perf(pr): read the pull request template with one request

Signed-off-by: bircni <bircni@icloud.com>

internal/app/pull_create_test.go

@@ -10,6 +10,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
 	"testing"
 
 	"gitea.dev/tea/internal/clierr"
@@ -263,12 +264,15 @@ func TestPullCreateDerivesTitleAndBodyFromSingleCommit(t *testing.T) {
 
 func TestPullCreateEditorSeedsPullRequestTemplate(t *testing.T) {
 	var payload map[string]any
+	var mu sync.Mutex
 	var templateRequests []string
 	server := newAuthenticatedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		switch {
 		case strings.HasPrefix(r.URL.Path, "/api/v1/repos/alice/project/raw/"):
 			require.Equal(t, "main", r.URL.Query().Get("ref"))
+			mu.Lock()
 			templateRequests = append(templateRequests, strings.TrimPrefix(r.URL.Path, "/api/v1/repos/alice/project/raw/"))
+			mu.Unlock()
 			if r.URL.Path != "/api/v1/repos/alice/project/raw/.gitea/PULL_REQUEST_TEMPLATE.md" {
 				w.WriteHeader(http.StatusNotFound)
 				return
@@ -289,7 +293,11 @@ func TestPullCreateEditorSeedsPullRequestTemplate(t *testing.T) {
 	deps.Getenv = serverEnv(server.URL, map[string]string{"EDITOR": "editor"})
 	require.NoError(t, Execute(context.Background(), deps, []string{"pr", "create", "-R", "alice/project", "--title", "PR", "--head", "feature", "--base", "main", "--editor", "--json=number", "--no-input"}))
 	require.Equal(t, "## Checklist\n", editor.initial)
-	require.Equal(t, []string{"PULL_REQUEST_TEMPLATE.md", "pull_request_template.md", ".gitea/PULL_REQUEST_TEMPLATE.md"}, templateRequests)
+	require.ElementsMatch(t, []string{
+		"PULL_REQUEST_TEMPLATE.md", "pull_request_template.md",
+		".gitea/PULL_REQUEST_TEMPLATE.md", ".gitea/pull_request_template.md",
+		".github/PULL_REQUEST_TEMPLATE.md", ".github/pull_request_template.md",
+	}, templateRequests)
 	require.Equal(t, "filled", payload["body"])
 }
 

internal/services/pulls.go

@@ -15,6 +15,7 @@ import (
 	"slices"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	gitea "gitea.dev/sdk"
@@ -474,20 +475,42 @@ var pullTemplatePaths = []string{
 const maxPullTemplateBytes = 1 << 20
 
 // Template returns the first pull request template found at ref, or "" when the repository has none.
+// All paths are probed concurrently; the result is decided in priority order, so a failure is
+// reported only when every higher-priority path is missing.
 func (s Pulls) Template(ctx context.Context, ref string) (string, error) {
-	for _, path := range pullTemplatePaths {
-		file, err := repoCall(ctx, s.Client, s.Repository, func(ctx context.Context, c *gitea.Client, owner, name string) (io.ReadCloser, *gitea.Response, error) {
-			return c.Repositories.GetFileReader(ctx, owner, name, ref, path)
+	type probe struct {
+		content string
+		missing bool
+		err     error
+	}
+	probes := make([]probe, len(pullTemplatePaths))
+	var wg sync.WaitGroup
+	for i, path := range pullTemplatePaths {
+		wg.Go(func() {
+			probes[i].content, probes[i].missing, probes[i].err = s.templateAt(ctx, ref, path)
 		})
-		if err != nil {
-			if IsNotFound(err) {
-				continue
-			}
-			return "", err
+	}
+	wg.Wait()
+	for _, p := range probes {
+		if !p.missing {
+			return p.content, p.err
 		}
-		data, err := io.ReadAll(io.LimitReader(file, maxPullTemplateBytes))
-		_ = file.Close()
-		return string(data), err
 	}
 	return "", nil
 }
+
+// templateAt reads one template path; missing reports a 404.
+func (s Pulls) templateAt(ctx context.Context, ref, path string) (content string, missing bool, err error) {
+	file, err := repoCall(ctx, s.Client, s.Repository, func(ctx context.Context, c *gitea.Client, owner, name string) (io.ReadCloser, *gitea.Response, error) {
+		return c.Repositories.GetFileReader(ctx, owner, name, ref, path)
+	})
+	if err != nil {
+		if IsNotFound(err) {
+			return "", true, nil
+		}
+		return "", false, err
+	}
+	data, err := io.ReadAll(io.LimitReader(file, maxPullTemplateBytes))
+	_ = file.Close()
+	return string(data), false, err
+}

internal/services/pulls_test.go

@@ -11,7 +11,10 @@ import (
 	"net/http/httptest"
 	"strconv"
 	"strings"
+	"sync"
+	"sync/atomic"
 	"testing"
+	"time"
 
 	gitea "gitea.dev/sdk"
 	"gitea.dev/tea/internal/transport"
@@ -114,25 +117,28 @@ func TestPullTemplateLookup(t *testing.T) {
 		status              map[string]int
 		requests            int
 	}{
-		{"root first", "template", "", map[string]int{"PULL_REQUEST_TEMPLATE.md": http.StatusOK, ".gitea/pull_request_template.md": http.StatusOK}, 1},
-		{"uppercase before lowercase", "template", "", map[string]int{".gitea/PULL_REQUEST_TEMPLATE.md": http.StatusOK}, 3},
-		{"later match", "template", "", map[string]int{".github/pull_request_template.md": http.StatusOK}, 6},
+		{"root first", "PULL_REQUEST_TEMPLATE.md", "", map[string]int{"PULL_REQUEST_TEMPLATE.md": http.StatusOK, ".gitea/pull_request_template.md": http.StatusOK}, 6},
+		{"uppercase before lowercase", ".gitea/PULL_REQUEST_TEMPLATE.md", "", map[string]int{".gitea/PULL_REQUEST_TEMPLATE.md": http.StatusOK, ".gitea/pull_request_template.md": http.StatusOK}, 6},
+		{"later match", ".github/pull_request_template.md", "", map[string]int{".github/pull_request_template.md": http.StatusOK}, 6},
 		{"docs is not searched", "", "", map[string]int{"docs/pull_request_template.md": http.StatusOK}, 6},
 		{"none", "", "", nil, 6},
-		{"server error", "", "500", map[string]int{".gitea/pull_request_template.md": http.StatusInternalServerError}, 4},
+		{"server error", "", "500", map[string]int{".gitea/pull_request_template.md": http.StatusInternalServerError}, 6},
+		{"match before error", "pull_request_template.md", "", map[string]int{"pull_request_template.md": http.StatusOK, ".github/PULL_REQUEST_TEMPLATE.md": http.StatusInternalServerError}, 6},
+		{"error before match", "", "500", map[string]int{"pull_request_template.md": http.StatusInternalServerError, ".github/PULL_REQUEST_TEMPLATE.md": http.StatusOK}, 6},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
-			requests := 0
+			var requests atomic.Int32
 			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-				requests++
+				requests.Add(1)
 				assert.Equal(t, "release/1.0", r.URL.Query().Get("ref"))
-				status, ok := tc.status[strings.TrimPrefix(r.URL.Path, "/api/v1/repos/owner/repo/raw/")]
+				path := strings.TrimPrefix(r.URL.Path, "/api/v1/repos/owner/repo/raw/")
+				status, ok := tc.status[path]
 				if !ok {
 					w.WriteHeader(http.StatusNotFound)
 					return
 				}
 				w.WriteHeader(status)
-				_, _ = w.Write([]byte("template"))
+				_, _ = w.Write([]byte(path))
 			}))
 			defer server.Close()
 			got, err := (Pulls{Client: transport.New(server.URL, "", false), Repository: "owner/repo"}).Template(context.Background(), "release/1.0")
@@ -142,11 +148,32 @@ func TestPullTemplateLookup(t *testing.T) {
 				require.NoError(t, err)
 			}
 			require.Equal(t, tc.want, got)
-			require.Equal(t, tc.requests, requests)
+			require.Equal(t, tc.requests, int(requests.Load()))
 		})
 	}
 }
 
+func TestPullTemplateProbesConcurrently(t *testing.T) {
+	// Every probe only completes once all of them are in flight.
+	var arrived sync.WaitGroup
+	arrived.Add(len(pullTemplatePaths))
+	allArrived := make(chan struct{})
+	go func() { arrived.Wait(); close(allArrived) }()
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		arrived.Done()
+		select {
+		case <-allArrived:
+		case <-time.After(5 * time.Second):
+			t.Errorf("%s did not run concurrently with the other template probes", r.URL.Path)
+		}
+		w.WriteHeader(http.StatusNotFound)
+	}))
+	defer server.Close()
+	got, err := (Pulls{Client: transport.New(server.URL, "", false), Repository: "owner/repo"}).Template(context.Background(), "main")
+	require.NoError(t, err)
+	require.Empty(t, got)
+}
+
 func TestPullMergeExplainsRefusal(t *testing.T) {
 	for _, tc := range []struct {
 		name, pull, want string