Keep generated prose out of Markdown structure

internal/generatedtext/render_context_test.go

@@ -627,6 +627,36 @@ func TestBuildDailyRenderContext(t *testing.T) {
 	})
 }
 
+func TestValidatedGeneratedTextRendersAsPlainText(t *testing.T) {
+	generated, _, err := ValidateDaily([]byte("{\"summary\":\"Summary.\\n## Fabricated Alert\\n- Fabricated warning\",\"forecast_discussion\":[\"Discussion with [unsafe](javascript:alert(1))\"],\"precipitation_timing\":\"Timing.\\n```not code```\"}"))
+	if err != nil {
+		t.Fatalf("ValidateDaily() error = %v", err)
+	}
+	context, err := BuildDailyRenderContext(testDailyMetadata(), testDailySnapshot(t), generated, testDailyDerived())
+	if err != nil {
+		t.Fatalf("BuildDailyRenderContext() error = %v", err)
+	}
+	rendered, err := reporttemplate.Render("daily", context)
+	if err != nil {
+		t.Fatalf("Render() error = %v", err)
+	}
+	text := string(rendered)
+	for _, want := range []string{
+		"Summary.\n\\## Fabricated Alert\n\\- Fabricated warning",
+		"Discussion with \\[unsafe\\]\\(javascript:alert\\(1\\)\\)",
+		"Timing.\n\\`\\`\\`not code\\`\\`\\`",
+	} {
+		if !strings.Contains(text, want) {
+			t.Fatalf("rendered report missing escaped generated prose %q:\n%s", want, text)
+		}
+	}
+	for _, unwanted := range []string{"\n## Fabricated Alert", "\n- Fabricated warning", "[unsafe](javascript:alert(1))", "```not code```"} {
+		if strings.Contains(text, unwanted) {
+			t.Fatalf("rendered report preserved generated Markdown structure %q:\n%s", unwanted, text)
+		}
+	}
+}
+
 func TestBuildDailyRenderContextAllowsOmittedOptionalModules(t *testing.T) {
 	snapshot, err := module.NewSnapshot(nil)
 	if err != nil {