Add pagination to "List files in PR" api call (#174)

* Support pagination for "List files in PR" API call
+relevant test

internal/pkg/githubapi/promotion.go

@@ -111,12 +111,21 @@ func getComponentConfig(ghPrClientDetails GhPrClientDetails, componentPath strin
 
 func GeneratePromotionPlan(ghPrClientDetails GhPrClientDetails, config *cfg.Config, configBranch string) (map[string]PromotionInstance, error) {
 	promotions := make(map[string]PromotionInstance)
+	opts := &github.ListOptions{}
+	prFiles := []*github.CommitFile{}
 
-	prFiles, resp, err := ghPrClientDetails.GhClientPair.v3Client.PullRequests.ListFiles(ghPrClientDetails.Ctx, ghPrClientDetails.Owner, ghPrClientDetails.Repo, ghPrClientDetails.PrNumber, &github.ListOptions{})
-	prom.InstrumentGhCall(resp)
-	if err != nil {
-		ghPrClientDetails.PrLogger.Errorf("could not get file list from GH API: err=%s\nresponse=%v", err, resp)
-		return promotions, err
+	for {
+		perPagePrFiles, resp, err := ghPrClientDetails.GhClientPair.v3Client.PullRequests.ListFiles(ghPrClientDetails.Ctx, ghPrClientDetails.Owner, ghPrClientDetails.Repo, ghPrClientDetails.PrNumber, opts)
+		prom.InstrumentGhCall(resp)
+		if err != nil {
+			ghPrClientDetails.PrLogger.Errorf("could not get file list from GH API: err=%s\nstatus code=%v", err, resp.Response.Status)
+			return promotions, err
+		}
+		prFiles = append(prFiles, perPagePrFiles...)
+		if resp.NextPage == 0 {
+			break
+		}
+		opts.Page = resp.NextPage
 	}
 
 	//first we build a **unique** list of relevant directories

internal/pkg/githubapi/promotion_test.go

@@ -481,3 +481,55 @@ func TestGenerateNestedSourceRegexPromotionPlan(t *testing.T) {
 	)
 	generatePromotionPlanTestHelper(t, config, expectedPromotion, mockedHTTPClient)
 }
+
+func TestGeneratePromotionPlanWithPagination(t *testing.T) {
+	t.Parallel()
+	config := &cfg.Config{
+		PromotionPaths: []cfg.PromotionPath{
+			{
+				SourcePath: "prod/us-east-4/",
+				PromotionPrs: []cfg.PromotionPr{
+					{
+						TargetPaths: []string{
+							"prod/eu-west-1/",
+							"prod/eu-east-1/",
+						},
+					},
+				},
+			},
+		},
+	}
+	expectedPromotion := map[string]PromotionInstance{
+		"prod/us-east-4/>prod/eu-east-1/|prod/eu-west-1/": {
+			ComputedSyncPaths: map[string]string{
+				"prod/eu-east-1/componentA": "prod/us-east-4/componentA",
+				"prod/eu-west-1/componentA": "prod/us-east-4/componentA",
+			},
+		},
+	}
+	// Note the "relevant" files are in the second page, to ensure pagination is working
+	mockedHTTPClient := mock.NewMockedHTTPClient(
+		mock.WithRequestMatchPages(
+			mock.GetReposPullsFilesByOwnerByRepoByPullNumber,
+			[]github.CommitFile{
+				{Filename: github.String(".ci-config/random-file.json")},
+				{Filename: github.String(".ci-config/random-file2.json")},
+			},
+			[]github.CommitFile{
+				{Filename: github.String("prod/us-east-4/componentA/file.yaml")},
+				{Filename: github.String("prod/us-east-4/componentA/file2.yaml")},
+			},
+		),
+		mock.WithRequestMatchHandler(
+			mock.GetReposContentsByOwnerByRepoByPath,
+			http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				mock.WriteError(
+					w,
+					http.StatusNotFound,
+					"no *optional* in-component telefonistka config file",
+				)
+			}),
+		),
+	)
+	generatePromotionPlanTestHelper(t, config, expectedPromotion, mockedHTTPClient)
+}