Harden chunk map export and retire completed plans

internal/framework/chunkmap/codec_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"os"
+	"reflect"
 	"strings"
 	"testing"
 
@@ -140,6 +141,62 @@ func TestCodecRejectsInvalidDurableBoundaries(t *testing.T) {
 	}
 }
 
+func TestDecodeEnforcesRequiredSchemaFieldsAndTypes(t *testing.T) {
+	request := acceptedBuildRequest(t)
+	request.Plan.Annotations = nil
+	var err error
+	request.Chunks, err = source.MaterializeChunkPlan(request.Source, request.Plan)
+	if err != nil {
+		t.Fatal(err)
+	}
+	artifact, err := Serialize(request)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, test := range []struct {
+		name   string
+		mutate func(map[string]any)
+	}{
+		{name: "missing plan annotations", mutate: func(value map[string]any) { delete(value, "plan_annotations") }},
+		{name: "null plan annotations", mutate: func(value map[string]any) { value["plan_annotations"] = nil }},
+		{name: "missing first index", mutate: func(value map[string]any) { delete(chunkDocument(value, 0), "index") }},
+		{name: "null first index", mutate: func(value map[string]any) { chunkDocument(value, 0)["index"] = nil }},
+		{name: "missing empty chunk annotations", mutate: func(value map[string]any) { delete(chunkDocument(value, 1), "annotations") }},
+		{name: "null empty chunk annotations", mutate: func(value map[string]any) { chunkDocument(value, 1)["annotations"] = nil }},
+		{name: "explicit empty llm profile", mutate: func(value map[string]any) {
+			value["producer"].(map[string]any)["llm_profile"] = ""
+		}},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			value := decodeJSONDocument(t, artifact.Content)
+			test.mutate(value)
+			content, err := json.Marshal(value)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if _, err := New().Decode(content); err == nil {
+				t.Fatalf("Decode(%s) error = nil, want schema rejection", content)
+			}
+		})
+	}
+}
+
+func TestEncodeDoesNotMutateValue(t *testing.T) {
+	value, err := Build(acceptedBuildRequest(t))
+	if err != nil {
+		t.Fatal(err)
+	}
+	value.Chunks[0].Annotations["dnd/scenes"] = json.RawMessage(" { \n \"kind\" : \"narrative\" \n } ")
+	before := clone(value)
+	if _, err := New().Encode(value); err != nil {
+		t.Fatalf("Encode() error = %v", err)
+	}
+	if !reflect.DeepEqual(value, before) {
+		t.Fatalf("Encode() mutated value:\nbefore: %#v\nafter: %#v", before, value)
+	}
+}
+
 func TestChunkMapOwnershipIsIndependent(t *testing.T) {
 	request := acceptedBuildRequest(t)
 	first, err := Build(request)
@@ -157,6 +214,21 @@ func TestChunkMapOwnershipIsIndependent(t *testing.T) {
 	}
 }
 
+func decodeJSONDocument(t *testing.T, content []byte) map[string]any {
+	t.Helper()
+	decoder := json.NewDecoder(bytes.NewReader(content))
+	decoder.UseNumber()
+	var value map[string]any
+	if err := decoder.Decode(&value); err != nil {
+		t.Fatal(err)
+	}
+	return value
+}
+
+func chunkDocument(value map[string]any, index int) map[string]any {
+	return value["chunks"].([]any)[index].(map[string]any)
+}
+
 func acceptedBuildRequest(t *testing.T) BuildRequest {
 	t.Helper()
 	document := &source.SourceDocument{