TST: Add typing tests for `np.rec`

2 files changed, 123 insertions, 0 deletions

diff --git a/numpy/typing/tests/data/fail/rec.py b/numpy/typing/tests/data/fail/rec.py
new file mode 100644
index 000000000..a57f1ba27
--- /dev/null
+++ b/numpy/typing/tests/data/fail/rec.py
@@ -0,0 +1,17 @@
+import numpy as np
+import numpy.typing as npt
+
+AR_i8: npt.NDArray[np.int64]
+
+np.rec.fromarrays(1)  # E: No overload variant
+np.rec.fromarrays([1, 2, 3], dtype=[("f8", "f8")], formats=["f8", "f8"])  # E: No overload variant
+
+np.rec.fromrecords(AR_i8)  # E: incompatible type
+np.rec.fromrecords([(1.5,)], dtype=[("f8", "f8")], formats=["f8", "f8"])  # E: No overload variant
+
+np.rec.fromstring("string", dtype=[("f8", "f8")])  # E: No overload variant
+np.rec.fromstring(b"bytes")  # E: No overload variant
+np.rec.fromstring(b"(1.5,)", dtype=[("f8", "f8")], formats=["f8", "f8"])  # E: No overload variant
+
+with open("test", "r") as f:
+    np.rec.fromfile(f, dtype=[("f8", "f8")])  # E: No overload variant
diff --git a/numpy/typing/tests/data/reveal/rec.py b/numpy/typing/tests/data/reveal/rec.py
new file mode 100644
index 000000000..2fa8cc7b9
--- /dev/null
+++ b/numpy/typing/tests/data/reveal/rec.py
@@ -0,0 +1,106 @@
+import io
+from typing import Any, List
+
+import numpy as np
+import numpy.typing as npt
+
+AR_i8: npt.NDArray[np.int64]
+REC_AR_V: np.recarray[Any, np.dtype[np.record]]
+AR_LIST: List[npt.NDArray[np.int64]]
+
+format_parser: np.format_parser
+record: np.record
+file_obj: io.BufferedIOBase
+
+reveal_type(np.format_parser(  # E: numpy.format_parser
+    formats=[np.float64, np.int64, np.bool_],
+    names=["f8", "i8", "?"],
+    titles=None,
+    aligned=True,
+))
+reveal_type(format_parser.dtype)  # E: numpy.dtype[numpy.void]
+
+reveal_type(record.field_a)  # E: Any
+reveal_type(record.field_b)  # E: Any
+reveal_type(record["field_a"])  # E: Any
+reveal_type(record["field_b"])  # E: Any
+reveal_type(record.pprint())  # E: str
+record.field_c = 5
+
+reveal_type(REC_AR_V.field(0))  # E: Any
+reveal_type(REC_AR_V.field("field_a"))  # E: Any
+reveal_type(REC_AR_V.field(0, AR_i8))  # E: None
+reveal_type(REC_AR_V.field("field_a", AR_i8))  # E: None
+reveal_type(REC_AR_V["field_a"])  # E: Any
+reveal_type(REC_AR_V.field_a)  # E: Any
+
+reveal_type(np.recarray(  # numpy.recarray[Any, numpy.dtype[numpy.record]]
+    shape=(10, 5),
+    formats=[np.float64, np.int64, np.bool_],
+    order="K",
+    byteorder="|",
+))
+reveal_type(np.recarray(  # numpy.recarray[Any, numpy.dtype[Any]]
+    shape=(10, 5),
+    dtype=[("f8", np.float64), ("i8", np.int64)],
+    strides=(5, 5),
+))
+
+reveal_type(np.rec.fromarrays(  # numpy.recarray[Any, numpy.dtype[numpy.record]]
+    AR_LIST,
+))
+reveal_type(np.rec.fromarrays(  # numpy.recarray[Any, numpy.dtype[Any]]
+    AR_LIST,
+    dtype=np.int64,
+))
+reveal_type(np.rec.fromarrays(  # numpy.recarray[Any, numpy.dtype[Any]]
+    AR_LIST,
+    formats=[np.int64, np.float64],
+    names=["i8", "f8"]
+))
+
+reveal_type(np.rec.fromrecords(  # numpy.recarray[Any, numpy.dtype[numpy.record]]
+    (1, 1.5),
+))
+reveal_type(np.rec.fromrecords(  # numpy.recarray[Any, numpy.dtype[numpy.record]]
+    [(1, 1.5)],
+    dtype=[("i8", np.int64), ("f8", np.float64)],
+))
+reveal_type(np.rec.fromrecords(  # numpy.recarray[Any, numpy.dtype[numpy.record]]
+    REC_AR_V,
+    formats=[np.int64, np.float64],
+    names=["i8", "f8"]
+))
+
+reveal_type(np.rec.fromstring(  # numpy.recarray[Any, numpy.dtype[numpy.record]]
+    b"(1, 1.5)",
+    dtype=[("i8", np.int64), ("f8", np.float64)],
+))
+reveal_type(np.rec.fromstring(  # numpy.recarray[Any, numpy.dtype[numpy.record]]
+    REC_AR_V,
+    formats=[np.int64, np.float64],
+    names=["i8", "f8"]
+))
+
+reveal_type(np.rec.fromfile(  # numpy.recarray[Any, numpy.dtype[Any]]
+    "test_file.txt",
+    dtype=[("i8", np.int64), ("f8", np.float64)],
+))
+reveal_type(np.rec.fromfile(  # numpy.recarray[Any, numpy.dtype[numpy.record]]
+    file_obj,
+    formats=[np.int64, np.float64],
+    names=["i8", "f8"]
+))
+
+reveal_type(np.rec.array(  # numpy.recarray[Any, numpy.dtype[{int64}]]
+    AR_i8,
+))
+reveal_type(np.rec.array(  # numpy.recarray[Any, numpy.dtype[Any]]
+    [(1, 1.5)],
+    dtype=[("i8", np.int64), ("f8", np.float64)],
+))
+reveal_type(np.rec.array(  # numpy.recarray[Any, numpy.dtype[numpy.record]]
+    [(1, 1.5)],
+    formats=[np.int64, np.float64],
+    names=["i8", "f8"]
+))