From 107a83ed06635847d5d1e6ff1ff9929952397a4d Mon Sep 17 00:00:00 2001
From: timofey <tim@ongoteam.yaconnect.com>
Date: Fri, 26 May 2023 20:34:10 +0000
Subject: [PATCH] `InjectedResolver`

---
 src/testing.rs        |  1 +
 src/testing/inject.rs | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 src/testing/inject.rs

diff --git a/src/testing.rs b/src/testing.rs
index 057bba4..7599578 100644
--- a/src/testing.rs
+++ b/src/testing.rs
@@ -1,4 +1,5 @@
 pub mod counted;
+pub mod inject;
 pub mod traced;
 
 use std::{error::Error, fmt::Display, rc::Rc};
diff --git a/src/testing/inject.rs b/src/testing/inject.rs
new file mode 100644
index 0000000..addbda9
--- /dev/null
+++ b/src/testing/inject.rs
@@ -0,0 +1,29 @@
+use std::rc::Rc;
+
+use crate::func::*;
+use crate::rcore::*;
+
+trait Inject<'a, Ctx: Context<'a>>: 'a {
+    fn inject<A: 'a>(fa: Wrapped<'a, Ctx, A>) -> Wrapped<'a, Ctx, A>;
+}
+
+struct InjectedResolver<'a, Ctx: Context<'a>, F: Inject<'a, Ctx>> {
+    resolver: Rc<dyn Resolver<'a, Ctx>>,
+    inject: Rc<F>,
+}
+
+impl<'a, Ctx: Context<'a>, F: Inject<'a, Ctx>> Resolver<'a, Ctx> for InjectedResolver<'a, Ctx, F> {
+    fn resolve(self: Rc<Self>, address: crate::rcore::Address) -> HashResolution<'a, Ctx> {
+        let inject = self.inject.clone();
+        <Ctx::T as Functor>::fmap(
+            |resolved| match resolved {
+                Ok((source, resolver)) => Ok((
+                    source,
+                    Rc::new(InjectedResolver { resolver, inject }) as Rc<dyn Resolver<'a, Ctx>>,
+                )),
+                Err(e) => Err(e),
+            },
+            self.resolver.clone().resolve(address),
+        )
+    }
+}