Break up test_display into individual test cases

tests/test_display.rs

@@ -1,91 +1,129 @@
 use std::fmt::Display;
 use thiserror::Error;
 
-#[derive(Error, Debug)]
-#[error("braced error: {msg}")]
-struct BracedError {
-    msg: String,
-}
-
-#[derive(Error, Debug)]
-#[error("braced error")]
-struct BracedUnused {
-    extra: usize,
-}
-
-#[derive(Error, Debug)]
-#[error("tuple error: {0}")]
-struct TupleError(usize);
-
-#[derive(Error, Debug)]
-#[error("unit error")]
-struct UnitError;
-
-#[derive(Error, Debug)]
-enum EnumError {
-    #[error("braced error: {id}")]
-    Braced { id: usize },
-    #[error("tuple error: {0}")]
-    Tuple(usize),
-    #[error("unit error")]
-    Unit,
-}
-
-#[derive(Error, Debug)]
-#[error("{MSG}: {id:?} (code {CODE:?})")]
-struct WithConstant {
-    id: &'static str,
-}
-
-const MSG: &str = "failed to do";
-const CODE: usize = 9;
-
-#[derive(Error, Debug)]
-#[error("{0}")]
-enum Inherit {
-    Unit(UnitError),
-    #[error("other error")]
-    Other(UnitError),
-}
-
-#[derive(Error, Debug)]
-#[error("fn main() {{}}")]
-struct Braces;
-
-#[derive(Error, Debug)]
-#[error("1 + 1 = {}", 1 + 1)]
-struct Arithmetic;
-
-#[derive(Error, Debug)]
-#[error("!bool = {}", not(.0))]
-struct NestedShorthand(bool);
-
-#[derive(Error, Debug)]
-#[error("...")]
-pub enum Void {}
-
-fn not(bool: &bool) -> bool {
-    !*bool
-}
-
 fn assert<T: Display>(expected: &str, value: T) {
     assert_eq!(expected, value.to_string());
 }
 
 #[test]
-fn test_display() {
+fn test_braced() {
+    #[derive(Error, Debug)]
+    #[error("braced error: {msg}")]
+    struct Error {
+        msg: String,
+    }
+
     let msg = "T".to_owned();
-    assert("braced error: T", BracedError { msg });
-    assert("braced error", BracedUnused { extra: 0 });
-    assert("tuple error: 0", TupleError(0));
-    assert("unit error", UnitError);
-    assert("braced error: 0", EnumError::Braced { id: 0 });
-    assert("tuple error: 0", EnumError::Tuple(0));
-    assert("unit error", EnumError::Unit);
-    assert("failed to do: \"\" (code 9)", WithConstant { id: "" });
-    assert("unit error", Inherit::Unit(UnitError));
-    assert("other error", Inherit::Other(UnitError));
-    assert("fn main() {}", Braces);
-    assert("1 + 1 = 2", Arithmetic);
-    assert("!bool = false", NestedShorthand(true));
+    assert("braced error: T", Error { msg });
+}
+
+#[test]
+fn test_braced_unused() {
+    #[derive(Error, Debug)]
+    #[error("braced error")]
+    struct Error {
+        extra: usize,
+    }
+
+    assert("braced error", Error { extra: 0 });
+}
+
+#[test]
+fn test_tuple() {
+    #[derive(Error, Debug)]
+    #[error("tuple error: {0}")]
+    struct Error(usize);
+
+    assert("tuple error: 0", Error(0));
+}
+
+#[test]
+fn test_unit() {
+    #[derive(Error, Debug)]
+    #[error("unit error")]
+    struct Error;
+
+    assert("unit error", Error);
+}
+
+#[test]
+fn test_enum() {
+    #[derive(Error, Debug)]
+    enum Error {
+        #[error("braced error: {id}")]
+        Braced { id: usize },
+        #[error("tuple error: {0}")]
+        Tuple(usize),
+        #[error("unit error")]
+        Unit,
+    }
+
+    assert("braced error: 0", Error::Braced { id: 0 });
+    assert("tuple error: 0", Error::Tuple(0));
+    assert("unit error", Error::Unit);
+}
+
+#[test]
+fn test_constants() {
+    #[derive(Error, Debug)]
+    #[error("{MSG}: {id:?} (code {CODE:?})")]
+    struct Error {
+        id: &'static str,
+    }
+
+    const MSG: &str = "failed to do";
+    const CODE: usize = 9;
+
+    assert("failed to do: \"\" (code 9)", Error { id: "" });
+}
+
+#[test]
+fn test_inherit() {
+    #[derive(Error, Debug)]
+    #[error("{0}")]
+    enum Error {
+        Some(&'static str),
+        #[error("other error")]
+        Other(&'static str),
+    }
+
+    assert("some error", Error::Some("some error"));
+    assert("other error", Error::Other("..."));
+}
+
+#[test]
+fn test_brace_escape() {
+    #[derive(Error, Debug)]
+    #[error("fn main() {{}}")]
+    struct Error;
+
+    assert("fn main() {}", Error);
+}
+
+#[test]
+fn test_expr() {
+    #[derive(Error, Debug)]
+    #[error("1 + 1 = {}", 1 + 1)]
+    struct Error;
+    assert("1 + 1 = 2", Error);
+}
+
+#[test]
+fn test_nested() {
+    #[derive(Error, Debug)]
+    #[error("!bool = {}", not(.0))]
+    struct Error(bool);
+
+    fn not(bool: &bool) -> bool {
+        !*bool
+    }
+
+    assert("!bool = false", Error(true));
+}
+
+#[test]
+fn test_void() {
+    #[derive(Error, Debug)]
+    #[error("...")]
+    pub enum Error {}
 }