feat: vibed out some slop over here also

tests/test_injection.py

@@ -0,0 +1,193 @@
+"""Unit tests for `history_injection` helpers.
+
+Pure functions, no claude / no filesystem. The seed-JSONL shape is regression
+tested against the same minimal contract that `probe_jsonl_injection.py`
+proved out empirically (see FINDINGS § *Native JSONL injection works on
+--resume*).
+"""
+
+from __future__ import annotations
+
+import json
+
+import pytest
+
+from claude_code_api.injection import (
+    build_concat_prompt,
+    build_seed_jsonl,
+    hash_history,
+)
+
+# --- hash_history ---------------------------------------------------------
+
+
+def test_hash_history_empty_is_stable() -> None:
+    assert hash_history([]) == hash_history([])
+
+
+def test_hash_history_distinguishes_content() -> None:
+    a = [{"role": "user", "content": "hi"}]
+    b = [{"role": "user", "content": "bye"}]
+    assert hash_history(a) != hash_history(b)
+
+
+def test_hash_history_ignores_block_key_order() -> None:
+    """Two clients that serialize the same block in different key orders
+    must collide. Canonical-JSON serialization handles this."""
+    a = [
+        {
+            "role": "assistant",
+            "content": [{"type": "tool_use", "id": "t1", "name": "echo", "input": {"x": 1}}],
+        }
+    ]
+    b = [
+        {
+            "role": "assistant",
+            "content": [{"input": {"x": 1}, "name": "echo", "id": "t1", "type": "tool_use"}],
+        }
+    ]
+    assert hash_history(a) == hash_history(b)
+
+
+def test_hash_history_rejects_unknown_role() -> None:
+    with pytest.raises(ValueError, match="role"):
+        hash_history([{"role": "system", "content": "x"}])
+
+
+def test_hash_history_text_blocks_collide_with_string_form() -> None:
+    """A bare string `content` and the equivalent single text block hash to
+    DIFFERENT values. They represent the same semantic content but appear
+    on the wire differently — the gateway must pick one form per role and
+    stay consistent. We don't try to paper over that here."""
+    a = [{"role": "user", "content": "hello"}]
+    b = [{"role": "user", "content": [{"type": "text", "text": "hello"}]}]
+    assert hash_history(a) != hash_history(b)
+
+
+# --- build_seed_jsonl -----------------------------------------------------
+
+
+def test_build_seed_jsonl_empty_is_empty_string() -> None:
+    assert build_seed_jsonl([], session_id="s", cwd="/tmp") == ""
+
+
+def test_build_seed_jsonl_two_records_for_one_turn() -> None:
+    seed = build_seed_jsonl(
+        [
+            {"role": "user", "content": "My name is Beaver."},
+            {"role": "assistant", "content": "Got it."},
+        ],
+        session_id="sid-1",
+        cwd="/work",
+    )
+    lines = [json.loads(line) for line in seed.strip().splitlines()]
+    assert len(lines) == 2
+    user_rec, asst_rec = lines
+
+    assert user_rec["type"] == "user"
+    assert user_rec["sessionId"] == "sid-1"
+    assert user_rec["cwd"] == "/work"
+    assert user_rec["parentUuid"] is None
+    assert user_rec["message"] == {"role": "user", "content": "My name is Beaver."}
+    assert user_rec["isMeta"] is False
+    assert "uuid" in user_rec and "timestamp" in user_rec
+
+    assert asst_rec["type"] == "assistant"
+    assert asst_rec["parentUuid"] == user_rec["uuid"]
+    assert asst_rec["message"]["role"] == "assistant"
+    assert asst_rec["message"]["content"] == [{"type": "text", "text": "Got it."}]
+    assert asst_rec["message"]["stop_reason"] == "end_turn"
+    assert asst_rec["sessionId"] == "sid-1"
+
+
+def test_build_seed_jsonl_chains_parent_uuids_across_turns() -> None:
+    """The parentUuid graph must form a linear chain across turns — that's
+    how claude reconstructs conversation order on resume."""
+    seed = build_seed_jsonl(
+        [
+            {"role": "user", "content": "u1"},
+            {"role": "assistant", "content": "a1"},
+            {"role": "user", "content": "u2"},
+            {"role": "assistant", "content": "a2"},
+        ],
+        session_id="s",
+        cwd="/tmp",
+    )
+    recs = [json.loads(line) for line in seed.strip().splitlines()]
+    assert len(recs) == 4
+    assert recs[0]["parentUuid"] is None
+    assert recs[1]["parentUuid"] == recs[0]["uuid"]
+    assert recs[2]["parentUuid"] == recs[1]["uuid"]
+    assert recs[3]["parentUuid"] == recs[2]["uuid"]
+
+
+def test_build_seed_jsonl_passes_list_content_through_for_user() -> None:
+    """A user record with a tool_result block (the only list-form user
+    content claude itself writes) must round-trip verbatim."""
+    seed = build_seed_jsonl(
+        [
+            {
+                "role": "user",
+                "content": [
+                    {"type": "tool_result", "tool_use_id": "t1", "content": "42"},
+                ],
+            }
+        ],
+        session_id="s",
+        cwd="/tmp",
+    )
+    rec = json.loads(seed.strip())
+    assert rec["message"]["content"] == [
+        {"type": "tool_result", "tool_use_id": "t1", "content": "42"},
+    ]
+
+
+def test_build_seed_jsonl_rejects_unknown_role() -> None:
+    with pytest.raises(ValueError, match="role"):
+        build_seed_jsonl([{"role": "system", "content": "x"}], session_id="s", cwd="/tmp")
+
+
+# --- build_concat_prompt --------------------------------------------------
+
+
+def test_build_concat_prompt_empty_history_returns_just_last_user() -> None:
+    assert build_concat_prompt([], "hello") == "hello"
+
+
+def test_build_concat_prompt_renders_alternating_history() -> None:
+    out = build_concat_prompt(
+        [
+            {"role": "user", "content": "u1"},
+            {"role": "assistant", "content": "a1"},
+            {"role": "user", "content": "u2"},
+            {"role": "assistant", "content": "a2"},
+        ],
+        "u3",
+    )
+    assert "Previous conversation context:" in out
+    assert "[User]: u1" in out
+    assert "[Assistant]: a1" in out
+    assert "[User]: u2" in out
+    assert "[Assistant]: a2" in out
+    assert "Continue from here. New user message: u3" in out
+    # The new prompt must come after the history, not interleaved.
+    assert out.index("[Assistant]: a2") < out.index("Continue from here")
+
+
+def test_build_concat_prompt_flattens_text_blocks_and_skips_tools() -> None:
+    """Content-as-list with text blocks gets flattened; tool blocks are
+    skipped (they don't round-trip through stdin in any useful form)."""
+    out = build_concat_prompt(
+        [
+            {
+                "role": "assistant",
+                "content": [
+                    {"type": "text", "text": "hello"},
+                    {"type": "tool_use", "id": "t1", "name": "x", "input": {}},
+                    {"type": "text", "text": "world"},
+                ],
+            },
+        ],
+        "ping",
+    )
+    assert "[Assistant]: hello world" in out