test hashing of lazy fields

Author: tclose

pydra/engine/lazy.py

@@ -30,7 +30,7 @@ class LazyField(ty.Generic[T], metaclass=abc.ABCMeta):
 
     def __bytes_repr__(self, cache):
         yield type(self).__name__.encode() + b"("
-        yield from bytes(hash_single(self.source, cache))
+        yield b"source=" + bytes(hash_single(self._source, cache))
         yield b"field=" + self._field.encode()
         yield b"type=" + bytes(hash_single(self._type, cache))
         yield b"cast_from=" + bytes(hash_single(self._cast_from, cache))

pydra/utils/tests/test_hash.py

@@ -21,6 +21,7 @@
 import random
 from fileformats.generic import Directory, File
 from pydra.utils.hash import hash_function
+from pydra.utils.tests.utils import Concatenate
 
 
 def test_hash_file(tmpdir):
@@ -558,3 +559,14 @@ def __repr__(self):
         ),
     ):
         hash_object(A())
+
+
+def test_hash_task(tmp_path):
+    """
+    Test that the hash of a task is consistent across runs
+    """
+
+    concatenate1 = Concatenate()
+    concatenate2 = Concatenate()
+
+    assert hash_function(concatenate1) == hash_function(concatenate2)

pydra/utils/tests/utils.py

@@ -1,3 +1,5 @@
+import typing as ty
+from pathlib import Path
 from fileformats.generic import File, BinaryFile
 from fileformats.core.mixin import WithSeparateHeader, WithMagicNumber
 from pydra.compose import shell, python
@@ -94,3 +96,38 @@ class Outputs(shell.Outputs):
         )
 
     executable = "echo"
+
+
+@python.define(outputs=["out_file"])
+def Concatenate(
+    in_file1: File,
+    in_file2: File,
+    out_file: ty.Optional[Path] = None,
+    duplicates: int = 1,
+) -> File:
+    """Concatenates the contents of two files and writes them to a third
+
+    Parameters
+    ----------
+    in_file1 : Path
+        A text file
+    in_file2 : Path
+        Another text file
+    out_file : Path
+       The path to write the output file to
+
+    Returns
+    -------
+    out_file: Path
+        A text file made by concatenating the two inputs
+    """
+    if out_file is None:
+        out_file = Path("out_file.txt").absolute()
+    contents = []
+    for _ in range(duplicates):
+        for fname in (in_file1, in_file2):
+            with open(fname) as f:
+                contents.append(f.read())
+    with open(out_file, "w") as f:
+        f.write("\n".join(contents))
+    return out_file