#8 Refactor achievable skill sort pipe

- Made methods private and static.
- Consequently use of null safe variable.
- Decompose logic

Signed-off-by: Sven Strittmatter <[email protected]>

src/main/webapp/app/custom/shared/pipe/achievable-skill-sort.pipe.ts

@@ -1,19 +1,33 @@
 import { Pipe, PipeTransform } from '@angular/core';
 import { IAchievableSkill } from 'app/custom/entities/achievable-skill/achievable-skill.model';
+import { TranslateModelService } from '../translate-model/translate-model.service';
 
-type sortArg = keyof IAchievableSkill;
+type SortableProperties = keyof IAchievableSkill;
 
-@Pipe({ name: 'achievableSkillSort' })
+@Pipe({
+  name: 'achievableSkillSort',
+  pure: false, // Must not be pure so that already rendered components will be rendered again after language switch.
+})
 export class AchievableSkillSortPipe implements PipeTransform {
-  transform(skills: IAchievableSkill[], sortProperty: sortArg): IAchievableSkill[] {
-    const sortPropertyNullSafe = this.defaultString(sortProperty);
-    const reverse = ['score', 'rateCount'].includes(sortPropertyNullSafe) ? -1 : 1;
-    return Array.from(skills).sort(
-      (skill1, skill2) => reverse * this.defaultString(skill1[sortProperty]).localeCompare(this.defaultString(skill2[sortProperty]))
-    );
+  constructor(private translation: TranslateModelService) {}
+
+  private static defaultString(smth: any): string {
+    return smth || smth === 0 ? String(smth) : '';
+  }
+
+  private static shouldSortReverse(propertyName: SortableProperties): boolean {
+    return ['score', 'rateCount'].includes(propertyName);
   }
 
-  private defaultString(smth: any): string {
-    return smth || smth === 0 ? String(smth) : String();
+  transform(skills: IAchievableSkill[], propertyName: SortableProperties): IAchievableSkill[] {
+    const nullSafePropertyName = AchievableSkillSortPipe.defaultString(propertyName) as SortableProperties;
+    const sortOrder = AchievableSkillSortPipe.shouldSortReverse(nullSafePropertyName) ? -1 : 1;
+
+    return Array.from(skills).sort((leftSkill, rightSkill) => {
+      const leftValue = AchievableSkillSortPipe.defaultString(leftSkill[nullSafePropertyName]);
+      const rightValue = AchievableSkillSortPipe.defaultString(rightSkill[nullSafePropertyName]);
+
+      return sortOrder * leftValue.localeCompare(rightValue);
+    });
   }
 }