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Overview ¶
Package fileuri spells a filesystem path as a file: URI.
It lives in its own leaf package because the tests of four packages need the same spelling and none of them may import another's unexported helper: xdm's external-entity tests stand in for xslt.FileResolver, which xdm cannot import, and the xslt tests build stylesheet base URIs of their own. Each had written "file://" + path by hand, and every one of them was wrong on Windows in the same two ways — see Of.
The production resolvers keep their own unexported copies (xslt.fileURIOf, dtd.fileURIOf, the CLI's fileURI), which are already correct; this package exists so that a caller which does not have one of those in scope stops reaching for string concatenation.
Index ¶
Constants ¶
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Variables ¶
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Functions ¶
func Dir ¶
Dir is Of for a directory, which differs only in the trailing slash that makes a relative reference resolve inside it rather than beside it.
func FromSlashedAbs ¶
FromSlashedAbs spells an already-absolute, already-slash-separated path as a file: URI. It is separate from Of so that both platforms' spellings can be tested on either platform: filepath.Abs and filepath.ToSlash are precisely what make Of answer differently on Windows and Unix, which is why a bug in this spelling survives every darwin and Linux test run and fails only in Windows CI.
Two things about the Windows spelling are easy to get wrong, and the hand -written "file://" + path got both.
The leading slash: an absolute Windows path is C:\dir\s.xsl and has none of its own, so "file://" + "C:/dir/s.xsl" makes C: the *authority* rather than the drive. Parsed back, that yields host "C:" and a path with the drive letter gone, so every URI resolved against it names a file that is not there. RFC 8089 gives a local path an empty authority, which is the three-slash form, and Saxon agrees: file:///C:/dir/s.xsl.
The separator: a file: URI path is written with forward slashes, so a raw C:\dir\s.xsl leaves backslashes in the URI. url.Parse rejects that outright — a backslash after the host reads as a port — so the base URI is not merely wrong, it does not parse.
func Of ¶
Of renders a filesystem path as an absolute file: URI.
A value that is already a file: URI is returned unchanged, so a caller that passes one does not get file:///file:/...
func OnHost ¶
OnHost spells a filesystem path as a file: URI carrying the given authority.
It exists for the tests that assert a foreign host is REFUSED. Of cannot build one: a local file's authority is empty by RFC 8089, which is the whole of what Of spells. Those tests were writing "file://evil.example.com" + path by hand, and on Windows the path has no leading slash of its own, so the drive fused onto the host and the URI named the host "evil.example.comC:". The refusal still happened, but for a host the test never wrote -- so the assertion on the host name failed, and, worse, a test whose subject is the authority check was no longer exercising the authority the vector uses.
The same fusion has a nastier form when the host is empty. "file://" + a Windows path yields "file://C:/dir/s.xsl", whose authority is the DRIVE, and `file://C:\dir\s.xsl` does not parse at all -- url.Parse reads the backslash run after the host as a port. A resolver that rejects foreign hosts and non-file schemes by inspecting the parsed URL sees neither in that case, because there is nothing to inspect; any refusal that follows comes from a later check and proves something other than what the test claims.
func ToPath ¶
ToPath turns a file: URI back into a filesystem path, and leaves anything that is not one alone. It is the inverse of Of.
It exists for the same reason Of does: stripping the "file://" prefix textually leaves "/C:/dir/s.xsl" from the three-slash form, which is not a path any filesystem call accepts, and it leaves a percent-escape unescaped, so a directory with a space in its name becomes one with "%20" in it.
func ToSlash ¶
ToSlash is filepath.ToSlash with the backslash case done unconditionally rather than only where the OS separator is "\".
filepath.ToSlash is a no-op on darwin and Linux, so a call site that omits it there behaves identically whether it is present or absent: nothing any test on those platforms runs can tell the two apart, and that is exactly how the unconverted separator reached Windows CI. Converting always makes the conversion observable on every platform, and costs nothing on the ones where a backslash is a legal filename character: a path that reaches here is about to become a URI path, and url.URL would otherwise escape the backslash to "%5C" — leaving "C:%5Cdir%5Cs.xsl" as one path segment naming a file that does not exist, rather than a file inside a directory.
Types ¶
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Source Files