Introduce typed D&D spell artifacts

internal/modules/dnd/codec/spells/codec_test.go

@@ -0,0 +1,111 @@
+package spells
+
+import (
+	"bytes"
+	"encoding/json"
+	"os"
+	"reflect"
+	"strings"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/notarius/internal/core/source"
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/pipeline"
+	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
+)
+
+func TestCodecMatchesMaintainedDurableFixture(t *testing.T) {
+	raw, err := os.ReadFile("testdata/dnd_spells.v1.json")
+	if err != nil {
+		t.Fatalf("read durable fixture: %v", err)
+	}
+	codec := New()
+	value, err := codec.Decode(raw)
+	if err != nil {
+		t.Fatalf("Decode() error = %v, want nil", err)
+	}
+	want := dnd.SpellList{SpellCasts: []dnd.SpellCast{
+		{Caster: "Aria", Spell: "Cure Wounds", Effect: "Heals an injured ally.", NarrativeDescription: "Aria restores the fighter after the fight.", SourceRefs: []source.SourceRef{{SourceID: "session-alpha", StartUnitID: 1, EndUnitID: 2}}},
+		{Caster: "Borin", Spell: "Fire Bolt", Effect: "Scorches the wight.", NarrativeDescription: "Borin hurls fire at the wight.", SourceRefs: []source.SourceRef{{SourceID: "session-alpha", StartUnitID: 3, EndUnitID: 3}}},
+	}}
+	if !reflect.DeepEqual(value, want) {
+		t.Fatalf("Decode() = %#v, want %#v", value, want)
+	}
+	encoded, err := codec.Encode(value)
+	if err != nil {
+		t.Fatalf("Encode() error = %v, want nil", err)
+	}
+	var compact bytes.Buffer
+	if err := json.Compact(&compact, raw); err != nil {
+		t.Fatalf("compact durable fixture: %v", err)
+	}
+	if !bytes.Equal(encoded, compact.Bytes()) {
+		t.Fatalf("Encode() = %s, want stable durable JSON %s", encoded, compact.Bytes())
+	}
+	second, err := codec.Encode(value)
+	if err != nil || !bytes.Equal(second, encoded) {
+		t.Fatalf("second Encode() = %s, %v; want deterministic bytes", second, err)
+	}
+}
+
+func TestCodecOwnsDurableSchemaAndRegistersExactType(t *testing.T) {
+	codec := New()
+	schema := codec.Schema()
+	if codec.Kind() != dnd.SpellListKind || codec.MediaType() != MediaType {
+		t.Fatalf("codec identity = %q/%q", codec.Kind(), codec.MediaType())
+	}
+	if schema.ID != SchemaID || schema.Name != SchemaName || schema.Version != SchemaVersion || !json.Valid(schema.JSONSchema) {
+		t.Fatalf("schema = %#v, want durable spell schema", schema)
+	}
+	var document map[string]any
+	if err := json.Unmarshal(schema.JSONSchema, &document); err != nil || document["$id"] != SchemaID {
+		t.Fatalf("durable schema document = %#v, %v", document, err)
+	}
+
+	registry := pipeline.NewArtifactCodecRegistry()
+	if err := pipeline.RegisterArtifactCodec(registry, codec); err != nil {
+		t.Fatalf("RegisterArtifactCodec() error = %v", err)
+	}
+	spec, ok := registry.Spec(dnd.SpellListKind)
+	if !ok || spec.SchemaDigest != contracts.DigestArtifactSchema(schema) {
+		t.Fatalf("registered spec = %#v, %t", spec, ok)
+	}
+}
+
+func TestCodecStrictlyRejectsInvalidRepresentations(t *testing.T) {
+	codec := New()
+	tests := []struct {
+		name string
+		raw  string
+		want string
+	}{
+		{name: "unknown", raw: `{"spell_casts":[],"unexpected":true}`, want: "unknown field"},
+		{name: "trailing", raw: `{"spell_casts":[]} {}`, want: "multiple JSON values"},
+		{name: "missing", raw: `{}`, want: "spell_casts must be present"},
+		{name: "invalid evidence", raw: `{"spell_casts":[{"caster":"Aria","spell":"Cure Wounds","effect":"Heals","narrative_description":"Aria heals","source_refs":[{"source_id":"session","start_unit_id":0,"end_unit_id":1}]}]}`, want: "start_unit_id"},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			_, err := codec.Decode([]byte(test.raw))
+			if err == nil || !strings.Contains(err.Error(), test.want) {
+				t.Fatalf("Decode() error = %v, want %q", err, test.want)
+			}
+		})
+	}
+}
+
+func TestCodecRejectsInvalidCanonicalValues(t *testing.T) {
+	_, err := New().Encode(dnd.SpellList{})
+	if err == nil || !strings.Contains(err.Error(), "spell_casts must be present") {
+		t.Fatalf("Encode() error = %v, want strict shape error", err)
+	}
+}
+
+func TestCodecSchemaIsMutationSafe(t *testing.T) {
+	first := New().Schema()
+	first.JSONSchema[0] = '['
+	second := New().Schema()
+	if !json.Valid(second.JSONSchema) || second.JSONSchema[0] == '[' {
+		t.Fatalf("Schema() returned shared bytes: %s", second.JSONSchema)
+	}
+}