Issue #21: Post Form Answer and Validate it

Signed-off-by: Matheus Horstmann <mch15@inf.ufpr.br>

CHANGELOG.md

@@ -4,6 +4,16 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 0.0.19 - 12-06-2019
+### Added
+- A route to POST a form Answer #21 (Horstmann)
+- Create ValidationError Class that extends error class, with the objective to return a dictionary of invalid answers (Horstmann)
+### Changed
+- DbHandler's tests to suite with new forms answers added (Horstmann)
+- ValidationHandler to validate a Forms Answer instead of inputsAnswer
+- ValidationHandler's tests to suite new method to validate a Forms Answer
+
+
 ## 0.0.18 - 25-05-2019
 ### Added
 - Create readFormAnswer method to read formAnswer from database #24 (Horstmann)
@@ -12,6 +22,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 - Fix OptHandler to return id in inputAnswer
 
+
 ## 0.0.17 - 25-05-2019
 ### Added
 - inputAnswer method in OptHandler #23 (Horstmann)

package.json

 {
   "name": "form-creator-api",
-  "version": "0.0.18",
+  "version": "0.0.19",
   "description": "RESTful API used to manage and answer forms.",
   "main": "index.js",
   "scripts": {

src/api/controllers/formAnswer.spec.ts

+/*
+ * form-creator-api. RESTful API to manage and answer forms.
+ * Copyright (C) 2019 Centro de Computacao Cientifica e Software Livre
+ * Departamento de Informatica - Universidade Federal do Parana - C3SL/UFPR
+ *
+ * This file is part of form-creator-api.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+ import * as request from "supertest";
+ import { expect } from "chai";
+ import * as server from "../../main";
+ import { EnumHandler,InputType, ValidationType } from "../../utils/enumHandler";
+ import { TestHandler } from "../../utils/testHandler";
+ import { OptHandler } from "../../utils/optHandler";
+ import { Form, FormOptions } from "../../core/form";
+ import { Input, InputOptions, Validation } from "../../core/input";
+
+
+ describe("API data controller", () => {
+
+        it("should respond 200 when posting valid form Answer", (done) => {
+
+             request(server)
+                 .post("/answer/1")
+                 .send({
+                     1:["Answer to Question 1 Form 1"]
+                     , 2:["12345-000"]
+                     , 3:["MAXCHAR 10"]
+                })
+                .expect(200)
+                .expect((res: any) => {
+                    expect(res.body.id).to.be.equal(7);
+                    expect(res.body.message).to.be.equal("Answered");
+                })
+                .end(done);
+        });
+
+        it("should respond 500 when posting invalid form Answer", (done) => {
+
+             request(server)
+                 .post("/answer/1")
+                 .send({
+                     1:["Answer to Question 1 Form 1"]
+                     , 2:["12a345-000"]
+                     , 3:["MAXCHAR 10 AND MORE"]
+                })
+                .expect(500)
+                .expect((res: any) => {
+                    const message = "Could not Create form Answer. Some error has occurred. Check error property for details.";
+                    expect(res.body).to.be.an("object");
+                    expect(res.body).to.have.property("error");
+                    expect(res.body.message).to.be.equal(message);
+                    expect(res.body.error["2"]).to.be.equal("RegEx do not match");
+                    expect(res.body.error["3"]).to.be.equal("Input answer must be lower than 10");
+                })
+                .end(done);
+        });
+
+ });

src/api/controllers/formAnswer.ts

+/*
+ * form-creator-api. RESTful API to manage and answer forms.
+ * Copyright (C) 2019 Centro de Computacao Cientifica e Software Livre
+ * Departamento de Informatica - Universidade Federal do Parana - C3SL/UFPR
+ *
+ * This file is part of form-creator-api.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import { OptHandler } from "../../utils/optHandler";
+import { InputAnswerOptions, InputAnswerOptionsDict } from "../../core/inputAnswer";
+import { Form, FormOptions } from "../../core/form";
+import { FormAnswer, FormAnswerOptions } from "../../core/formAnswer";
+import { ValidationHandler } from "../../utils/validationHandler";
+import { Response, NextFunction } from "express";
+import { Request } from "../apiTypes";
+
+export class AnswerCtrl {
+
+    public static write(req: Request, res: Response, next: NextFunction) {
+
+        req.db.readForm(req.params.id, (err: Error, form?: Form) => {
+            if (err) {
+                res.status(500).json({
+                    message: "Form with id: '" + req.params.id + "' not found. Some error has occurred. Check error property for details.",
+                    error: err
+                });
+                return;
+            }
+            else {
+                let inputAnswerOptionsDict: InputAnswerOptionsDict = {}
+
+                for (const key of Object.keys(req.body)) {
+                    inputAnswerOptionsDict[parseInt(key, 10)] = [];
+                    for (const i in req.body[key]) {
+                        const tmpInputAnswerOption: InputAnswerOptions = {
+                            idInput: parseInt(key, 10)
+                            , placement: parseInt(i, 10)
+                            , value: req.body[key][i]
+                        }
+                        inputAnswerOptionsDict[parseInt(key, 10)].push(tmpInputAnswerOption);
+                    }
+                }
+
+
+                let formAnswerOpt: FormAnswerOptions = {
+                    form: form
+                    , timestamp: new Date(Date.now())
+                    , inputsAnswerOptions: inputAnswerOptionsDict
+                }
+
+                try{
+                    const formAnswer: FormAnswer = new FormAnswer(OptHandler.formAnswer(formAnswerOpt));
+                    ValidationHandler.validateFormAnswer(formAnswer);
+                    req.db.writeFormAnswer(formAnswer, (err: Error, formAnswerResult: FormAnswer) => {
+                        if (err){
+                            throw err;
+                        }
+                        else{
+                            res.json({
+                                id: formAnswerResult.id
+                                , message: "Answered"
+                            });
+                           return;
+                        }
+                    });
+                }
+                catch (e) {
+
+                    if( e.validationDict !== undefined){
+                        res.status(500).json({
+                            message: "Could not Create form Answer. Some error has occurred. Check error property for details."
+                            , error: e.validationDict
+                        });
+                    }else{
+                        res.status(500).json({
+                            message: "Could not Create form Answer. Some error has occurred. Check error property for details."
+                            , error: e.message
+                        });
+                    }
+                    return
+                }
+
+            }
+        });
+
+    }
+
+
+}

src/main.ts

@@ -40,6 +40,7 @@ import { DbHandlerMw } from "./api/middlewares/dbHandler";
 
 // Include controllers
 import { FormCtrl } from "./api/controllers/form";
+import { AnswerCtrl } from "./api/controllers/formAnswer";
 
 // Setup middlewares
 app.use("/", bodyParser.json());
@@ -50,6 +51,7 @@ app.use("/", DbHandlerMw());
 app.get("/forms/", FormCtrl.list);
 app.get("/forms/:id", FormCtrl.read);
 app.post("/forms", FormCtrl.write);
+app.post("/answer/:id", AnswerCtrl.write);
 
 
 // Listening

src/utils/dbHandler.spec.ts

@@ -267,10 +267,10 @@ describe("Database Handler", () => {
     });
 
     it("should insert a form answers", (done) => {
-        const queryString: string = "INSERT INTO form_answer(id, id_form, answered_at)\
+        const queryString: string = "INSERT INTO form_answer(id ,id_form, answered_at)\
         VALUES\
-        (7, 2, '2018-07-02 10:10:25-03'),\
-        (8, 3, '2018-06-03 10:11:25-03');";
+        (8, 2, '2018-07-02 10:10:25-03'),\
+        (9, 3, '2018-06-03 10:11:25-03');";
         const query: QueryOptions = {query: queryString, parameters: []};
 
         dbhandler.executeQuery(query, (err: Error, result?: QueryResult) => {
@@ -288,7 +288,7 @@ describe("Database Handler", () => {
         dbhandler.executeQuery(query, (err: Error, result?: QueryResult) => {
             expect(err).to.be.a("null");
             expect(result.command).to.be.equal("SELECT");
-            expect(result.rowCount).to.be.equal(8);
+            expect(result.rowCount).to.be.equal(9);
             done();
         });
     });
@@ -306,7 +306,7 @@ describe("Database Handler", () => {
     });
 
     it("should remove existent form answers", (done) => {
-        const queryString: string = "DELETE FROM form_answer WHERE id=7 OR id=8;";
+        const queryString: string = "DELETE FROM form_answer WHERE id=8 OR id=9;";
         const query: QueryOptions = {query: queryString, parameters: []};
 
         dbhandler.executeQuery(query, (err: Error, result?: QueryResult) => {
@@ -321,8 +321,8 @@ describe("Database Handler", () => {
     it("should insert a input answers", (done) => {
         const queryString: string = "INSERT INTO input_answer(id, id_form_answer, id_input, value, placement)\
         VALUES\
-        (15,1, 6,'Answer to Question 1 Form 3',1),\
-        (16,1, 7,'Answer to Question 2 Form 3',2);";
+        (18,1, 6,'Answer to Question 1 Form 3',1),\
+        (19,1, 7,'Answer to Question 2 Form 3',2);";
         const query: QueryOptions = {query: queryString, parameters: []};
 
         dbhandler.executeQuery(query, (err: Error, result?: QueryResult) => {
@@ -340,13 +340,13 @@ describe("Database Handler", () => {
         dbhandler.executeQuery(query, (err: Error, result?: QueryResult) => {
             expect(err).to.be.a("null");
             expect(result.command).to.be.equal("SELECT");
-            expect(result.rowCount).to.be.equal(16);
+            expect(result.rowCount).to.be.equal(19);
             done();
         });
     });
 
     it("should remove non existent input answer", (done) => {
-        const queryString: string = "DELETE FROM input_answer WHERE id=17;";
+        const queryString: string = "DELETE FROM input_answer WHERE id=25;";
         const query: QueryOptions = {query: queryString, parameters: []};
 
         dbhandler.executeQuery(query, (err: Error, result?: QueryResult) => {
@@ -358,7 +358,7 @@ describe("Database Handler", () => {
     });
 
     it("should remove existent input answers", (done) => {
-        const queryString: string = "DELETE FROM input_answer WHERE id=15 OR id=16;";
+        const queryString: string = "DELETE FROM input_answer WHERE id=18 OR id=19;";
         const query: QueryOptions = {query: queryString, parameters: []};
 
         dbhandler.executeQuery(query, (err: Error, result?: QueryResult) => {
@@ -573,8 +573,8 @@ describe("Read and Write on Database", () => {
 
            dbhandler.writeFormAnswer(formAnswer, (err: Error, formAnswerResult: FormAnswer) => {
                expect(err).to.be.a("null");
-               expect(formAnswerResult.id).to.be.equal(7);
-               let inputAnswerId: number = 15;
+               expect(formAnswerResult.id).to.be.equal(8);
+               let inputAnswerId: number = 18;
                for (const key of Object.keys(formAnswerResult.inputAnswers)){
                    for (const inputAnswer of formAnswerResult.inputAnswers[parseInt(key, 10)]){
                        expect(inputAnswer.id).to.be.equal(inputAnswerId);

src/utils/validationError.spec.ts

+/*
+ * form-creator-api. RESTful API to manage and answer forms.
+ * Copyright (C) 2019 Centro de Computacao Cientifica e Software Livre
+ * Departamento de Informatica - Universidade Federal do Parana - C3SL/UFPR
+ *
+ * This file is part of form-creator-api.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */

src/utils/validationError.ts

+/*
+ * form-creator-api. RESTful API to manage and answer forms.
+ * Copyright (C) 2019 Centro de Computacao Cientifica e Software Livre
+ * Departamento de Informatica - Universidade Federal do Parana - C3SL/UFPR
+ *
+ * This file is part of form-creator-api.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+ /**
+  * Parameters used to create a dictionary to uses as an object of erro, returning all validations erros just once
+  */
+ export interface ValidationDict {
+      /** A key is a identifier of a Input instance, and the string is all invalid messages */
+     [key: number]: string;
+ }
+
+ /**
+  * ValidationError: Extends Error class
+  * Has a dict that allow us to know which answer is invalide
+  */
+ export class ValidationError extends Error{
+     /** A dict that allows user to know which Input Answer is invalid. */
+     public readonly validationDict: ValidationDict;
+
+     constructor(validationDict: ValidationDict, ...params: any[]){
+         super(...params);
+         this.validationDict = validationDict;
+     }
+ }

src/utils/validationHandler.spec.ts

@@ -20,84 +20,168 @@
  */
 
 import { expect } from "chai";
-import { Input, InputOptions, Validation } from "../core/input";
+import { Form } from "../core/form";
+import { FormAnswer, FormAnswerOptions } from "../core/formAnswer";
+import { InputAnswerOptions, InputAnswerOptionsDict } from "../core/inputAnswer";
+import { configs } from "./config";
+import { DbHandler } from "./dbHandler";
 import { EnumHandler, InputType, ValidationType } from "./enumHandler";
 import { OptHandler } from "./optHandler";
-import {ValidationHandler } from "./validationHandler";
+import { ValidationHandler } from "./validationHandler";
 
 describe("Validation Handler", () => {
-    it("should test when Input is mandatory", () => {
+    const dbhandler = new DbHandler(configs.poolconfig);
 
-        const inputObj: InputOptions = {
-            placement: 0
-            , description: "Description"
-            , question: "Question"
-            , type: InputType.TEXT
-            , validation: [
-                { type: ValidationType.MANDATORY, arguments: [] }
-            ]
+    it("should test when Input has a minimum char number", (done) => {
+        const inputAnswersOpt1: InputAnswerOptions = {
+            idInput: 4
+            , placement: 0
+            , value: "MIN 8"
+        };
+        const inputAnswersOpt2: InputAnswerOptions = {
+            idInput: 5
+            , placement: 0
+            , value: "Answer to Question 2 Form 2"
+        };
+        const inputAnswerOptionsDict: InputAnswerOptionsDict = {
+            4: [inputAnswersOpt1]
+            , 5: [inputAnswersOpt2]
         };
 
-        const input = new Input (OptHandler.input(inputObj));
-        expect(ValidationHandler.validateInput(input, "FOOL")).to.be.true;
-        expect(ValidationHandler.validateInput(input, "")).to.be.false;
-        expect(ValidationHandler.validateInput(input, null)).to.be.false;
-        expect(ValidationHandler.validateInput(input, undefined)).to.be.false;
+        const data: Date = new Date(2019, 6, 4);
+        dbhandler.readForm(2, (error: Error, form: Form) => {
+            const formAnswerOptions: FormAnswerOptions = {
+                form
+                , timestamp: data
+                , inputsAnswerOptions: inputAnswerOptionsDict
+            };
+            const formAnswer = new FormAnswer(OptHandler.formAnswer(formAnswerOptions));
+            try {
+                ValidationHandler.validateFormAnswer(formAnswer);
+            } catch (e) {
+                expect(e.validationDict["4"]).to.be.equal("Input answer must be greater than 8");
+                expect(e.validationDict["5"]).to.be.a("undefined");
+            }
+            done();
+        });
     });
 
-    it("should test when Input has a regex", () => {
-        const inputObj: InputOptions = {
-            placement: 0
-            , description: "Description"
-            , question: "Question"
-            , type: InputType.TEXT
-            , validation: [
-                { type: ValidationType.REGEX, arguments: ["\\d{5}-\\d{3}"] }
-            ]
+    it("should test when Input is mandatory", (done) => {
+        const inputAnswersOpt1: InputAnswerOptions = {
+            idInput: 4
+            , placement: 0
+            , value: "Answer to Question 1 Form 2"
+        };
+        const inputAnswersOpt2: InputAnswerOptions = {
+            idInput: 5
+            , placement: 0
+            , value: ""
+        };
+        const inputAnswerOptionsDict: InputAnswerOptionsDict = {
+            4: [inputAnswersOpt1]
+            , 5: [inputAnswersOpt2]
         };
-        const input = new Input (OptHandler.input(inputObj));
-        expect(ValidationHandler.validateInput(input, "88888-888")).to.be.true;
-        expect(ValidationHandler.validateInput(input, "88888-88")).to.be.false;
-        expect(ValidationHandler.validateInput(input, "")).to.be.false;
-        expect(ValidationHandler.validateInput(input, null)).to.be.false;
-        expect(ValidationHandler.validateInput(input, undefined)).to.be.false;
+
+        const data: Date = new Date(2019, 6, 4);
+        dbhandler.readForm(2, (error: Error, form: Form) => {
+            const formAnswerOptions: FormAnswerOptions = {
+                form
+                , timestamp: data
+                , inputsAnswerOptions: inputAnswerOptionsDict
+            };
+            const formAnswer = new FormAnswer(OptHandler.formAnswer(formAnswerOptions));
+            try {
+                ValidationHandler.validateFormAnswer(formAnswer);
+            } catch (e) {
+                expect(e.validationDict["4"]).to.be.a("undefined");
+                expect(e.validationDict["5"]).to.be.equal("Input answer is mandatory");
+            }
+            done();
+        });
     });
 
-    it("should test when Input has a minimum char number", () => {
-        const inputObj: InputOptions = {
-            placement: 0
-            , description: "Description"
-            , question: "Question"
-            , type: InputType.TEXT
-            , validation: [
-                { type: ValidationType.MINCHAR, arguments: ["5"] }
-            ]
+    it("should test when Input has a maximum char number", (done) => {
+
+        const inputAnswersOpt1: InputAnswerOptions = {
+            idInput: 1
+            , placement: 0
+            , value: "Answer to Question 1 Form 1"
+        };
+        const inputAnswersOpt2: InputAnswerOptions = {
+            idInput: 2
+            , placement: 0
+            , value: "12345-000"
+        };
+        const inputAnswersOpt3: InputAnswerOptions = {
+            idInput: 3
+            , placement: 0
+            , value: "MORE THEN 10 CHAR"
         };
-        const input = new Input (OptHandler.input(inputObj));
+        const inputAnswerOptionsDict: InputAnswerOptionsDict = {
+            1: [inputAnswersOpt1]
+            , 2: [inputAnswersOpt2]
+            , 3: [inputAnswersOpt3]
+        };
+        const data: Date = new Date(2019, 6, 4);
+        dbhandler.readForm(1, (error: Error, form: Form) => {
+            const formAnswerOptions: FormAnswerOptions = {
+                form
+                , timestamp: data
+                , inputsAnswerOptions: inputAnswerOptionsDict
+            };
+            const formAnswer = new FormAnswer(OptHandler.formAnswer(formAnswerOptions));
+            try {
+                ValidationHandler.validateFormAnswer(formAnswer);
+            } catch (e) {
+                expect(e.validationDict["1"]).to.be.a("undefined");
+                expect(e.validationDict["2"]).to.be.a("undefined");
+                expect(e.validationDict["3"]).to.be.equal("Input answer must be lower than 10");
+            }
+            done();
+        });
 
-        expect(ValidationHandler.validateInput(input, "12345")).to.be.true;
-        expect(ValidationHandler.validateInput(input, "123456")).to.be.true;
-        expect(ValidationHandler.validateInput(input, "1234")).to.be.false;
-        expect(ValidationHandler.validateInput(input, "")).to.be.false;
-        expect(ValidationHandler.validateInput(input, null)).to.be.false;
-        expect(ValidationHandler.validateInput(input, undefined)).to.be.false;
     });
-    it("should test when Input has a maximum char number", () => {
-        const inputObj: InputOptions = {
-            placement: 0
-            , description: "Description"
-            , question: "Question"
-            , type: InputType.TEXT
-            , validation: [
-                { type: ValidationType.MAXCHAR, arguments: ["5"] }
-            ]
+
+    it("should test when Input has a RegEx", (done) => {
+
+        const inputAnswersOpt1: InputAnswerOptions = {
+            idInput: 1
+            , placement: 0
+            , value: "Answer to Question 1 Form 1"
+        };
+        const inputAnswersOpt2: InputAnswerOptions = {
+            idInput: 2
+            , placement: 0
+            , value: "12aa345-000"
         };
-        const input = new Input (OptHandler.input(inputObj));
-        expect(ValidationHandler.validateInput(input, "1234")).to.be.true;
-        expect(ValidationHandler.validateInput(input, "12345")).to.be.true;
-        expect(ValidationHandler.validateInput(input, "")).to.be.true;
-        expect(ValidationHandler.validateInput(input, "123456")).to.be.false;
-        expect(ValidationHandler.validateInput(input, null)).to.be.false;
-        expect(ValidationHandler.validateInput(input, undefined)).to.be.false;
+        const inputAnswersOpt3: InputAnswerOptions = {
+            idInput: 3
+            , placement: 0
+            , value: "MAXCHAR 10"
+        };
+        const inputAnswerOptionsDict: InputAnswerOptionsDict = {
+            1: [inputAnswersOpt1]
+            , 2: [inputAnswersOpt2]
+            , 3: [inputAnswersOpt3]
+        };
+        const data: Date = new Date(2019, 6, 4);
+        dbhandler.readForm(1, (error: Error, form: Form) => {
+            const formAnswerOptions: FormAnswerOptions = {
+                form
+                , timestamp: data
+                , inputsAnswerOptions: inputAnswerOptionsDict
+            };
+            const formAnswer = new FormAnswer(OptHandler.formAnswer(formAnswerOptions));
+            try {
+                ValidationHandler.validateFormAnswer(formAnswer);
+            } catch (e) {
+                expect(e.validationDict["1"]).to.be.a("undefined");
+                expect(e.validationDict["3"]).to.be.a("undefined");
+                expect(e.validationDict["2"]).to.be.equal("RegEx do not match");
+            }
+            done();
+        });
+
     });
+
 });

src/utils/validationHandler.ts

@@ -19,8 +19,10 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+import { FormAnswer } from "../core/formAnswer";
 import { Input } from "../core/input";
 import { ValidationType } from "./enumHandler";
+import { ValidationDict, ValidationError  } from "./validationError";
 
 /**
  * Validation's handler. Manage parse validation through the project.
@@ -71,30 +73,54 @@ export class ValidationHandler {
      * Validate if answer has minimum number of chars
      * @param input - Input to validate answer.
      * @param answer - Answer of input
-     * @returns - true if answer is valid according a given Input.
+     * @returns - A string with all errors.
      */
-    public static