Add --derive-for-type to cli (paritytech#708)

* Add `--derive-for-type` to cli

* Remove clippy warnings

cli/src/commands/codegen.rs

@@ -28,38 +28,52 @@ pub struct Opts {
     /// Additional derives
     #[clap(long = "derive")]
     derives: Vec<String>,
+    /// Additional derives for a given type.
+    ///
+    /// Example `--derive-for-type my_module::my_type=serde::Serialize`.
+    #[clap(long = "derive-for-type", value_parser = derive_for_type_parser)]
+    derives_for_type: Vec<(String, String)>,
     /// The `subxt` crate access path in the generated code.
     /// Defaults to `::subxt`.
     #[clap(long = "crate")]
     crate_path: Option<String>,
 }
 
+fn derive_for_type_parser(src: &str) -> Result<(String, String), String> {
+    let (ty, derive) = src
+        .split_once('=')
+        .ok_or_else(|| String::from("Invalid pattern for `derive-for-type`. It should be `type=derive`, like `my_type=serde::Serialize`"))?;
+
+    Ok((ty.to_string(), derive.to_string()))
+}
+
 pub async fn run(opts: Opts) -> color_eyre::Result<()> {
-    if let Some(file) = opts.file.as_ref() {
+    let bytes = if let Some(file) = opts.file.as_ref() {
         if opts.url.is_some() {
             eyre::bail!("specify one of `--url` or `--file` but not both")
         };
 
         let mut file = fs::File::open(file)?;
         let mut bytes = Vec::new();
         file.read_to_end(&mut bytes)?;
-        codegen(&bytes, opts.derives, opts.crate_path)?;
-        return Ok(())
-    }
+        bytes
+    } else {
+        let url = opts.url.unwrap_or_else(|| {
+            "http://localhost:9933"
+                .parse::<Uri>()
+                .expect("default url is valid")
+        });
+        subxt_codegen::utils::fetch_metadata_bytes(&url).await?
+    };
 
-    let url = opts.url.unwrap_or_else(|| {
-        "http://localhost:9933"
-            .parse::<Uri>()
-            .expect("default url is valid")
-    });
-    let bytes = subxt_codegen::utils::fetch_metadata_bytes(&url).await?;
-    codegen(&bytes, opts.derives, opts.crate_path)?;
+    codegen(&bytes, opts.derives, opts.derives_for_type, opts.crate_path)?;
     Ok(())
 }
 
 fn codegen(
     metadata_bytes: &[u8],
     raw_derives: Vec<String>,
+    derives_for_type: Vec<(String, String)>,
     crate_path: Option<String>,
 ) -> color_eyre::Result<()> {
     let item_mod = syn::parse_quote!(
@@ -75,6 +89,12 @@ fn codegen(
     let mut derives = DerivesRegistry::new(&crate_path);
     derives.extend_for_all(p.into_iter());
 
+    for (ty, derive) in derives_for_type.into_iter() {
+        let ty = syn::parse_str(&ty)?;
+        let derive = syn::parse_str(&derive)?;
+        derives.extend_for_type(ty, std::iter::once(derive), &crate_path)
+    }
+
     let runtime_api = subxt_codegen::generate_runtime_api_from_bytes(
         item_mod,
         metadata_bytes,

examples/examples/storage_iterating.rs

@@ -39,7 +39,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
         println!("\nExample 1. Obtained keys:");
         while let Some((key, value)) = iter.next().await? {
-            println!("Key: 0x{}", hex::encode(&key));
+            println!("Key: 0x{}", hex::encode(key));
             println!("  Value: {}", value);
         }
     }

macro/src/lib.rs

@@ -160,7 +160,7 @@ pub fn subxt(args: TokenStream, input: TokenStream) -> TokenStream {
             let path = root_path.join(rest_of_path);
             subxt_codegen::generate_runtime_api_from_path(
                 item_mod,
-                &path,
+                path,
                 derives_registry,
                 crate_path,
             )

testing/test-runtime/build.rs

@@ -80,7 +80,7 @@ async fn run() {
     // Save metadata to a file:
     let out_dir = env::var_os("OUT_DIR").unwrap();
     let metadata_path = Path::new(&out_dir).join("metadata.scale");
-    fs::write(&metadata_path, &metadata_bytes.0).expect("Couldn't write metadata output");
+    fs::write(&metadata_path, metadata_bytes.0).expect("Couldn't write metadata output");
 
     // Write out our expression to generate the runtime API to a file. Ideally, we'd just write this code
     // in lib.rs, but we must pass a string literal (and not `concat!(..)`) as an arg to `runtime_metadata_path`,
@@ -101,7 +101,7 @@ async fn run() {
             .expect("Path to metadata should be stringifiable")
     );
     let runtime_path = Path::new(&out_dir).join("runtime.rs");
-    fs::write(&runtime_path, runtime_api_contents)
+    fs::write(runtime_path, runtime_api_contents)
         .expect("Couldn't write runtime rust output");
 
     let substrate_path =

testing/ui-tests/src/lib.rs

@@ -28,21 +28,21 @@ fn ui_tests() {
     t.pass("src/correct/*.rs");
 
     // Check that storage maps with no keys are handled properly.
-    t.pass(&m.path_to_ui_test_for_metadata(
+    t.pass(m.path_to_ui_test_for_metadata(
         "storage_map_no_keys",
         storage::metadata_storage_map_no_keys(),
     ));
 
     // Test that the codegen can handle the different types of DispatchError.
-    t.pass(&m.path_to_ui_test_for_metadata(
+    t.pass(m.path_to_ui_test_for_metadata(
         "named_field_dispatch_error",
         dispatch_errors::metadata_named_field_dispatch_error(),
     ));
-    t.pass(&m.path_to_ui_test_for_metadata(
+    t.pass(m.path_to_ui_test_for_metadata(
         "legacy_dispatch_error",
         dispatch_errors::metadata_legacy_dispatch_error(),
     ));
-    t.pass(&m.path_to_ui_test_for_metadata(
+    t.pass(m.path_to_ui_test_for_metadata(
         "array_dispatch_error",
         dispatch_errors::metadata_array_dispatch_error(),
     ));

testing/ui-tests/src/utils/metadata_test_runner.rs

@@ -52,9 +52,9 @@ impl MetadataTestRunner {
 
         std::fs::create_dir_all(&tmp_dir).expect("could not create tmp ui test dir");
         // Write metadata to tmp folder:
-        std::fs::write(&tmp_metadata_path, &encoded_metadata).unwrap();
+        std::fs::write(&tmp_metadata_path, encoded_metadata).unwrap();
         // Write test file to tmp folder (it'll be moved by trybuild):
-        std::fs::write(&tmp_rust_path, &rust_file).unwrap();
+        std::fs::write(&tmp_rust_path, rust_file).unwrap();
 
         tmp_rust_path
     }