Strict typescript

src/app/data-structure/has-id-and-title.ts

@@ -1,5 +1,5 @@
 export class HasIdAndTitle {
-  public id: string;
-  public title: string;
-  public link: string;
+  public id: string = "";
+  public title: string = "";
+  public link: string = "";
 }

src/app/data-structure/login-info.ts

@@ -5,15 +5,15 @@ export class LoginInfo {
     return plainToClass(LoginInfo, obj as object);
   }
 
-  public loggedIn: boolean;
-  public nickname: string;
+  public loggedIn: boolean = false;
+  public nickname: string = "";
 
-  public googleLinked: boolean;
-  public googleProfileUrl: string;
-  public gitHubLinked: boolean;
-  public gitHubProfileUrl: string;
-  public facebookLinked: boolean;
-  public facebookProfileUrl: string;
+  public googleLinked: boolean = false;
+  public googleProfileUrl: string = "";
+  public gitHubLinked: boolean = false;
+  public gitHubProfileUrl: string = "";
+  public facebookLinked: boolean = false;
+  public facebookProfileUrl: string = "";
 
-  public errorMessage: string;
+  public errorMessage: string = "";
 }

src/app/data-structure/quiz-question-and-answer.ts

@@ -4,8 +4,8 @@ import { QuizText } from "./quiz-text";
 
 export class QuizQuestionAndAnswer {
   @Type(() => QuizQuestion)
-  public question: QuizQuestion;
+  public question?: QuizQuestion;
 
   @Type(() => QuizText)
-  public answer: QuizText;
+  public answer?: QuizText;
 }

src/app/data-structure/quiz-question.ts

@@ -8,25 +8,25 @@ export class QuizQuestion extends HasIdAndTitle {
   }
 
   @Type(() => QuizText)
-  public text: QuizText;
+  public text?: QuizText;
 
-  public note: string;
-  public videoUrl: string;
-  public codeUrl: string;
+  public note: string = "";
+  public videoUrl: string = "";
+  public codeUrl: string = "";
 
   @Type(() => QuizText)
-  public choices: QuizText[];
+  public choices?: QuizText[];
 
-  public sectionId: string;
-  public subSectionId: string;
+  public sectionId: string = "";
+  public subSectionId: string = "";
 
-  public quizTitle: string;
+  public quizTitle: string = "";
 
   @Type(() => HasIdAndTitle)
-  public section: HasIdAndTitle;
+  public section?: HasIdAndTitle;
 
   @Type(() => HasIdAndTitle)
-  public subSection: HasIdAndTitle;
+  public subSection?: HasIdAndTitle;
 
-  public quizUsesMathML: boolean;
+  public quizUsesMathML: boolean = false;
 }

src/app/data-structure/quiz-section.ts

@@ -1,22 +1,21 @@
 import { plainToClass, Type } from "class-transformer";
-import {isUndefined} from "util";
 import { HasIdAndTitle } from "./has-id-and-title";
 import { QuizQuestionAndAnswer } from "./quiz-question-and-answer";
 import { QuizSubSection } from "./quiz-sub-section";
 
 export class QuizSection extends HasIdAndTitle {
-  public static fromJson(obj: any): QuizSection {
-    if (isUndefined(obj)) {
+  public static fromJson(obj: any): QuizSection | undefined {
+    if (!obj!) {
       return undefined;
     }
 
     return plainToClass(QuizSection, obj as object);
   }
 
   @Type(() => QuizSubSection)
-  public subSections: QuizSubSection[];
+  public subSections: QuizSubSection[] = [];
 
   // defaultChoices
   @Type(() => QuizQuestionAndAnswer)
-  public questions: QuizQuestionAndAnswer[];
+  public questions: QuizQuestionAndAnswer[] = [];
 }

src/app/data-structure/quiz-sub-section.ts

@@ -5,7 +5,7 @@ import { QuizQuestionAndAnswer } from "./quiz-question-and-answer";
 export class QuizSubSection extends HasIdAndTitle {
 
   @Type(() => QuizQuestionAndAnswer)
-  public questions: QuizQuestionAndAnswer[];
+  public questions: QuizQuestionAndAnswer[] = [];
 
   public addQuestion(qa: QuizQuestionAndAnswer): void {
     if (!this.questions) {

src/app/data-structure/quiz-text.ts

@@ -1,4 +1,4 @@
 export class QuizText {
-  public text: string;
-  public isHtml: boolean;
+  public text: string = "";
+  public isHtml: boolean = false;
 }

src/app/data-structure/quiz.ts

@@ -8,9 +8,9 @@ export class Quiz extends HasIdAndTitle {
     return plainToClass(Quiz, obj as object);
   }
 
-  public isPrivate: boolean;
-  public usesMathML: boolean;
+  public isPrivate: boolean = false;
+  public usesMathML: boolean = false;
 
   @Type(() => QuizSection)
-  public sections: QuizSection[];
+  public sections: QuizSection[] = [];
 }

src/app/data-structure/submission-result.ts

@@ -7,11 +7,11 @@ export class SubmissionResult {
     return plainToClass(SubmissionResult, obj as object);
   }
 
-  public result: boolean;
+  public result: boolean = false;
 
   @Type(() => QuizText)
-  public correctAnswer: QuizText;
+  public correctAnswer?: QuizText = undefined;
 
   @Type(() => QuizQuestion)
-  public nextQuestion: QuizQuestion;
+  public nextQuestion?: QuizQuestion = undefined;
 }

src/app/data-structure/submission.ts

@@ -1,3 +1,3 @@
 export class Submission {
-  public answer: string;
+  public answer: string = "";
 }

src/app/data-structure/user-history-quizzes.ts

@@ -7,5 +7,5 @@ export class UserHistoryQuizzes {
   }
 
   @Type(() => UserStats)
-  public stats: UserStats[];
+  public stats: UserStats[] = [];
 }

src/app/data-structure/user-history-sections.ts

@@ -17,27 +17,27 @@ export class UserHistorySections {
       }
 
       // After parsing, we will use only statsMap.
-      result.stats = undefined;
+      result.stats = [];
     }
 
     return result;
   }
 
   @Type(() => LoginInfo)
-  public loginInfo: LoginInfo;
+  public loginInfo?: LoginInfo = undefined;
 
-  public quizId: string;
-  public quizTitle: string;
+  public quizId: string = "";
+  public quizTitle: string = "";
 
   // Only used when parsing from JSON.
   @Type(() => UserStats)
-  public stats: UserStats[];
+  public stats: UserStats[] = [];
 
   // Map of section IDs to stats.
   // This is built from stats
-  public statsMap: Map<string, UserStats>;
+  public statsMap: Map<string, UserStats> = new Map<string, UserStats>();
 
-  public getUserStatsForSection(sectionId: string): UserStats {
+  public getUserStatsForSection(sectionId: string): UserStats | undefined {
     if (!this.statsMap) {
       return undefined;
     }
@@ -46,10 +46,6 @@ export class UserHistorySections {
   }
 
   public setUserStatsForSection(sectionId: string, userStats: UserStats) {
-    if (!this.statsMap) {
-      this.statsMap = new Map<string, UserStats>();
-    }
-
     // Update in the map.
     this.statsMap.set(sectionId, userStats);
   }

src/app/data-structure/user-question-history.ts

@@ -15,13 +15,13 @@ export class UserQuestionHistory {
     return result;
   }
 
-  public questionId: string;
+  public questionId: string = "";
 
   @Type(() => QuizText)
-  public questionTitle: QuizText;
+  public questionTitle?: QuizText = undefined;
 
-  public sectionId: string;
-  public subSectionTitle: string;
+  public sectionId: string = "";
+  public subSectionTitle: string = "";
 
   public answeredCorrectlyOnce = false;
   public countAnsweredWrong = 0;

src/app/data-structure/user-stats.ts

@@ -17,7 +17,7 @@ export class UserStats {
         result.questionHistoriesMap.set(questionId, questionHistory);
 
         // After this point, we will only use questionHistoriesMap.
-        result.questionHistories = undefined;
+        result.questionHistories = [];
       }
     }
 
@@ -41,29 +41,29 @@ export class UserStats {
     return Number((part / total) * 100).toFixed(2) + "%";
   }
 
-  public quizId: string;
-  public quizTitle: string;
-  public sectionId: string;
-  public sectionTitle: string;
+  public quizId: string = "";
+  public quizTitle: string = "";
+  public sectionId: string = "";
+  public sectionTitle: string = "";
 
   public answered = 0;
   public correct = 0;
   public countQuestions = 0;
   public countQuestionsAnsweredOnce = 0;
   public countQuestionsCorrectOnce = 0;
 
-  public problemQuestionHistoriesCount: number;
+  public problemQuestionHistoriesCount: number = 0;
 
   @Type(() => UserQuestionHistory)
-  public topProblemQuestionHistories: UserQuestionHistory[];
+  public topProblemQuestionHistories: UserQuestionHistory[] = [];
 
   // Only used for parsing from JSON.
   @Type(() => UserQuestionHistory)
-  public questionHistories: UserQuestionHistory[];
+  public questionHistories: UserQuestionHistory[] = [];
 
   // Built from questionHistories.
   @Exclude()
-  public questionHistoriesMap: Map<string, UserQuestionHistory>;
+  public questionHistoriesMap: Map<string, UserQuestionHistory> = new Map<string, UserQuestionHistory>();
 
   public percentAnsweredOnce(total: number): string {
     return UserStats.percentageString(total, this.countQuestionsAnsweredOnce);
@@ -83,7 +83,7 @@ export class UserStats {
       this.questionHistoriesMap = new Map<string, UserQuestionHistory>();
     }
 
-    let history: UserQuestionHistory = this.questionHistoriesMap.get(questionId);
+    let history: UserQuestionHistory | undefined = this.questionHistoriesMap.get(questionId);
 
     // Add a new one, if necessary:
     if (!history) {
@@ -114,7 +114,7 @@ export class UserStats {
   private updateTopProblemQuestions(): void {
     this.problemQuestionHistoriesCount = 0;
 
-    this.topProblemQuestionHistories = undefined;
+    this.topProblemQuestionHistories = [];
 
     if (!this.questionHistoriesMap) {
       return;
@@ -123,18 +123,10 @@ export class UserStats {
     // Copy the values of the array.
     this.questionHistoriesMap.forEach((value: UserQuestionHistory, key: string) => {
       if (value.countAnsweredWrong > 0) {
-        if (!this.topProblemQuestionHistories) {
-          this.topProblemQuestionHistories = [];
-        }
-
         this.topProblemQuestionHistories.push(value);
       }
     });
 
-    if (!this.topProblemQuestionHistories) {
-      return;
-    }
-
     // Sort the array.
     this.topProblemQuestionHistories.sort((a, b) => {
       if (!a) {
@@ -169,25 +161,17 @@ export class UserStats {
 
   private clearNonProblemQuestions() {
     // TODO: Use a Set when/if TypeScript has one.
-    let idsToRemove: Map<string, boolean>;
+    const idsToRemove: Map<string, boolean> = new Map<string, boolean>();
     for (const history of this.topProblemQuestionHistories) {
       if (!history) {
         continue;
       }
 
       if (history.countAnsweredWrong <= 0) {
-        if (!idsToRemove) {
-          idsToRemove = new Map<string, boolean>();
-        }
-
         idsToRemove.set(history.questionId, true);
       }
     }
 
-    if (!idsToRemove) {
-      return;
-    }
-
     const list: UserQuestionHistory[] = [];
     for (const history of this.topProblemQuestionHistories) {
       if (!history) {

src/app/history.component.ts

@@ -13,20 +13,24 @@ import { UserHistorySectionsComponent } from "./user-history-sections.component"
 })
 export class HistoryComponent extends BaseComponent {
 
-  public quizId: string;
-  public quizTitle: string;
+  public quizId: string = "";
+  public quizTitle: string = "";
   @ViewChild(UserHistorySectionsComponent, { static: true })
-  private sectionsComponent: UserHistorySectionsComponent;
+  private sectionsComponent?: UserHistorySectionsComponent;
 
   constructor(private userHistoryService: UserHistoryService,
               titleService: Title) {
    super(titleService);
   }
 
   public onViewChildJsonParsed() {
-    const sections: UserHistorySections = this.sectionsComponent.userHistorySections;
-    this.quizId = sections.quizId;
-    this.quizTitle = sections.quizTitle;
+    if (this.sectionsComponent) {
+      const sections: UserHistorySections | undefined = this.sectionsComponent.userHistorySections;
+      if (sections) {
+        this.quizId = sections.quizId;
+        this.quizTitle = sections.quizTitle;
+      }
+    }
 
     this.setTitle("History: " + this.quizTitle);
   }

src/app/login.component.ts

@@ -1,6 +1,6 @@
 import { Component, Input, NgZone, OnInit } from "@angular/core";
 import { Title } from "@angular/platform-browser";
-import { ActivatedRoute, ParamMap } from "@angular/router";
+import {ActivatedRoute, ParamMap, Params} from "@angular/router";
 
 import { BaseComponent } from "./base.component";
 import { Config } from "./config";
@@ -20,10 +20,10 @@ export class LoginComponent extends BaseComponent implements OnInit {
   private static redirectSuffix = `?redirect=${Config.baseUrl}/user`;
   // We don't want to show the logout button in the header,
   // but we do want to show it on the user/profile page.
-  @Input() public showLogOutWhenAppropriate: boolean;
+  @Input() public showLogOutWhenAppropriate: boolean = false;
 
-  public loginInfo: LoginInfo;
-  public loginFailed: boolean;
+  public loginInfo?: LoginInfo;
+  public loginFailed: boolean = false;
   public googleLoginUrl = `${Config.googleLoginPrefix}${LoginComponent.redirectSuffix}`;
   public gitHubLoginUrl = `${Config.gitHubLoginPrefix}${LoginComponent.redirectSuffix}`;
   public facebookLoginUrl = `${Config.facebookLoginPrefix}${LoginComponent.redirectSuffix}`;