lib.fileset.maybeMissing: init

This commit is contained in:
Silvan Mosberger 2023-11-07 01:04:13 +01:00
parent 5d08323dda
commit 1cc2c2f13d
4 changed files with 69 additions and 7 deletions

View file

@ -252,8 +252,3 @@ The `fileFilter` function takes a path, and not a file set, as its second argume
- (+) That can change depending on which files are included, so if it's used for `fileFilter`
it would change the `subpath`/`components` value depending on which files are included.
- (+) If necessary, this restriction can be relaxed later, the opposite wouldn't be possible
## To update in the future
Here's a list of places in the library that need to be updated in the future:
- If/Once a function exists that can optionally include a path depending on whether it exists, the error message for the path not existing in `_coerce` should mention the new function

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@ -11,6 +11,10 @@
Basics:
- [Implicit coercion from paths to file sets](#sec-fileset-path-coercion)
- [`lib.fileset.maybeMissing`](#function-library-lib.fileset.maybeMissing):
Create a file set from a path that may be missing.
- [`lib.fileset.trace`](#function-library-lib.fileset.trace)/[`lib.fileset.traceVal`](#function-library-lib.fileset.trace):
Pretty-print file sets for debugging.
@ -105,6 +109,7 @@ let
_difference
_mirrorStorePath
_fetchGitSubmodulesMinver
_emptyWithoutBase
;
inherit (builtins)
@ -148,6 +153,32 @@ let
in {
/*
Create a file set from a path that may or may not exist:
- If the path does exist, the path is [coerced to a file set](#sec-fileset-path-coercion).
- If the path does not exist, a file set containing no files is returned.
Type:
maybeMissing :: Path -> FileSet
Example:
# All files in the current directory, but excluding main.o if it exists
difference ./. (maybeMissing ./main.o)
*/
maybeMissing =
path:
if ! isPath path then
if isStringLike path then
throw ''
lib.fileset.maybeMissing: Argument ("${toString path}") is a string-like value, but it should be a path instead.''
else
throw ''
lib.fileset.maybeMissing: Argument is of type ${typeOf path}, but it should be a path instead.''
else if ! pathExists path then
_emptyWithoutBase
else
_singleton path;
/*
Incrementally evaluate and trace a file set in a pretty way.
This function is only intended for debugging purposes.

View file

@ -181,7 +181,8 @@ rec {
${context} is of type ${typeOf value}, but it should be a file set or a path instead.''
else if ! pathExists value then
throw ''
${context} (${toString value}) is a path that does not exist.''
${context} (${toString value}) is a path that does not exist.
To create a file set from a path that may not exist, use `lib.fileset.maybeMissing`.''
else
_singleton value;

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@ -413,7 +413,8 @@ expectFailure 'toSource { root = ./.; fileset = cleanSourceWith { src = ./.; };
\s*Note that this only works for sources created from paths.'
# Path coercion errors for non-existent paths
expectFailure 'toSource { root = ./.; fileset = ./a; }' 'lib.fileset.toSource: `fileset` \('"$work"'/a\) is a path that does not exist.'
expectFailure 'toSource { root = ./.; fileset = ./a; }' 'lib.fileset.toSource: `fileset` \('"$work"'/a\) is a path that does not exist.
\s*To create a file set from a path that may not exist, use `lib.fileset.maybeMissing`.'
# File sets cannot be evaluated directly
expectFailure 'union ./. ./.' 'lib.fileset: Directly evaluating a file set is not supported.
@ -1450,6 +1451,40 @@ checkGitTracked
rm -rf -- *
## lib.fileset.maybeMissing
# Argument must be a path
expectFailure 'maybeMissing "someString"' 'lib.fileset.maybeMissing: Argument \("someString"\) is a string-like value, but it should be a path instead.'
expectFailure 'maybeMissing null' 'lib.fileset.maybeMissing: Argument is of type null, but it should be a path instead.'
tree=(
)
checkFileset 'maybeMissing ./a'
checkFileset 'maybeMissing ./b'
checkFileset 'maybeMissing ./b/c'
# Works on single files
tree=(
[a]=1
[b/c]=0
[b/d]=0
)
checkFileset 'maybeMissing ./a'
tree=(
[a]=0
[b/c]=1
[b/d]=0
)
checkFileset 'maybeMissing ./b/c'
# Works on directories
tree=(
[a]=0
[b/c]=1
[b/d]=1
)
checkFileset 'maybeMissing ./b'
# TODO: Once we have combinators and a property testing library, derive property tests from https://en.wikipedia.org/wiki/Algebra_of_sets
echo >&2 tests ok