lib.path: Minor improvements

- Use isValid when possible instead of subpathInvalidReason: https://github.com/NixOS/nixpkgs/pull/209099#discussion_r1068714681
- Add documentation to function arguments
- Use newlines for error messages: https://github.com/NixOS/nixpkgs/pull/208887#discussion_r1069737602
- Add short comments for the unit test groups: https://github.com/NixOS/nixpkgs/pull/208887#discussion_r1072913051
- Slight formatting improvement for laws: https://github.com/NixOS/nixpkgs/pull/209099#discussion_r1068707955
This commit is contained in:
Silvan Mosberger 2023-01-18 18:06:21 +01:00
parent 0667ef5dd5
commit 5c4f616198
2 changed files with 20 additions and 7 deletions

View file

@ -25,6 +25,10 @@ let
assertMsg
;
inherit (lib.path.subpath)
isValid
;
# Return the reason why a subpath is invalid, or `null` if it's valid
subpathInvalidReason = value:
if ! isString value then
@ -133,7 +137,9 @@ in /* No rec! Add dependencies on this file at the top. */ {
subpath.isValid "./foo//bar/"
=> true
*/
subpath.isValid = value:
subpath.isValid =
# The value to check
value:
subpathInvalidReason value == null;
@ -150,11 +156,11 @@ in /* No rec! Add dependencies on this file at the top. */ {
Laws:
- (Idempotency) Normalising multiple times gives the same result:
- Idempotency - normalising multiple times gives the same result:
subpath.normalise (subpath.normalise p) == subpath.normalise p
- (Uniqueness) There's only a single normalisation for the paths that lead to the same file system node:
- Uniqueness - there's only a single normalisation for the paths that lead to the same file system node:
subpath.normalise p != subpath.normalise q -> $(realpath ${p}) != $(realpath ${q})
@ -210,9 +216,12 @@ in /* No rec! Add dependencies on this file at the top. */ {
subpath.normalise "/foo"
=> <error>
*/
subpath.normalise = path:
assert assertMsg (subpathInvalidReason path == null)
"lib.path.subpath.normalise: Argument is not a valid subpath string: ${subpathInvalidReason path}";
joinRelPath (splitRelPath path);
subpath.normalise =
# The subpath string to normalise
subpath:
assert assertMsg (isValid subpath) ''
lib.path.subpath.normalise: Argument is not a valid subpath string:
${subpathInvalidReason subpath}'';
joinRelPath (splitRelPath subpath);
}

View file

@ -6,6 +6,7 @@ let
inherit (lib.path) subpath;
cases = lib.runTests {
# Test examples from the lib.path.subpath.isValid documentation
testSubpathIsValidExample1 = {
expr = subpath.isValid null;
expected = false;
@ -30,6 +31,7 @@ let
expr = subpath.isValid "./foo//bar/";
expected = true;
};
# Some extra tests
testSubpathIsValidTwoDotsEnd = {
expr = subpath.isValid "foo/..";
expected = false;
@ -71,6 +73,7 @@ let
expected = true;
};
# Test examples from the lib.path.subpath.normalise documentation
testSubpathNormaliseExample1 = {
expr = subpath.normalise "foo//bar";
expected = "./foo/bar";
@ -107,6 +110,7 @@ let
expr = (builtins.tryEval (subpath.normalise "/foo")).success;
expected = false;
};
# Some extra tests
testSubpathNormaliseIsValidDots = {
expr = subpath.normalise "./foo/.bar/.../baz...qux";
expected = "./foo/.bar/.../baz...qux";