macro: add wildcard matching to router macro

router!{
    /path/{parameter}*: {
        methods...
    }
}

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

proxmox-api-macro/src/router_macro.rs

@@ -41,6 +41,7 @@ pub fn router_macro(input: TokenStream) -> Result<TokenStream, Error> {
 pub enum SubRoute {
     Directories(HashMap<LitStr, Router>),
     Parameter(LitStr, Box<Router>),
+    Wildcard(LitStr),
 }
 
 impl SubRoute {
@@ -80,8 +81,12 @@ enum Entry {
 enum Component {
     /// This component is a fixed sub directory name. Eg. `foo` or `baz` in `/foo/{bar}/baz`.
     Name(LitStr),
+
     /// This component matches everything into a parameter. Eg. `bar` in `/foo/{bar}/baz`.
     Match(LitStr),
+
+    /// Matches the rest of the path into a parameters
+    Wildcard(LitStr),
 }
 
 /// A path is just a list of components.
@@ -91,7 +96,7 @@ impl Router {
     /// Insert a new router at a specific path.
     ///
     /// Note that this does not allow replacing an already existing router node.
-    fn insert(&mut self, path: Path, router: Router) -> Result<(), Error> {
+    fn insert(&mut self, path: Path, mut router: Router) -> Result<(), Error> {
         let mut at = self;
         let mut created = false;
         for component in path {
@@ -106,9 +111,12 @@ impl Router {
                                 Router::default()
                             });
                         }
-                        SubRoute::Parameter(_param, _router) => {
+                        SubRoute::Parameter(_, _) => {
                             bail!("subdir '{}' clashes with matched parameter", name.value());
                         }
+                        SubRoute::Wildcard(_) => {
+                            bail!("cannot add subdir '{}', it is already matched by a wildcard");
+                        }
                     }
                 }
                 Component::Match(name) => {
@@ -117,12 +125,6 @@ impl Router {
                         SubRoute::parameter(name.clone())
                     });
                     match subroute {
-                        SubRoute::Directories(_) => {
-                            bail!(
-                                "parameter matcher '{}' clashes with existing directory",
-                                name.value()
-                            );
-                        }
                         SubRoute::Parameter(existing_name, router) => {
                             if name != *existing_name {
                                 bail!(
@@ -133,7 +135,26 @@ impl Router {
                             }
                             at = router.as_mut();
                         }
+                        SubRoute::Directories(_) => {
+                            bail!(
+                                "parameter matcher '{}' clashes with existing directory",
+                                name.value()
+                            );
                         }
+                        SubRoute::Wildcard(_) => {
+                            bail!("parameter matcher '{}' clashes with wildcard", name.value());
+                        }
+                    }
+                }
+                Component::Wildcard(name) => {
+                    if at.subroute.is_some() {
+                        bail!("wildcard clashes with existing subdirectory");
+                    }
+                    created = true;
+                    if router.subroute.is_some() {
+                        bail!("wildcard sub router cannot have subdirectories!");
+                    }
+                    router.subroute = Some(SubRoute::Wildcard(name.clone()));
                 }
             }
         }
@@ -188,6 +209,11 @@ impl Router {
                     });
                 }
             }
+            Some(SubRoute::Wildcard(name)) => {
+                out.extend(quote! {
+                    .wildcard(#name)
+                });
+            }
         }
 
         if let Some(name) = name {
@@ -364,6 +390,18 @@ fn parse_path_name(tokens: &mut TokenIter) -> Result<Path, Error> {
                     push_component(&mut path, &mut component, &mut span);
                     // `component` is cleared, we start the next one
                 }
+                '*' => {
+                    // must be the last component, after a matcher
+                    if !component.is_empty() {
+                        bail!("wildcard must be the final matcher");
+                    }
+                    if let Some(Component::Match(name)) = path.pop() {
+                        path.push(Component::Wildcard(name));
+                        match_colon(&mut *tokens)?;
+                        break;
+                    }
+                    bail!("asterisk only allowed at the end of a match pattern");
+                }
                 other => bail!("invalid punctuation in path: {:?}", other),
             },
             Some(other) => bail!(

proxmox-api-macro/tests/basic.rs

@@ -90,6 +90,8 @@ proxmox_api_macro::router! {
 
             /dir: { GET: non_async_test },
         },
+
+        /wild/{param}*: { GET: get_loopback },
     };
 }
 
@@ -128,6 +130,12 @@ fn router() {
     check_body(&TEST_ROUTER, "/another/foo", r#"{"data":"foo"}"#);
     check_body(&TEST_ROUTER, "/another/foo/dir", r#"{"data":"foo"}"#);
 
+    check_body(&TEST_ROUTER, "/wild", r#"{"data":""}"#);
+    check_body(&TEST_ROUTER, "/wild/", r#"{"data":""}"#);
+    check_body(&TEST_ROUTER, "/wild/asdf", r#"{"data":"asdf"}"#);
+    check_body(&TEST_ROUTER, "/wild//asdf", r#"{"data":"asdf"}"#);
+    check_body(&TEST_ROUTER, "/wild/asdf/poiu", r#"{"data":"asdf/poiu"}"#);
+
     // And can I...
     let res = futures::executor::block_on(get_loopback("FOO".to_string()))
         .expect("expected result from get_loopback");