Update to actix-web 4.0.0-beta.7. (#24)

Add two new error types implementing ResponseError, as required, for our extractors.

Add public docs for new errors.

Co-authored-by: LukeMathWalker <rust@lpalmieri.com>

Cargo.toml

@@ -24,8 +24,8 @@ opentelemetry_0_13 = ["opentelemetry", "tracing-opentelemetry"]
 emit_event_on_error = []
 
 [dependencies]
-actix-web = "=4.0.0-beta.6"
-actix-http = "=3.0.0-beta.6"
+actix-web = "=4.0.0-beta.7"
+actix-http = "=3.0.0-beta.7"
 actix-service = "^2.0.0"
 tracing = "0.1.19"
 tracing-futures = "0.2.4"

examples/custom-root-span/Cargo.toml

@@ -7,7 +7,7 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-actix-web = "4.0.0-beta.6"
+actix-web = "4.0.0-beta.7"
 opentelemetry = { version = "0.13", features = ["rt-tokio-current-thread"] }
 opentelemetry-jaeger = { version = "0.12", features = ["tokio"] }
 tracing-opentelemetry = { version = "0.12" }

examples/opentelemetry/Cargo.toml

@@ -7,7 +7,7 @@ edition = "2018"
 license = "MIT/Apache-2.0"
 
 [dependencies]
-actix-web = "=4.0.0-beta.6"
+actix-web = "=4.0.0-beta.7"
 tracing = "0.1.19"
 opentelemetry = { version = "0.13", features = ["rt-tokio-current-thread"] }
 opentelemetry-jaeger = { version = "0.12", features = ["tokio"] }

src/request_id.rs

@@ -1,5 +1,5 @@
 use actix_web::dev::Payload;
-use actix_web::{FromRequest, HttpRequest};
+use actix_web::{FromRequest, HttpRequest, ResponseError};
 use std::future::{ready, Ready};
 use uuid::Uuid;
 
@@ -54,11 +54,47 @@ impl std::fmt::Display for RequestId {
     }
 }
 impl FromRequest for RequestId {
-    type Error = ();
+    type Error = RequestIdExtractionError;
     type Future = Ready<Result<Self, Self::Error>>;
     type Config = ();
 
     fn from_request(req: &HttpRequest, _: &mut Payload) -> Self::Future {
-        ready(req.extensions().get::<RequestId>().copied().ok_or(()))
+        ready(
+            req.extensions()
+                .get::<RequestId>()
+                .copied()
+                .ok_or(RequestIdExtractionError { _priv: () }),
+        )
     }
 }
+
+#[derive(Debug)]
+/// Error returned by the [`RequestId`] extractor when it fails to retrieve
+/// the current request id from request-local storage.
+///
+/// It only happens if you try to extract the current request id without having
+/// registered [`TracingLogger`] as a middleware for your application.
+///
+/// [`TracingLogger`]: crate::TracingLogger
+pub struct RequestIdExtractionError {
+    // It turns out that a unit struct has a public constructor!
+    // Therefore adding fields to it (either public or private) later on
+    // is an API breaking change.
+    // Therefore we are adding a dummy private field that the compiler is going
+    // to optimise away to make sure users cannot construct this error
+    // manually in their own code.
+    _priv: (),
+}
+
+impl ResponseError for RequestIdExtractionError {}
+
+impl std::fmt::Display for RequestIdExtractionError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "Failed to retrieve request id from request-local storage."
+        )
+    }
+}
+
+impl std::error::Error for RequestIdExtractionError {}

src/root_span.rs

@@ -1,5 +1,5 @@
 use actix_web::dev::Payload;
-use actix_web::{FromRequest, HttpRequest};
+use actix_web::{FromRequest, HttpRequest, ResponseError};
 use std::future::{ready, Ready};
 use tracing::Span;
 
@@ -47,11 +47,47 @@ impl std::convert::Into<Span> for RootSpan {
 }
 
 impl FromRequest for RootSpan {
-    type Error = ();
+    type Error = RootSpanExtractionError;
     type Future = Ready<Result<Self, Self::Error>>;
     type Config = ();
 
     fn from_request(req: &HttpRequest, _: &mut Payload) -> Self::Future {
-        ready(req.extensions().get::<RootSpan>().cloned().ok_or(()))
+        ready(
+            req.extensions()
+                .get::<RootSpan>()
+                .cloned()
+                .ok_or(RootSpanExtractionError { _priv: () }),
+        )
     }
 }
+
+#[derive(Debug)]
+/// Error returned by the [`RootSpan`] extractor when it fails to retrieve
+/// the root span from request-local storage.
+///
+/// It only happens if you try to extract the root span without having
+/// registered [`TracingLogger`] as a middleware for your application.
+///
+/// [`TracingLogger`]: crate::TracingLogger
+pub struct RootSpanExtractionError {
+    // It turns out that a unit struct has a public constructor!
+    // Therefore adding fields to it (either public or private) later on
+    // is an API breaking change.
+    // Therefore we are adding a dummy private field that the compiler is going
+    // to optimise away to make sure users cannot construct this error
+    // manually in their own code.
+    _priv: (),
+}
+
+impl ResponseError for RootSpanExtractionError {}
+
+impl std::fmt::Display for RootSpanExtractionError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "Failed to retrieve the root span from request-local storage."
+        )
+    }
+}
+
+impl std::error::Error for RootSpanExtractionError {}