Rework tests

tests/nixos/fetch-git/test-cases/lfs/default.nix

@@ -5,15 +5,13 @@
   script = ''
     from tempfile import TemporaryDirectory
 
-    expected_max_size_lfs_pointer = 1024 # 1 KiB (values >= than this cannot be pointers, and test files are >= 1 MiB)
+    expected_max_size_lfs_pointer = 1024 # 1 KiB (values >= than this cannot be pointers, and test files are 1 MiB)
 
     # purge nix git cache to make sure we start with a clean slate
     client.succeed("rm -rf ~/.cache/nix")
 
 
-    # Request lfs fetch without any .gitattributes file
+    with subtest("Request lfs fetch without any .gitattributes file"):
-    ############################################################################
-
       client.succeed(f"dd if=/dev/urandom of={repo.path}/regular bs=1M count=1 >&2")
       client.succeed(f"{repo.git} add : >&2")
       client.succeed(f"{repo.git} commit -m 'no .gitattributes' >&2")
@@ -32,15 +30,14 @@
         }}
       """
       fetched_no_gitattributes = client.succeed(f"""
-      nix eval --impure --raw --expr '({fetchGit_no_gitattributes_expr}).outPath'
+        nix eval --debug --impure --raw --expr '({fetchGit_no_gitattributes_expr}).outPath'
       """)
       client.succeed(f"cmp {repo.path}/regular {fetched_no_gitattributes}/regular >&2")
 
 
-    # Add a file that should be tracked by lfs, but isn't
+    with subtest("Add a file that should be tracked by lfs, but isn't"):
       # (git lfs cli only throws a warning "Encountered 1 file that should have
       # been a pointer, but wasn't")
-    ############################################################################
 
       client.succeed(f"dd if=/dev/urandom of={repo.path}/black_sheep bs=1M count=1 >&2")
       client.succeed(f"echo 'black_sheep filter=lfs -text' >>{repo.path}/.gitattributes")
@@ -60,8 +57,8 @@
 
         # check that the file is not a pointer, as expected
         file_size_git = client.succeed(f"stat -c %s {tempdir}/black_sheep").strip()
-      assert int(file_size_git) >= expected_max_size_lfs_pointer, \
+        assert int(file_size_git) == 1024 * 1024, \
-        f"non lfs file is {file_size_git}b (<{expected_max_size_lfs_pointer}b), probably a test implementation error"
+          f"non lfs file is {file_size_git}b (!= 1MiB), probably a test implementation error"
 
         lfs_files = client.succeed(f"git -C {tempdir} lfs ls-files").strip()
         assert lfs_files == "", "non lfs file is tracked by lfs, probably a test implementation error"
@@ -78,14 +75,14 @@
         }}
       """
       fetched_bad_lfs_without_lfs = client.succeed(f"""
-      nix eval --impure --raw --expr '({fetchGit_bad_lfs_without_lfs_expr}).outPath'
+        nix eval --debug --impure --raw --expr '({fetchGit_bad_lfs_without_lfs_expr}).outPath'
       """)
 
       # check that file was not somehow turned into a pointer
       file_size_bad_lfs_without_lfs = client.succeed(f"stat -c %s {fetched_bad_lfs_without_lfs}/black_sheep").strip()
 
-    assert int(file_size_bad_lfs_without_lfs) >= expected_max_size_lfs_pointer, \
+      assert int(file_size_bad_lfs_without_lfs) == 1024 * 1024, \
-      f"non lfs-enrolled file is {file_size_bad_lfs_without_lfs}b (<{expected_max_size_lfs_pointer}b), probably a test implementation error"
+        f"non lfs-enrolled file is {file_size_bad_lfs_without_lfs}b (!= 1MiB), probably a test implementation error"
       client.succeed(f"cmp {repo.path}/black_sheep {fetched_bad_lfs_without_lfs}/black_sheep >&2")
 
       # finally fetch with lfs=true, and check that the bad file does not break anything
@@ -98,15 +95,13 @@
         }}
       """
       fetchGit_bad_lfs_with_lfs = client.succeed(f"""
-      nix eval --impure --raw --expr '({fetchGit_bad_lfs_with_lfs_expr}).outPath'
+        nix eval --debug --impure --raw --expr '({fetchGit_bad_lfs_with_lfs_expr}).outPath'
       """)
 
       client.succeed(f"cmp {repo.path}/black_sheep {fetchGit_bad_lfs_with_lfs}/black_sheep >&2")
 
 
-    # Add an lfs-enrolled file to the repo
+    with subtest("Add an lfs-enrolled file to the repo"):
-    ############################################################################
-
       client.succeed(f"dd if=/dev/urandom of={repo.path}/beeg bs=1M count=1 >&2")
       client.succeed(f"{repo.git} lfs install >&2")
       client.succeed(f"{repo.git} lfs track --filename beeg >&2")
@@ -127,14 +122,14 @@
         }}
       """
       fetched_nolfs = client.succeed(f"""
-      nix eval --impure --raw --expr '({fetchGit_nolfs_expr}).outPath'
+        nix eval --debug --impure --raw --expr '({fetchGit_nolfs_expr}).outPath'
       """)
 
       # check that file was not smudged
       file_size_nolfs = client.succeed(f"stat -c %s {fetched_nolfs}/beeg").strip()
 
       assert int(file_size_nolfs) < expected_max_size_lfs_pointer, \
-      f"did not set lfs=true, yet lfs-enrolled file is {file_size_nolfs}b (>{expected_max_size_lfs_pointer}b), probably smudged when we should not have"
+        f"did not set lfs=true, yet lfs-enrolled file is {file_size_nolfs}b (>= 1KiB), probably smudged when we should not have"
 
       # now fetch with lfs=true and check that the file was smudged
       fetchGit_lfs_expr = f"""
@@ -146,7 +141,7 @@
         }}
       """
       fetched_lfs = client.succeed(f"""
-      nix eval --impure --raw --expr '({fetchGit_lfs_expr}).outPath'
+        nix eval --debug --impure --raw --expr '({fetchGit_lfs_expr}).outPath'
       """)
 
       assert fetched_lfs != fetched_nolfs, \
@@ -154,12 +149,11 @@
 
       # check that file was smudged
       file_size_lfs = client.succeed(f"stat -c %s {fetched_lfs}/beeg").strip()
-    assert int(file_size_lfs) >= expected_max_size_lfs_pointer, \
+      assert int(file_size_lfs) == 1024 * 1024, \
-      f"set lfs=true, yet lfs-enrolled file is {file_size_lfs}b (<{expected_max_size_lfs_pointer}), probably did not smudge when we should have"
+        f"set lfs=true, yet lfs-enrolled file is {file_size_lfs}b (!= 1MiB), probably did not smudge when we should have"
 
 
-    # Check that default is lfs=false
+    with subtest("Check that default is lfs=false"):
-    ############################################################################
       fetchGit_default_expr = f"""
         builtins.fetchGit {{
           url = "{repo.remote}";
@@ -168,17 +162,18 @@
         }}
       """
       fetched_default = client.succeed(f"""
-      nix eval --impure --raw --expr '({fetchGit_default_expr}).outPath'
+        nix eval --debug --impure --raw --expr '({fetchGit_default_expr}).outPath'
       """)
 
       # check that file was not smudged
       file_size_default = client.succeed(f"stat -c %s {fetched_default}/beeg").strip()
 
       assert int(file_size_default) < expected_max_size_lfs_pointer, \
-      f"did not set lfs, yet lfs-enrolled file is {file_size_default}b (>{expected_max_size_lfs_pointer}b), probably bad default value"
+        f"did not set lfs, yet lfs-enrolled file is {file_size_default}b (>= 1KiB), probably bad default value"
 
-    # Use as flake input
+    with subtest("Use as flake input"):
-    ############################################################################
+      # May seem reduntant, but this has minor differences compared to raw
+      # fetchGit which caused failures before
       with TemporaryDirectory() as tempdir:
         client.succeed(f"mkdir -p {tempdir}")
         client.succeed(f"""
@@ -193,7 +188,7 @@
           }}' >{tempdir}/flake.nix
         """)
         fetched_flake = client.succeed(f"""
-        nix eval --raw {tempdir}#.outPath
+          nix eval --debug --raw {tempdir}#.outPath
         """)
 
       assert fetched_lfs == fetched_flake, \