[Test] Batch Invariant: Rename and organize tests (#27421)

Signed-off-by: yewentao256 <zhyanwentao@126.com>

tests/v1/determinism/utils.py

@@ -0,0 +1,74 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import random
+
+import pytest
+import torch
+
+from vllm.platforms import current_platform
+
+skip_unsupported = pytest.mark.skipif(
+    not (current_platform.is_cuda() and current_platform.has_device_capability(90)),
+    reason="Requires CUDA and >= Hopper (SM90)",
+)
+
+
+def _random_prompt(min_words: int = 1024, max_words: int = 1024 * 2) -> str:
+    # Generate more realistic prompts that will actually produce varied tokens
+    # Use a mix of common English text patterns
+
+    prompt_templates = [
+        # Question-answer style
+        "Question: What is the capital of France?\nAnswer: The capital of France is",
+        "Q: How does photosynthesis work?\nA: Photosynthesis is the process by which",
+        "User: Can you explain quantum mechanics?\nAssistant: Quantum mechanics is",
+        # Story/narrative style
+        "Once upon a time in a distant galaxy, there lived",
+        "The old man walked slowly down the street, remembering",
+        "In the year 2157, humanity finally discovered",
+        # Technical/code style
+        "To implement a binary search tree in Python, first we need to",
+        "The algorithm works by iterating through the array and",
+        "Here's how to optimize database queries using indexing:",
+        # Factual/informative style
+        "The Renaissance was a period in European history that",
+        "Climate change is caused by several factors including",
+        "The human brain contains approximately 86 billion neurons which",
+        # Conversational style
+        "I've been thinking about getting a new laptop because",
+        "Yesterday I went to the store and bought",
+        "My favorite thing about summer is definitely",
+    ]
+
+    # Pick a random template
+    base_prompt = random.choice(prompt_templates)
+
+    if max_words < min_words:
+        max_words = min_words
+    target_words = random.randint(min_words, max_words)
+
+    if target_words > 50:
+        # For longer prompts, repeat context
+        padding_text = (
+            " This is an interesting topic that deserves more explanation. "
+            * (target_words // 50)
+        )
+        base_prompt = base_prompt + padding_text
+
+    return base_prompt
+
+
+def _extract_step_logprobs(request_output):
+    if getattr(request_output, "outputs", None):
+        inner = request_output.outputs[0]
+        if hasattr(inner, "logprobs") and inner.logprobs is not None:
+            t = torch.tensor(
+                [
+                    inner.logprobs[i][tid].logprob
+                    for i, tid in enumerate(inner.token_ids)
+                ],
+                dtype=torch.float32,
+            )
+            return t, inner.token_ids
+
+    return None, None