TDD quiz (#29)

* reading csv

* refactored problem to it's own module

* new quiz test

* checks answer

* started tests for asking questions

* running quiz

* supporting flags

* able to set timer

* start timer

* fully running quiz

* renamed quiz to myquiz

students/hackeryarn/main.go

@@ -0,0 +1,120 @@
+package main
+
+import (
+	"encoding/csv"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"time"
+
+	quiz "github.com/gophercises/quiz/students/hackeryarn/myquiz"
+	"github.com/gophercises/quiz/students/hackeryarn/problem"
+)
+
+const (
+	// FileFlag is used to set a file for the questions
+	FileFlag = "file"
+	// FileFlagValue is the value used when no FileFlag is provided
+	FileFlagValue = "problems.csv"
+	// FileFlagUsage is the help string for the FileFlag
+	FileFlagUsage = "Questions file"
+
+	// TimerFlag is used for setting a timer for the quiz
+	TimerFlag = "timer"
+	// TimerFlagValue is the value used when no TimerFlag is provided
+	TimerFlagValue = 30
+	// TimerFlagUsage is the help string for the TimerFlag
+	TimerFlagUsage = "Amount of seconds the quiz will allow"
+)
+
+// Flagger configures the flags used
+type Flagger interface {
+	StringVar(p *string, name, value, usage string)
+	IntVar(p *int, name string, value int, usage string)
+}
+
+type quizFlagger struct{}
+
+func (q *quizFlagger) StringVar(p *string, name, value, usage string) {
+	flag.StringVar(p, name, value, usage)
+}
+
+func (q *quizFlagger) IntVar(p *int, name string, value int, usage string) {
+	flag.IntVar(p, name, value, usage)
+}
+
+// Timer is used to start a timer
+type Timer interface {
+	NewTimer(d time.Duration) *time.Timer
+}
+
+type quizTimer struct{}
+
+func (q quizTimer) NewTimer(d time.Duration) *time.Timer {
+	return time.NewTimer(d)
+}
+
+// ReadCSV parses the CSV file into a Problem struct
+func ReadCSV(reader io.Reader) quiz.Quiz {
+	csvReader := csv.NewReader(reader)
+
+	problems := []problem.Problem{}
+	for {
+		record, err := csvReader.Read()
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			log.Fatalln("Error reading CSV:", err)
+		}
+
+		problems = append(problems, problem.New(record))
+	}
+
+	return quiz.New(problems)
+}
+
+// TimerSeconds is the amount of time allowed for the quiz
+var TimerSeconds int
+var file string
+
+// ConfigFlags sets all the flags used by the application
+func ConfigFlags(f Flagger) {
+	f.StringVar(&file, FileFlag, FileFlagValue, FileFlagUsage)
+	f.IntVar(&TimerSeconds, TimerFlag, TimerFlagValue, TimerFlagUsage)
+}
+
+// StartTimer begins a timer once the user provides input
+func StartTimer(w io.Writer, r io.Reader, timer Timer) *time.Timer {
+	fmt.Fprint(w, "Ready to start?")
+	fmt.Fscanln(r)
+
+	return timer.NewTimer(time.Second * time.Duration(TimerSeconds))
+}
+
+func init() {
+	flagger := &quizFlagger{}
+	ConfigFlags(flagger)
+
+	flag.Parse()
+}
+
+func main() {
+	file, err := os.Open(file)
+	if err != nil {
+		log.Fatalln("Could not open file", err)
+	}
+
+	quiz := ReadCSV(file)
+
+	timer := StartTimer(os.Stdout, os.Stdin, quizTimer{})
+	go func() {
+		<-timer.C
+		fmt.Println("")
+		quiz.PrintResults(os.Stdout)
+		os.Exit(0)
+	}()
+
+	quiz.Run(os.Stdout, os.Stdin)
+}

students/hackeryarn/myquiz/myquiz.go

@@ -0,0 +1,40 @@
+package quiz
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/gophercises/quiz/students/hackeryarn/problem"
+)
+
+// Quiz represents the quiz to be given to the user
+type Quiz struct {
+	problems     []problem.Problem
+	rightAnswers int
+}
+
+// Run runs the quiz for all the problems keeping track of correct answers
+func (q *Quiz) Run(w io.Writer, r io.Reader) {
+	for _, problem := range q.problems {
+		problem.AskQuestion(w)
+		correct := problem.CheckAnswer(r)
+		if correct {
+			q.rightAnswers++
+		}
+	}
+
+	q.PrintResults(w)
+}
+
+// PrintResults outputs the results of the quiz
+func (q Quiz) PrintResults(w io.Writer) {
+	fmt.Fprintf(w, "You got %d questions right!\n", q.rightAnswers)
+}
+
+// New creates a new quiz from the supplied slice of problems
+func New(problems []problem.Problem) Quiz {
+	return Quiz{
+		problems:     problems,
+		rightAnswers: 0,
+	}
+}

students/hackeryarn/myquiz/myquiz_test.go

@@ -0,0 +1,66 @@
+package quiz
+
+import (
+	"bytes"
+	"io"
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/gophercises/quiz/students/hackeryarn/problem"
+)
+
+func TestNew(t *testing.T) {
+	problems := sampleProblems()
+
+	want := Quiz{problems: problems, rightAnswers: 0}
+	got := New(problems)
+
+	if !reflect.DeepEqual(want, got) {
+		t.Errorf("expeted to create quiz %v got %v", want, got)
+	}
+}
+
+func TestRun(t *testing.T) {
+	t.Run("it runs the quiz", func(t *testing.T) {
+		buffer := &bytes.Buffer{}
+		quiz := createQuiz()
+		runQuiz(buffer, &quiz)
+
+		expectedResults := 2
+		results := quiz.rightAnswers
+
+		if expectedResults != results {
+			t.Errorf("expected right answers of %v, got %v",
+				expectedResults, results)
+		}
+
+		expectedOutput := "7+3: 1+1: You got 2 questions right!\n"
+
+		if buffer.String() != expectedOutput {
+			t.Errorf("expected full output %v, got %v",
+				expectedOutput, buffer)
+		}
+
+	})
+}
+
+func sampleProblems() []problem.Problem {
+	record1 := []string{"7+3", "10"}
+	record2 := []string{"1+1", "2"}
+
+	return []problem.Problem{
+		problem.New(record1),
+		problem.New(record2),
+	}
+}
+
+func createQuiz() Quiz {
+	problems := sampleProblems()
+	return New(problems)
+}
+
+func runQuiz(buffer io.Writer, quiz *Quiz) {
+	answers := strings.NewReader("10\n2\n")
+	quiz.Run(buffer, answers)
+}

students/hackeryarn/problem/problem.go

@@ -0,0 +1,49 @@
+package problem
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"strings"
+)
+
+// Problem represents a single question answer pair
+type Problem struct {
+	question string
+	answer   string
+}
+
+// CheckAnswer checks the answer against the provided input
+func (p Problem) CheckAnswer(r io.Reader) bool {
+	answer := readAnswer(r)
+
+	if answer != p.answer {
+		return false
+	}
+	return true
+}
+
+func readAnswer(r io.Reader) (answer string) {
+	_, err := fmt.Fscanln(r, &answer)
+	if err != nil {
+		log.Fatalln("Error reading in answer", err)
+	}
+
+	return strings.TrimSpace(answer)
+}
+
+// AskQuestion prints out the question
+func (p Problem) AskQuestion(w io.Writer) {
+	_, err := fmt.Fprintf(w, "%s: ", p.question)
+	if err != nil {
+		log.Fatalln("Could not ask the question", err)
+	}
+}
+
+// New creates a Problem from a provided CSV record
+func New(record []string) Problem {
+	return Problem{
+		question: record[0],
+		answer:   record[1],
+	}
+}

students/hackeryarn/problem/problem_test.go

@@ -0,0 +1,68 @@
+package problem
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestNew(t *testing.T) {
+	record := []string{"question", "answer"}
+
+	want := Problem{"question", "answer"}
+	got := New(record)
+
+	if got != want {
+		t.Errorf("expected to create problem %v got %v", want, got)
+	}
+}
+
+func TestCheckAnswer(t *testing.T) {
+	problem := createProblem()
+
+	t.Run("it checks the correct answer", func(t *testing.T) {
+		answer := getAnswer(problem, "10\n")
+
+		checkAnswer(t, answer, true)
+	})
+
+	t.Run("it checks incorrect answer", func(t *testing.T) {
+		answer := getAnswer(problem, "2\n")
+
+		checkAnswer(t, answer, false)
+	})
+}
+
+func TestAskQuestion(t *testing.T) {
+	problem := createProblem()
+
+	t.Run("it asks the question", func(t *testing.T) {
+		buffer := bytes.NewBuffer(nil)
+
+		problem.AskQuestion(buffer)
+
+		want := "7+3: "
+		got := buffer.String()
+
+		if want != got {
+			t.Errorf("Expected question %s, got %s", want, got)
+		}
+	})
+
+}
+
+func createProblem() Problem {
+	record := []string{"7+3", "10"}
+	return New(record)
+}
+
+func getAnswer(problem Problem, input string) bool {
+	r := bytes.NewBufferString(input)
+
+	return problem.CheckAnswer(r)
+}
+
+func checkAnswer(t *testing.T, got, want bool) {
+	if want != got {
+		t.Errorf("Expected to return %v got %v", want, got)
+	}
+}

students/hackeryarn/problems.csv

@@ -0,0 +1,12 @@
+5+5,10
+1+1,2
+8+3,11
+1+2,3
+8+6,14
+3+1,4
+1+4,5
+5+1,6
+2+3,5
+3+3,6
+2+4,6
+5+2,7