Reduce comparison bundle recognition reads

internal/comparison/publish_test.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
+	"io"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -222,6 +224,75 @@ func TestPlanDestinationAcceptsRecognizedReplacement(t *testing.T) {
 	}
 }
 
+func TestRecognizeBundleReadsOnlyRequiredArtifactContents(t *testing.T) {
+	for _, reportCount := range []int{2, 12} {
+		t.Run(fmt.Sprintf("%d reports", reportCount), func(t *testing.T) {
+			bundle := testBundleWithReports(t, reportCount)
+			directory := publishTestBundle(t, bundle)
+			bytesRead := make(map[string]int)
+			opens := make(map[string]int)
+			operations := defaultRecognitionOperations
+			operations.open = func(path string) (io.ReadCloser, error) {
+				file, err := os.Open(path)
+				if err != nil {
+					return nil, err
+				}
+				name := filepath.Base(path)
+				opens[name]++
+				return &countingReadCloser{ReadCloser: file, count: func(n int) {
+					bytesRead[name] += n
+				}}, nil
+			}
+
+			if _, err := recognizeBundle(directory, operations); err != nil {
+				t.Fatalf("recognizeBundle() error = %v", err)
+			}
+			for _, name := range []string{ManifestFilename, DataPackageFilename} {
+				data := readFile(t, filepath.Join(directory, name))
+				if opens[name] != 1 || bytesRead[name] != len(data) {
+					t.Fatalf("%s opens/bytes = %d/%d, want 1/%d", name, opens[name], bytesRead[name], len(data))
+				}
+			}
+			for _, report := range bundle.Reports {
+				if opens[report.Path] != 1 || bytesRead[report.Path] != 0 {
+					t.Fatalf("report %s opens/bytes = %d/%d, want 1/0", report.Path, opens[report.Path], bytesRead[report.Path])
+				}
+			}
+		})
+	}
+}
+
+func TestReplacementUsesEarlyAndFinalRecognition(t *testing.T) {
+	workingDirectory := t.TempDir()
+	target := filepath.Join(workingDirectory, "comparison-daily")
+	bundle := testBundleWithReports(t, 12)
+	initialPlan, err := PlanDestination(workingDirectory, target, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := Publish(context.Background(), initialPlan, bundle); err != nil {
+		t.Fatal(err)
+	}
+
+	recognitions := 0
+	recognize := func(directory string) (Manifest, error) {
+		recognitions++
+		return RecognizeBundle(directory)
+	}
+	plan, err := planDestination(workingDirectory, target, true, recognize)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := publish(context.Background(), plan, bundle, publishOperations{
+		rename: os.Rename, removeAll: os.RemoveAll, recognize: recognize,
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if recognitions != 2 {
+		t.Fatalf("full bundle recognitions = %d, want early and final authorization", recognitions)
+	}
+}
+
 func TestPublishReauthorizesMovedDestination(t *testing.T) {
 	tests := []struct {
 		name            string
@@ -995,6 +1066,41 @@ func testBundle() LogicalBundle {
 	}
 }
 
+func testBundleWithReports(t *testing.T, count int) LogicalBundle {
+	t.Helper()
+	dataPackage := []byte("report: daily\n")
+	manifest := validManifest()
+	manifest.Total, manifest.Succeeded, manifest.Failed = count, count, 0
+	manifest.Results = make([]Result, count)
+	reports := make([]BundleReport, count)
+	for i := range manifest.Results {
+		position := i + 1
+		profileID := fmt.Sprintf("weather-%d", position)
+		path, err := ReportFilename(position, count, profileID)
+		if err != nil {
+			t.Fatal(err)
+		}
+		manifest.Results[i] = Result{
+			Position: position, ProfileID: profileID, ModelName: "gpt-5-mini",
+			Status: StatusSucceeded, ValidationStatus: "passed", ReportPath: path,
+		}
+		reports[i] = BundleReport{Position: position, Path: path, Markdown: []byte("# Daily\n")}
+	}
+	manifest.DataPackage.SHA256 = SHA256(dataPackage)
+	return LogicalBundle{Manifest: manifest, DataPackage: dataPackage, Reports: reports}
+}
+
+type countingReadCloser struct {
+	io.ReadCloser
+	count func(int)
+}
+
+func (reader *countingReadCloser) Read(buffer []byte) (int, error) {
+	n, err := reader.ReadCloser.Read(buffer)
+	reader.count(n)
+	return n, err
+}
+
 func assertMode(t *testing.T, path string, want os.FileMode) {
 	t.Helper()
 	info, err := os.Stat(path)