Improve error handling

Cargo.lock

@@ -13,6 +13,15 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "aho-corasick"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "67fc08ce920c31afb70f013dcce1bfc3a3195de6a228474e45e1f145b36f8d04"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "android_system_properties"
 version = "0.1.5"
@@ -171,7 +180,7 @@ dependencies = [
  "num-integer",
  "num-traits",
  "serde",
- "time",
+ "time 0.1.45",
  "wasm-bindgen",
  "winapi",
 ]
@@ -221,12 +230,15 @@ dependencies = [
  "dotenvy",
  "reqwest",
  "serde",
+ "serde_with",
  "sqlx",
+ "thiserror",
  "tokio",
  "tower",
  "tower-http",
  "tracing",
  "tracing-subscriber",
+ "validator",
 ]
 
 [[package]]
@@ -317,6 +329,41 @@ dependencies = [
  "syn 2.0.15",
 ]
 
+[[package]]
+name = "darling"
+version = "0.20.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0558d22a7b463ed0241e993f76f09f30b126687447751a8638587b864e4b3944"
+dependencies = [
+ "darling_core",
+ "darling_macro",
+]
+
+[[package]]
+name = "darling_core"
+version = "0.20.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab8bfa2e259f8ee1ce5e97824a3c55ec4404a0d772ca7fa96bf19f0752a046eb"
+dependencies = [
+ "fnv",
+ "ident_case",
+ "proc-macro2",
+ "quote",
+ "strsim",
+ "syn 2.0.15",
+]
+
+[[package]]
+name = "darling_macro"
+version = "0.20.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29a358ff9f12ec09c3e61fef9b5a9902623a695a46a917b07f269bff1445611a"
+dependencies = [
+ "darling_core",
+ "quote",
+ "syn 2.0.15",
+]
+
 [[package]]
 name = "digest"
 version = "0.10.6"
@@ -694,6 +741,23 @@ dependencies = [
  "cxx-build",
 ]
 
+[[package]]
+name = "ident_case"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
+
+[[package]]
+name = "idna"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "418a0a6fab821475f634efe3ccc45c013f742efe03d853e8d3355d5cb850ecf8"
+dependencies = [
+ "matches",
+ "unicode-bidi",
+ "unicode-normalization",
+]
+
 [[package]]
 name = "idna"
 version = "0.3.0"
@@ -704,6 +768,12 @@ dependencies = [
  "unicode-normalization",
 ]
 
+[[package]]
+name = "if_chain"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb56e1aa765b4b4f3aadfab769793b7087bb03a4ea4920644a6d238e2df5b9ed"
+
 [[package]]
 name = "indexmap"
 version = "1.9.3"
@@ -712,6 +782,7 @@ checksum = "bd070e393353796e801d209ad339e89596eb4c8d430d18ede6a1cced8fafbd99"
 dependencies = [
  "autocfg",
  "hashbrown",
+ "serde",
 ]
 
 [[package]]
@@ -810,6 +881,12 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "matches"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2532096657941c2fea9c289d370a250971c689d4f143798ff67113ec042024a5"
+
 [[package]]
 name = "matchit"
 version = "0.7.0"
@@ -1082,6 +1159,30 @@ version = "0.2.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5b40af805b3121feab8a3c29f04d8ad262fa8e0561883e7653e024ae4479e6de"
 
+[[package]]
+name = "proc-macro-error"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da25490ff9892aab3fcf7c36f08cfb902dd3e71ca0f9f9517bea02a73a5ce38c"
+dependencies = [
+ "proc-macro-error-attr",
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+ "version_check",
+]
+
+[[package]]
+name = "proc-macro-error-attr"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1be40180e52ecc98ad80b184934baf3d0d29f979574e439af5a55274b35f869"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "version_check",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.56"
@@ -1159,6 +1260,23 @@ dependencies = [
  "thiserror",
 ]
 
+[[package]]
+name = "regex"
+version = "1.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af83e617f331cc6ae2da5443c602dfa5af81e517212d9d611a5b3ba1777b5370"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a5996294f19bd3aae0453a862ad728f60e6600695733dd5df01da90c54363a3c"
+
 [[package]]
 name = "reqwest"
 version = "0.11.17"
@@ -1318,6 +1436,34 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_with"
+version = "3.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9f02d8aa6e3c385bf084924f660ce2a3a6bd333ba55b35e8590b321f35d88513"
+dependencies = [
+ "base64 0.21.0",
+ "chrono",
+ "hex",
+ "indexmap",
+ "serde",
+ "serde_json",
+ "serde_with_macros",
+ "time 0.3.21",
+]
+
+[[package]]
+name = "serde_with_macros"
+version = "3.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "edc7d5d3932fb12ce722ee5e64dd38c504efba37567f0c402f6ca728c3b8b070"
+dependencies = [
+ "darling",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.15",
+]
+
 [[package]]
 name = "sha1"
 version = "0.10.5"
@@ -1496,6 +1642,12 @@ dependencies = [
  "unicode-normalization",
 ]
 
+[[package]]
+name = "strsim"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
+
 [[package]]
 name = "subtle"
 version = "2.4.1"
@@ -1593,6 +1745,33 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "time"
+version = "0.3.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f3403384eaacbca9923fa06940178ac13e4edb725486d70e8e15881d0c836cc"
+dependencies = [
+ "itoa",
+ "serde",
+ "time-core",
+ "time-macros",
+]
+
+[[package]]
+name = "time-core"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7300fbefb4dadc1af235a9cef3737cea692a9d97e1b9cbcd4ebdae6f8868e6fb"
+
+[[package]]
+name = "time-macros"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "372950940a5f07bf38dbe211d7283c9e6d7327df53794992d293e534c733d09b"
+dependencies = [
+ "time-core",
+]
+
 [[package]]
 name = "tinyvec"
 version = "1.6.0"
@@ -1837,10 +2016,52 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0d68c799ae75762b8c3fe375feb6600ef5602c883c5d21eb51c09f22b83c4643"
 dependencies = [
  "form_urlencoded",
- "idna",
+ "idna 0.3.0",
  "percent-encoding",
 ]
 
+[[package]]
+name = "validator"
+version = "0.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32ad5bf234c7d3ad1042e5252b7eddb2c4669ee23f32c7dd0e9b7705f07ef591"
+dependencies = [
+ "idna 0.2.3",
+ "lazy_static",
+ "regex",
+ "serde",
+ "serde_derive",
+ "serde_json",
+ "url",
+ "validator_derive",
+]
+
+[[package]]
+name = "validator_derive"
+version = "0.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bc44ca3088bb3ba384d9aecf40c6a23a676ce23e09bdaca2073d99c207f864af"
+dependencies = [
+ "if_chain",
+ "lazy_static",
+ "proc-macro-error",
+ "proc-macro2",
+ "quote",
+ "regex",
+ "syn 1.0.109",
+ "validator_types",
+]
+
+[[package]]
+name = "validator_types"
+version = "0.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "111abfe30072511849c5910134e8baf8dc05de4c0e5903d681cbd5c9c4d611e3"
+dependencies = [
+ "proc-macro2",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "valuable"
 version = "0.1.0"

Cargo.toml

@@ -12,9 +12,12 @@ chrono = { version = "0.4", features = ["serde"] }
 dotenvy = "0.15"
 reqwest = { version = "0.11", features = ["json"] }
 serde = { version = "1", features = ["derive"] }
+serde_with = "3"
 sqlx = { version = "0.6", features = ["runtime-tokio-native-tls", "postgres", "macros", "migrate", "chrono"] }
+thiserror = "1"
 tokio = { version = "1", features = ["full"] }
 tower = "0.4"
 tower-http = { version = "0.4", features = ["trace"] }
 tracing = "0.1"
 tracing-subscriber = "0.3"
+validator = { version = "0.16", features = ["derive"] }

src/error.rs

@@ -1,26 +1,67 @@
-use axum::{http::StatusCode, response::{IntoResponse, Response}};
+use axum::http::StatusCode;
+use axum::response::{IntoResponse, Response};
+use axum::Json;
+use tracing::error;
+use serde_with::DisplayFromStr;
+use validator::ValidationErrors;
 
-// Make our own error that wraps `anyhow::Error`.
+/// An API-friendly error type.
-pub struct AppError(anyhow::Error);
+#[derive(thiserror::Error, Debug)]
+pub enum Error {
+    /// A SQLx call returned an error.
+    ///
+    /// The exact error contents are not reported to the user in order to avoid leaking
+    /// information about database internals.
+    #[error("an internal database error occurred")]
+    Sqlx(#[from] sqlx::Error),
 
-// Tell axum how to convert `AppError` into a response.
+    /// Similarly, we don't want to report random `anyhow` errors to the user.
-impl IntoResponse for AppError {
+    #[error("an internal server error occurred")]
+    Anyhow(#[from] anyhow::Error),
+
+    #[error("validation error in request body")]
+    InvalidEntity(#[from] ValidationErrors),
+}
+
+impl IntoResponse for Error {
     fn into_response(self) -> Response {
+        #[serde_with::serde_as]
+        #[serde_with::skip_serializing_none]
+        #[derive(serde::Serialize)]
+        struct ErrorResponse<'a> {
+            // Serialize the `Display` output as the error message
+            #[serde_as(as = "DisplayFromStr")]
+            message: &'a Error,
+
+            errors: Option<&'a ValidationErrors>,
+        }
+
+        let errors = match &self {
+            Error::InvalidEntity(errors) => Some(errors),
+            _ => None,
+        };
+
+        error!("API error: {:?}", self);
+
         (
-            StatusCode::INTERNAL_SERVER_ERROR,
+            self.status_code(),
-            format!("Something went wrong: {}", self.0),
+            Json(ErrorResponse {
+                message: &self,
+                errors,
+            }),
         )
             .into_response()
     }
 }
 
-// This enables using `?` on functions that return `Result<_, anyhow::Error>` to turn them into
+impl Error {
-// `Result<_, AppError>`. That way you don't need to do that manually.
+    fn status_code(&self) -> StatusCode {
-impl<E> From<E> for AppError
+        use Error::*;
-where
+
-    E: Into<anyhow::Error>,
+        match self {
-{
+            Sqlx(sqlx::Error::RowNotFound) => StatusCode::NOT_FOUND,
-    fn from(err: E) -> Self {
+            Sqlx(_) | Anyhow(_) => StatusCode::INTERNAL_SERVER_ERROR,
-        Self(err.into())
+            InvalidEntity(_) => StatusCode::UNPROCESSABLE_ENTITY,
+        }
     }
 }

src/handlers/item.rs

@@ -1,19 +1,19 @@
 use axum::{extract::{State, Path}, Json};
 use sqlx::PgPool;
 
-use crate::error::AppError;
+use crate::error::Error;
 use crate::models::item::{create_item, get_item, CreateItem, Item};
 
 pub async fn get(
     State(pool): State<PgPool>,
     Path(id): Path<i32>,
-) -> Result<Json<Item>, AppError> {
+) -> Result<Json<Item>, Error> {
     Ok(Json(get_item(pool, id).await?))
 }
 
 pub async fn post(
     State(pool): State<PgPool>,
     Json(payload): Json<CreateItem>,
-) -> Result<Json<Item>, AppError> {
+) -> Result<Json<Item>, Error> {
     Ok(Json(create_item(pool, payload).await?))
 }

src/handlers/items.rs

@@ -1,9 +1,9 @@
 use axum::{extract::State, Json};
 use sqlx::PgPool;
 
-use crate::error::AppError;
+use crate::error::Error;
 use crate::models::item::{get_items, Item};
 
-pub async fn get(State(pool): State<PgPool>) -> Result<Json<Vec<Item>>, AppError> {
+pub async fn get(State(pool): State<PgPool>) -> Result<Json<Vec<Item>>, Error> {
     Ok(Json(get_items(pool).await?))
 }

src/main.rs

@@ -27,9 +27,9 @@ async fn main() -> anyhow::Result<()> {
     sqlx::migrate!().run(&pool).await?;
 
     let app = Router::new()
-        .route("/items", get(handlers::items::get))
+        .route("/v1/items", get(handlers::items::get))
-        .route("/item", post(handlers::item::post))
+        .route("/v1/item", post(handlers::item::post))
-        .route("/item/:id", get(handlers::item::get))
+        .route("/v1/item/:id", get(handlers::item::get))
         .with_state(pool)
         .layer(ServiceBuilder::new().layer(TraceLayer::new_for_http()));
 

src/models/item.rs

@@ -1,4 +1,3 @@
-use anyhow::Context;
 use chrono::NaiveDateTime;
 use serde::{Deserialize, Serialize};
 use sqlx::PgPool;
@@ -21,21 +20,19 @@ pub struct CreateItem {
     description: Option<String>,
 }
 
-pub async fn get_item(pool: PgPool, id: i32) -> anyhow::Result<Item> {
+pub async fn get_item(pool: PgPool, id: i32) -> sqlx::Result<Item> {
     sqlx::query_as!(Item, "SELECT * FROM items WHERE id = $1", id)
         .fetch_one(&pool)
         .await
-        .context("Failed to fetch item")
 }
 
-pub async fn get_items(pool: PgPool) -> anyhow::Result<Vec<Item>> {
+pub async fn get_items(pool: PgPool) -> sqlx::Result<Vec<Item>> {
     sqlx::query_as!(Item, "SELECT * FROM items")
         .fetch_all(&pool)
         .await
-        .context("Failed to fetch items")
 }
 
-pub async fn create_item(pool: PgPool, payload: CreateItem) -> anyhow::Result<Item> {
+pub async fn create_item(pool: PgPool, payload: CreateItem) -> sqlx::Result<Item> {
     sqlx::query_as!(
         Item,
         "INSERT INTO items (
@@ -49,5 +46,4 @@ pub async fn create_item(pool: PgPool, payload: CreateItem) -> anyhow::Result<It
     )
     .fetch_one(&pool)
     .await
-    .context("Failed to create item")
 }