fix gh run download <run-id> not getting > 100 artifacts (#5799)

Co-authored-by: Mislav Marohnić <mislav@github.com>

pkg/cmd/run/shared/artifacts.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"regexp"
 
 	"github.com/cli/cli/v2/api"
 	"github.com/cli/cli/v2/internal/ghinstance"
@@ -17,37 +18,69 @@ type Artifact struct {
 	Expired     bool   `json:"expired"`
 }
 
+type artifactsPayload struct {
+	Artifacts []Artifact
+}
+
 func ListArtifacts(httpClient *http.Client, repo ghrepo.Interface, runID string) ([]Artifact, error) {
+	var results []Artifact
+
 	perPage := 100
 	path := fmt.Sprintf("repos/%s/%s/actions/artifacts?per_page=%d", repo.RepoOwner(), repo.RepoName(), perPage)
 	if runID != "" {
 		path = fmt.Sprintf("repos/%s/%s/actions/runs/%s/artifacts?per_page=%d", repo.RepoOwner(), repo.RepoName(), runID, perPage)
 	}
 
-	req, err := http.NewRequest("GET", ghinstance.RESTPrefix(repo.RepoHost())+path, nil)
+	url := fmt.Sprintf("%s%s", ghinstance.RESTPrefix(repo.RepoHost()), path)
+
+	for {
+		var payload artifactsPayload
+		nextURL, err := apiGet(httpClient, url, &payload)
+		if err != nil {
+			return nil, err
+		}
+		results = append(results, payload.Artifacts...)
+
+		if nextURL == "" {
+			break
+		}
+		url = nextURL
+	}
+
+	return results, nil
+}
+
+func apiGet(httpClient *http.Client, url string, data interface{}) (string, error) {
+	req, err := http.NewRequest("GET", url, nil)
 	if err != nil {
-		return nil, err
+		return "", err
 	}
 
 	resp, err := httpClient.Do(req)
 	if err != nil {
-		return nil, err
+		return "", err
 	}
 	defer resp.Body.Close()
 
 	if resp.StatusCode > 299 {
-		return nil, api.HandleHTTPError(resp)
-	}
-
-	var response struct {
-		TotalCount uint16 `json:"total_count"`
-		Artifacts  []Artifact
+		return "", api.HandleHTTPError(resp)
 	}
 
 	dec := json.NewDecoder(resp.Body)
-	if err := dec.Decode(&response); err != nil {
-		return response.Artifacts, fmt.Errorf("error parsing JSON: %w", err)
+	if err := dec.Decode(data); err != nil {
+		return "", err
 	}
 
-	return response.Artifacts, nil
+	return findNextPage(resp), nil
+}
+
+var linkRE = regexp.MustCompile(`<([^>]+)>;\s*rel="([^"]+)"`)
+
+func findNextPage(resp *http.Response) string {
+	for _, m := range linkRE.FindAllStringSubmatch(resp.Header.Get("Link"), -1) {
+		if len(m) > 2 && m[2] == "next" {
+			return m[1]
+		}
+	}
+	return ""
 }

pkg/cmd/run/shared/artifacts_test.go

@@ -0,0 +1,66 @@
+package shared
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+	"testing"
+
+	"github.com/cli/cli/v2/internal/ghrepo"
+	"github.com/cli/cli/v2/pkg/httpmock"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDownloadWorkflowArtifactsPageinates(t *testing.T) {
+	testRepoOwner := "OWNER"
+	testRepoName := "REPO"
+	testRunId := "1234567890"
+
+	reg := &httpmock.Registry{}
+	defer reg.Verify(t)
+
+	firstReq := httpmock.QueryMatcher(
+		"GET",
+		fmt.Sprintf("repos/%s/%s/actions/runs/%s/artifacts", testRepoOwner, testRepoName, testRunId),
+		url.Values{"per_page": []string{"100"}},
+	)
+
+	firstArtifact := Artifact{
+		Name:        "artifact-0",
+		Size:        2,
+		DownloadURL: fmt.Sprintf("https://api.github.com/repos/%s/%s/actions/artifacts/987654320/zip", testRepoOwner, testRepoName),
+		Expired:     true,
+	}
+	firstRes := httpmock.JSONResponse(artifactsPayload{Artifacts: []Artifact{firstArtifact}})
+	testLinkUri := fmt.Sprintf("repositories/123456789/actions/runs/%s/artifacts", testRunId)
+	testLinkUrl := fmt.Sprintf("https://api.github.com/%s", testLinkUri)
+	firstRes = httpmock.WithHeader(
+		firstRes,
+		"Link",
+		fmt.Sprintf(`<%s?per_page=100&page=2>; rel="next", <%s?per_page=100&page=2>; rel="last"`, testLinkUrl, testLinkUrl),
+	)
+
+	secondReq := httpmock.QueryMatcher(
+		"GET",
+		testLinkUri,
+		url.Values{"per_page": []string{"100"}, "page": []string{"2"}},
+	)
+
+	secondArtifact := Artifact{
+		Name:        "artifact-1",
+		Size:        2,
+		DownloadURL: fmt.Sprintf("https://api.github.com/repos/%s/%s/actions/artifacts/987654321/zip", testRepoOwner, testRepoName),
+		Expired:     false,
+	}
+	secondRes := httpmock.JSONResponse(artifactsPayload{Artifacts: []Artifact{secondArtifact}})
+
+	reg.Register(firstReq, firstRes)
+	reg.Register(secondReq, secondRes)
+
+	httpClient := &http.Client{Transport: reg}
+	repo := ghrepo.New(testRepoOwner, testRepoName)
+
+	result, err := ListArtifacts(httpClient, repo, testRunId)
+	assert.NoError(t, err)
+	assert.Equal(t, []Artifact{firstArtifact, secondArtifact}, result)
+}