Improve CLI doc

Author: lerouxrgd

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "rsgen-avro"
-version = "0.18.0"
+version = "0.18.1"
 authors = ["Romain Leroux <[email protected]>"]
 edition = "2024"
 description = "Command line and library for generating Rust types from Avro schemas"

Cargo.toml

@@ -25,16 +25,16 @@ Arguments:
   <OUTPUT_FILE>   The file where Rust types will be written, '-' for stdout
 
 Options:
-      --fmt              Run rustfmt on the resulting <output-file>
-      --nullable         Replace null fields with their default value when deserializing
-      --precision <P>    Precision for f32/f64 default values that aren't round numbers [default: 3]
-      --union-deser      Custom deserialization for apache-avro multi-valued union types
-      --chrono-dates     Use chrono::NaiveDateTime for date/timestamps logical types
-      --derive-builders  Derive builders for generated record structs
-      --derive-schemas   Derive AvroSchema for generated record structs
-      --extra_derives    Append extra derive macros list to the generated record structs
-  -h, --help             Print help
-  -V, --version          Print version
+      --fmt                      Run rustfmt on the resulting <output-file>
+      --nullable                 Replace null fields with their default value when deserializing
+      --precision <P>            Precision for f32/f64 default values that aren't round numbers [default: 3]
+      --union-deser              Custom deserialization for apache-avro multi-valued union types
+      --chrono-dates             Use chrono::NaiveDateTime for date/timestamps logical types
+      --derive-builders          Derive builders for generated record structs
+      --impl-schemas <METHOD>    Implement AvroSchema for generated record structs [default: None] [possible values: derive, copy-build-schema, none]
+      --extra-derives <DERIVES>  Extract Derives for generated record structs, comma separated, e.g. `std::fmt::Display,std::string::ToString`
+  -h, --help                     Print help (see more with '--help')
+  -V, --version                  Print version
 ```
 
 ## Library usage

README.md

@@ -302,25 +302,42 @@ impl Default for GeneratorBuilder {
     }
 }
 
-#[derive(PartialEq, Debug, Clone, Copy)]
+#[derive(PartialEq, Debug, Clone, Copy, Default)]
 #[cfg_attr(feature = "build-cli", derive(clap::ValueEnum))]
-/// How to implement [`AvroSchema`].
+/// How to implement [`AvroSchema`][avsc].
+///
+/// [avsc]: apache_avro::schema::AvroSchema
 pub enum ImplementAvroSchema {
-    /// Use the [`AvroSchema`] derive.
+    /// Use the [`AvroSchema`][derive] derive.
+    ///
+    /// This might result in a slightly different schema, as names can have different
+    /// capitalisation.
     ///
-    /// This might result in a slightly different schema, as names can have different capitalisation.
+    /// [derive]: derive@apache_avro::AvroSchema
     Derive,
+
     /// Copy the schema used at build time.
     ///
-    /// This will use the [canonical form](Schema::canonical_form) to create an exact (canonical) match.
+    /// This will use the [canonical form](Schema::canonical_form) to create an exact
+    /// (canonical) match. Implementations generated by this functionality won't use the
+    /// [`AvroSchemaComponent`][avsc-compo] implementation of subtypes.
     ///
-    /// Implementations generated by this functionality won't use the [`AvroSchemaComponent`] implementation
-    /// of subtypes.
+    /// [avsc-compo]: apache_avro::schema::derive::AvroSchemaComponent
     CopyBuildSchema,
-    /// Do not implement or derive [`AvroSchema`].
+
+    /// Do not implement or derive [`AvroSchema`][avsc].
+    ///
+    /// [avsc]: apache_avro::schema::AvroSchema
+    #[default]
     None,
 }
 
+impl std::fmt::Display for ImplementAvroSchema {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(f, "{self:?}")
+    }
+}
+
 impl GeneratorBuilder {
     /// Creates a new [`GeneratorBuilder`](GeneratorBuilder).
     pub fn new() -> GeneratorBuilder {
@@ -364,12 +381,14 @@ impl GeneratorBuilder {
         self
     }
 
-    /// Add an implementation of [`AvroSchema`].
+    /// Add an implementation of [`AvroSchema`][avsc].
     ///
     /// This implementation can either use a derive or copy the schema used to generate the type.
     /// See [`ImplementAvroSchema`] for more information.
     ///
     /// Applies to record structs.
+    ///
+    /// [avsc]: apache_avro::schema::AvroSchema
     pub fn implement_avro_schema(mut self, impl_schemas: ImplementAvroSchema) -> GeneratorBuilder {
         self.impl_schemas = impl_schemas;
         self

src/generator.rs

@@ -41,12 +41,12 @@ struct Args {
     #[clap(long)]
     pub derive_builders: bool,
 
-    /// Derive AvroSchema for generated record structs
-    #[clap(long)]
+    /// Implement AvroSchema for generated record structs
+    #[clap(long, value_name = "METHOD", default_value_t = Default::default())]
     pub impl_schemas: ImplementAvroSchema,
 
     /// Extract Derives for generated record structs, comma separated, e.g. `std::fmt::Display,std::string::ToString`
-    #[clap(long, value_delimiter = ',')]
+    #[clap(long, value_name = "DERIVES", value_delimiter = ',')]
     pub extra_derives: Vec<String>,
 }