Merge feat/api-endpoint: FastAPI surface with NDJSON streaming and CORS for Vite

backend/tests/test_api.py

@@ -0,0 +1,154 @@
+"""Tests for the FastAPI surface in ``cyclone.api``.
+
+All tests use ``fastapi.testclient.TestClient`` — no real network or uvicorn
+process is started. The fixture file is the same one used by the parser's
+own end-to-end test (``co_medicaid_837p.txt`` → 2 claims, both pass).
+"""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+import pytest
+from fastapi.testclient import TestClient
+
+from cyclone.api import app
+from cyclone import __version__
+
+
+FIXTURE = Path(__file__).parent / "fixtures" / "co_medicaid_837p.txt"
+
+
+@pytest.fixture
+def client() -> TestClient:
+    return TestClient(app)
+
+
+# --------------------------------------------------------------------------- #
+# Health
+# --------------------------------------------------------------------------- #
+
+
+def test_health_endpoint(client: TestClient):
+    resp = client.get("/api/health")
+    assert resp.status_code == 200
+    body = resp.json()
+    assert body == {"status": "ok", "version": __version__}
+
+
+# --------------------------------------------------------------------------- #
+# JSON response path
+# --------------------------------------------------------------------------- #
+
+
+def test_parse_837_endpoint_returns_json(client: TestClient):
+    text = FIXTURE.read_text()
+    resp = client.post(
+        "/api/parse-837",
+        files={"file": ("co_medicaid_837p.txt", text, "text/plain")},
+        headers={"Accept": "application/json"},
+    )
+    assert resp.status_code == 200, resp.text
+    body = resp.json()
+    assert "envelope" in body
+    assert body["envelope"] is not None
+    assert "claims" in body and len(body["claims"]) == 2
+    assert "summary" in body
+    assert body["summary"]["total_claims"] == 2
+    assert body["summary"]["passed"] == 2
+
+
+# --------------------------------------------------------------------------- #
+# NDJSON streaming path
+# --------------------------------------------------------------------------- #
+
+
+def test_parse_837_endpoint_streams_ndjson(client: TestClient):
+    text = FIXTURE.read_text()
+    resp = client.post(
+        "/api/parse-837",
+        files={"file": ("co_medicaid_837p.txt", text, "text/plain")},
+    )
+    assert resp.status_code == 200, resp.text
+    assert resp.headers["content-type"].startswith("application/x-ndjson")
+
+    # Consume line-by-line (this is exactly what the React frontend will do).
+    lines = list(resp.iter_lines())
+    # 1 envelope + 2 claims + 1 summary
+    assert len(lines) == 4
+
+    parsed = [json.loads(line) for line in lines]
+    assert parsed[0]["type"] == "envelope"
+    assert parsed[0]["data"] is not None
+    assert parsed[1]["type"] == "claim"
+    assert parsed[2]["type"] == "claim"
+    assert parsed[3]["type"] == "summary"
+
+    # When include_raw_segments defaults to True, each claim carries raw segments.
+    for obj in parsed[1:3]:
+        assert "raw_segments" in obj["data"]
+        assert isinstance(obj["data"]["raw_segments"], list)
+
+    # Summary numbers match the JSON path.
+    assert parsed[3]["data"]["total_claims"] == 2
+    assert parsed[3]["data"]["passed"] == 2
+
+
+def test_parse_837_endpoint_streams_ndjson_without_raw_segments(client: TestClient):
+    text = FIXTURE.read_text()
+    resp = client.post(
+        "/api/parse-837?include_raw_segments=false",
+        files={"file": ("co_medicaid_837p.txt", text, "text/plain")},
+    )
+    assert resp.status_code == 200
+    assert resp.headers["content-type"].startswith("application/x-ndjson")
+
+    claims = [json.loads(line) for line in resp.iter_lines() if json.loads(line)["type"] == "claim"]
+    assert len(claims) == 2
+    for c in claims:
+        assert c["data"]["raw_segments"] == []
+
+
+# --------------------------------------------------------------------------- #
+# Validation / error paths
+# --------------------------------------------------------------------------- #
+
+
+def test_parse_837_endpoint_rejects_missing_file(client: TestClient):
+    # FastAPI's `File(...)` (no default) → 422 Unprocessable Entity.
+    resp = client.post("/api/parse-837")
+    assert resp.status_code == 422
+
+
+def test_parse_837_endpoint_handles_payer_query_param(client: TestClient):
+    text = FIXTURE.read_text()
+    for payer in ("co_medicaid", "generic_837p"):
+        resp = client.post(
+            f"/api/parse-837?payer={payer}",
+            files={"file": ("co_medicaid_837p.txt", text, "text/plain")},
+            headers={"Accept": "application/json"},
+        )
+        assert resp.status_code == 200, (payer, resp.text)
+        body = resp.json()
+        assert body["summary"]["passed"] == 2
+        assert body["summary"]["total_claims"] == 2
+
+
+# --------------------------------------------------------------------------- #
+# CORS
+# --------------------------------------------------------------------------- #
+
+
+def test_cors_headers_present(client: TestClient):
+    # Simulate a preflight from the Vite dev origin.
+    resp = client.options(
+        "/api/parse-837",
+        headers={
+            "Origin": "http://localhost:5173",
+            "Access-Control-Request-Method": "POST",
+            "Access-Control-Request-Headers": "content-type",
+        },
+    )
+    assert resp.headers.get("access-control-allow-origin") == "http://localhost:5173"
+    assert "POST" in resp.headers.get("access-control-allow-methods", "").upper()