fix: UTF-8 safe truncation, deduplicate url_encode, add Display impls, fix pricing display, simplify model matching, fix changelog links, add PartialEq for Tool (#3)

CHANGELOG.md

@@ -324,7 +324,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Hooks system and config profiles
 - Example skills and launch assets
 
-[Unreleased]: https://github.com/Hmbown/DeepSeek-TUI/compare/v0.3.22...HEAD
+[Unreleased]: https://github.com/Hmbown/DeepSeek-TUI/compare/v0.3.23...HEAD
+[0.3.23]: https://github.com/Hmbown/DeepSeek-TUI/compare/v0.3.22...v0.3.23
 [0.3.22]: https://github.com/Hmbown/DeepSeek-TUI/compare/v0.3.21...v0.3.22
 [0.3.21]: https://github.com/Hmbown/DeepSeek-TUI/compare/v0.3.17...v0.3.21
 [0.3.17]: https://github.com/Hmbown/DeepSeek-TUI/compare/v0.3.16...v0.3.17

src/error_taxonomy.rs

@@ -3,6 +3,8 @@
 //! Not yet wired into consumers; will be adopted incrementally.
 #![allow(dead_code)]
 
+use std::fmt;
+
 use crate::llm_client::LlmError;
 use crate::tools::spec::ToolError;
 
@@ -42,6 +44,44 @@ pub struct ErrorEnvelope {
     pub message: String,
 }
 
+impl fmt::Display for ErrorCategory {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let label = match self {
+            Self::Network => "network",
+            Self::Authentication => "authentication",
+            Self::Authorization => "authorization",
+            Self::RateLimit => "rate_limit",
+            Self::Timeout => "timeout",
+            Self::InvalidInput => "invalid_input",
+            Self::Parse => "parse",
+            Self::Tool => "tool",
+            Self::State => "state",
+            Self::Internal => "internal",
+        };
+        f.write_str(label)
+    }
+}
+
+impl fmt::Display for ErrorSeverity {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let label = match self {
+            Self::Info => "info",
+            Self::Warning => "warning",
+            Self::Error => "error",
+            Self::Critical => "critical",
+        };
+        f.write_str(label)
+    }
+}
+
+impl fmt::Display for ErrorEnvelope {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "[{}] {}: {}", self.severity, self.code, self.message)
+    }
+}
+
+impl std::error::Error for ErrorEnvelope {}
+
 impl ErrorEnvelope {
     #[must_use]
     pub fn new(

src/features.rs

@@ -2,8 +2,10 @@
 
 #![allow(dead_code)]
 
-use serde::{Deserialize, Serialize};
 use std::collections::{BTreeMap, BTreeSet};
+use std::fmt;
+
+use serde::{Deserialize, Serialize};
 
 /// Lifecycle stage for a feature flag.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -32,6 +34,19 @@ pub enum Feature {
     ExecPolicy,
 }
 
+impl fmt::Display for Stage {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let label = match self {
+            Self::Experimental => "experimental",
+            Self::Beta => "beta",
+            Self::Stable => "stable",
+            Self::Deprecated => "deprecated",
+            Self::Removed => "removed",
+        };
+        f.write_str(label)
+    }
+}
+
 impl Feature {
     pub fn key(self) -> &'static str {
         self.info().key

src/models.rs

@@ -124,7 +124,7 @@ pub struct ToolCaller {
 }
 
 /// Tool definition exposed to the model.
-#[derive(Debug, Serialize, Deserialize, Clone)]
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
 pub struct Tool {
     #[serde(rename = "type", skip_serializing_if = "Option::is_none")]
     pub tool_type: Option<String>,
@@ -188,15 +188,7 @@ pub struct Usage {
 #[must_use]
 pub fn context_window_for_model(model: &str) -> Option<u32> {
     let lower = model.to_lowercase();
-    if lower.contains("deepseek-v3.2") {
-        return Some(DEFAULT_CONTEXT_WINDOW_TOKENS);
-    }
-    if lower.contains("deepseek-chat")
-        || lower.contains("deepseek-reasoner")
-        || lower.contains("deepseek-r1")
-    {
-        return Some(DEFAULT_CONTEXT_WINDOW_TOKENS);
-    }
+    // All DeepSeek models currently share the same 128k context window.
     if lower.contains("deepseek") {
         return Some(DEFAULT_CONTEXT_WINDOW_TOKENS);
     }

src/pricing.rs

@@ -101,7 +101,7 @@ pub fn calculate_turn_cost(model: &str, input_tokens: u32, output_tokens: u32) -
 #[must_use]
 pub fn format_cost(cost: f64) -> String {
     if cost < 0.0001 {
-        "<$0.01".to_string()
+        "<$0.0001".to_string()
     } else if cost < 0.01 {
         format!("${:.4}", cost)
     } else if cost < 1.0 {

src/tools/finance.rs

@@ -3,6 +3,7 @@
 use super::spec::{
     ApprovalRequirement, ToolCapability, ToolContext, ToolError, ToolResult, ToolSpec, required_str,
 };
+use crate::utils::url_encode;
 use async_trait::async_trait;
 use serde::Serialize;
 use serde_json::{Value, json};
@@ -334,17 +335,3 @@ fn normalize_stooq_symbol(ticker: &str, market: &str) -> String {
 fn parse_f64(input: &str) -> Option<f64> {
     input.parse::<f64>().ok()
 }
-
-fn url_encode(input: &str) -> String {
-    let mut encoded = String::new();
-    for ch in input.bytes() {
-        match ch {
-            b'A'..=b'Z' | b'a'..=b'z' | b'0'..=b'9' | b'-' | b'_' | b'.' | b'~' => {
-                encoded.push(ch as char)
-            }
-            b' ' => encoded.push('+'),
-            _ => encoded.push_str(&format!("%{ch:02X}")),
-        }
-    }
-    encoded
-}

src/tools/weather.rs

@@ -4,6 +4,7 @@ use super::spec::{
     ApprovalRequirement, ToolCapability, ToolContext, ToolError, ToolResult, ToolSpec,
     optional_str, optional_u64, required_str,
 };
+use crate::utils::url_encode;
 use async_trait::async_trait;
 use chrono::{NaiveDate, Utc};
 use serde::Serialize;
@@ -320,17 +321,3 @@ async fn fetch_forecast(
 fn c_to_f(c: f64) -> f64 {
     c * 9.0 / 5.0 + 32.0
 }
-
-fn url_encode(input: &str) -> String {
-    let mut encoded = String::new();
-    for ch in input.bytes() {
-        match ch {
-            b'A'..=b'Z' | b'a'..=b'z' | b'0'..=b'9' | b'-' | b'_' | b'.' | b'~' => {
-                encoded.push(ch as char)
-            }
-            b' ' => encoded.push('+'),
-            _ => encoded.push_str(&format!("%{ch:02X}")),
-        }
-    }
-    encoded
-}

src/utils.rs

@@ -187,15 +187,42 @@ pub fn output_path(output_dir: &Path, filename: &str) -> PathBuf {
     output_dir.join(filename)
 }
 
-/// Truncate a string to a maximum length, adding an ellipsis if truncated
+/// Truncate a string to a maximum length, adding an ellipsis if truncated.
+///
+/// Uses char boundaries to avoid panicking on multi-byte UTF-8 characters.
 #[must_use]
 pub fn truncate_with_ellipsis(s: &str, max_len: usize, ellipsis: &str) -> String {
     if s.len() <= max_len {
-        s.to_string()
-    } else {
-        let truncate_at = max_len.saturating_sub(ellipsis.len());
-        format!("{}{}", &s[..truncate_at], ellipsis)
+        return s.to_string();
     }
+    let budget = max_len.saturating_sub(ellipsis.len());
+    // Find the last char boundary that fits within the byte budget.
+    let safe_end = s
+        .char_indices()
+        .map(|(i, _)| i)
+        .take_while(|&i| i <= budget)
+        .last()
+        .unwrap_or(0);
+    format!("{}{}", &s[..safe_end], ellipsis)
+}
+
+/// Percent-encode a string for use in URL query parameters.
+///
+/// Encodes all characters except unreserved characters (A-Z, a-z, 0-9, `-`, `_`, `.`, `~`).
+/// Spaces are encoded as `+`.
+#[must_use]
+pub fn url_encode(input: &str) -> String {
+    let mut encoded = String::new();
+    for ch in input.bytes() {
+        match ch {
+            b'A'..=b'Z' | b'a'..=b'z' | b'0'..=b'9' | b'-' | b'_' | b'.' | b'~' => {
+                encoded.push(ch as char)
+            }
+            b' ' => encoded.push('+'),
+            _ => encoded.push_str(&format!("%{ch:02X}")),
+        }
+    }
+    encoded
 }
 
 /// Estimate the total character count across message content blocks.