Minor improvements of stats display in dashboard

Display token count estimator name
Display short message if no stats were collected

src/serena/analytics.py

@@ -2,7 +2,7 @@ from __future__ import annotations
 
 import logging
 import threading
-from abc import ABC
+from abc import ABC, abstractmethod
 from collections import defaultdict
 from copy import copy
 from dataclasses import asdict, dataclass
@@ -15,6 +15,7 @@ log = logging.getLogger(__name__)
 
 
 class TokenCountEstimator(ABC):
+    @abstractmethod
     def estimate_token_count(self, text: str) -> int:
         """
         Estimate the number of tokens in the given text.
@@ -84,9 +85,9 @@ class RegisteredTokenCountEstimator(Enum):
 
     def _create_estimator(self) -> TokenCountEstimator:
         match self:
-            case self.TIKTOKEN_GPT4O:
+            case RegisteredTokenCountEstimator.TIKTOKEN_GPT4O:
                 return TiktokenCountEstimator(model_name="gpt-4o")
-            case self.ANTHROPIC_CLAUDE_SONNET_4:
+            case RegisteredTokenCountEstimator.ANTHROPIC_CLAUDE_SONNET_4:
                 return AnthropicTokenCount(model_name="claude-sonnet-4-20250514")
             case _:
                 raise ValueError(f"Unknown token count estimator: {self.value}")
@@ -110,6 +111,13 @@ class ToolUsageStats:
         self._tool_stats: dict[str, ToolUsageStats.Entry] = defaultdict(ToolUsageStats.Entry)
         self._tool_stats_lock = threading.Lock()
 
+    @property
+    def token_estimator_name(self) -> str:
+        """
+        Get the name of the registered token count estimator used.
+        """
+        return self._token_estimator_name
+
     @dataclass(kw_only=True)
     class Entry:
         num_times_called: int = 0

src/serena/dashboard.py

@@ -130,6 +130,11 @@ class SerenaDashboardAPI:
             self._clear_tool_stats()
             return {"status": "cleared"}
 
+        @self._app.route("/get_token_count_estimator_name", methods=["GET"])
+        def get_token_count_estimator_name() -> dict[str, str]:
+            estimator_name = self._tool_usage_stats.token_estimator_name if self._tool_usage_stats else "unknown"
+            return {"token_count_estimator_name": estimator_name}
+
         @self._app.route("/shutdown", methods=["PUT"])
         def shutdown() -> dict[str, str]:
             self._shutdown()
@@ -150,7 +155,8 @@ class SerenaDashboardAPI:
             return ResponseToolStats(stats={})
 
     def _clear_tool_stats(self) -> None:
-        self._tool_usage_stats.clear()
+        if self._tool_usage_stats is not None:
+            self._tool_usage_stats.clear()
 
     def _shutdown(self) -> None:
         log.info("Shutting down Serena")

src/serena/resources/dashboard/dashboard.js

@@ -201,18 +201,19 @@ class Dashboard {
 
     loadStats() {
         let self = this;
-        $.ajax({
-            url: '/get_tool_stats',
-            type: 'GET',
-            success: function(response) {
-                self.displayStats(response.stats || {});
-            },
-            error: function(xhr, status, error) {
-                console.error('Error loading stats:', error);
-            }
+        $.when(
+            $.ajax({ url: '/get_tool_stats', type: 'GET' }),
+            $.ajax({ url: '/get_token_count_estimator_name', type: 'GET' })
+        ).done(function(statsResp, estimatorResp) {
+            const stats = statsResp[0].stats;
+            const tokenCountEstimatorName = estimatorResp[0].token_count_estimator_name;
+            self.displayStats(stats, tokenCountEstimatorName);
+        }).fail(function() {
+            console.error('Error loading stats or estimator name');
         });
     }
 
+
     clearStats() {
         let self = this;
         $.ajax({
@@ -227,8 +228,27 @@ class Dashboard {
         });
     }
 
-    displayStats(stats) {
+    displayStats(stats, tokenCountEstimatorName) {
         const names = Object.keys(stats);
+      // If no stats collected
+        if (names.length === 0) {
+            // hide summary, charts, estimator name
+            $('#stats-summary').hide();
+            $('#estimator-name').hide();
+            $('.charts-container').hide();
+            // show no-stats message
+            $('#no-stats-message').show();
+            return;
+        } else {
+            // Ensure everything is visible
+            $('#estimator-name').show();
+            $('#stats-summary').show();
+            $('.charts-container').show();
+            $('#no-stats-message').hide();
+        }
+
+        $('#estimator-name').html(`<strong>Token count estimator:</strong> ${tokenCountEstimatorName}`);
+
         const counts = names.map(n => stats[n].num_times_called);
         const inputTokens = names.map(n => stats[n].input_tokens);
         const outputTokens = names.map(n => stats[n].output_tokens);
@@ -252,18 +272,6 @@ class Dashboard {
         if (this.inputChart) this.inputChart.destroy();
         if (this.outputChart) this.outputChart.destroy();
 
-        if (names.length === 0) {
-            this.countChart = null;
-            this.tokensChart = null;
-            this.inputChart = null;
-            this.outputChart = null;
-            countCtx.getContext('2d').clearRect(0,0,countCtx.width,countCtx.height);
-            tokensCtx.getContext('2d').clearRect(0,0,tokensCtx.width,tokensCtx.height);
-            inputCtx.getContext('2d').clearRect(0,0,inputCtx.width,inputCtx.height);
-            outputCtx.getContext('2d').clearRect(0,0,outputCtx.width,outputCtx.height);
-            return;
-        }
-
         // Update summary table
         this.updateSummaryTable(totalCalls, totalInputTokens, totalOutputTokens);
 

src/serena/resources/dashboard/index.html

@@ -186,6 +186,11 @@
         </div>
         
         <div id="stats-summary" style="margin-bottom:20px; text-align:center;"></div>
+        <div id="estimator-name" style="text-align:center; margin-bottom:10px;"></div>
+        <div id="no-stats-message" style="text-align:center; color:#666; font-style:italic; display:none;">
+          No tool stats collected. Have you enabled tool stats collection in the configuration?
+        </div>
+
         
         <div class="charts-container">
             <div class="chart-group">