Schneems/smaller strum

Cargo.toml

@@ -1,7 +1,6 @@
 [workspace]
 resolver = "2"
 members = [
-    "usage",
     "cache_diff",
     "cache_diff_derive",
 ]

cache_diff/Cargo.toml

@@ -13,6 +13,10 @@ documentation.workspace = true
 cache_diff_derive = { version = "1" , optional = true, path = "../cache_diff_derive" }
 bullet_stream = { version = "0", optional = true }
 
+[dev-dependencies]
+trybuild = "1.0.104"
+serde.workspace = true
+
 [features]
 default = ["derive"]
 derive = ["dep:cache_diff_derive"]

cache_diff/src/lib.rs

@@ -252,4 +252,5 @@ pub trait CacheDiff {
         format!("`{}`", value)
     }
 }
+#[cfg(feature = "derive")]
 pub use cache_diff_derive::CacheDiff;

usage/tests/fails/accidental_custom_field.stderr → cache_diff/tests/fails/accidental_custom_field.stderr

@@ -1,4 +1,10 @@
 error: Unknown cache_diff attribute: `custom`. Must be one of `rename`, `display`, `ignore`
+ --> tests/fails/accidental_custom_field.rs:5:18
+  |
+5 |     #[cache_diff(custom = function)]
+  |                  ^^^^^^
+
+error:
        The cache_diff attribute `custom` is available on the struct, not the field
  --> tests/fails/accidental_custom_field.rs:5:18
   |

cache_diff/tests/fails/duplicate_field.rs

@@ -0,0 +1,9 @@
+use cache_diff::CacheDiff;
+
+#[derive(CacheDiff)]
+struct CustomDiffFn {
+    #[cache_diff(rename = "foo", rename = "bar")]
+    name: String,
+}
+
+fn main() {}

cache_diff/tests/fails/duplicate_field.stderr

@@ -0,0 +1,11 @@
+error: CacheDiff duplicate attribute: `rename`
+ --> tests/fails/duplicate_field.rs:5:34
+  |
+5 |     #[cache_diff(rename = "foo", rename = "bar")]
+  |                                  ^^^^^^
+
+error: previously `rename` defined here
+ --> tests/fails/duplicate_field.rs:5:18
+  |
+5 |     #[cache_diff(rename = "foo", rename = "bar")]
+  |                  ^^^^^^

cache_diff/tests/fails/missing_custom.stderr

@@ -0,0 +1,13 @@
+error: `Expected `MissingCustom` to implement the `custom` attribute `#[cache_diff(custom = <function>)]`, but it does not
+ --> tests/fails/missing_custom.rs:3:10
+  |
+3 | #[derive(CacheDiff)]
+  |          ^^^^^^^^^
+  |
+  = note: this error originates in the derive macro `CacheDiff` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: Field `i_am_a_custom_field` is ignored and requires `MissingCustom` to implement `custom`
+ --> tests/fails/missing_custom.rs:6:5
+  |
+6 |     i_am_a_custom_field: String,
+  |     ^^^^^^^^^^^^^^^^^^^

usage/tests/fails/missing_display.stderr → cache_diff/tests/fails/missing_display.stderr

@@ -8,7 +8,7 @@ error[E0277]: `NotDisplay` doesn't implement `std::fmt::Display`
   = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
   = note: required for `&NotDisplay` to implement `std::fmt::Display`
 note: required by a bound in `fmt_value`
- --> $WORKSPACE/cache_diff/src/lib.rs
+ --> src/lib.rs
   |
   |     fn fmt_value<T: std::fmt::Display>(&self, value: &T) -> String {
   |                     ^^^^^^^^^^^^^^^^^ required by this bound in `CacheDiff::fmt_value`

cache_diff/tests/pass/struct_with_generics.rs

@@ -0,0 +1,22 @@
+use cache_diff::CacheDiff;
+
+#[derive(CacheDiff)]
+struct Example<T>
+where
+    T: std::fmt::Display + Eq,
+{
+    name: String,
+    other: T,
+}
+
+fn main() {
+    let now = Example::<String> {
+        name: "Richard".to_string(),
+        other: "John Jacob Jingleheimer Schmidt (his name is my name too)".to_string(),
+    };
+
+    let _ = now.diff(&Example::<String> {
+        name: "Richard".to_string(),
+        other: "schneems".to_string(),
+    });
+}

cache_diff_derive/Cargo.toml

@@ -14,7 +14,7 @@ quote = "1.0"
 syn = { version = "2.0", features = ["extra-traits"] }
 proc-macro2 = "1.0"
 bullet_stream = { version = "0", optional = true }
-strum = {version = "0.26", features = ["derive"] }
+strum = {version = "0.27", features = ["derive"] }
 
 [lib]
 proc-macro = true