add edition support

src/cargo.rs

@@ -2,6 +2,7 @@ use serde::Serialize;
 use toml::value::Table;
 
 use crate::errors::CargoPlayError;
+use crate::opt::RustEdition;
 
 #[derive(Clone, Debug, Serialize)]
 struct CargoPackage {
@@ -11,11 +12,11 @@ struct CargoPackage {
 }
 
 impl CargoPackage {
-    fn new(name: String) -> Self {
+    fn new(name: String, edition: RustEdition) -> Self {
         Self {
             name: name.to_lowercase(),
             version: "0.1.0".into(),
-            edition: "2018".into(),
+            edition: edition.into(),
         }
     }
 }
@@ -27,7 +28,11 @@ pub(crate) struct CargoManifest {
 }
 
 impl CargoManifest {
-    pub(crate) fn new(name: String, dependencies: Vec<String>) -> Result<Self, CargoPlayError> {
+    pub(crate) fn new(
+        name: String,
+        dependencies: Vec<String>,
+        edition: RustEdition,
+    ) -> Result<Self, CargoPlayError> {
         let dependencies = dependencies
             .into_iter()
             .map(|dependency| dependency.parse::<toml::Value>())
@@ -45,7 +50,7 @@ impl CargoManifest {
             .collect();
 
         Ok(Self {
-            package: CargoPackage::new(name),
+            package: CargoPackage::new(name, edition),
             dependencies,
         })
     }

src/errors.rs

@@ -12,6 +12,9 @@ pub enum CargoPlayError {
     #[fail(display = "Unable to compute relative path of {:?}", _0)]
     DiffPathError(std::path::PathBuf),
 
+    #[fail(display = "Unexpected edition {:?}. Edition must be 2015/2018.", _0)]
+    InvalidEdition(String),
+
     /// Helper error kind only exists for development purpose.
     #[fail(display = "{:?}", _0)]
     _Message(String),

src/main.rs

@@ -5,7 +5,6 @@ mod errors;
 mod opt;
 
 use log::debug;
-use opt::Opt;
 use pathdiff::diff_paths;
 use std::env::temp_dir;
 use std::fs::File;
@@ -18,6 +17,7 @@ use structopt::StructOpt;
 
 use crate::cargo::CargoManifest;
 use crate::errors::CargoPlayError;
+use crate::opt::{Opt, RustEdition};
 
 fn parse_inputs(inputs: &Vec<PathBuf>) -> Result<Vec<String>, CargoPlayError> {
     inputs
@@ -65,8 +65,9 @@ fn write_cargo_toml(
     dir: &PathBuf,
     name: String,
     dependencies: Vec<String>,
+    edition: RustEdition,
 ) -> Result<(), CargoPlayError> {
-    let manifest = CargoManifest::new(name, dependencies)?;
+    let manifest = CargoManifest::new(name, dependencies, edition)?;
     let mut cargo = File::create(dir.join("Cargo.toml"))?;
 
     cargo.write_all(&toml::to_vec(&manifest).map_err(CargoPlayError::from_serde)?)?;
@@ -140,7 +141,7 @@ fn main() -> Result<(), CargoPlayError> {
     let dependencies = extract_headers(&files);
     let temp = mktemp(opt.temp_dirname());
 
-    write_cargo_toml(&temp, opt.src_hash(), dependencies)?;
+    write_cargo_toml(&temp, opt.src_hash(), dependencies, opt.edition)?;
     copy_sources(&temp, &opt.src)?;
 
     match run_cargo_build(&temp)?.code() {

src/opt.rs

@@ -2,9 +2,41 @@ use base64;
 use sha1;
 use std::ffi::{OsStr, OsString};
 use std::path::PathBuf;
+use std::str::FromStr;
 use std::vec::Vec;
 use structopt::StructOpt;
 
+use crate::errors::CargoPlayError;
+
+#[derive(Debug)]
+pub(crate) enum RustEdition {
+    E2015,
+    E2018,
+}
+
+impl FromStr for RustEdition {
+    type Err = CargoPlayError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        if s == "2018" {
+            Ok(Self::E2018)
+        } else if s == "2015" {
+            Ok(Self::E2015)
+        } else {
+            Err(CargoPlayError::InvalidEdition(s.into()))
+        }
+    }
+}
+
+impl Into<String> for RustEdition {
+    fn into(self) -> String {
+        match self {
+            RustEdition::E2015 => "2015".into(),
+            RustEdition::E2018 => "2018".into(),
+        }
+    }
+}
+
 #[derive(Debug, StructOpt)]
 #[structopt(name = "cargo-play", about = "Single file cargo runner.")]
 pub(crate) struct Opt {
@@ -17,6 +49,13 @@ pub(crate) struct Opt {
         raw(required = "true", validator = "file_exist")
     )]
     pub src: Vec<PathBuf>,
+    #[structopt(
+        short = "e",
+        long = "edition",
+        default_value = "2018",
+        raw(possible_values = r#"&["2015", "2018"]"#)
+    )]
+    pub edition: RustEdition,
 }
 
 impl Opt {