lib.filesystem.resolveDefaultNix: init (ecc039f3) · Commits · nix / nixpkgs

lib/filesystem.nix

+42 −0

Original line number	Diff line number	Diff line
		@@ -454,4 +454,46 @@ in
		)
		else
		processDir args;

		/**
		Append `/default.nix` if the passed path is a directory.

		# Type

		```
		resolveDefaultNix :: (Path \| String) -> (Path \| String)
		```

		# Inputs

		A single argument which can be a [path](https://nix.dev/manual/nix/stable/language/types#type-path) value or a string containing an absolute path.

		# Output

		If the input refers to a directory that exists, the output is that same path with `/default.nix` appended.
		Furthermore, if the input is a string that ends with `/`, `default.nix` is appended to it.
		Otherwise, the input is returned unchanged.

		# Examples
		:::{.example}
		## `lib.filesystem.resolveDefaultNix` usage example

		This expression checks whether `a` and `b` refer to the same locally available Nix file path.

		```nix
		resolveDefaultNix a == resolveDefaultNix b
		```

		For instance, if `a` is `/some/dir` and `b` is `/some/dir/default.nix`, and `/some/dir/` exists, the expression evaluates to `true`, despite `a` and `b` being different references to the same Nix file.
		*/
		resolveDefaultNix =
		v:
		if pathIsDirectory v then
		v + "/default.nix"
		else if lib.isString v && hasSuffix "/" v then
		# A path ending in `/` can only refer to a directory, so we take the hint, even if we can't verify the validity of the path's `/` assertion.
		# A `/` is already present, so we don't add another one.
		v + "default.nix"
		else
		v;
		}

lib/tests/misc.nix

+46 −0

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		@@ -4255,4 +4255,50 @@ runTests {
		};
		};
		};

		testFilesystemResolveDefaultNixFile1 = {
		expr = lib.filesystem.resolveDefaultNix ./foo.nix;
		expected = ./foo.nix;
		};

		testFilesystemResolveDefaultNixFile2 = {
		expr = lib.filesystem.resolveDefaultNix ./default.nix;
		expected = ./default.nix;
		};

		testFilesystemResolveDefaultNixDir1 = {
		expr = lib.filesystem.resolveDefaultNix ./.;
		expected = ./default.nix;
		};

		testFilesystemResolveDefaultNixFile1_toString = {
		expr = lib.filesystem.resolveDefaultNix (toString ./foo.nix);
		expected = toString ./foo.nix;
		};

		testFilesystemResolveDefaultNixFile2_toString = {
		expr = lib.filesystem.resolveDefaultNix (toString ./default.nix);
		expected = toString ./default.nix;
		};

		testFilesystemResolveDefaultNixDir1_toString = {
		expr = lib.filesystem.resolveDefaultNix (toString ./.);
		expected = toString ./default.nix;
		};

		testFilesystemResolveDefaultNixDir1_toString2 = {
		expr = lib.filesystem.resolveDefaultNix (toString ./.);
		expected = toString ./. + "/default.nix";
		};

		testFilesystemResolveDefaultNixNonExistent = {
		expr = lib.filesystem.resolveDefaultNix "/non-existent/this/does/not/exist/for/real/please-dont-mess-with-your-local-fs";
		expected = "/non-existent/this/does/not/exist/for/real/please-dont-mess-with-your-local-fs";
		};

		testFilesystemResolveDefaultNixNonExistentDir = {
		expr = lib.filesystem.resolveDefaultNix "/non-existent/this/does/not/exist/for/real/please-dont-mess-with-your-local-fs/";
		expected = "/non-existent/this/does/not/exist/for/real/please-dont-mess-with-your-local-fs/default.nix";
		};

		}

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