y']}      | ${'DEFAULT'} | ${'z'}
+      ${['foo']}         | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['x']}           | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['foo']}         | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['x']}           | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
     `(
       'should return $expected when resource names are $resources and keys are $keys',
       ({ resources, keys, defaultValue, expected }) => {
diff --git a/npm/ng-packs/packages/core/src/lib/utils/index.ts b/npm/ng-packs/packages/core/src/lib/utils/index.ts
index 6f6b0585d9..4dde8134ef 100644
--- a/npm/ng-packs/packages/core/src/lib/utils/index.ts
+++ b/npm/ng-packs/packages/core/src/lib/utils/index.ts
@@ -3,6 +3,7 @@ export * from './form-utils';
 export * from './generator-utils';
 export * from './initial-utils';
 export * from './lazy-load-utils';
+export * from './localization-utils';
 export * from './number-utils';
 export * from './route-utils';
 export * from './rxjs-utils';
diff --git a/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts b/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
index 2a14b8d014..31a73b818d 100644
--- a/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
+++ b/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
@@ -1,8 +1,8 @@
 import { ApplicationConfiguration } from '../models/application-configuration';
 
-export function localize(resourceName: string, key: string, defaultValue: string) {
+export function createLocalizer(localization: ApplicationConfiguration.Localization) {
   /* tslint:disable-next-line:only-arrow-functions */
-  return function(localization: ApplicationConfiguration.Localization) {
+  return function(resourceName: string, key: string, defaultValue: string) {
     if (resourceName === '_') return key;
 
     const resource = localization.values[resourceName];
@@ -13,13 +13,20 @@ export function localize(resourceName: string, key: string, defaultValue: string
   };
 }
 
-export function localizeWithFallback(
-  resourceNames: string[],
-  keys: string[],
-  defaultValue: string,
-) {
+export function createLocalizerWithFallback(localization: ApplicationConfiguration.Localization) {
+  const findLocalization = createLocalizationFinder(localization);
   /* tslint:disable-next-line:only-arrow-functions */
-  return function(localization: ApplicationConfiguration.Localization) {
+  return function(resourceNames: string[], keys: string[], defaultValue: string) {
+    const { localized } = findLocalization(resourceNames, keys);
+    return localized || defaultValue;
+  };
+}
+
+function createLocalizationFinder(localization: ApplicationConfiguration.Localization) {
+  const localize = createLocalizer(localization);
+
+  /* tslint:disable-next-line:only-arrow-functions */
+  return function(resourceNames: string[], keys: string[]) {
     resourceNames = resourceNames.concat(localization.defaultResourceName).filter(Boolean);
 
     const resourceCount = resourceNames.length;
@@ -29,11 +36,12 @@ export function localizeWithFallback(
       const resourceName = resourceNames[i];
 
       for (let j = 0; j < keyCount; j++) {
-        const localized = localize(resourceName, keys[j], null)(localization);
-        if (localized) return localized;
+        const key = keys[j];
+        const localized = localize(resourceName, key, null);
+        if (localized) return { resourceName, key, localized };
       }
     }
 
-    return defaultValue;
+    return { resourceName: undefined, key: undefined, localized: undefined };
   };
 }

From 024a64015789d35fee98425458cb0fd10d9d8618 Mon Sep 17 00:00:00 2001
From: Arman Ozak <arman@armanozak.com>
Date: Tue, 19 May 2020 17:34:31 +0300
Subject: [PATCH 5/7] feat: add createLocalizationPipeKeyGenerator

---
 .../src/lib/tests/localization-utils.spec.ts  | 52 ++++++++++++++++++-
 .../core/src/lib/utils/localization-utils.ts  | 12 +++++
 2 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/npm/ng-packs/packages/core/src/lib/tests/localization-utils.spec.ts b/npm/ng-packs/packages/core/src/lib/tests/localization-utils.spec.ts
index f8bead7eda..f5319edc2d 100644
--- a/npm/ng-packs/packages/core/src/lib/tests/localization-utils.spec.ts
+++ b/npm/ng-packs/packages/core/src/lib/tests/localization-utils.spec.ts
@@ -1,4 +1,8 @@
-import { createLocalizer, createLocalizerWithFallback } from '../utils/localization-utils';
+import {
+  createLocalizationPipeKeyGenerator,
+  createLocalizer,
+  createLocalizerWithFallback,
+} from '../utils/localization-utils';
 
 describe('Localization Utils', () => {
   describe('#createLocalizer', () => {
@@ -87,4 +91,50 @@ describe('Localization Utils', () => {
       },
     );
   });
+
+  describe('#createLocalizationPipeKeyGenerator', () => {
+    const generateLocalizationPipeKey = createLocalizationPipeKeyGenerator({
+      values: { foo: { bar: 'baz' }, x: { y: 'z' } },
+      defaultResourceName: 'x',
+      currentCulture: null,
+      languages: [],
+    });
+
+    test.each`
+      resources          | keys                 | defaultKey   | expected
+      ${['', '_']}       | ${['TEST', 'OTHER']} | ${'DEFAULT'} | ${'TEST'}
+      ${['foo']}         | ${['bar']}           | ${'DEFAULT'} | ${'foo::bar'}
+      ${['x']}           | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${['bar']}           | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['foo']}         | ${['y']}             | ${'DEFAULT'} | ${'x::y'}
+      ${['x']}           | ${['y']}             | ${'DEFAULT'} | ${'x::y'}
+      ${['a', 'b', 'c']} | ${['y']}             | ${'DEFAULT'} | ${'x::y'}
+      ${['']}            | ${['y']}             | ${'DEFAULT'} | ${'x::y'}
+      ${[]}              | ${['y']}             | ${'DEFAULT'} | ${'x::y'}
+      ${['foo']}         | ${['bar', 'y']}      | ${'DEFAULT'} | ${'foo::bar'}
+      ${['x']}           | ${['bar', 'y']}      | ${'DEFAULT'} | ${'x::y'}
+      ${['a', 'b', 'c']} | ${['bar', 'y']}      | ${'DEFAULT'} | ${'x::y'}
+      ${['']}            | ${['bar', 'y']}      | ${'DEFAULT'} | ${'x::y'}
+      ${[]}              | ${['bar', 'y']}      | ${'DEFAULT'} | ${'x::y'}
+      ${['foo']}         | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['x']}           | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${['']}              | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['foo']}         | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['x']}           | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['a', 'b', 'c']} | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${['']}            | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+      ${[]}              | ${[]}                | ${'DEFAULT'} | ${'DEFAULT'}
+    `(
+      'should return $expected when resource names are $resources and keys are $keys',
+      ({ resources, keys, defaultKey, expected }) => {
+        const result = generateLocalizationPipeKey(resources, keys, defaultKey);
+
+        expect(result).toBe(expected);
+      },
+    );
+  });
 });
diff --git a/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts b/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
index 31a73b818d..a30c4e25a6 100644
--- a/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
+++ b/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
@@ -22,6 +22,18 @@ export function createLocalizerWithFallback(localization: ApplicationConfigurati
   };
 }
 
+export function createLocalizationPipeKeyGenerator(
+  localization: ApplicationConfiguration.Localization,
+) {
+  const findLocalization = createLocalizationFinder(localization);
+
+  /* tslint:disable-next-line:only-arrow-functions */
+  return function(resourceNames: string[], keys: string[], defaultKey: string) {
+    const { resourceName, key } = findLocalization(resourceNames, keys);
+    return !resourceName ? defaultKey : resourceName === '_' ? key : `${resourceName}::${key}`;
+  };
+}
+
 function createLocalizationFinder(localization: ApplicationConfiguration.Localization) {
   const localize = createLocalizer(localization);
 

From 8c184b7f41125034841e7c96ce128f85a3f9c122 Mon Sep 17 00:00:00 2001
From: Arman Ozak <arman@armanozak.com>
Date: Tue, 19 May 2020 22:43:35 +0300
Subject: [PATCH 6/7] refactor: use arrow functions

---
 .../core/src/lib/utils/localization-utils.ts        | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts b/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
index a30c4e25a6..ed094f7fc7 100644
--- a/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
+++ b/npm/ng-packs/packages/core/src/lib/utils/localization-utils.ts
@@ -1,8 +1,7 @@
 import { ApplicationConfiguration } from '../models/application-configuration';
 
 export function createLocalizer(localization: ApplicationConfiguration.Localization) {
-  /* tslint:disable-next-line:only-arrow-functions */
-  return function(resourceName: string, key: string, defaultValue: string) {
+  return (resourceName: string, key: string, defaultValue: string) => {
     if (resourceName === '_') return key;
 
     const resource = localization.values[resourceName];
@@ -15,8 +14,8 @@ export function createLocalizer(localization: ApplicationConfiguration.Localizat
 
 export function createLocalizerWithFallback(localization: ApplicationConfiguration.Localization) {
   const findLocalization = createLocalizationFinder(localization);
-  /* tslint:disable-next-line:only-arrow-functions */
-  return function(resourceNames: string[], keys: string[], defaultValue: string) {
+
+  return (resourceNames: string[], keys: string[], defaultValue: string) => {
     const { localized } = findLocalization(resourceNames, keys);
     return localized || defaultValue;
   };
@@ -27,8 +26,7 @@ export function createLocalizationPipeKeyGenerator(
 ) {
   const findLocalization = createLocalizationFinder(localization);
 
-  /* tslint:disable-next-line:only-arrow-functions */
-  return function(resourceNames: string[], keys: string[], defaultKey: string) {
+  return (resourceNames: string[], keys: string[], defaultKey: string) => {
     const { resourceName, key } = findLocalization(resourceNames, keys);
     return !resourceName ? defaultKey : resourceName === '_' ? key : `${resourceName}::${key}`;
   };
@@ -37,8 +35,7 @@ export function createLocalizationPipeKeyGenerator(
 function createLocalizationFinder(localization: ApplicationConfiguration.Localization) {
   const localize = createLocalizer(localization);
 
-  /* tslint:disable-next-line:only-arrow-functions */
-  return function(resourceNames: string[], keys: string[]) {
+  return (resourceNames: string[], keys: string[]) => {
     resourceNames = resourceNames.concat(localization.defaultResourceName).filter(Boolean);
 
     const resourceCount = resourceNames.length;

From a3fb373e013f4048fa38d7b0fab4cde14fd13462 Mon Sep 17 00:00:00 2001
From: Arman Ozak <arman@armanozak.com>
Date: Tue, 19 May 2020 23:21:55 +0300
Subject: [PATCH 7/7] refactor: add a getter for languageChange stream

---
 .../core/src/lib/services/localization.service.ts         | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/npm/ng-packs/packages/core/src/lib/services/localization.service.ts b/npm/ng-packs/packages/core/src/lib/services/localization.service.ts
index 8708eecfdb..408dea1058 100644
--- a/npm/ng-packs/packages/core/src/lib/services/localization.service.ts
+++ b/npm/ng-packs/packages/core/src/lib/services/localization.service.ts
@@ -20,6 +20,10 @@ export class LocalizationService {
     return this.store.selectSnapshot(state => state.SessionState.language);
   }
 
+  get languageChange(): Observable<SetLanguage> {
+    return this.actions.pipe(ofActionSuccessful(SetLanguage));
+  }
+
   constructor(
     private actions: Actions,
     private store: Store,
@@ -35,9 +39,7 @@ export class LocalizationService {
   }
 
   private listenToSetLanguage() {
-    this.actions
-      .pipe(ofActionSuccessful(SetLanguage))
-      .subscribe(({ payload }) => this.registerLocale(payload));
+    this.languageChange.subscribe(({ payload }) => this.registerLocale(payload));
   }
 
   setRouteReuse(reuse: ShouldReuseRoute) {