implement check command

check_command_test.go

@@ -0,0 +1,120 @@
+package resource_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"github.com/google/go-github/github"
+
+	"github.com/concourse/github-release-resource"
+	"github.com/concourse/github-release-resource/fakes"
+)
+
+var _ = Describe("Check Command", func() {
+	var (
+		githubClient *fakes.FakeGitHub
+		command      *resource.CheckCommand
+
+		returnedReleases []github.RepositoryRelease
+	)
+
+	BeforeEach(func() {
+		githubClient = &fakes.FakeGitHub{}
+		command = resource.NewCheckCommand(githubClient)
+
+		returnedReleases = []github.RepositoryRelease{}
+	})
+
+	JustBeforeEach(func() {
+		githubClient.ListReleasesReturns(returnedReleases, nil)
+	})
+
+	Context("when this is the first time that the resource has been run", func() {
+		Context("when there are no releases", func() {
+			BeforeEach(func() {
+				returnedReleases = []github.RepositoryRelease{}
+			})
+
+			It("returns an error when there are no releases", func() {
+				_, err := command.Run(resource.CheckRequest{})
+				Ω(err).Should(HaveOccurred())
+			})
+		})
+
+		Context("when there are releases", func() {
+			BeforeEach(func() {
+				returnedReleases = []github.RepositoryRelease{
+					{TagName: github.String("0.4.0")},
+					{TagName: github.String("0.1.3")},
+					{TagName: github.String("0.1.2")},
+				}
+			})
+
+			It("outputs the most recent version only", func() {
+				command := resource.NewCheckCommand(githubClient)
+
+				response, err := command.Run(resource.CheckRequest{})
+				Ω(err).ShouldNot(HaveOccurred())
+
+				Ω(response).Should(HaveLen(1))
+				Ω(response[0]).Should(Equal(resource.Version{
+					Tag: "0.4.0",
+				}))
+			})
+		})
+	})
+
+	Context("when there are prior versions", func() {
+		Context("when there are no releases", func() {
+			BeforeEach(func() {
+				returnedReleases = []github.RepositoryRelease{}
+			})
+
+			It("returns an error when there are no releases", func() {
+				_, err := command.Run(resource.CheckRequest{})
+				Ω(err).Should(HaveOccurred())
+			})
+		})
+
+		Context("when there are releases", func() {
+			BeforeEach(func() {
+				returnedReleases = []github.RepositoryRelease{
+					{TagName: github.String("0.4.0")},
+					{TagName: github.String("0.1.4")},
+					{TagName: github.String("0.1.3")},
+					{TagName: github.String("0.1.2")},
+				}
+			})
+
+			It("returns an empty list if the lastet version has been checked", func() {
+				command := resource.NewCheckCommand(githubClient)
+
+				response, err := command.Run(resource.CheckRequest{
+					Version: resource.Version{
+						Tag: "0.4.0",
+					},
+				})
+				Ω(err).ShouldNot(HaveOccurred())
+
+				Ω(response).Should(BeEmpty())
+			})
+
+			It("all of the versions that are newer", func() {
+				command := resource.NewCheckCommand(githubClient)
+
+				response, err := command.Run(resource.CheckRequest{
+					Version: resource.Version{
+						Tag: "0.1.3",
+					},
+				})
+				Ω(err).ShouldNot(HaveOccurred())
+
+				Ω(response).Should(HaveLen(2))
+				Ω(response).Should(Equal([]resource.Version{
+					{Tag: "0.1.4"},
+					{Tag: "0.4.0"},
+				}))
+			})
+		})
+	})
+})