Establish prepared metadata identity

internal/briefing/package.go

@@ -26,6 +26,21 @@ type Metadata struct {
 	Alerts           *AlertStatus                `json:"alerts,omitempty"`
 }
 
+// PreparedIdentity is the single prepared authority for report identity,
+// timing, configuration context, and source warnings.
+type PreparedIdentity struct {
+	RunID          string                      `json:"runId"`
+	ReportID       report.ID                   `json:"reportId"`
+	Variant        string                      `json:"variant,omitempty"`
+	PromptID       string                      `json:"promptId"`
+	GeneratedAt    time.Time                   `json:"generatedAt"`
+	Units          string                      `json:"units"`
+	Timezone       string                      `json:"timezone"`
+	ValidPeriod    timeutil.Period             `json:"validPeriod"`
+	Location       *LocationContext            `json:"location,omitempty"`
+	SourceWarnings []weatherdata.SourceWarning `json:"sourceWarnings,omitempty"`
+}
+
 type LocationContext struct {
 	ID       string `json:"id,omitempty"`
 	Name     string `json:"name,omitempty"`
@@ -59,24 +74,39 @@ type BuildContext struct {
 	Location *LocationContext
 }
 
-func BuildMetadata(ctx BuildContext) Metadata {
+func BuildPreparedIdentity(ctx BuildContext) PreparedIdentity {
 	metadata := ctx.Resolved.Metadata()
-	sourceLocationID, sourceLocation := sourceLocation(ctx.Bundle)
+	return PreparedIdentity{
+		RunID:          metadata.RunID,
+		ReportID:       metadata.ReportID,
+		Variant:        variantForReport(metadata.ReportID),
+		PromptID:       metadata.PromptID,
+		GeneratedAt:    metadata.GeneratedAt,
+		Units:          ctx.Units,
+		Timezone:       ctx.Timezone,
+		ValidPeriod:    metadata.ValidPeriod,
+		Location:       copyLocation(ctx.Location),
+		SourceWarnings: append([]weatherdata.SourceWarning(nil), sourceWarnings(ctx.Bundle)...),
+	}
+}
+
+func BuildMetadata(identity PreparedIdentity, bundle *weatherdata.Bundle) Metadata {
+	sourceLocationID, sourceLocation := sourceLocation(bundle)
 	return Metadata{
-		RunID:            metadata.RunID,
-		ReportID:         metadata.ReportID,
-		Variant:          variantForReport(metadata.ReportID),
-		PromptID:         metadata.PromptID,
-		GeneratedAt:      metadata.GeneratedAt,
-		Units:            ctx.Units,
-		Timezone:         ctx.Timezone,
-		ValidPeriod:      metadata.ValidPeriod,
-		Location:         copyLocation(ctx.Location),
+		RunID:            identity.RunID,
+		ReportID:         identity.ReportID,
+		Variant:          identity.Variant,
+		PromptID:         identity.PromptID,
+		GeneratedAt:      identity.GeneratedAt,
+		Units:            identity.Units,
+		Timezone:         identity.Timezone,
+		ValidPeriod:      identity.ValidPeriod,
+		Location:         copyLocation(identity.Location),
 		SourceLocationID: sourceLocationID,
 		SourceLocation:   sourceLocation,
-		Sources:          sourceMetadata(ctx.Bundle),
-		SourceWarnings:   sourceWarnings(ctx.Bundle),
-		Alerts:           alertStatus(ctx.Bundle),
+		Sources:          sourceMetadata(bundle),
+		SourceWarnings:   append([]weatherdata.SourceWarning(nil), identity.SourceWarnings...),
+		Alerts:           alertStatus(bundle),
 	}
 }
 

internal/briefing/prepared_identity_test.go

@@ -0,0 +1,32 @@
+package briefing
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestPreparedIdentityBuildsEquivalentMetadata(t *testing.T) {
+	moduleContext := testModuleContext()
+	context := BuildContext{
+		Resolved: moduleContext.Resolved,
+		Bundle:   moduleContext.Collected.Bundle(),
+		Units:    moduleContext.Units,
+		Timezone: moduleContext.Timezone,
+		Location: moduleContext.Location,
+	}
+	identity := BuildPreparedIdentity(context)
+	metadata := BuildMetadata(identity, context.Bundle)
+
+	if metadata.RunID != identity.RunID || metadata.ReportID != identity.ReportID || metadata.Variant != identity.Variant || metadata.PromptID != identity.PromptID || !metadata.GeneratedAt.Equal(identity.GeneratedAt) || metadata.Units != identity.Units || metadata.Timezone != identity.Timezone || metadata.ValidPeriod != identity.ValidPeriod {
+		t.Fatalf("metadata identity = %#v, want %#v", metadata, identity)
+	}
+	if !reflect.DeepEqual(metadata.Location, identity.Location) || !reflect.DeepEqual(metadata.SourceWarnings, identity.SourceWarnings) {
+		t.Fatalf("metadata location/warnings = %#v/%#v, want %#v/%#v", metadata.Location, metadata.SourceWarnings, identity.Location, identity.SourceWarnings)
+	}
+
+	metadata.Location.Name = "consumer mutation"
+	metadata.SourceWarnings = append(metadata.SourceWarnings, moduleContext.Collected.SourceWarnings[0])
+	if identity.Location.Name == "consumer mutation" || len(identity.SourceWarnings) != len(moduleContext.Collected.SourceWarnings) {
+		t.Fatalf("identity changed through metadata mutation: %#v", identity)
+	}
+}