Fix parser for #[default] attr for bool, PathBuf, and OsString (#27)

Fixes #16
parasyte · Feb 12, 2024 · e838124 · e838124
1 parent 732d059
commit e838124
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Showing 2 changed files with 47 additions and 17 deletions.
diff --git a/onlyargs_derive/src/lib.rs b/onlyargs_derive/src/lib.rs
@@ -66,6 +66,9 @@
 //!   will be `-N`.
 //!   - If `#[long]` and `#[short]` are used together, `#[long]` takes precedence.
 //! - `#[default(T)]`: Specify a default value for an argument. Where `T` is a literal value.
+//!   - Accepts string literals for `PathBuf`.
+//!   - Accepts numeric literals for numeric types.
+//!   - Accepts `true` and `false` idents and `"true"` and `"false"` string literals for `boolean`.
 //!
 //! # Supported types
 //!
@@ -127,18 +130,16 @@ pub fn derive_parser(input: TokenStream) -> TokenStream {
     };
 
     let mut flags = vec![
-        ArgFlag {
-            name: Ident::new("help", Span::call_site()),
-            short: Some('h'),
-            doc: vec!["Show this help message.".to_string()],
-            output: false,
-        },
-        ArgFlag {
-            name: Ident::new("version", Span::call_site()),
-            short: Some('V'),
-            doc: vec!["Show the application version.".to_string()],
-            output: false,
-        },
+        ArgFlag::new_priv(
+            Ident::new("help", Span::call_site()),
+            Some('h'),
+            vec!["Show this help message.".to_string()],
+        ),
+        ArgFlag::new_priv(
+            Ident::new("version", Span::call_site()),
+            Some('V'),
+            vec!["Show the application version.".to_string()],
+        ),
     ];
     flags.extend(ast.flags);
 
@@ -186,7 +187,13 @@ pub fn derive_parser(input: TokenStream) -> TokenStream {
             .iter()
             .filter(|&flag| flag.output)
             .fold(String::new(), |mut flags, flag| {
-                write!(flags, "let mut {name} = false;", name = &flag.name).unwrap();
+                write!(
+                    flags,
+                    "let mut {name} = {default:?};",
+                    name = flag.name,
+                    default = flag.default,
+                )
+                .unwrap();
                 flags
             });
     let options_vars = ast
@@ -195,7 +202,7 @@ pub fn derive_parser(input: TokenStream) -> TokenStream {
         .map(|opt| {
             let name = &opt.name;
             if let Some(default) = opt.default.as_ref() {
-                format!("let mut {name} = {default};")
+                format!("let mut {name} = {default}.into();")
             } else {
                 format!("let mut {name} = None;")
             }
@@ -367,7 +374,6 @@ pub fn derive_parser(input: TokenStream) -> TokenStream {
                     "\n",
                 );
 
-                /// The application name and version.
                 const VERSION: &'static str = concat!(
                     env!("CARGO_PKG_NAME"),
                     " v",

diff --git a/onlyargs_derive/src/parser.rs b/onlyargs_derive/src/parser.rs
@@ -22,6 +22,7 @@ pub(crate) struct ArgFlag {
     pub(crate) name: Ident,
     pub(crate) short: Option<char>,
     pub(crate) doc: Vec<String>,
+    pub(crate) default: bool,
     pub(crate) output: bool,
 }
 
@@ -129,7 +130,14 @@ impl Argument {
                     "default" => {
                         let mut stream = attr.tree.expect_group(Delimiter::Parenthesis)?;
 
-                        default = Some(stream.try_lit()?);
+                        default = Some(stream.try_lit().or_else(|_| {
+                            stream
+                                .try_ident()
+                                .and_then(|ident| match ident.to_string().as_str() {
+                                    boolean @ ("true" | "false") => Ok(Literal::string(boolean)),
+                                    _ => Err(spanned_error("Unexpected identifier", ident.span())),
+                                })
+                        })?);
                     }
                     "long" => long = true,
                     "short" => {
@@ -158,7 +166,12 @@ impl Argument {
             };
 
             if path == "bool" {
-                args.push(Self::Flag(ArgFlag::new(name, short, doc)));
+                let mut flag = ArgFlag::new(name, short, doc);
+                match default {
+                    Some(lit) if lit.to_string() == r#""true""# => flag.default = true,
+                    _ => (),
+                }
+                args.push(Self::Flag(flag));
             } else {
                 let mut opt = ArgOption::new(name, short, doc, &path).map_err(|()| {
                     spanned_error(
@@ -198,10 +211,21 @@ impl ArgFlag {
             name,
             short,
             doc,
+            default: false,
             output: true,
         }
     }
 
+    pub(crate) fn new_priv(name: Ident, short: Option<char>, doc: Vec<String>) -> Self {
+        ArgFlag {
+            name,
+            short,
+            doc,
+            default: false,
+            output: false,
+        }
+    }
+
     pub(crate) fn as_view(&self) -> ArgView {
         ArgView {
             name: &self.name,