Add support for tokio to sqlx-macros

Author: mehcode

.github/workflows/mariadb.yml

@@ -48,7 +48,7 @@ jobs:
 
     # -----------------------------------------------------
 
-    - run: cargo test -p sqlx --no-default-features --features 'mysql macros chrono'
+    - run: cargo test -p sqlx --no-default-features --features 'runtime-async-std mysql macros chrono'
       env:
         DATABASE_URL: mariadb://root:password@localhost:${{ job.services.mariadb.ports[3306] }}/sqlx
 

.github/workflows/mysql.yml

@@ -51,7 +51,7 @@ jobs:
 
     # -----------------------------------------------------
 
-    - run: cargo test -p sqlx --no-default-features --features 'mysql macros chrono tls'
+    - run: cargo test -p sqlx --no-default-features --features 'runtime-async-std mysql macros chrono tls'
       env:
         # pass the path to the CA that the MySQL service generated
         # Github Actions' YML parser doesn't handle multiline strings correctly

Cargo.lock

@@ -33,8 +33,8 @@ macros = [ "sqlx-macros" ]
 tls = [ "sqlx-core/tls" ]
 
 # runtime
-runtime-async-std = [ "sqlx-core/runtime-async-std" ]
-runtime-tokio = [ "sqlx-core/runtime-tokio" ]
+runtime-async-std = [ "sqlx-core/runtime-async-std", "sqlx-macros/runtime-async-std" ]
+runtime-tokio = [ "sqlx-core/runtime-tokio", "sqlx-macros/runtime-tokio" ]
 
 # database
 postgres = [ "sqlx-core/postgres", "sqlx-macros/postgres" ]

Cargo.toml

@@ -18,6 +18,9 @@ proc-macro = true
 [features]
 default = []
 
+runtime-async-std = [ "sqlx/runtime-async-std", "async-std" ]
+runtime-tokio = [ "sqlx/runtime-tokio", "tokio", "once_cell" ]
+
 # database
 mysql = [ "sqlx/mysql" ]
 postgres = [ "sqlx/postgres" ]
@@ -27,7 +30,9 @@ chrono = [ "sqlx/chrono" ]
 uuid = [ "sqlx/uuid" ]
 
 [dependencies]
-async-std = { version = "1.4.0", default-features = false }
+async-std = { version = "1.4.0", default-features = false, optional = true }
+tokio = { version = "0.2", optional = true }
+once_cell = { version = "1.3", optional = true }
 dotenv = { version = "0.15.0", default-features = false }
 futures = { version = "0.3.1", default-features = false }
 proc-macro2 = { version = "1.0.6", default-features = false }

sqlx-macros/Cargo.toml

@@ -10,7 +10,8 @@ use quote::quote;
 
 use syn::parse_macro_input;
 
-use async_std::task;
+#[cfg(feature = "runtime-async-std")]
+use async_std::task::block_on;
 
 use url::Url;
 
@@ -24,6 +25,12 @@ mod query_macros;
 
 use query_macros::*;
 
+#[cfg(feature = "runtime-tokio")]
+fn block_on<F: std::future::Future>(future: F) -> F::Output {
+    // TODO: Someone think of something better for async proc macros + tokio
+    tokio::runtime::Runtime::new().unwrap().block_on(future)
+} 
+
 fn macro_result(tokens: proc_macro2::TokenStream) -> TokenStream {
     quote!(
         macro_rules! macro_result {
@@ -40,7 +47,7 @@ macro_rules! async_macro (
             Err(e) => return macro_result(e.to_compile_error()),
         };
 
-        let res: Result<proc_macro2::TokenStream> = task::block_on(async {
+        let res: Result<proc_macro2::TokenStream> = block_on(async {
             use sqlx::Connect;
 
             let db_url = Url::parse(&dotenv::var("DATABASE_URL").map_err(|_| "DATABASE_URL not set")?)?;