test(build): cover form contract metadata

Assert that slhx-build lowers Surface form controls into generated FormContract field metadata, including names, control kinds, required flags, and handle-to-form syms.

req: codegen/004

req: form/001

slhx-build/src/lib.rs

@@ -1036,6 +1036,49 @@ mod tests {
         let _ = std::fs::remove_dir_all(&base);
     }
 
+    #[test]
+    fn emits_form_contract_metadata_from_surface_controls() {
+        // req: codegen/004 req: form/001
+        let base = test_dir("slhx-build-form-contract-test");
+        let templates = base.join("templates");
+        let out = base.join("out");
+        let _ = std::fs::remove_dir_all(&base);
+        std::fs::create_dir_all(&templates).unwrap();
+        std::fs::write(
+            templates.join("profile.heml"),
+            r#"<form data-slhx-handle="save" data-slhx-form="profile">
+                <input name="title" required>
+                <input name="count" type="number" min="1" max="10" step="1">
+                <select name="labels" multiple></select>
+                <input name="avatar" type="file">
+            </form>"#,
+        )
+        .unwrap();
+
+        app().template_dir(&templates).out_dir(&out).run().unwrap();
+
+        let generated = std::fs::read_to_string(out.join("slhx.generated.rs")).unwrap();
+        assert!(generated.contains("pub const PROFILE_CONTRACT: ::slhx::FormContract"));
+        assert!(generated.contains("pub const PROFILE_FIELDS: &[::slhx::FormField]"));
+        assert!(generated.contains(
+            "::slhx::FormField { name: \"title\", kind: ::slhx::FormControlKind::Text, required: true }"
+        ));
+        assert!(generated.contains(
+            "::slhx::FormField { name: \"count\", kind: ::slhx::FormControlKind::Number { min: Some(\"1\"), max: Some(\"10\"), step: Some(\"1\") }, required: false }"
+        ));
+        assert!(generated.contains(
+            "::slhx::FormField { name: \"labels\", kind: ::slhx::FormControlKind::Select { multiple: true }, required: false }"
+        ));
+        assert!(generated.contains(
+            "::slhx::FormField { name: \"avatar\", kind: ::slhx::FormControlKind::File, required: false }"
+        ));
+
+        let syms = std::fs::read_to_string(out.join("slhx.syms")).unwrap();
+        assert!(syms.contains("handle_form\tsave\tprofile\n"));
+
+        let _ = std::fs::remove_dir_all(&base);
+    }
+
     #[test]
     fn emits_checked_css_class_tokens_from_templates_and_stylesheets() {
         // req: style/001, req: codegen/001