GET api update for image vector

tests/test_image_match.py

@@ -93,6 +93,52 @@ def test_unsearchable_vectors_are_refused_with_a_reason(bad, msg):
         im.normalise_vector(bad)
 
 
+# ---------------------------------------------------------------------------
+# the query-string forms of the vector (GET /search/image-vector)
+# ---------------------------------------------------------------------------
+
+def test_base64_round_trips_to_float32_precision():
+    v = _unit()
+    encoded = im.encode_vector_b64(v)
+
+    assert len(encoded) < 5_500 and "=" not in encoded          # 5,462 chars, unpadded
+    back = im.parse_vector_param(encoded)
+    assert len(back) == 1024 and max(abs(a - b) for a, b in zip(v, back)) < 1e-6
+
+
+def test_the_standard_base64_alphabet_and_padding_are_accepted_too():
+    import base64, struct
+    v = _unit()
+    standard = base64.b64encode(struct.pack("<1024f", *v)).decode()     # '+', '/', '=' padding
+
+    assert max(abs(a - b) for a, b in zip(v, im.parse_vector_param(standard))) < 1e-6
+
+
+def test_comma_separated_values_tolerate_brackets_whitespace_and_newlines():
+    v = _unit()
+    text = "[ " + ("," + chr(10) + " ").join(f"{x:.6f}" for x in v) + " ]"
+
+    back = im.parse_vector_param(text)
+    assert len(back) == 1024 and max(abs(a - b) for a, b in zip(v, back)) < 1e-6
+
+
+@pytest.mark.parametrize("raw, msg", [
+    ("", "empty"),
+    ("   ", "empty"),
+    ("0.1, 0.2, x, 0.4", "value 3"),
+    ("MTIz", "decodes to 3 bytes"),
+    ("!!!not base64!!!", "comma-separated numbers or base64"),
+])
+def test_unparseable_query_vectors_say_what_is_wrong(raw, msg):
+    with pytest.raises(im.InvalidVectorError, match=msg):
+        im.parse_vector_param(raw)
+
+
+def test_a_short_csv_vector_is_caught_by_the_same_length_rule_as_the_post_body():
+    with pytest.raises(im.InvalidVectorError, match="1024 values"):
+        im.normalise_vector(im.parse_vector_param(",".join(["0.1"] * 1023)))
+
+
 # ---------------------------------------------------------------------------
 # the label text
 # ---------------------------------------------------------------------------

tests/test_image_search_api.py

@@ -116,6 +116,57 @@ def test_a_service_rejection_is_422_not_500(client, monkeypatch):
     assert res.status_code == 422 and "all zeros" in res.text
 
 
+# ---------------------------------------------------------------------------
+# GET /search/image-vector
+# ---------------------------------------------------------------------------
+
+def test_get_with_a_base64_vector_returns_the_same_cards_and_stays_under_8kb(client, fake_search):
+    from app.services.image_match import encode_vector_b64
+    v = _unit()
+    params = {"vector": encode_vector_b64(v), "text": "Britannia Marie Gold 300 g", "top_k": 5, "min_score": 0.1}
+
+    res = client.get("/api/search/image-vector", params=params)
+
+    assert res.status_code == 200, res.text
+    assert res.json()["results"][0]["product_name"] == "Britannia Marie Gold 300g"
+    call = fake_search[0]
+    assert len(call["vector"]) == 1024 and max(abs(a - b) for a, b in zip(v, call["vector"])) < 1e-6
+    assert call["text"] == "Britannia Marie Gold 300 g" and call["top_k"] == 5 and call["min_score"] == 0.1
+    # the nginx on the app domain allows an 8 KB request line; base64 must fit it
+    assert len(str(res.request.url)) < 8_000
+
+
+def test_get_with_comma_separated_values_works_on_the_api_host(client, fake_search):
+    v = _unit()
+    res = client.get("/api/search/image-vector", params={"vector": ",".join(f"{x:.5f}" for x in v)})
+
+    assert res.status_code == 200, res.text
+    assert len(fake_search[0]["vector"]) == 1024
+    assert max(abs(a - b) for a, b in zip(v, fake_search[0]["vector"])) < 1e-5
+
+
+@pytest.mark.parametrize("params, fragment", [
+    ({}, "vector"),
+    ({"vector": "0.1,0.2,x"}, "value 3"),
+    ({"vector": "MTIz"}, "decodes to 3 bytes"),
+    ({"vector": ",".join(["0.1"] * 1023)}, "1024 values"),
+    ({"vector": ",".join(["0.0"] * 1024)}, "all zeros"),
+    ({"vector": ",".join(["0.1"] * 1024), "top_k": 51}, "top_k"),
+])
+def test_get_rejects_bad_input_with_422_and_a_reason(client, fake_search, params, fragment):
+    res = client.get("/api/search/image-vector", params=params)
+    assert res.status_code == 422 and fragment in res.text
+    assert fake_search == []
+
+
+def test_get_and_post_agree(client, fake_search):
+    from app.services.image_match import encode_vector_b64
+    v = _unit()
+    a = client.get("/api/search/image-vector", params={"vector": encode_vector_b64(v), "top_k": 3}).json()
+    b = client.post("/api/search/image-vector", json={"vector": v, "top_k": 3}).json()
+    assert [r["image_id"] for r in a["results"]] == [r["image_id"] for r in b["results"]]
+
+
 # ---------------------------------------------------------------------------
 # /search/image
 # ---------------------------------------------------------------------------
@@ -172,3 +223,4 @@ def test_both_routes_are_documented(client):
     paths = client.get("/openapi.json").json()["paths"]
     assert "/api/search/image-vector" in paths and "/api/search/image" in paths
     assert "post" in paths["/api/search/image"] and "get" in paths["/api/search"]
+    assert {"get", "post"} <= set(paths["/api/search/image-vector"])