tests: don't mock sampling functions

tests/test_llama.py

@@ -47,7 +47,6 @@ def test_llama_cpp_tokenization():
 @pytest.fixture
 def mock_llama(monkeypatch):
     def setup_mock(llama: llama_cpp.Llama, output_text: str):
-        llama.reset()
         n_vocab = llama.n_vocab()
         output_tokens = llama.tokenize(
             output_text.encode("utf-8"), add_bos=True, special=True
@@ -59,28 +58,41 @@ def mock_llama(monkeypatch):
             nonlocal n
             nonlocal last_n_tokens
             # Test some basic invariants of this mocking technique
-            assert ctx == llama._ctx.ctx
-            assert llama.n_tokens == n
-            assert batch.n_tokens > 0
-            n += batch.n_tokens
+            assert ctx == llama._ctx.ctx, "context does not match mock_llama"
+            assert batch.n_tokens > 0, "no tokens in batch"
+            assert all(
+                batch.n_seq_id[i] == 1 for i in range(batch.n_tokens)
+            ), "n_seq >1 not supported by mock_llama"
+            assert all(
+                batch.seq_id[i][0] == 0 for i in range(batch.n_tokens)
+            ), "n_seq >1 not supported by mock_llama"
+            assert batch.logits[
+                batch.n_tokens - 1
+            ], "logits not allocated for last token"
+            # Update the mock context state
+            n = max(batch.pos[i] for i in range(batch.n_tokens)) + 1
             last_n_tokens = batch.n_tokens
             return 0
 
         def mock_get_logits(*args, **kwargs):
-            nonlocal last_n_tokens
-            size = n_vocab * last_n_tokens
-            return (llama_cpp.c_float * size)()
-
-        def mock_sample(*args, **kwargs):
             nonlocal n
-            if n < len(output_tokens):
-                return output_tokens[n]
-            else:
-                return llama.token_eos()
+            nonlocal last_n_tokens
+            assert n > 0, "mock_llama_decode not called"
+            assert last_n_tokens > 0, "mock_llama_decode not called"
+            logits = (llama_cpp.c_float * (last_n_tokens * n_vocab))(-100.0)
+            for logits_idx, output_idx in enumerate(
+                range(n - last_n_tokens + 1, n + 1)
+            ):
+                if output_idx < len(output_tokens):
+                    logits[
+                        logits_idx * last_n_tokens + output_tokens[output_idx]
+                    ] = 100.0
+                else:
+                    logits[logits_idx * last_n_tokens + llama.token_eos()] = 100.0
+            return logits
 
         monkeypatch.setattr("llama_cpp.llama_cpp.llama_decode", mock_decode)
         monkeypatch.setattr("llama_cpp.llama_cpp.llama_get_logits", mock_get_logits)
-        monkeypatch.setattr("llama_cpp.llama_cpp.llama_sample_token", mock_sample)
 
     return setup_mock