improved error messages

CHANGELOG.md

@@ -3,4 +3,5 @@
 ## cli
 - optimized listing by not searching on the client but on the server
 - categories now shown with name instead of just ID
+- improved API response deserialize error messages
 

cli/Cargo.toml

@@ -15,6 +15,7 @@ anyhow = "1.0.34"
 clap = "2.33.3"
 env_logger = "0.8.2"
 fuzzy-matcher = "0.3.7"
+lazy_static = "1.4.0"
 log = "0.4.11"
 once_cell = "1.5.2"
 opener = "0.4.1"
@@ -24,7 +25,7 @@ serde_json = "1.0.60"
 structopt = "0.3.21"
 term-table = "1.3.0"
 term_size = "0.3.2"
+thiserror = "1.0.23"
 tokio = { version = "0.2.23", features = ["macros", "fs", "process"] }
 url = "2.2.0"
-lazy_static = "1.4.0"
 

cli/src/commands/up.rs

@@ -41,7 +41,7 @@ pub async fn run(
         .await?;
 
     let status = res.status();
-    let res = serde_json::from_slice::<UpResp>(&res.bytes().await?)?;
+    let res = util::api::try_deserialize_api_reponse::<UpResp>(&res.bytes().await?)?;
 
     println!("Server responded with code {}", status);
 

cli/src/util.rs

@@ -35,6 +35,7 @@ pub mod api {
         collections::HashMap,
         sync::{Arc, Mutex},
     };
+    use thiserror::Error;
     use url::Url;
 
     // cached api responses
@@ -46,6 +47,14 @@ pub mod api {
             Mutex::new(HashMap::new());
     }
 
+    #[derive(Error, Debug)]
+    #[error("Error Deserializing JSON api response: \n{json}\nError: {error}")]
+    pub struct ApiDeserializeError {
+        pub json: String,
+        #[source]
+        pub error: serde_json::Error,
+    }
+
     pub async fn cats(http: &Client) -> Result<&Vec<Category>> {
         Ok(init_once_cell!(CATS, {
             info!("Requesting categories from server");
@@ -53,7 +62,7 @@ pub mod api {
                 .get("https://data.tilera.xyz/api/jensmemes/categories")
                 .send()
                 .await?;
-            let cats = serde_json::from_slice::<CatsResp>(&res.bytes().await?)?;
+            let cats = try_deserialize_api_reponse::<CatsResp>(&res.bytes().await?)?;
             cats.categories.into_iter().collect()
         }))
     }
@@ -84,7 +93,7 @@ pub mod api {
 
         info!("Requesting memes from server");
         let res = http.get(url).send().await?;
-        let memes = serde_json::from_slice::<MemesResp>(&res.bytes().await?)?;
+        let memes = try_deserialize_api_reponse::<MemesResp>(&res.bytes().await?)?;
 
         Ok(MEMES
             .lock()
@@ -101,10 +110,41 @@ pub mod api {
                 .get("https://data.tilera.xyz/api/jensmemes/users")
                 .send()
                 .await?;
-            let users = serde_json::from_slice::<UsersResp>(&res.bytes().await?)?;
+            let users = try_deserialize_api_reponse::<UsersResp>(&res.bytes().await?)?;
             users.users
         }))
     }
+
+    /// tries to deserialize `json` as `T`, and if it fails converts the error
+    /// to a `ApiDeserializeError`
+    pub fn try_deserialize_api_reponse<'a, T: serde::Deserialize<'a>>(json: &'a [u8]) -> Result<T> {
+        let result = serde_json::from_slice::<T>(&json);
+        result.map_err(|error| match std::str::from_utf8(json) {
+            Err(e) => e.into(),
+            Ok(json) => ApiDeserializeError {
+                json: json.into(),
+                error,
+            }
+            .into(),
+        })
+    }
+
+    #[cfg(test)]
+    mod tests {
+        use super::*;
+
+        #[test]
+        fn api_deserialize_error() {
+            let incorrect_json = r#"
+                {
+                    "foo": "bar"
+                }
+            "#;
+
+            let result = try_deserialize_api_reponse::<UsersResp>(incorrect_json.as_bytes());
+            println!("{}", result.unwrap_err());
+        }
+    }
 }
 
 pub async fn open_link(url: &str) -> anyhow::Result<()> {