tvl-depot/nix/utils/tests/default.nix
sterni 66fa718ceb feat(nix/utils): expose pathType of symlink target
In order to make readTree import symlinked directories I've been looking
into how to detect if a symlink points to a directory (since this would
allow us to use symlinks for //nix/sparseTree). I've found a hack for
this:

    symlinkPointsToDir = path: isSymlink path &&
      builtins.pathExists (toString path + "/.")

Unfortunately it doesn't seem to be possible to distinguish whether the
symlink target does not exist or is a regular file.

Since it's possible, I thought might as well add this to
`pathType`. To make returning the extra information workable, I've
elected to use the attribute set layout used by `//nix/tag`. This
doesn't require us to depend anything (as opposed to yants), but gives
us pattern matching (via `nix.tag.match`) and also quite idiomatic
checking of pathTypes:

    pathType ./foo ? file
    (pathType ./foo).symlink or null == "symlink-directory"

Nonexistent paths are encoded like this:

    pathType ./foo ? missing

Of course we can't use this in readTree (since it must be zero
dependency), but we can easily inline this hack at some point.

Change-Id: I15b64a1ea69953c95dc3239ef5860623652b3089
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3535
Tested-by: BuildkiteCI
Reviewed-by: Profpatsch <mail@profpatsch.de>
Reviewed-by: tazjin <mail@tazj.in>
2021-10-02 18:24:49 +00:00

104 lines
3.8 KiB
Nix

{ depot, lib, ... }:
let
inherit (depot.nix.runTestsuite)
runTestsuite
it
assertEq
assertThrows
assertDoesNotThrow
;
inherit (depot.nix.utils)
isDirectory
realPathIsDirectory
isRegularFile
isSymlink
pathType
storePathName
;
assertUtilsPred = msg: act: exp: [
(assertDoesNotThrow "${msg} does not throw" act)
(assertEq msg (builtins.tryEval act).value exp)
];
pathPredicates = it "judges paths correctly" (lib.flatten [
# isDirectory
(assertUtilsPred "directory isDirectory"
(isDirectory ./directory) true)
(assertUtilsPred "symlink not isDirectory"
(isDirectory ./symlink-directory) false)
(assertUtilsPred "file not isDirectory"
(isDirectory ./directory/file) false)
# realPathIsDirectory
(assertUtilsPred "directory realPathIsDirectory"
(realPathIsDirectory ./directory) true)
(assertUtilsPred "symlink to directory realPathIsDirectory"
(realPathIsDirectory ./symlink-directory) true)
(assertUtilsPred "realPathIsDirectory resolves chained symlinks"
(realPathIsDirectory ./symlink-symlink-directory) true)
# isRegularFile
(assertUtilsPred "file isRegularFile"
(isRegularFile ./directory/file) true)
(assertUtilsPred "symlink not isRegularFile"
(isRegularFile ./symlink-file) false)
(assertUtilsPred "directory not isRegularFile"
(isRegularFile ./directory) false)
# isSymlink
(assertUtilsPred "symlink to file isSymlink"
(isSymlink ./symlink-file) true)
(assertUtilsPred "symlink to directory isSymlink"
(isSymlink ./symlink-directory) true)
(assertUtilsPred "symlink to symlink isSymlink"
(isSymlink ./symlink-symlink-file) true)
(assertUtilsPred "symlink to missing file isSymlink"
(isSymlink ./missing) true)
(assertUtilsPred "directory not isSymlink"
(isSymlink ./directory) false)
(assertUtilsPred "file not isSymlink"
(isSymlink ./directory/file) false)
# missing files throw
(assertThrows "isDirectory throws on missing file"
(isDirectory ./does-not-exist))
(assertThrows "realPathIsDirectory throws on missing file"
(realPathIsDirectory ./does-not-exist))
(assertThrows "isRegularFile throws on missing file"
(isRegularFile ./does-not-exist))
(assertThrows "isSymlink throws on missing file"
(isSymlink ./does-not-exist))
]);
symlinkPathTypeTests = it "correctly judges symlinks" [
(assertEq "symlinks to directories are detected correcty"
((pathType ./symlink-directory).symlink or null) "directory")
(assertEq "symlinks to symlinks to directories are detected correctly"
((pathType ./symlink-symlink-directory).symlink or null) "directory")
(assertEq "symlinks to files are detected-ish"
((pathType ./symlink-file).symlink or null) "regular-or-missing")
(assertEq "symlinks to symlinks to files are detected-ish"
((pathType ./symlink-symlink-file).symlink or null) "regular-or-missing")
(assertEq "symlinks to nowhere are not distinguished from files"
((pathType ./missing).symlink or null) "regular-or-missing")
];
cheddarStorePath =
builtins.unsafeDiscardStringContext depot.tools.cheddar.outPath;
storePathNameTests = it "correctly gets the basename of a store path" [
(assertEq "base name of a derivation"
(storePathName depot.tools.cheddar) depot.tools.cheddar.name)
(assertEq "base name of a store path string"
(storePathName cheddarStorePath) depot.tools.cheddar.name)
(assertEq "base name of a path within a store path"
(storePathName "${cheddarStorePath}/bin/cheddar") "cheddar")
(assertEq "base name of a path"
(storePathName ../default.nix) "default.nix")
];
in
runTestsuite "nix.utils" [
pathPredicates
symlinkPathTypeTests
storePathNameTests
]