proof-of-concept of type overrides using the CLI

cli/Cargo.toml

@@ -6,5 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-clap = { version = "4", features = ["derive"]}
+clap = { version = "4", features = ["derive"] }
 color-eyre = "0.6"
+serde = { version = "1", features = ["derive"] }
+toml = "0.8"

cli/src/cargo.rs

@@ -2,7 +2,8 @@ use std::process::{Command, Stdio};
 
 use color_eyre::Result;
 
-use crate::{args::Args, path};
+use crate::config::Config;
+use crate::path;
 
 macro_rules! feature {
     ($cargo_invocation: expr, $args: expr, { $($field: ident => $feature: literal),* $(,)? }) => {
@@ -16,7 +17,7 @@ macro_rules! feature {
     };
 }
 
-pub fn invoke(args: &Args) -> Result<()> {
+pub fn invoke(cfg: &Config) -> Result<()> {
     let mut cargo_invocation = Command::new("cargo");
 
     cargo_invocation
@@ -26,20 +27,25 @@ pub fn invoke(args: &Args) -> Result<()> {
         .arg("ts-rs/export")
         .arg("--features")
         .arg("ts-rs/generate-metadata")
-        .stdout(if args.no_capture {
+        .stdout(if cfg.no_capture {
             Stdio::inherit()
         } else {
             Stdio::piped()
         })
-        .env("TS_RS_EXPORT_DIR", path::absolute(&args.output_directory)?);
+        .env("TS_RS_EXPORT_DIR", path::absolute(&cfg.output_directory)?);
 
-    feature!(cargo_invocation, args, {
+    for (rust, ts) in &cfg.overrides {
+        let env = format!("TS_RS_INTERNAL_OVERRIDE_{rust}");
+        cargo_invocation.env(env, ts);
+    }
+
+    feature!(cargo_invocation, cfg, {
         no_warnings => "no-serde-warnings",
         esm_imports => "import-esm",
         format => "format",
     });
 
-    if args.no_capture {
+    if cfg.no_capture {
         cargo_invocation.arg("--").arg("--nocapture");
     } else {
         cargo_invocation.arg("--quiet");

cli/src/config.rs

@@ -0,0 +1,104 @@
+use clap::Parser;
+use color_eyre::Result;
+use serde::Deserialize;
+use std::collections::HashMap;
+use std::path::{Path, PathBuf};
+use color_eyre::eyre::bail;
+
+#[derive(Parser, Debug)]
+#[allow(clippy::struct_excessive_bools)]
+pub struct Args {
+    /// Defines where your TS bindings will be saved by setting TS_RS_EXPORT_DIR
+    #[arg(long, short)]
+    pub output_directory: PathBuf,
+
+    /// Disables warnings caused by using serde attributes that ts-rs cannot process
+    #[arg(long)]
+    pub no_warnings: bool,
+
+    /// Adds the ".js" extension to import paths
+    #[arg(long)]
+    pub esm_imports: bool,
+
+    /// Formats the generated TypeScript files
+    #[arg(long)]
+    pub format: bool,
+
+    /// Generates an index.ts file in your --output-directory that re-exports all
+    /// types generated by ts-rs
+    #[arg(long = "index")]
+    pub generate_index_ts: bool,
+
+    /// Generates only a single index.ts file in your --output-directory that
+    /// contains all exported types
+    #[arg(long = "merge")]
+    pub merge_files: bool,
+
+    /// Do not capture `cargo test`'s output, and pass --nocapture to the test binary
+    #[arg(long = "nocapture")]
+    pub no_capture: bool,
+}
+
+// keeping this separate from `Args` for now :shrug:
+#[derive(Default, Deserialize)]
+#[serde(deny_unknown_fields, default)]
+pub struct Config {
+    // type overrides for types implemented inside ts-rs.
+    pub overrides: HashMap<String, String>,
+    pub output_directory: PathBuf,
+    pub no_warnings: bool,
+    pub esm_imports: bool,
+    pub format: bool,
+    pub generate_index_ts: bool,
+    pub merge_files: bool,
+    pub no_capture: bool,
+}
+
+impl Config {
+    pub fn load() -> Result<Self> {
+        let mut cfg = Self::load_from_file()?;
+        cfg.merge(Args::parse());
+        cfg.verify()?;
+        Ok(cfg)
+    }
+
+    fn load_from_file() -> Result<Self> {
+        // TODO: from where do we actually load the config?
+        let path = Path::new("./ts-rs.toml");
+        if !path.is_file() {
+            return Ok(Self::default());
+        }
+        let content = std::fs::read_to_string(path)?;
+        Ok(toml::from_str::<Config>(&content)?)
+    }
+
+    fn verify(&self) -> Result<()> {
+        if self.merge_files && self.generate_index_ts {
+            bail!("--index is not compatible with --merge");
+        }
+        Ok(())
+    }
+
+    fn merge(
+        &mut self,
+        Args {
+            output_directory,
+            no_warnings,
+            esm_imports,
+            format,
+            generate_index_ts,
+            merge_files,
+            no_capture,
+        }: Args,
+    ) {
+        self.output_directory = output_directory;
+        self.no_warnings = no_warnings;
+        self.esm_imports = esm_imports;
+        self.format = format;
+        self.generate_index_ts = generate_index_ts;
+        self.merge_files = merge_files;
+        self.no_capture = no_capture;
+    }
+}
+
+

cli/src/main.rs

@@ -5,45 +5,45 @@ use std::{
     io::{Read, Write},
 };
 
-use clap::Parser;
 use color_eyre::{owo_colors::OwoColorize, Result};
 
-mod args;
 mod cargo;
 mod metadata;
 mod path;
+mod config;
 
-use args::Args;
 use metadata::{Metadata, FILE_NAME};
+use crate::config::Config;
 
 const BLANK_LINE: [u8; 2] = [b'\n', b'\n'];
 const NOTE: &[u8; 109] = b"// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.\n";
 
+struct Cleanup<'a>(&'a Config);
+impl<'a> Drop for Cleanup<'a> {
+    fn drop(&mut self) {
+        _ = fs::remove_file(self.0.output_directory.join(FILE_NAME));
+    }
+}
+
 fn main() -> Result<()> {
     color_eyre::install()?;
 
-    let args = Args::parse();
+    let cfg = Config::load()?;
+    let _cleanup = Cleanup(&cfg);
 
-    let metadata_path = args.output_directory.join(FILE_NAME);
+    let metadata_path = cfg.output_directory.join(FILE_NAME);
     if metadata_path.exists() {
         fs::remove_file(&metadata_path)?;
     }
 
-    if args.merge_files && args.generate_index_ts {
-        eprintln!(
-            "{} --index is not compatible with --merge",
-            "Error:".red().bold()
-        );
 
-        return Ok(());
-    }
 
-    cargo::invoke(&args)?;
+    cargo::invoke(&cfg)?;
 
     let metadata_content = fs::read_to_string(&metadata_path)?;
     let metadata = Metadata::try_from(&*metadata_content)?;
 
-    let demand_unique_names = args.merge_files || args.generate_index_ts;
+    let demand_unique_names = cfg.merge_files || cfg.generate_index_ts;
 
     if !demand_unique_names || metadata.is_empty() {
         return Ok(());
@@ -60,7 +60,7 @@ fn main() -> Result<()> {
         return Ok(());
     }
 
-    let index_path = args.output_directory.join("index.ts");
+    let index_path = cfg.output_directory.join("index.ts");
 
     if index_path.exists() {
         fs::remove_file(&index_path)?;
@@ -73,17 +73,17 @@ fn main() -> Result<()> {
 
     index.write_all(NOTE)?;
 
-    if args.generate_index_ts {
+    if cfg.generate_index_ts {
         for path in metadata.export_paths() {
             index.write_fmt(format_args!("\nexport * from {path:?};"))?;
         }
 
         return Ok(());
     }
 
-    if args.merge_files {
+    if cfg.merge_files {
         for path in metadata.export_paths() {
-            let path = path::absolute(args.output_directory.join(path))?;
+            let path = path::absolute(cfg.output_directory.join(path))?;
             let mut file = OpenOptions::new().read(true).open(&path)?;
 
             let mut buf = Vec::with_capacity(file.metadata()?.len().try_into()?);
@@ -98,7 +98,7 @@ fn main() -> Result<()> {
             fs::remove_file(path)?;
         }
 
-        path::remove_empty_subdirectories(&args.output_directory)?;
+        path::remove_empty_subdirectories(&cfg.output_directory)?;
 
         return Ok(());
     }