Display errors more humanely

src/cli.rs

 use std::fs;
 use std::io;
 
-use crate::client::{build_url_from_config, create_snippet, OutgoingSnippet, ServerConfig};
+use crate::client::{
+    build_url_from_config, create_snippet, ApiResult, OutgoingSnippet, ServerConfig,
+};
 
 fn build_snippet_from_matches(matches: &ArgMatches) -> io::Result<OutgoingSnippet> {
     let title = matches.value_of("name").unwrap();
     let url = build_url_from_config(&config);
 
     match create_snippet(snippet, &config) {
-        Ok(resp) => println!(
-            "Success! Your new snippet is available at {}/snippets/{}",
-            url, resp.id
-        ),
+        Ok(resp) => match resp {
+            ApiResult::IncomingSnippet { id, .. } => println!(
+                "Success! Your new snippet is available at {}/snippets/{}",
+                url, id
+            ),
+            ApiResult::IncomingError { message } => println!("error: {}", message),
+        },
         Err(err) => println!("{}", err),
     }
 

src/client.rs

     pub filetype: String,
 }
 
-#[derive(Serialize, Deserialize, Debug)]
-pub struct IncomingSnippet {
-    pub id: i32,
-    pub title: String,
-    pub body: String,
-    pub created_at: NaiveDateTime,
-}
-
 #[derive(Debug)]
 pub struct ServerConfig {
     pub hostname: String,
     pub port: i32,
 }
 
+#[derive(Serialize, Deserialize, Debug)]
+#[serde(untagged)]
+pub enum ApiResult {
+    IncomingSnippet {
+        id: i32,
+        title: String,
+        body: String,
+        created_at: NaiveDateTime,
+    },
+    IncomingError {
+        message: String,
+    },
+}
+
 pub fn build_url_from_config(config: &ServerConfig) -> String {
     match config.port {
         80 => format!("{}://{}", config.protocol, config.hostname),
 pub fn create_snippet(
     snippet: OutgoingSnippet,
     config: &ServerConfig,
-) -> Result<IncomingSnippet, Box<std::error::Error>> {
+) -> Result<ApiResult, Box<std::error::Error>> {
     let client = reqwest::Client::new();
     let url = build_url_from_config(config);
-    let resp: IncomingSnippet = client
+    let resp: ApiResult = client
         .post(&format!("{}/api/snippets", url))
         .json(&snippet)
         .send()?
         .json()?;
+
     Ok(resp)
 }