Add const support for integer types (#218)

* Add Rust constant type
* Add constant parsing functionality
* Add basic structure for generating consts
* Add Go const generation
* Add Python const generation
* Add Typescript const generation
* Add test for generating constants

Author: edif2008

core/data/tests/can_generate_const/input.rs

@@ -0,0 +1,2 @@
+#[typeshare]
+pub const MY_VAR: u32 = 12;

core/data/tests/can_generate_const/output.go

@@ -0,0 +1,5 @@
+package proto
+
+import "encoding/json"
+
+const MyVar uint32 = 12

core/data/tests/can_generate_const/output.py

@@ -0,0 +1,6 @@
+from __future__ import annotations
+
+
+
+
+MY_VAR: int = 12

core/data/tests/can_generate_const/output.ts

@@ -0,0 +1 @@
+export const MY_VAR: number = 12;

core/src/language/go.rs

@@ -3,7 +3,7 @@ use std::io::Write;
 use crate::language::SupportedLanguage;
 use crate::parser::ParsedData;
 use crate::rename::RenameExt;
-use crate::rust_types::{RustItem, RustTypeFormatError, SpecialRustType};
+use crate::rust_types::{RustConst, RustConstExpr, RustItem, RustTypeFormatError, SpecialRustType};
 use crate::{
     language::Language,
     rust_types::{RustEnum, RustEnumVariant, RustField, RustStruct, RustTypeAlias},
@@ -58,6 +58,7 @@ impl Language for Go {
             structs,
             enums,
             aliases,
+            consts,
             ..
         } = data;
 
@@ -66,6 +67,7 @@ impl Language for Go {
             .map(RustItem::Alias)
             .chain(structs.into_iter().map(RustItem::Struct))
             .chain(enums.into_iter().map(RustItem::Enum))
+            .chain(consts.into_iter().map(RustItem::Const))
             .collect::<Vec<_>>();
 
         topsort(&mut items);
@@ -96,6 +98,7 @@ impl Language for Go {
                 RustItem::Enum(e) => self.write_enum(w, e, &types_mapping_to_struct)?,
                 RustItem::Struct(s) => self.write_struct(w, s)?,
                 RustItem::Alias(a) => self.write_type_alias(w, a)?,
+                RustItem::Const(c) => self.write_const(w, c)?,
             }
         }
 
@@ -189,6 +192,23 @@ impl Language for Go {
         Ok(())
     }
 
+    fn write_const(&mut self, w: &mut dyn Write, c: &RustConst) -> std::io::Result<()> {
+        match c.expr {
+            RustConstExpr::Int(val) => {
+                let const_type = self
+                    .format_type(&c.r#type, &[])
+                    .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, e))?;
+                writeln!(
+                    w,
+                    "const {} {} = {}",
+                    c.id.renamed.to_pascal_case(),
+                    const_type,
+                    val
+                )
+            }
+        }
+    }
+
     fn write_struct(&mut self, w: &mut dyn Write, rs: &RustStruct) -> std::io::Result<()> {
         write_comments(w, 0, &rs.comments)?;
         // TODO: Support generic bounds: https://github.com/1Password/typeshare/issues/222

core/src/language/kotlin.rs

@@ -4,7 +4,7 @@ use crate::parser::{remove_dash_from_identifier, DecoratorKind, ParsedData};
 use crate::rust_types::{RustTypeFormatError, SpecialRustType};
 use crate::{
     rename::RenameExt,
-    rust_types::{Id, RustEnum, RustEnumVariant, RustField, RustStruct, RustTypeAlias},
+    rust_types::{Id, RustConst, RustEnum, RustEnumVariant, RustField, RustStruct, RustTypeAlias},
 };
 use itertools::Itertools;
 use joinery::JoinableIterator;
@@ -174,6 +174,10 @@ impl Language for Kotlin {
         Ok(())
     }
 
+    fn write_const(&mut self, _w: &mut dyn Write, _c: &RustConst) -> std::io::Result<()> {
+        todo!()
+    }
+
     fn write_struct(&mut self, w: &mut dyn Write, rs: &RustStruct) -> std::io::Result<()> {
         self.write_comments(w, 0, &rs.comments)?;
         writeln!(w, "@Serializable")?;

core/src/language/mod.rs

@@ -1,7 +1,7 @@
 use crate::{
     parser::{ParseError, ParsedData},
     rust_types::{
-        Id, RustEnum, RustEnumVariant, RustItem, RustStruct, RustType, RustTypeAlias,
+        Id, RustConst, RustEnum, RustEnumVariant, RustItem, RustStruct, RustType, RustTypeAlias,
         RustTypeFormatError, SpecialRustType,
     },
     topsort::topsort,
@@ -173,6 +173,7 @@ pub trait Language {
             structs,
             enums,
             aliases,
+            consts,
             ..
         } = data;
 
@@ -181,7 +182,8 @@ pub trait Language {
                 .into_iter()
                 .map(RustItem::Alias)
                 .chain(structs.into_iter().map(RustItem::Struct))
-                .chain(enums.into_iter().map(RustItem::Enum)),
+                .chain(enums.into_iter().map(RustItem::Enum))
+                .chain(consts.into_iter().map(RustItem::Const)),
         );
 
         topsort(&mut items);
@@ -191,6 +193,7 @@ pub trait Language {
                 RustItem::Enum(e) => self.write_enum(writable, e)?,
                 RustItem::Struct(s) => self.write_struct(writable, s)?,
                 RustItem::Alias(a) => self.write_type_alias(writable, a)?,
+                RustItem::Const(c) => self.write_const(writable, c)?,
             }
         }
 
@@ -299,6 +302,15 @@ pub trait Language {
         Ok(())
     }
 
+    /// Write a constant variable.
+    /// Example of a constant variable:
+    /// ```
+    /// const ANSWER_TO_EVERYTHING: u32 = 42;
+    /// ```
+    fn write_const(&mut self, _w: &mut dyn Write, _c: &RustConst) -> std::io::Result<()> {
+        Ok(())
+    }
+
     /// Write a struct by converting it
     /// Example of a struct:
     /// ```ignore

core/src/language/python.rs

@@ -1,9 +1,12 @@
 use crate::parser::ParsedData;
 use crate::rust_types::{RustEnumShared, RustItem, RustType, RustTypeFormatError, SpecialRustType};
 use crate::topsort::topsort;
+use crate::RenameExt;
 use crate::{
     language::Language,
-    rust_types::{RustEnum, RustEnumVariant, RustField, RustStruct, RustTypeAlias},
+    rust_types::{
+        RustConst, RustConstExpr, RustEnum, RustEnumVariant, RustField, RustStruct, RustTypeAlias,
+    },
 };
 use std::collections::HashSet;
 use std::hash::Hash;
@@ -98,6 +101,7 @@ impl Language for Python {
             structs,
             enums,
             aliases,
+            consts,
             ..
         } = data;
 
@@ -106,6 +110,7 @@ impl Language for Python {
             .map(RustItem::Alias)
             .chain(structs.into_iter().map(RustItem::Struct))
             .chain(enums.into_iter().map(RustItem::Enum))
+            .chain(consts.into_iter().map(RustItem::Const))
             .collect::<Vec<_>>();
 
         topsort(&mut items);
@@ -116,6 +121,7 @@ impl Language for Python {
                 RustItem::Enum(e) => self.write_enum(&mut body, &e)?,
                 RustItem::Struct(rs) => self.write_struct(&mut body, &rs)?,
                 RustItem::Alias(t) => self.write_type_alias(&mut body, &t)?,
+                RustItem::Const(c) => self.write_const(&mut body, &c)?,
             };
         }
 
@@ -243,6 +249,23 @@ impl Language for Python {
         Ok(())
     }
 
+    fn write_const(&mut self, w: &mut dyn Write, c: &RustConst) -> std::io::Result<()> {
+        match c.expr {
+            RustConstExpr::Int(val) => {
+                let const_type = self
+                    .format_type(&c.r#type, &[])
+                    .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, e))?;
+                writeln!(
+                    w,
+                    "{}: {} = {}",
+                    c.id.renamed.to_snake_case().to_uppercase(),
+                    const_type,
+                    val
+                )
+            }
+        }
+    }
+
     fn write_struct(&mut self, w: &mut dyn Write, rs: &RustStruct) -> std::io::Result<()> {
         {
             rs.generic_types

core/src/language/scala.rs

@@ -1,8 +1,10 @@
 use super::{CrateTypes, Language};
 use crate::language::SupportedLanguage;
 use crate::parser::{remove_dash_from_identifier, ParsedData};
-use crate::rust_types::{RustEnum, RustEnumVariant, RustField, RustStruct, RustTypeAlias};
-use crate::rust_types::{RustType, RustTypeFormatError, SpecialRustType};
+use crate::rust_types::{
+    RustConst, RustEnum, RustEnumVariant, RustField, RustStruct, RustType, RustTypeAlias,
+    RustTypeFormatError, SpecialRustType,
+};
 use itertools::Itertools;
 use joinery::JoinableIterator;
 use lazy_format::lazy_format;
@@ -150,6 +152,10 @@ impl Language for Scala {
         Ok(())
     }
 
+    fn write_const(&mut self, _w: &mut dyn Write, _c: &RustConst) -> std::io::Result<()> {
+        todo!()
+    }
+
     fn write_struct(&mut self, w: &mut dyn Write, rs: &RustStruct) -> std::io::Result<()> {
         self.write_comments(w, 0, &rs.comments)?;
 

core/src/language/swift.rs

@@ -3,8 +3,8 @@ use crate::{
     parser::{remove_dash_from_identifier, DecoratorKind, ParsedData},
     rename::RenameExt,
     rust_types::{
-        DecoratorMap, RustEnum, RustEnumVariant, RustStruct, RustTypeAlias, RustTypeFormatError,
-        SpecialRustType,
+        DecoratorMap, RustConst, RustEnum, RustEnumVariant, RustStruct, RustTypeAlias,
+        RustTypeFormatError, SpecialRustType,
     },
     GenerationError,
 };
@@ -258,6 +258,10 @@ impl Language for Swift {
         Ok(())
     }
 
+    fn write_const(&mut self, _w: &mut dyn Write, _c: &RustConst) -> std::io::Result<()> {
+        todo!()
+    }
+
     fn write_struct(&mut self, w: &mut dyn Write, rs: &RustStruct) -> io::Result<()> {
         let mut coding_keys = vec![];
         let mut should_write_coding_keys = false;