fix(rust): fixed rust namer isses, resolve #7865 and ##7782 (#7964)

Co-authored-by: Derek Bailey <derekbailey@google.com>

scripts/generate_code.py

@@ -339,6 +339,12 @@ def glob(path, pattern):
     schema="arrays_test.fbs",
 )
 
+flatc(
+    RUST_OPTS,
+    prefix="rust_namer_test",
+    schema="rust_namer_test.fbs",
+)
+
 flatc(
     BASE_OPTS + PYTHON_OPTS,
     schema="arrays_test.fbs",

src/idl_namer.h

@@ -146,7 +146,8 @@ class IdlNamer : public Namer {
 
   std::string LegacyRustUnionTypeMethod(const FieldDef &d) {
     // assert d is a union
-    return Method(d.name + "_type");
+    // d should convert case but not escape keywords due to historical reasons
+    return ConvertCase(d.name, config_.fields, Case::kLowerCamel) + "_type";
   }
 
  private:

tests/rust_namer_test.fbs

@@ -0,0 +1,27 @@
+namespace RustNamerTest;
+
+table FieldTable {}
+
+union FieldUnion {
+  f :FieldTable (id: 0),
+}
+
+table RootTable {
+  field42 :FieldUnion (id: 1);
+}
+
+table PlayerStatEvent {}
+table PlayerSpectate {}
+table PlayerInputChange {}
+
+union GameMessage
+{
+    PlayerStatEvent,
+    PlayerSpectate,
+	PlayerInputChange
+}
+
+table GameMessageWrapper
+{
+	Message:GameMessage;
+}

tests/rust_namer_test/mod.rs

@@ -0,0 +1,21 @@
+// Automatically generated by the Flatbuffers compiler. Do not modify.
+// @generated
+pub mod rust_namer_test {
+  use super::*;
+  mod field_union_generated;
+  pub use self::field_union_generated::*;
+  mod game_message_generated;
+  pub use self::game_message_generated::*;
+  mod field_table_generated;
+  pub use self::field_table_generated::*;
+  mod root_table_generated;
+  pub use self::root_table_generated::*;
+  mod player_stat_event_generated;
+  pub use self::player_stat_event_generated::*;
+  mod player_spectate_generated;
+  pub use self::player_spectate_generated::*;
+  mod player_input_change_generated;
+  pub use self::player_input_change_generated::*;
+  mod game_message_wrapper_generated;
+  pub use self::game_message_wrapper_generated::*;
+} // rust_namer_test

tests/rust_namer_test/rust_namer_test/field_table_generated.rs

@@ -0,0 +1,117 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+// @generated
+extern crate alloc;
+extern crate flatbuffers;
+use alloc::boxed::Box;
+use alloc::string::{String, ToString};
+use alloc::vec::Vec;
+use core::mem;
+use core::cmp::Ordering;
+use self::flatbuffers::{EndianScalar, Follow};
+use super::*;
+pub enum FieldTableOffset {}
+#[derive(Copy, Clone, PartialEq)]
+
+pub struct FieldTable<'a> {
+  pub _tab: flatbuffers::Table<'a>,
+}
+
+impl<'a> flatbuffers::Follow<'a> for FieldTable<'a> {
+  type Inner = FieldTable<'a>;
+  #[inline]
+  unsafe fn follow(buf: &'a [u8], loc: usize) -> Self::Inner {
+    Self { _tab: flatbuffers::Table::new(buf, loc) }
+  }
+}
+
+impl<'a> FieldTable<'a> {
+
+  pub const fn get_fully_qualified_name() -> &'static str {
+    "RustNamerTest.FieldTable"
+  }
+
+  #[inline]
+  pub unsafe fn init_from_table(table: flatbuffers::Table<'a>) -> Self {
+    FieldTable { _tab: table }
+  }
+  #[allow(unused_mut)]
+  pub fn create<'bldr: 'args, 'args: 'mut_bldr, 'mut_bldr>(
+    _fbb: &'mut_bldr mut flatbuffers::FlatBufferBuilder<'bldr>,
+    _args: &'args FieldTableArgs
+  ) -> flatbuffers::WIPOffset<FieldTable<'bldr>> {
+    let mut builder = FieldTableBuilder::new(_fbb);
+    builder.finish()
+  }
+
+  pub fn unpack(&self) -> FieldTableT {
+    FieldTableT {
+    }
+  }
+}
+
+impl flatbuffers::Verifiable for FieldTable<'_> {
+  #[inline]
+  fn run_verifier(
+    v: &mut flatbuffers::Verifier, pos: usize
+  ) -> Result<(), flatbuffers::InvalidFlatbuffer> {
+    use self::flatbuffers::Verifiable;
+    v.visit_table(pos)?
+     .finish();
+    Ok(())
+  }
+}
+pub struct FieldTableArgs {
+}
+impl<'a> Default for FieldTableArgs {
+  #[inline]
+  fn default() -> Self {
+    FieldTableArgs {
+    }
+  }
+}
+
+pub struct FieldTableBuilder<'a: 'b, 'b> {
+  fbb_: &'b mut flatbuffers::FlatBufferBuilder<'a>,
+  start_: flatbuffers::WIPOffset<flatbuffers::TableUnfinishedWIPOffset>,
+}
+impl<'a: 'b, 'b> FieldTableBuilder<'a, 'b> {
+  #[inline]
+  pub fn new(_fbb: &'b mut flatbuffers::FlatBufferBuilder<'a>) -> FieldTableBuilder<'a, 'b> {
+    let start = _fbb.start_table();
+    FieldTableBuilder {
+      fbb_: _fbb,
+      start_: start,
+    }
+  }
+  #[inline]
+  pub fn finish(self) -> flatbuffers::WIPOffset<FieldTable<'a>> {
+    let o = self.fbb_.end_table(self.start_);
+    flatbuffers::WIPOffset::new(o.value())
+  }
+}
+
+impl core::fmt::Debug for FieldTable<'_> {
+  fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+    let mut ds = f.debug_struct("FieldTable");
+      ds.finish()
+  }
+}
+#[non_exhaustive]
+#[derive(Debug, Clone, PartialEq)]
+pub struct FieldTableT {
+}
+impl Default for FieldTableT {
+  fn default() -> Self {
+    Self {
+    }
+  }
+}
+impl FieldTableT {
+  pub fn pack<'b>(
+    &self,
+    _fbb: &mut flatbuffers::FlatBufferBuilder<'b>
+  ) -> flatbuffers::WIPOffset<FieldTable<'b>> {
+    FieldTable::create(_fbb, &FieldTableArgs{
+    })
+  }
+}

tests/rust_namer_test/rust_namer_test/field_union_generated.rs

@@ -0,0 +1,145 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+// @generated
+extern crate alloc;
+extern crate flatbuffers;
+use alloc::boxed::Box;
+use alloc::string::{String, ToString};
+use alloc::vec::Vec;
+use core::mem;
+use core::cmp::Ordering;
+use self::flatbuffers::{EndianScalar, Follow};
+use super::*;
+#[deprecated(since = "2.0.0", note = "Use associated constants instead. This will no longer be generated in 2021.")]
+pub const ENUM_MIN_FIELD_UNION: u8 = 0;
+#[deprecated(since = "2.0.0", note = "Use associated constants instead. This will no longer be generated in 2021.")]
+pub const ENUM_MAX_FIELD_UNION: u8 = 1;
+#[deprecated(since = "2.0.0", note = "Use associated constants instead. This will no longer be generated in 2021.")]
+#[allow(non_camel_case_types)]
+pub const ENUM_VALUES_FIELD_UNION: [FieldUnion; 2] = [
+  FieldUnion::NONE,
+  FieldUnion::f,
+];
+
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Default)]
+#[repr(transparent)]
+pub struct FieldUnion(pub u8);
+#[allow(non_upper_case_globals)]
+impl FieldUnion {
+  pub const NONE: Self = Self(0);
+  pub const f: Self = Self(1);
+
+  pub const ENUM_MIN: u8 = 0;
+  pub const ENUM_MAX: u8 = 1;
+  pub const ENUM_VALUES: &'static [Self] = &[
+    Self::NONE,
+    Self::f,
+  ];
+  /// Returns the variant's name or "" if unknown.
+  pub fn variant_name(self) -> Option<&'static str> {
+    match self {
+      Self::NONE => Some("NONE"),
+      Self::f => Some("f"),
+      _ => None,
+    }
+  }
+}
+impl core::fmt::Debug for FieldUnion {
+  fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+    if let Some(name) = self.variant_name() {
+      f.write_str(name)
+    } else {
+      f.write_fmt(format_args!("<UNKNOWN {:?}>", self.0))
+    }
+  }
+}
+impl<'a> flatbuffers::Follow<'a> for FieldUnion {
+  type Inner = Self;
+  #[inline]
+  unsafe fn follow(buf: &'a [u8], loc: usize) -> Self::Inner {
+    let b = flatbuffers::read_scalar_at::<u8>(buf, loc);
+    Self(b)
+  }
+}
+
+impl flatbuffers::Push for FieldUnion {
+    type Output = FieldUnion;
+    #[inline]
+    unsafe fn push(&self, dst: &mut [u8], _written_len: usize) {
+        flatbuffers::emplace_scalar::<u8>(dst, self.0);
+    }
+}
+
+impl flatbuffers::EndianScalar for FieldUnion {
+  type Scalar = u8;
+  #[inline]
+  fn to_little_endian(self) -> u8 {
+    self.0.to_le()
+  }
+  #[inline]
+  #[allow(clippy::wrong_self_convention)]
+  fn from_little_endian(v: u8) -> Self {
+    let b = u8::from_le(v);
+    Self(b)
+  }
+}
+
+impl<'a> flatbuffers::Verifiable for FieldUnion {
+  #[inline]
+  fn run_verifier(
+    v: &mut flatbuffers::Verifier, pos: usize
+  ) -> Result<(), flatbuffers::InvalidFlatbuffer> {
+    use self::flatbuffers::Verifiable;
+    u8::run_verifier(v, pos)
+  }
+}
+
+impl flatbuffers::SimpleToVerifyInSlice for FieldUnion {}
+pub struct FieldUnionUnionTableOffset {}
+
+#[allow(clippy::upper_case_acronyms)]
+#[non_exhaustive]
+#[derive(Debug, Clone, PartialEq)]
+pub enum FieldUnionT {
+  NONE,
+  F(Box<FieldTableT>),
+}
+impl Default for FieldUnionT {
+  fn default() -> Self {
+    Self::NONE
+  }
+}
+impl FieldUnionT {
+  pub fn field_union_type(&self) -> FieldUnion {
+    match self {
+      Self::NONE => FieldUnion::NONE,
+      Self::F(_) => FieldUnion::f,
+    }
+  }
+  pub fn pack(&self, fbb: &mut flatbuffers::FlatBufferBuilder) -> Option<flatbuffers::WIPOffset<flatbuffers::UnionWIPOffset>> {
+    match self {
+      Self::NONE => None,
+      Self::F(v) => Some(v.pack(fbb).as_union_value()),
+    }
+  }
+  /// If the union variant matches, return the owned FieldTableT, setting the union to NONE.
+  pub fn take_f(&mut self) -> Option<Box<FieldTableT>> {
+    if let Self::F(_) = self {
+      let v = core::mem::replace(self, Self::NONE);
+      if let Self::F(w) = v {
+        Some(w)
+      } else {
+        unreachable!()
+      }
+    } else {
+      None
+    }
+  }
+  /// If the union variant matches, return a reference to the FieldTableT.
+  pub fn as_f(&self) -> Option<&FieldTableT> {
+    if let Self::F(v) = self { Some(v.as_ref()) } else { None }
+  }
+  /// If the union variant matches, return a mutable reference to the FieldTableT.
+  pub fn as_f_mut(&mut self) -> Option<&mut FieldTableT> {
+    if let Self::F(v) = self { Some(v.as_mut()) } else { None }
+  }
+}