Fix abbreviation formatting in visualizer (#989)

Co-authored-by: openhands <[email protected]>

Author: SmartManoj

openhands-sdk/openhands/sdk/conversation/visualizer.py

@@ -294,14 +294,14 @@ def _format_metrics_subtitle(self) -> str | None:
         def abbr(n: int | float) -> str:
             n = int(n or 0)
             if n >= 1_000_000_000:
-                s = f"{n / 1_000_000_000:.2f}B"
+                val, suffix = n / 1_000_000_000, "B"
             elif n >= 1_000_000:
-                s = f"{n / 1_000_000:.2f}M"
+                val, suffix = n / 1_000_000, "M"
             elif n >= 1_000:
-                s = f"{n / 1_000:.2f}K"
+                val, suffix = n / 1_000, "K"
             else:
                 return str(n)
-            return s.replace(".0", "")
+            return f"{val:.2f}".rstrip("0").rstrip(".") + suffix
 
         input_tokens = abbr(usage.prompt_tokens or 0)
         output_tokens = abbr(usage.completion_tokens or 0)

tests/sdk/conversation/test_visualizer.py

@@ -333,13 +333,53 @@ def test_metrics_formatting():
     # Test the metrics subtitle formatting
     subtitle = visualizer._format_metrics_subtitle()
     assert subtitle is not None
-    assert "1.50K" in subtitle  # Input tokens abbreviated
+    assert "1.5K" in subtitle  # Input tokens abbreviated (trailing zeros removed)
     assert "500" in subtitle  # Output tokens
     assert "20.00%" in subtitle  # Cache hit rate
     assert "200" in subtitle  # Reasoning tokens
     assert "0.0234" in subtitle  # Cost
 
 
+def test_metrics_abbreviation_formatting():
+    """Test number abbreviation with various edge cases."""
+    from openhands.sdk.conversation.conversation_stats import ConversationStats
+    from openhands.sdk.llm.utils.metrics import Metrics
+
+    test_cases = [
+        # (input_tokens, expected_abbr)
+        (999, "999"),  # Below threshold
+        (1000, "1K"),  # Exact K boundary, trailing zeros removed
+        (1500, "1.5K"),  # K with one decimal, trailing zero removed
+        (89080, "89.08K"),  # K with two decimals (regression test for bug)
+        (89000, "89K"),  # K with trailing zeros removed
+        (1000000, "1M"),  # Exact M boundary
+        (1234567, "1.23M"),  # M with decimals
+        (1000000000, "1B"),  # Exact B boundary
+    ]
+
+    for tokens, expected in test_cases:
+        stats = ConversationStats()
+        metrics = Metrics(model_name="test-model")
+        metrics.add_token_usage(
+            prompt_tokens=tokens,
+            completion_tokens=100,
+            cache_read_tokens=0,
+            cache_write_tokens=0,
+            reasoning_tokens=0,
+            context_window=8000,
+            response_id="test",
+        )
+        stats.usage_to_metrics["test"] = metrics
+
+        visualizer = ConversationVisualizer(conversation_stats=stats)
+        subtitle = visualizer._format_metrics_subtitle()
+
+        assert subtitle is not None, f"Failed for {tokens}"
+        assert expected in subtitle, (
+            f"Expected '{expected}' in subtitle for {tokens}, got: {subtitle}"
+        )
+
+
 def test_event_base_fallback_visualize():
     """Test that Event provides fallback visualization."""
     from openhands.sdk.event.base import Event