Upgrade trustfall_derive to syn v2. (#411)

* Upgrade `trustfall_derive` to `syn` v2.

* fmt

Cargo.toml

@@ -38,3 +38,6 @@ once_cell = "1.17"
 ron = "0.8.0"
 similar-asserts = "1.4.2"
 maplit = "1.0.2"
+syn = "2.0"
+quote = "1.0"
+proc-macro2 = "1.0.51"

trustfall/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "trustfall"
-version = "0.6.0"
+version = "0.6.1"
 license = "Apache-2.0"
 description = "The trustfall query engine, empowering you to query everything."
 repository = "https://github.com/obi1kenobi/trustfall"
@@ -17,7 +17,7 @@ rustdoc-args = ["--cfg", "docsrs"]
 [dependencies]
 anyhow = { workspace = true }
 trustfall_core = { version = "=0.6.0", path = "../trustfall_core" }
-trustfall_derive = { version = "=0.3.0", path = "../trustfall_derive" }
+trustfall_derive = { version = "=0.3.1", path = "../trustfall_derive" }
 
 [dev-dependencies]  # including examples dependencies
 ron = { workspace = true }

trustfall_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "trustfall_derive"
-version = "0.3.0"
+version = "0.3.1"
 license = "Apache-2.0"
 description = "Derive macros for the trustfall query engine."
 repository = "https://github.com/obi1kenobi/trustfall"
@@ -15,9 +15,9 @@ authors.workspace = true
 proc-macro = true
 
 [dependencies]
-quote = "1.0"
-syn = "1.0"
-proc-macro2 = "1.0.51"
+quote = { workspace = true }
+syn = { workspace = true }
+proc-macro2 = { workspace = true }
 
 [dev-dependencies]
 trybuild = "1.0"

trustfall_derive/src/lib.rs

@@ -249,57 +249,25 @@ fn generate_conversion_method(variant: &syn::Variant) -> syn::Result<proc_macro2
     // Check if we should skip generating the conversion method
     // because of a `#[trustfall(skip_conversion)]` attribute on the variant.
     for attr in &variant.attrs {
-        if let Some(ident) = attr.path.get_ident() {
-            if ident != TRUSTFALL_ATTRIBUTE {
-                // Not one of our attributes, skip.
-                continue;
-            }
+        if !attr.path().is_ident(TRUSTFALL_ATTRIBUTE) {
+            // Not one of our attributes, skip.
+            continue;
         }
 
-        // If we ever add more attribute contents, here's how to make the parsing smarter:
-        // https://blog.turbo.fish/proc-macro-parsing/
-        match attr.parse_meta()? {
-            syn::Meta::Path { .. } => {
-                return Err(syn::Error::new_spanned(
-                    attr,
-                    "no arguments found, did you mean `#[trustfall(skip_conversion)]`?",
-                ));
-            }
-            syn::Meta::List(values) => {
-                let mut skipping = false;
-                for nested in values.nested.iter() {
-                    match nested {
-                        syn::NestedMeta::Meta(syn::Meta::Path(path)) => {
-                            if let Some(ident) = path.get_ident() {
-                                if ident == SKIP_CONVERSION_ATTRIBUTE {
-                                    skipping = true;
-                                } else {
-                                    return Err(syn::Error::new_spanned(
-                                        nested,
-                                        "unexpected arguments found, did you mean `#[trustfall(skip_conversion)]`?",
-                                    ));
-                                }
-                            }
-                        }
-                        _ => {
-                            return Err(syn::Error::new_spanned(
-                                attr,
-                                "unexpected arguments found, did you mean `#[trustfall(skip_conversion)]`?",
-                            ));
-                        }
-                    }
-                }
-                if skipping {
-                    return Ok(Default::default());
-                }
-            }
-            syn::Meta::NameValue(name_value) => {
-                return Err(syn::Error::new_spanned(
-                    &name_value.lit,
-                    "unexpected arguments found, did you mean `#[trustfall(skip_conversion)]`?",
-                ));
-            }
-        };
+        let content: syn::Ident = attr.parse_args().map_err(|_| {
+            syn::Error::new_spanned(
+                attr,
+                "unexpected attribute, did you mean `#[trustfall(skip_conversion)]`?",
+            )
+        })?;
+        if content == SKIP_CONVERSION_ATTRIBUTE {
+            return Ok(Default::default());
+        } else {
+            return Err(syn::Error::new_spanned(
+                attr,
+                "unexpected attribute, did you mean `#[trustfall(skip_conversion)]`?",
+            ));
+        }
     }
 
     let variant_ident = &variant.ident;

trustfall_derive/tests/ui/invalid_attr_as_path_only.stderr

@@ -1,4 +1,4 @@
-error: no arguments found, did you mean `#[trustfall(skip_conversion)]`?
+error: unexpected attribute, did you mean `#[trustfall(skip_conversion)]`?
  --> tests/ui/invalid_attr_as_path_only.rs:5:5
   |
 5 |     #[trustfall]

trustfall_derive/tests/ui/invalid_attr_unexpected_assignment.stderr

@@ -1,4 +1,4 @@
-error: unexpected arguments found, did you mean `#[trustfall(skip_conversion)]`?
+error: unexpected attribute, did you mean `#[trustfall(skip_conversion)]`?
  --> tests/ui/invalid_attr_unexpected_assignment.rs:6:5
   |
 6 |     #[trustfall(skip_conversion = "yes")]

trustfall_derive/tests/ui/invalid_attr_unexpected_list_element.stderr

@@ -1,11 +1,11 @@
-error: unexpected arguments found, did you mean `#[trustfall(skip_conversion)]`?
- --> tests/ui/invalid_attr_unexpected_list_element.rs:5:34
+error: unexpected attribute, did you mean `#[trustfall(skip_conversion)]`?
+ --> tests/ui/invalid_attr_unexpected_list_element.rs:5:5
   |
 5 |     #[trustfall(skip_conversion, unexpected_arg)]
-  |                                  ^^^^^^^^^^^^^^
+  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: unexpected arguments found, did you mean `#[trustfall(skip_conversion)]`?
-  --> tests/ui/invalid_attr_unexpected_list_element.rs:13:17
+error: unexpected attribute, did you mean `#[trustfall(skip_conversion)]`?
+  --> tests/ui/invalid_attr_unexpected_list_element.rs:13:5
    |
 13 |     #[trustfall(unexpected_arg, skip_conversion)]
-   |                 ^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

trustfall_stubgen/Cargo.toml

@@ -20,9 +20,9 @@ default = ["cli"]
 cli = ["dep:clap"]
 
 [dependencies]
-quote = "1.0"
-syn = "2.0"
-proc-macro2 = "1.0.51"
+quote = { workspace = true }
+syn = { workspace = true }
+proc-macro2 = { workspace = true }
 trustfall = { path = "../trustfall", version = "0.6.0" }
 maplit = { workspace = true }
 async-graphql-parser = { workspace = true }