check that crate type includes cdylib

src/command.rs

@@ -211,6 +211,19 @@ fn init(
     #[cfg(target_os = "windows")]
     info!(&log, "Copied readme from crate to {}\\pkg.", &crate_path);
 
+    info!(&log, "Checking the crate type from the manifest...");
+    manifest::check_crate_type(&crate_path)?;
+    #[cfg(not(target_os = "windows"))]
+    info!(
+        &log,
+        "Checked crate type from the manifest at {}/Cargo.toml.", &crate_path
+    );
+    #[cfg(target_os = "windows")]
+    info!(
+        &log,
+        "Checked crate type from the manifest at {}\\Cargo.toml.", &crate_path
+    );
+
     info!(&log, "Installing wasm-bindgen-cli...");
     bindgen::cargo_install_wasm_bindgen()?;
     info!(&log, "Installing wasm-bindgen-cli was successful.");

src/error.rs

@@ -15,6 +15,8 @@ pub enum Error {
     SerdeToml(#[cause] toml::de::Error),
     #[fail(display = "{}. stderr:\n\n{}", message, stderr)]
     Cli { message: String, stderr: String },
+    #[fail(display = "{}", message)]
+    Config { message: String },
 }
 
 impl Error {
@@ -25,6 +27,12 @@ impl Error {
         })
     }
 
+    pub fn config(message: &str) -> Result<(), Self> {
+        Err(Error::Config {
+            message: message.to_string(),
+        })
+    }
+
     pub fn error_type(&self) -> String {
         match self {
             Error::Io(_) => "There was an I/O error. Details:\n\n",
@@ -34,6 +42,7 @@ impl Error {
                 message: _,
                 stderr: _,
             } => "There was an error while calling another CLI tool. Details:\n\n",
+            Error::Config { message: _ } => "There was a configuration error. Details:\n\n",
         }.to_string()
     }
 }

src/manifest.rs

@@ -11,6 +11,7 @@ use PBAR;
 #[derive(Deserialize)]
 struct CargoManifest {
     package: CargoPackage,
+    lib: Option<CargoLib>,
 }
 
 #[derive(Deserialize)]
@@ -23,6 +24,11 @@ struct CargoPackage {
     repository: Option<String>,
 }
 
+#[derive(Deserialize)]
+struct CargoLib {
+    crate_type: Option<Vec<String>>,
+}
+
 #[derive(Serialize)]
 struct NpmPackage {
     name: String,
@@ -49,7 +55,9 @@ fn read_cargo_toml(path: &str) -> Result<CargoManifest, Error> {
     let mut cargo_contents = String::new();
     cargo_file.read_to_string(&mut cargo_contents)?;
 
-    Ok(toml::from_str(&cargo_contents)?)
+    Ok(toml::from_str(
+        &cargo_contents.replace("crate-type", "crate_type"),
+    )?)
 }
 
 impl CargoManifest {
@@ -136,3 +144,21 @@ pub fn write_package_json(
 pub fn get_crate_name(path: &str) -> Result<String, Error> {
     Ok(read_cargo_toml(path)?.package.name)
 }
+
+fn has_cdylib(path: &str) -> bool {
+    match read_cargo_toml(path).unwrap().lib {
+        Some(lib) => match lib.crate_type {
+            Some(types) => types.iter().any(|s| s == "cdylib"),
+            _ => false,
+        },
+        _ => false,
+    }
+}
+
+pub fn check_crate_type(path: &str) -> Result<(), Error> {
+    if !has_cdylib(path) {
+        Error::config("crate-type must include cdylib to compile to wasm32-unknown-unknown")
+    } else {
+        Ok(())
+    }
+}

tests/fixtures/bad-cargo-toml/Cargo.toml

@@ -3,5 +3,8 @@ name = "bad-cargo-toml"
 version = "0.1.0"
 authors = ["Michael Gattozzi <mgattozzi@gmail.com>"]
 
+[lib]
+crate-type = ["foo"]
+
 [dependencies]
 wasm-bindgen = "0.2"

tests/manifest/main.rs

@@ -25,6 +25,21 @@ fn it_gets_the_crate_name_provided_path() {
     );
 }
 
+#[test]
+fn it_checks_has_cdylib_default_path() {
+    assert!(manifest::check_crate_type(".").is_err());
+}
+
+#[test]
+fn it_checks_has_cdylib_provided_path() {
+    assert!(manifest::check_crate_type("tests/fixtures/js-hello-world").is_ok());
+}
+
+#[test]
+fn it_checks_has_cdylib_wrong_crate_type() {
+    assert!(manifest::check_crate_type("tests/fixtures/bad-cargo-toml").is_err());
+}
+
 #[test]
 fn it_creates_a_package_json_default_path() {
     let path = ".".to_string();