⚡ Bolt: optimize format reports by eliminating redundant String allocations

.jules/bolt.md

@@ -0,0 +1,3 @@
+## 2024-04-09 - Rust String Cloning Optimization
+**Learning:** In Rust, building lists of string parts for joining (e.g., `vec![string1.clone(), string2.clone()].join(" ")`) is a common pattern that can lead to unnecessary heap allocations. This codebase frequently does this when formatting reports. When the source values are already `String`s, borrowing them as `&str` and pushing them to a `Vec<&str>` before calling `.join()` entirely avoids these intermediate heap allocations. Additionally, calling `.to_string()` on static string slices just to appease a `Vec<String>` is wasteful when `Vec<&str>` works perfectly.
+**Action:** When constructing strings from parts using `Vec` and `.join()`, look for opportunities to use a `Vec<&str>` populated with borrowed string slices (`.as_str()`) instead of a `Vec<String>` populated with cloned strings (`.clone()`).

patch_pr.py

@@ -0,0 +1,42 @@
+import sys
+
+def replace_in_file(filepath, search_str, replace_str):
+    with open(filepath, 'r') as f:
+        content = f.read()
+
+    if search_str in content:
+        content = content.replace(search_str, replace_str)
+        with open(filepath, 'w') as f:
+            f.write(content)
+        print("Replacement successful.")
+    else:
+        print("Search string not found.")
+
+search = """fn agent_detail(agent: &AgentSummary) -> String {
+    let mut parts = vec![agent.name.as_str()];
+    if let Some(description) = &agent.description {
+        parts.push(description.as_str());
+    }
+    if let Some(model) = &agent.model {
+        parts.push(model.as_str());
+    }
+    if let Some(reasoning) = &agent.reasoning_effort {
+        parts.push(reasoning.as_str());
+    }
+    parts.join(" · ")
+}"""
+
+replace = """fn agent_detail(agent: &AgentSummary) -> String {
+    let parts: Vec<&str> = [
+        Some(agent.name.as_str()),
+        agent.description.as_deref(),
+        agent.model.as_deref(),
+        agent.reasoning_effort.as_deref(),
+    ]
+    .into_iter()
+    .flatten()
+    .collect();
+    parts.join(" · ")
+}"""
+
+replace_in_file('rust/crates/commands/src/lib.rs', search, replace)

rust/crates/commands/src/lib.rs

@@ -3290,16 +3290,15 @@ fn render_agents_report_json(cwd: &Path, agents: &[AgentSummary]) -> Value {
 }
 
 fn agent_detail(agent: &AgentSummary) -> String {
-    let mut parts = vec![agent.name.clone()];
-    if let Some(description) = &agent.description {
-        parts.push(description.clone());
-    }
-    if let Some(model) = &agent.model {
-        parts.push(model.clone());
-    }
-    if let Some(reasoning) = &agent.reasoning_effort {
-        parts.push(reasoning.clone());
-    }
+    let parts: Vec<&str> = [
+        Some(agent.name.as_str()),
+        agent.description.as_deref(),
+        agent.model.as_deref(),
+        agent.reasoning_effort.as_deref(),
+    ]
+    .into_iter()
+    .flatten()
+    .collect();
     parts.join(" · ")
 }
 
@@ -3333,13 +3332,14 @@ fn render_skills_report(skills: &[SkillSummary]) -> String {
 
         lines.push(format!("{}:", scope.label()));
         for skill in group {
-            let mut parts = vec![skill.name.clone()];
-            if let Some(description) = &skill.description {
-                parts.push(description.clone());
-            }
-            if let Some(detail) = skill.origin.detail_label() {
-                parts.push(detail.to_string());
-            }
+            let parts: Vec<&str> = [
+                Some(skill.name.as_str()),
+                skill.description.as_deref(),
+                skill.origin.detail_label(),
+            ]
+            .into_iter()
+            .flatten()
+            .collect();
             let detail = parts.join(" · ");
             match skill.shadowed_by {
                 Some(winner) => lines.push(format!("  (shadowed by {}) {detail}", winner.label())),