add contest FetchIncoming command (#78)

Author: yuchiki

Dockerfile

@@ -3,6 +3,7 @@ WORKDIR /src
 COPY go.mod go.sum Makefile .git ./
 COPY cmd cmd
 COPY internal internal
+COPY pkg pkg
 RUN go mod download
 RUN make install
 

docs/cmd/ach_contest.md

@@ -4,6 +4,14 @@ set -eux
 mkdir work
 cd work
 
+# show incoming contests
+ach contest incoming
+
+# create a contest working directory
 ach contest create --default-template contestFoo
+
+# in a contest directory, ...
+
+# test command should succeeds
 cd contestFoo/A
 ach test

docs/cmd/ach_contest_incoming.md

@@ -3,6 +3,8 @@ package contest
 import (
 	"github.com/spf13/cobra"
 	"github.com/yuchiki/atcoderHelper/internal/cmd/ach/contest/create"
+	"github.com/yuchiki/atcoderHelper/internal/cmd/ach/contest/incoming"
+	"github.com/yuchiki/atcoderHelper/internal/repository"
 )
 
 func NewContestCmd() *cobra.Command {
@@ -19,4 +21,5 @@ func NewContestCmd() *cobra.Command {
 
 func registerSubcommands(cmd *cobra.Command) {
 	cmd.AddCommand(create.NewContestCreateCmd())
+	cmd.AddCommand(incoming.NewContestIncomingCmd(repository.FetchIncoming))
 }

integration/integration.sh

@@ -10,6 +10,7 @@ func TestAch_Execute(t *testing.T) {
 	testutil.TestCaseTemplates{
 		testutil.HasName("contest"),
 		testutil.HasSubcommands("create"),
+		testutil.HasSubcommands("incoming"),
 	}.
 		Build(NewContestCmd).
 		Run(t)

internal/cmd/ach/contest/contest.go

@@ -0,0 +1,29 @@
+package incoming
+
+import (
+	"github.com/spf13/cobra"
+	"github.com/yuchiki/atcoderHelper/internal/repository"
+)
+
+func NewContestIncomingCmd(fetcher func() ([]repository.ContestInfo, error)) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "incoming",
+		Short: "show incoming contests",
+		Long:  "show incoming contests.",
+		Args:  cobra.ExactArgs(0),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			contests, err := fetcher()
+			if err != nil {
+				return err
+			}
+
+			for _, contest := range contests {
+				cmd.Printf("%v: %v\n", contest.ID, contest.Name)
+			}
+
+			return nil
+		},
+	}
+
+	return cmd
+}

internal/cmd/ach/contest/contest_test.go

@@ -0,0 +1,43 @@
+package incoming
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/spf13/cobra"
+	"github.com/yuchiki/atcoderHelper/internal/repository"
+	"github.com/yuchiki/atcoderHelper/internal/testutil"
+)
+
+var errUnknownInRepositoryLayer = errors.New("an error thrown in fetcher function")
+
+func TestIncoming_Execute(t *testing.T) {
+	generateBuilder := func(infos []repository.ContestInfo, err error) func() *cobra.Command {
+		return func() *cobra.Command {
+			return NewContestIncomingCmd(func() ([]repository.ContestInfo, error) {
+				return infos, err
+			})
+		}
+	}
+
+	testutil.TestCaseTemplates{
+		testutil.HasName("incoming"),
+	}.Build(generateBuilder(nil, nil)).Run(t)
+
+	testutil.TestCases{
+		{
+			Name: "OK",
+			CmdBuilder: generateBuilder([]repository.ContestInfo{
+				{ID: "id1", Name: "name1"},
+				{ID: "id2", Name: "name2"},
+				{ID: "id3", Name: "name3"},
+			}, nil),
+			OutputCheck: testutil.OutputShouldBe("id1: name1\nid2: name2\nid3: name3\n"),
+		},
+		{
+			Name:       "returns an error when the repository layer fails",
+			CmdBuilder: generateBuilder(nil, errUnknownInRepositoryLayer),
+			ErrorCheck: testutil.AnyError(),
+		},
+	}.Run(t)
+}

internal/cmd/ach/contest/incoming/incoming.go

@@ -0,0 +1,104 @@
+package repository
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/yuchiki/atcoderHelper/pkg/queryablehtml"
+)
+
+const (
+	AtCoderURL   = "https://atcoder.jp"
+	IncomingPath = "/contests"
+)
+
+var errContestPathCannotBeParsed = errors.New("contest path cannot be parsed")
+
+type ContestInfo struct {
+	ID   string
+	Name string
+}
+
+// FetchIncoming fetches information of incoming contests.
+func FetchIncoming() ([]ContestInfo, error) {
+	node, err := queryablehtml.Fetch(AtCoderURL + IncomingPath)
+	if err != nil {
+		return nil, err
+	}
+
+	contestTRs, err := node.
+		GetNodeByID("contest-table-upcoming").
+		GetChildByTag("div").
+		GetChildByTag("div").
+		GetChildByTag("table").
+		GetChildByTag("tbody").
+		GetChildrenByTag("tr")
+	if err != nil {
+		return nil, err
+	}
+
+	contestInfos := []ContestInfo{}
+
+	for _, tr := range contestTRs {
+		contestInfo, err := trToContestInfo(tr)
+		if err != nil {
+			return nil, err
+		}
+
+		contestInfos = append(contestInfos, contestInfo)
+	}
+
+	return contestInfos, nil
+}
+
+func trToContestInfo(tr queryablehtml.QueryableNode) (ContestInfo, error) {
+	tds, err := tr.GetChildrenByTag("td")
+	if err != nil {
+		return ContestInfo{}, err
+	}
+
+	//nolint: gomnd
+	if len(tds) < 2 {
+		return ContestInfo{}, fmt.Errorf("second td does not exist: %w", queryablehtml.ErrNodeNotFound)
+	}
+
+	link := tds[1].GetChildByTag("a")
+	if link.Err != nil {
+		return ContestInfo{}, err
+	}
+
+	url, err := link.GetAttr("href")
+	if err != nil {
+		return ContestInfo{}, err
+	}
+
+	id, err := getContestID(url)
+	if err != nil {
+		return ContestInfo{}, err
+	}
+
+	name, err := link.GetText()
+	if err != nil {
+		return ContestInfo{}, err
+	}
+
+	return ContestInfo{
+		ID:   id,
+		Name: name,
+	}, nil
+}
+
+func getContestID(contestRelativePath string) (string, error) {
+	each := strings.Split(contestRelativePath, "/")
+
+	//nolint:gomnd
+	if len(each) != 3 {
+		return "", fmt.Errorf(
+			"path '%s' cannot be parsed: %w",
+			contestRelativePath,
+			errContestPathCannotBeParsed)
+	}
+
+	return each[2], nil
+}