Add tools for Bot/Request type erasure

CHANGELOG.md

@@ -9,11 +9,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- `ErasedRequester` bot adaptor, `ErasedRequest` struct, `{Request, RequesterExt}::erase` functions ([#105][pr105])
 - `Trace` bot adaptor ([#104][pr104])
 - `HasPayload`, `Request` and `Requester` implementations for `either::Either` ([#103][pr103])
 
 [pr103]: https://github.com/teloxide/teloxide-core/pull/103
 [pr104]: https://github.com/teloxide/teloxide-core/pull/104
+[pr105]: https://github.com/teloxide/teloxide-core/pull/105
 
 ## 0.3.1 - 2021-07-07
 

Cargo.toml

@@ -56,6 +56,9 @@ either = "1.6.1"
 vecrem = { version = "0.1", optional = true }
 bitflags = { version = "1.2", optional = true }
 
+[dev-dependencies]
+pretty_env_logger = "0.4"
+
 [features]
 default = ["native-tls"]
 
@@ -74,13 +77,16 @@ throttle = ["vecrem"]
 # Trace bot adaptor
 trace_adaptor = ["bitflags"]
 
+# Erased bot adaptor
+erased = []
+
 # CacheMe bot adaptor
 cache_me = []
 
 # AutoSend bot adaptor
 auto_send = []
 
-full = ["throttle", "trace_adaptor", "cache_me", "auto_send"]
+full = ["throttle", "trace_adaptor", "erased", "cache_me", "auto_send"]
 
 [package.metadata.docs.rs]
 all-features = true
@@ -89,3 +95,7 @@ rustdoc-args = ["--cfg", "docsrs", "-Znormalize-docs"]
 [[example]]
 name = "self_info"
 required-features = ["tokio/macros", "tokio/rt-multi-thread", "auto_send"]
+
+[[example]]
+name = "erased"
+required-features = ["tokio/macros", "tokio/rt-multi-thread", "auto_send", "erased"]

examples/erased.rs

@@ -0,0 +1,43 @@
+use std::{env::VarError, time::Duration};
+
+use teloxide_core::{adaptors::trace, prelude::*, types::ChatAction};
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    pretty_env_logger::init();
+
+    let chat_id = std::env::var("CHAT_ID")
+        .expect("Expected CHAT_ID env var")
+        .parse::<i64>()?;
+
+    let trace_settings = match std::env::var("TRACE").as_deref() {
+        Ok("EVERYTHING_VERBOSE") => trace::Settings::TRACE_EVERYTHING_VERBOSE,
+        Ok("EVERYTHING") => trace::Settings::TRACE_EVERYTHING,
+        Ok("REQUESTS_VERBOSE") => trace::Settings::TRACE_REQUESTS_VERBOSE,
+        Ok("REQUESTS") => trace::Settings::TRACE_REQUESTS,
+        Ok("RESPONSES_VERBOSE") => trace::Settings::TRACE_RESPONSES_VERBOSE,
+        Ok("RESPONSES") => trace::Settings::TRACE_RESPONSES,
+        Ok("EMPTY") | Ok("") | Err(VarError::NotPresent) => trace::Settings::empty(),
+        Ok(_) | Err(VarError::NotUnicode(_)) => {
+            panic!(
+                "Expected `TRACE` environment variable to be equal to any of the following: \
+                 `EVERYTHING_VERBOSE`, `EVERYTHING`, `REQUESTS_VERBOSE`, `REQUESTS`, \
+                 `RESPONSES_VERBOSE`, `RESPONSES`, `EMPTY`, `` (empty string)"
+            )
+        }
+    };
+
+    log::info!("Trace settings: {:?}", trace_settings);
+
+    let bot = if trace_settings.is_empty() {
+        Bot::from_env().erase().auto_send()
+    } else {
+        Bot::from_env().trace(trace_settings).erase().auto_send()
+    };
+
+    bot.send_chat_action(chat_id, ChatAction::Typing).await?;
+    tokio::time::sleep(Duration::from_secs(1)).await;
+    bot.send_message(chat_id, "Hey hey hey").await?;
+
+    Ok(())
+}

examples/self_info.rs

@@ -5,6 +5,8 @@ use teloxide_core::{
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    pretty_env_logger::init();
+
     let chat_id = std::env::var("CHAT_ID")
         .expect("Expected CHAT_ID env var")
         .parse::<i64>()?;

src/adaptors.rs

@@ -41,6 +41,18 @@ pub mod cache_me;
 )]
 pub mod trace;
 
+/// [`ErasedErasedRequester`] bot adaptor which allows to erase type of
+/// [`Requester`].
+///
+/// [`ErasedRequester`]: erased::ErasedRequester
+/// [`Requester`]: crate::requests::Requester
+#[cfg(feature = "erased")]
+#[cfg_attr(
+    all(any(docsrs, dep_docsrs), feature = "nightly"),
+    doc(cfg(feature = "erased"))
+)]
+pub mod erased;
+
 /// [`Throttle`] bot adaptor which allows automatically throttle when hitting
 /// API limits.
 ///
@@ -66,6 +78,12 @@ pub use auto_send::AutoSend;
     doc(cfg(feature = "cache_me"))
 )]
 pub use cache_me::CacheMe;
+#[cfg(feature = "erased")]
+#[cfg_attr(
+    all(any(docsrs, dep_docsrs), feature = "nightly"),
+    doc(cfg(feature = "erased"))
+)]
+pub use erased::ErasedRequester;
 #[cfg(feature = "throttle")]
 #[cfg_attr(
     all(any(docsrs, dep_docsrs), feature = "nightly"),

src/lib.rs

@@ -48,6 +48,7 @@
 //! - `rustls` — use [`rustls`] tls implementation
 //! - `auto_send` — enables [`AutoSend`] bot adaptor
 //! - `trace_adaptor` — enables [`Trace`] bot adaptor
+//! - `erased` — enables [`ErasedRequester`] bot adaptor
 //! - `throttle` — enables [`Throttle`] bot adaptor
 //! - `cache_me` — enables [`CacheMe`] bot adaptor
 //! - `full` — enables all features except `nigthly`
@@ -57,6 +58,7 @@
 //!
 //! [`AutoSend`]: adaptors::AutoSend
 //! [`Trace`]: adaptors::Trace
+//! [`ErasedRequester`]: adaptors::ErasedRequester
 //! [`Throttle`]: adaptors::Throttle
 //! [`CacheMe`]: adaptors::CacheMe
 //! [`native-tls`]: https://docs.rs/native-tls

src/requests/request.rs

@@ -87,6 +87,18 @@ pub trait Request: HasPayload {
     /// # };
     /// ```
     fn send_ref(&self) -> Self::SendRef;
+
+    #[cfg(feature = "erased")]
+    #[cfg_attr(
+        all(any(docsrs, dep_docsrs), feature = "nightly"),
+        doc(cfg(feature = "erased"))
+    )]
+    fn erase<'a>(self) -> crate::adaptors::erased::ErasedRequest<'a, Self::Payload, Self::Err>
+    where
+        Self: Sized + 'a,
+    {
+        crate::adaptors::erased::ErasedRequest::erase(self)
+    }
 }
 
 impl<L, R> Request for Either<L, R>

src/requests/requester_ext.rs

@@ -6,6 +6,9 @@ use crate::adaptors::CacheMe;
 #[cfg(feature = "auto_send")]
 use crate::adaptors::AutoSend;
 
+#[cfg(feature = "erased")]
+use crate::adaptors::ErasedRequester;
+
 #[cfg(feature = "trace_adaptor")]
 use crate::adaptors::trace::{Settings, Trace};
 
@@ -42,6 +45,20 @@ pub trait RequesterExt: Requester {
         AutoSend::new(self)
     }
 
+    /// Erase requester type.
+    #[cfg(feature = "erased")]
+    #[cfg_attr(
+        all(any(docsrs, dep_docsrs), feature = "nightly"),
+        doc(cfg(feature = "erased"))
+    )]
+    fn erase<'a>(self) -> ErasedRequester<'a, Self::Err>
+    where
+        Self: 'a,
+        Self: Sized,
+    {
+        ErasedRequester::new(self)
+    }
+
     /// Trace requests, see [`Trace`] for more.
     #[cfg(feature = "trace_adaptor")]
     #[cfg_attr(