refactor(client): extract constants and clean up patterns (#10)

- Extract repeated (200..300) status range to SUCCESS_STATUS constant
- Remove trailing comma in format string (get_duckling_config)
- Extract trim().to_string() pattern to trimmed() helper in auth

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: lostmygithubaccount

crates/dkdc-md-cli/src/auth.rs

@@ -9,6 +9,11 @@ const ENV_VARS: &[&str] = &[
     "MOTHERDUCK_API_KEY",
 ];
 
+/// Trim whitespace and convert to an owned `String`.
+fn trimmed(s: &str) -> String {
+    s.trim().to_string()
+}
+
 /// Resolve token: CLI flag takes precedence over env vars.
 /// Pass `Some("-")` to read from stdin.
 pub fn resolve_token_or(cli_token: Option<&str>) -> Result<String> {
@@ -24,9 +29,9 @@ fn resolve_token_or_with(
         if token == "-" {
             return read_token_from_reader(stdin);
         }
-        let trimmed = token.trim();
-        anyhow::ensure!(!trimmed.is_empty(), "--token value must not be empty");
-        return Ok(trimmed.to_string());
+        let t = trimmed(token);
+        anyhow::ensure!(!t.is_empty(), "--token value must not be empty");
+        return Ok(t);
     }
     resolve_token_with(env_var)
 }
@@ -36,19 +41,19 @@ fn read_token_from_reader(mut reader: impl Read) -> Result<String> {
     reader
         .read_to_string(&mut buf)
         .context("failed to read token from stdin")?;
-    let trimmed = buf.trim().to_string();
-    anyhow::ensure!(!trimmed.is_empty(), "stdin was empty; expected a token");
-    Ok(trimmed)
+    let t = trimmed(&buf);
+    anyhow::ensure!(!t.is_empty(), "stdin was empty; expected a token");
+    Ok(t)
 }
 
 fn resolve_token_with(
     env_var: impl Fn(&str) -> Result<String, std::env::VarError>,
 ) -> Result<String> {
     for var in ENV_VARS {
         if let Ok(val) = env_var(var) {
-            let trimmed = val.trim().to_string();
-            if !trimmed.is_empty() {
-                return Ok(trimmed);
+            let t = trimmed(&val);
+            if !t.is_empty() {
+                return Ok(t);
             }
         }
     }

crates/dkdc-md-cli/src/client.rs

@@ -9,6 +9,7 @@ use ureq::{Agent, http};
 const BASE_URL: &str = "https://api.motherduck.com";
 const TIMEOUT: Duration = Duration::from_secs(10);
 const USER_AGENT: &str = concat!("dkdc-md-cli/", env!("CARGO_PKG_VERSION"));
+const SUCCESS_STATUS: std::ops::Range<u16> = 200..300;
 
 /// Characters that must be percent-encoded in a URL path segment.
 const PATH_SEGMENT: &AsciiSet = &CONTROLS.add(b' ').add(b'#').add(b'%').add(b'/').add(b'?');
@@ -150,7 +151,7 @@ impl MotherduckClient {
     // -- Ducklings --
 
     pub fn get_duckling_config(&self, username: &str) -> Result<Value> {
-        self.get(&format!("/v1/users/{}/instances", encode_path(username),))
+        self.get(&format!("/v1/users/{}/instances", encode_path(username)))
     }
 
     pub fn set_duckling_config(
@@ -189,15 +190,15 @@ fn handle_response(mut resp: http::Response<ureq::Body>) -> Result<Value> {
 
 fn parse_response(status: u16, text: String) -> Result<Value> {
     match serde_json::from_str::<Value>(&text) {
-        Ok(body) if (200..300).contains(&status) => Ok(body),
+        Ok(body) if SUCCESS_STATUS.contains(&status) => Ok(body),
         Ok(body) => {
             let message = body
                 .get("message")
                 .and_then(|m| m.as_str())
                 .unwrap_or(&text);
             bail!("API error ({status}): {message}");
         }
-        Err(_) if (200..300).contains(&status) => Ok(Value::String(text)),
+        Err(_) if SUCCESS_STATUS.contains(&status) => Ok(Value::String(text)),
         Err(_) => bail!("API error ({status}): {text}"),
     }
 }