assistant tools: Add Tool::icon method instead of matching on name (#27444)

Release Notes:

- N/A

crates/assistant2/src/active_thread.rs

@@ -1251,23 +1251,6 @@ impl ActiveThread {
 
         let lighter_border = cx.theme().colors().border.opacity(0.5);
 
-        let tool_icon = match tool_use.name.as_ref() {
-            "bash" => IconName::Terminal,
-            "copy-path" => IconName::Clipboard,
-            "delete-path" => IconName::Trash,
-            "diagnostics" => IconName::Warning,
-            "edit-files" | "find-replace-file" => IconName::Pencil,
-            "fetch" => IconName::Globe,
-            "list-directory" => IconName::Folder,
-            "move-path" => IconName::ArrowRightLeft,
-            "now" => IconName::Info,
-            "path-search" => IconName::SearchCode,
-            "read-file" => IconName::Eye,
-            "regex-search" => IconName::Regex,
-            "thinking" => IconName::Brain,
-            _ => IconName::Cog,
-        };
-
         div().py_2().child(
             v_flex()
                 .rounded_lg()
@@ -1293,7 +1276,7 @@ impl ActiveThread {
                             h_flex()
                                 .gap_1p5()
                                 .child(
-                                    Icon::new(tool_icon)
+                                    Icon::new(tool_use.icon)
                                         .size(IconSize::XSmall)
                                         .color(Color::Muted),
                                 )

crates/assistant2/src/tool_use.rs

@@ -10,6 +10,7 @@ use language_model::{
     LanguageModelRequestMessage, LanguageModelToolResult, LanguageModelToolUse,
     LanguageModelToolUseId, MessageContent, Role,
 };
+use ui::IconName;
 
 use crate::thread::MessageId;
 use crate::thread_store::SerializedMessage;
@@ -21,6 +22,7 @@ pub struct ToolUse {
     pub ui_text: SharedString,
     pub status: ToolUseStatus,
     pub input: serde_json::Value,
+    pub icon: ui::IconName,
 }
 
 #[derive(Debug, Clone)]
@@ -179,12 +181,19 @@ impl ToolUseState {
                 }
             })();
 
+            let icon = if let Some(tool) = self.tools.tool(&tool_use.name, cx) {
+                tool.icon()
+            } else {
+                IconName::Cog
+            };
+
             tool_uses.push(ToolUse {
                 id: tool_use.id.clone(),
                 name: tool_use.name.clone().into(),
                 ui_text: self.tool_ui_label(&tool_use.name, &tool_use.input, cx),
                 input: tool_use.input.clone(),
                 status,
+                icon,
             })
         }