1 files changed, 123 insertions, 0 deletions
diff --git a/e2etest-macros/src/webtest.rs b/e2etest-macros/src/webtest.rs
new file mode 100644
index 0000000..6b47559
--- /dev/null
+++ b/e2etest-macros/src/webtest.rs
@@ -0,0 +1,123 @@
+use proc_macro::TokenStream;
+use proc_macro2::Span;
+use quote::{format_ident, quote};
+use syn::{
+    parse_macro_input, FnArg, ItemFn, PatType, ReturnType,
+    Visibility,
+};
+
+/**
+* wrap webtest annotated functions in an async Pin<Box>
+**/
+pub fn webtest_impl(_args: TokenStream, input: TokenStream) -> TokenStream {
+    let input_fn = parse_macro_input!(input as ItemFn);
+
+    if let Err(err) = validate_function(&input_fn) {
+        return syn::Error::new(Span::call_site(), err)
+            .to_compile_error()
+            .into();
+    }
+
+    let fn_name = &input_fn.sig.ident;
+    let fn_name_str = fn_name.to_string();
+    let vis = &input_fn.vis;
+    let attrs = &input_fn.attrs;
+    let fn_block = &input_fn.block;
+    let fn_inputs = &input_fn.sig.inputs;
+    let fn_output = &input_fn.sig.output;
+    let fn_generics = &input_fn.sig.generics;
+    let fn_asyncness = &input_fn.sig.asyncness;
+
+    let original_fn_name = format_ident!("{}_original", fn_name);
+
+    let expanded = quote! {
+        #(#attrs)*
+        #vis #fn_asyncness fn #original_fn_name #fn_generics(#fn_inputs) #fn_output #fn_block
+
+        fn #fn_name #fn_generics(
+            driver: &::thirtyfour::WebDriver
+        ) -> ::std::pin::Pin<Box<dyn ::std::future::Future<Output = crate::TestResult> + Send + '_>> {
+            Box::pin(async move {
+                #original_fn_name(driver).await
+            })
+        }
+
+        ::inventory::submit! {
+            crate::TestFunction {
+                name: #fn_name_str,
+                func: #fn_name,
+            }
+        }
+    };
+
+    TokenStream::from(expanded)
+}
+
+fn validate_function(func: &ItemFn) -> Result<(), String> {
+    is_async(func)?;
+    is_visible(func)?;
+    matches_arguments(&["WebDriver"], func)?;
+    matches_return_type("TestResult", func)?;
+
+    Ok(())
+}
+
+fn is_async(func: &ItemFn) -> Result<(), String> {
+    if func.sig.asyncness.is_none() {
+        Err("Test functions must be async".to_string())
+    } else { Ok(()) }
+}
+
+fn is_visible(func: &ItemFn) -> Result<(), String> {
+    match func.vis {
+        Visibility::Inherited | Visibility::Public(_) => {
+            Ok(())
+        }
+        _ => {
+            Err("Test functions should be pub or have default visibility".to_string())
+        }
+    }
+}
+
+fn matches_arguments(types: &[&str], func: &ItemFn) -> Result<(), String> {
+    let args = matches_argument_count(types.len(), func)?;
+    for index in 0..args.len() {
+        matches_argument_type(types.get(index).unwrap(), args.get(index).unwrap())?;
+    }
+    Ok(())
+}
+
+fn matches_argument_count(expected: usize, func: &ItemFn) -> Result<Vec<&FnArg>, String> {
+    let inputs: Vec<_> = func.sig.inputs.iter().collect();
+    if inputs.len() != expected {
+        Err(format!("Test functions must take exactly {} parameters", expected))
+    } else { Ok(inputs) }
+}
+
+fn matches_argument_type(expected: &str, arg: &FnArg) -> Result<(), String> {
+    match arg {
+        FnArg::Receiver(_) => {
+            Err("Test functions cannot be methods (no self parameter)".to_string())
+        }
+        FnArg::Typed(PatType { ty, .. }) => {
+            let type_str = quote!(#ty).to_string();
+            if !type_str.contains(expected) {
+                Err("First parameter must be &WebDriver".to_string())
+            } else { Ok(()) }
+        }
+    }
+}
+
+fn matches_return_type(expected: &str, func: &ItemFn) -> Result<(), String> {
+    match &func.sig.output {
+        ReturnType::Default => {
+            Err("Test functions must return TestResult".to_string())
+        }
+        ReturnType::Type(_, ty) => {
+            let type_str = quote!(#ty).to_string();
+            if !type_str.contains(expected) && !type_str.contains("Result") {
+                Err("Test functions must return TestResult".to_string())
+            } else { Ok(()) }
+        }
+    }
+}