Add support for async functions in pdk_query_types (#9)

* Add support for async functions in pdk_query_types

Currently it is impossible to use an asynchronous handler when using the
convenience macro `pdk_query_types`.

This adds the ability to append `.await` to the handler property to tell the macro to expect an
asynchronous handler.

Cargo.toml

@@ -6,16 +6,16 @@ exclude = ["providers/.cargo"]
 authors = ["Fiberplane <[email protected]>"]
 edition = "2021"
 rust-version = "1.65"
-version = "1.0.0-alpha.2"
+version = "1.0.0-alpha.3"
 license = "MIT OR Apache-2.0"
 
 [workspace.dependencies]
 fp-bindgen = { version = "3.0.0-alpha.1" }
 fp-bindgen-support = { version = "3.0.0-alpha.1" }
 #fiberplane-models = { version = "1.0.0-alpha.2", registry = "artifactory" }
 fiberplane-models = { git = "ssh://[email protected]/fiberplane/fiberplane-rs.git", branch = "main" }
-fiberplane-pdk = { version = "1.0.0-alpha.1", path = "fiberplane-pdk" }
-fiberplane-pdk-macros = { version = "1.0.0-alpha.1", path = "fiberplane-pdk-macros" }
+fiberplane-pdk = { version = "1.0.0-alpha.3", path = "fiberplane-pdk" }
+fiberplane-pdk-macros = { version = "1.0.0-alpha.3", path = "fiberplane-pdk-macros" }
 #fiberplane-provider-bindings = { version = "1.0.0-alpha.2", registry = "artifactory" }
 fiberplane-provider-bindings = { git = "ssh://[email protected]/fiberplane/fiberplane-rs.git", branch = "main" }
 

fiberplane-pdk-macros/src/lib.rs

@@ -21,7 +21,8 @@ use quote::quote;
 ///   requests of the given type. Handlers may have one or two arguments, the
 ///   types of which are given between parentheses. The first argument is always
 ///   the type of the query data, while the second optionally specifies a type
-///   for the provider's config. Providing a handler is mandatory.
+///   for the provider's config. Add a `.await` call to the handler
+///   if the handler is asynchronous. Providing a handler is mandatory.
 /// * **label** - A label that is used when presenting the query type to the
 ///   user. Some query types are not intended to be user-selected (such as the
 ///   `status` query type) in which case they should not define a label.
@@ -49,7 +50,7 @@ use quote::quote;
 ///     },
 ///     "x-custom-query-type" => {
 ///         label: "My custom query",
-///         handler: query_custom(ExampleQueryData),
+///         handler: query_custom(ExampleQueryData).await,
 ///         supported_mime_types: ["application/vnd.fiberplane.provider.my-provider.custom-data"],
 ///     }
 /// }
@@ -58,7 +59,7 @@ use quote::quote;
 ///     todo!("Implement timeseries query handling")
 /// }
 ///
-/// fn query_custom(query_data: ExampleQueryData) -> Result<Blob> {
+/// async fn query_custom(query_data: ExampleQueryData) -> Result<Blob> {
 ///     todo!("Implement custom query handling")
 /// }
 /// ```

fiberplane-pdk-macros/src/query_types.rs

@@ -64,7 +64,11 @@ pub fn define_query_types(input: TokenStream) -> TokenStream {
                     };
                     quote! { #ty::parse(#parse_arg)? }
                 });
-                quote! { #fn_name(#(#args),*) }
+                if handler.is_async {
+                    quote! { #fn_name(#(#args),*).await }
+                } else {
+                    quote! { #fn_name(#(#args),*) }
+                }
             });
 
             quote! { #identifier => #handler }
@@ -172,6 +176,7 @@ impl Parse for QueryTypeField {
 }
 
 struct QueryHandler {
+    is_async: bool,
     ident: Ident,
     _parens: token::Paren,
     arg_types: Punctuated<Ident, Token![,]>,
@@ -180,10 +185,23 @@ struct QueryHandler {
 impl Parse for QueryHandler {
     fn parse(input: ParseStream) -> Result<Self> {
         let content;
+
+        let ident = input.parse::<Ident>()?;
+        let _parens = parenthesized!(content in input);
+        let arg_types = content.parse_terminated(Ident::parse)?;
+        let is_async = if input.peek(Token![.]) && input.peek2(Token![await]) {
+            input.parse::<Token![.]>()?;
+            input.parse::<Token![await]>()?;
+            true
+        } else {
+            false
+        };
+
         Ok(Self {
-            ident: input.parse()?,
-            _parens: parenthesized!(content in input),
-            arg_types: content.parse_terminated(Ident::parse)?,
+            is_async,
+            ident,
+            _parens,
+            arg_types,
         })
     }
 }