chore: add tracking for new testset generation (#1419)

Author: jjmachan

src/ragas/_analytics.py

@@ -97,6 +97,7 @@ class TestsetGenerationEvent(BaseEvent):
     num_rows: int
     language: str
     is_experiment: bool = False
+    version: str = "3"  # the version of testset generation pipeline
 
 
 @silent

src/ragas/testset/synthesizers/generate.py

@@ -4,6 +4,7 @@
 import typing as t
 from dataclasses import dataclass, field
 
+from ragas._analytics import TestsetGenerationEvent, track
 from ragas.callbacks import new_group
 from ragas.executor import Executor
 from ragas.llms import BaseRagasLLM, LangchainLLMWrapper
@@ -202,4 +203,17 @@ def generate(
             testsets.append(TestsetSample(eval_sample=sample, **additional_info))
         testset = Testset(samples=testsets)
         testset_generation_rm.on_chain_end({"testset": testset})
+
+        # tracking how many samples were generated
+        track(
+            TestsetGenerationEvent(
+                event_type="testset_generation",
+                evolution_names=[
+                    e.__class__.__name__.lower() for e, _ in query_distribution
+                ],
+                evolution_percentages=[p for _, p in query_distribution],
+                num_rows=test_size,
+                language="english",
+            )
+        )
         return testset