init

crates/domain/tests/user/display_name_test.rs

@@ -0,0 +1,40 @@
+use domain::errors::DomainError;
+use domain::user::DisplayName;
+
+#[test]
+fn valid_display_name_is_created() {
+    let name = DisplayName::new("Alice").unwrap();
+    assert_eq!(name.value(), "Alice");
+}
+
+#[test]
+fn display_name_trims_whitespace() {
+    let name = DisplayName::new("  Bob  ").unwrap();
+    assert_eq!(name.value(), "Bob");
+}
+
+#[test]
+fn empty_display_name_is_rejected() {
+    let result = DisplayName::new("");
+    assert!(matches!(result, Err(DomainError::InvalidInput(_))));
+}
+
+#[test]
+fn whitespace_only_display_name_is_rejected() {
+    let result = DisplayName::new("   ");
+    assert!(matches!(result, Err(DomainError::InvalidInput(_))));
+}
+
+#[test]
+fn display_name_over_100_chars_is_rejected() {
+    let long = "a".repeat(101);
+    let result = DisplayName::new(long);
+    assert!(matches!(result, Err(DomainError::InvalidInput(_))));
+}
+
+#[test]
+fn display_name_at_100_chars_is_valid() {
+    let exact = "a".repeat(100);
+    let name = DisplayName::new(exact).unwrap();
+    assert_eq!(name.value().len(), 100);
+}