Implement quote::ToTokens for FoundCrate

.github/workflows/rust.yml

@@ -17,6 +17,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: dtolnay/rust-toolchain@stable
       - run: cargo test --all
+      - run: cargo test --all --all-features
   msrv:
     name: "Check MSRV: 1.82.0"
     runs-on: ubuntu-latest
@@ -29,7 +30,7 @@ jobs:
         toolchain: 1.82.0  # MSRV
     - uses: Swatinem/rust-cache@v2
     - name: Default features
-      run: cargo test --all
+      run: cargo test --all --all-features
   rustfmt:
     name: rustfmt
     runs-on: ubuntu-latest
@@ -43,7 +44,7 @@ jobs:
         components: rustfmt
     - uses: Swatinem/rust-cache@v2
     - name: Check formatting
-      run: cargo fmt --all -- --check
+      run: cargo fmt --all --all-features -- --check
   clippy:
     name: cargo clippy (forbidden methods)
     runs-on: ubuntu-latest
@@ -52,4 +53,4 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
       # We just use clippy to spot forbidden methods.
       # We disable the default lint set which has much questionable output.
-      - run: cargo clippy --all -- -A clippy::all -D clippy::disallowed_methods
+      - run: cargo clippy --all --all-features -- -A clippy::all -D clippy::disallowed_methods

Cargo.toml

@@ -15,11 +15,16 @@ readme = "./README.md"
 rust-version = "1.82.0"
 
 [dependencies]
+proc-macro2 = { version = "1.0.0", optional = true }
 toml_edit = { version = "0.25.0", default-features = false, features = [
     "parse",
 ] }
+quote = { version = "1.0.0", optional = true }
 
 [dev-dependencies]
 quote = "1.0.39"
 syn = "2.0.99"
 proc-macro2 = "1.0.94"
+
+[features]
+to_tokens = ["dep:proc-macro2", "dep:quote"]

src/lib.rs

@@ -94,6 +94,10 @@ use std::{
     time::SystemTime,
 };
 
+#[cfg(feature = "to_tokens")]
+use proc_macro2::{Ident, Span, TokenStream};
+#[cfg(feature = "to_tokens")]
+use quote::{quote, ToTokens};
 use toml_edit::{DocumentMut, Item, TableLike, TomlError};
 
 /// Error type used by this crate.
@@ -152,6 +156,22 @@ pub enum FoundCrate {
     Name(String),
 }
 
+#[cfg(feature = "to_tokens")]
+impl ToTokens for FoundCrate {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        match self {
+            Self::Itself => {
+                quote!(crate)
+            },
+            Self::Name(name) => {
+                let name = Ident::new_raw(name, Span::call_site());
+                quote!(::#name)
+            },
+        }
+        .to_tokens(tokens);
+    }
+}
+
 // In a rustc invocation, there will only ever be one entry in this map, since every crate is
 // compiled with its own rustc process. However, the same is not (currently) the case for
 // rust-analyzer.
@@ -574,4 +594,19 @@ mod tests {
         "#,
         Ok(Some(FoundCrate::Name(name))) if name == "my_crate_cool"
     }
+
+    #[cfg(feature = "to_tokens")]
+    #[test]
+    fn itself_to_tokens() {
+        assert_eq!(quote!(crate).to_string(), FoundCrate::Itself.into_token_stream().to_string());
+    }
+
+    #[cfg(feature = "to_tokens")]
+    #[test]
+    fn name_to_tokens() {
+        assert_eq!(
+            quote!(::r#my_crate).to_string(),
+            FoundCrate::Name("my_crate".to_string()).into_token_stream().to_string()
+        );
+    }
 }