Harden chunk map export and retire completed plans

internal/modules/generic/output/json/encoder.go

@@ -1,9 +1,11 @@
 package json
 
 import (
+	"bytes"
 	"context"
 	stdjson "encoding/json"
 	"fmt"
+	"io"
 	"mime"
 	"regexp"
 	"sort"
@@ -247,10 +249,16 @@ func serializedOutputFile(name string, artifact contracts.SerializedArtifact) (c
 	if !isJSONMediaType(mediaType) {
 		return contracts.OutputFile{}, encoderErrorf("normalized output %q has unsupported media type %q", name, mediaType)
 	}
+	decoder := stdjson.NewDecoder(bytes.NewReader(content))
+	decoder.UseNumber()
 	var decoded any
-	if err := stdjson.Unmarshal(content, &decoded); err != nil {
+	if err := decoder.Decode(&decoded); err != nil {
 		return contracts.OutputFile{}, encoderErrorf("normalized output %q contains invalid JSON: %w", name, err)
 	}
+	var trailing any
+	if err := decoder.Decode(&trailing); err != io.EOF {
+		return contracts.OutputFile{}, encoderErrorf("normalized output %q contains multiple JSON values", name)
+	}
 	pretty, err := marshalPretty(decoded)
 	if err != nil {
 		return contracts.OutputFile{}, err

internal/modules/generic/output/json/encoder_test.go

@@ -234,6 +234,23 @@ func TestEncodeIncludesValidatedChunkMap(t *testing.T) {
 	}
 }
 
+func TestEncodePreservesChunkMapAnnotationNumbers(t *testing.T) {
+	artifact := acceptedChunkMapArtifactWithPlanAnnotation(t, stdjson.RawMessage(`{"decimal":1.0,"large":9007199254740993}`))
+	result, err := NewWithOptions(Options{IncludeChunkMap: true}).Encode(context.Background(), contracts.OutputRequest{
+		ChunkMap: &artifact,
+	})
+	if err != nil {
+		t.Fatalf("Encode() error = %v", err)
+	}
+	value, err := chunkmap.New().Decode(fileBytes(t, result.Files, chunkMapFileName))
+	if err != nil {
+		t.Fatalf("Decode(emitted chunk map) error = %v", err)
+	}
+	if got, want := string(value.PlanAnnotations["test/numbers"]), `{"decimal":1.0,"large":9007199254740993}`; got != want {
+		t.Fatalf("numeric annotation = %s, want %s", got, want)
+	}
+}
+
 func TestEncodeOmitsChunkMapWithoutAcceptedArtifact(t *testing.T) {
 	result, err := NewWithOptions(Options{IncludeChunkMap: true}).Encode(context.Background(), contracts.OutputRequest{
 		Manifest: artifacts.RunManifest{RunID: "run-1"},
@@ -544,6 +561,10 @@ func normalizeOutput(laneID string, content string) contracts.SerializedOutput {
 }
 
 func acceptedChunkMapArtifact(t *testing.T) contracts.SerializedArtifact {
+	return acceptedChunkMapArtifactWithPlanAnnotation(t, nil)
+}
+
+func acceptedChunkMapArtifactWithPlanAnnotation(t *testing.T, annotation stdjson.RawMessage) contracts.SerializedArtifact {
 	t.Helper()
 	document := &source.SourceDocument{
 		ID:     "source-1",
@@ -562,6 +583,9 @@ func acceptedChunkMapArtifact(t *testing.T) contracts.SerializedArtifact {
 	}
 	document.Digest = digest
 	plan := source.ChunkPlan{SourceDigest: digest, Ranges: []source.ChunkRange{{StartUnitID: 1, EndUnitID: 1}}}
+	if annotation != nil {
+		plan.Annotations = source.ChunkAnnotations{"test/numbers": append(stdjson.RawMessage(nil), annotation...)}
+	}
 	chunks, err := source.MaterializeChunkPlan(document, plan)
 	if err != nil {
 		t.Fatal(err)