Fix MR Selection, Go Code Refactor (#358)

refactor: Refactors the Go codebase into a more modular and idiomatic approach
fix: require selection of specific MR when there are multiple targets for a given source branch
feat: Allows for the passing of Gitlab's filter options when choosing an MR, improves MR selection
feat: API to choose an MR from a list based on the provided username's involvement as an assignee/reviewer/author

This is a #MINOR release

cmd/app/pipeline_test.go

@@ -0,0 +1,86 @@
+package app
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/xanzy/go-gitlab"
+)
+
+type fakePipelineManager struct {
+	testBase
+}
+
+func (f fakePipelineManager) ListProjectPipelines(pid interface{}, opt *gitlab.ListProjectPipelinesOptions, options ...gitlab.RequestOptionFunc) ([]*gitlab.PipelineInfo, *gitlab.Response, error) {
+	resp, err := f.handleGitlabError()
+	if err != nil {
+		return nil, nil, err
+	}
+	return []*gitlab.PipelineInfo{{ID: 1234}}, resp, err
+}
+
+func (f fakePipelineManager) ListPipelineJobs(pid interface{}, pipelineID int, opts *gitlab.ListJobsOptions, options ...gitlab.RequestOptionFunc) ([]*gitlab.Job, *gitlab.Response, error) {
+	resp, err := f.handleGitlabError()
+	if err != nil {
+		return nil, nil, err
+	}
+	return []*gitlab.Job{}, resp, err
+}
+
+func (f fakePipelineManager) RetryPipelineBuild(pid interface{}, pipeline int, options ...gitlab.RequestOptionFunc) (*gitlab.Pipeline, *gitlab.Response, error) {
+	resp, err := f.handleGitlabError()
+	if err != nil {
+		return nil, nil, err
+	}
+	return &gitlab.Pipeline{}, resp, err
+}
+
+func TestPipelineGetter(t *testing.T) {
+	t.Run("Gets all pipeline jobs", func(t *testing.T) {
+		request := makeRequest(t, http.MethodGet, "/pipeline", nil)
+		svc := pipelineService{testProjectData, fakePipelineManager{}, FakeGitManager{}}
+		data := getSuccessData(t, svc, request)
+		assert(t, data.Message, "Pipeline retrieved")
+		assert(t, data.Status, http.StatusOK)
+	})
+	t.Run("Disallows non-GET, non-POST methods", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPatch, "/pipeline", nil)
+		svc := pipelineService{testProjectData, fakePipelineManager{}, FakeGitManager{}}
+		data := getFailData(t, svc, request)
+		checkBadMethod(t, data, http.MethodGet, http.MethodPost)
+	})
+	t.Run("Handles errors from Gitlab client", func(t *testing.T) {
+		request := makeRequest(t, http.MethodGet, "/pipeline", nil)
+		svc := pipelineService{testProjectData, fakePipelineManager{testBase{errFromGitlab: true}}, FakeGitManager{}}
+		data := getFailData(t, svc, request)
+		checkErrorFromGitlab(t, data, "Failed to get latest pipeline for some-branch branch")
+	})
+	t.Run("Handles non-200s from Gitlab client", func(t *testing.T) {
+		request := makeRequest(t, http.MethodGet, "/pipeline", nil)
+		svc := pipelineService{testProjectData, fakePipelineManager{testBase: testBase{status: http.StatusSeeOther}}, FakeGitManager{}}
+		data := getFailData(t, svc, request)
+		assert(t, data.Message, "Failed to get latest pipeline for some-branch branch") // Expected, we treat this as an error
+	})
+}
+
+func TestPipelineTrigger(t *testing.T) {
+	t.Run("Retriggers pipeline", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPost, "/pipeline/trigger/3", nil)
+		svc := pipelineService{testProjectData, fakePipelineManager{}, FakeGitManager{}}
+		data := getSuccessData(t, svc, request)
+		assert(t, data.Message, "Pipeline retriggered")
+		assert(t, data.Status, http.StatusOK)
+	})
+	t.Run("Handles errors from Gitlab client", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPost, "/pipeline/trigger/3", nil)
+		svc := pipelineService{testProjectData, fakePipelineManager{testBase{errFromGitlab: true}}, FakeGitManager{}}
+		data := getFailData(t, svc, request)
+		checkErrorFromGitlab(t, data, "Could not retrigger pipeline")
+	})
+	t.Run("Handles non-200s from Gitlab client", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPost, "/pipeline/trigger/3", nil)
+		svc := pipelineService{testProjectData, fakePipelineManager{testBase: testBase{status: http.StatusSeeOther}}, FakeGitManager{}}
+		data := getFailData(t, svc, request)
+		checkNon200(t, data, "Could not retrigger pipeline", "/pipeline")
+	})
+}