implement parsing human-readable names from URLs

Based off of commit 257b768436a0e8ab7887f9b790c5b92a7fe51ef5

Upstream-PR: https://github.com/NixOS/nix/pull/8678
Co-authored-by: Felix Uhl <felix.uhl@outlook.com>
Change-Id: Idcb7f6191ca3310ef9dc854197f7798260c3f71d
This commit is contained in:
Qyriad 2024-04-30 18:11:14 -06:00
parent e2ab89a74b
commit 1425aa0b7c
7 changed files with 157 additions and 1 deletions

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@ -31,6 +31,7 @@ libutil_sources = files(
'tarfile.cc',
'thread-pool.cc',
'url.cc',
'url-name.cc',
'util.cc',
'xml-writer.cc',
)
@ -92,6 +93,7 @@ libutil_headers = files(
'topo-sort.hh',
'types.hh',
'url-parts.hh',
'url-name.hh',
'url.hh',
'util.hh',
'variant-wrapper.hh',

59
src/libutil/url-name.cc Normal file
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@ -0,0 +1,59 @@
#include <iostream>
#include <regex>
#include "url-name.hh"
namespace nix {
static std::string const attributeNamePattern("[a-z0-9_-]+");
static std::regex const lastAttributeRegex("(?:" + attributeNamePattern + "\\.)*(?!default)(" + attributeNamePattern +")(\\^.*)?");
static std::string const pathSegmentPattern("[a-zA-Z0-9_-]+");
static std::regex const lastPathSegmentRegex(".*/(" + pathSegmentPattern +")");
static std::regex const secondPathSegmentRegex("(?:" + pathSegmentPattern + ")/(" + pathSegmentPattern +")(?:/.*)?");
static std::regex const gitProviderRegex("github|gitlab|sourcehut");
static std::regex const gitSchemeRegex("git($|\\+.*)");
static std::regex const defaultOutputRegex(".*\\.default($|\\^.*)");
std::optional<std::string> getNameFromURL(ParsedURL const & url)
{
std::smatch match;
/* If there is a dir= argument, use its value */
if (url.query.count("dir") > 0) {
return url.query.at("dir");
}
/* If the fragment isn't a "default" and contains two attribute elements, use the last one */
if (std::regex_match(url.fragment, match, lastAttributeRegex)) {
return match.str(1);
}
/* If this is a github/gitlab/sourcehut flake, use the repo name */
if (
std::regex_match(url.scheme, gitProviderRegex)
&& std::regex_match(url.path, match, secondPathSegmentRegex)
) {
return match.str(1);
}
/* If it is a regular git flake, use the directory name */
if (
std::regex_match(url.scheme, gitSchemeRegex)
&& std::regex_match(url.path, match, lastPathSegmentRegex)
) {
return match.str(1);
}
/* If everything failed but there is a non-default fragment, use it in full */
if (!url.fragment.empty() && !std::regex_match(url.fragment, defaultOutputRegex))
return url.fragment;
/* If there is no fragment, take the last element of the path */
if (std::regex_match(url.path, match, lastPathSegmentRegex))
return match.str(1);
/* If even that didn't work, the URL does not contain enough info to determine a useful name */
return {};
}
}

26
src/libutil/url-name.hh Normal file
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@ -0,0 +1,26 @@
#pragma once
///@file url-name.hh, for some hueristic-ish URL parsing.
#include <string>
#include <optional>
#include "url.hh"
#include "url-parts.hh"
#include "util.hh"
#include "split.hh"
namespace nix {
/**
* Try to extract a reasonably unique and meaningful, human-readable
* name of a flake output from a parsed URL.
* When nullopt is returned, the callsite should use information available
* to it outside of the URL to determine a useful name.
* This is a heuristic approach intended for user interfaces.
* @return nullopt if the extracted name is not useful to identify a
* flake output, for example because it is empty or "default".
* Otherwise returns the extracted name.
*/
std::optional<std::string> getNameFromURL(ParsedURL const & url);
}

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@ -19,6 +19,7 @@ const static std::string userRegex = "(?:(?:" + unreservedRegex + "|" + pctEncod
const static std::string authorityRegex = "(?:" + userRegex + "@)?" + hostRegex + "(?::[0-9]+)?";
const static std::string pcharRegex = "(?:" + unreservedRegex + "|" + pctEncoded + "|" + subdelimsRegex + "|[:@])";
const static std::string queryRegex = "(?:" + pcharRegex + "|[/? \"])*";
const static std::string fragmentRegex = "(?:" + pcharRegex + "|[/? \"^])*";
const static std::string segmentRegex = "(?:" + pcharRegex + "*)";
const static std::string absPathRegex = "(?:(?:/" + segmentRegex + ")*/?)";
const static std::string pathRegex = "(?:" + segmentRegex + "(?:/" + segmentRegex + ")*/?)";

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@ -16,7 +16,7 @@ ParsedURL parseURL(const std::string & url)
"((" + schemeRegex + "):"
+ "(?:(?://(" + authorityRegex + ")(" + absPathRegex + "))|(/?" + pathRegex + ")))"
+ "(?:\\?(" + queryRegex + "))?"
+ "(?:#(" + queryRegex + "))?",
+ "(?:#(" + fragmentRegex + "))?",
std::regex::ECMAScript);
std::smatch match;

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@ -0,0 +1,67 @@
#include "url-name.hh"
#include <gtest/gtest.h>
namespace nix {
/* ----------- tests for url-name.hh --------------------------------------------------*/
TEST(getNameFromURL, getsNameFromURL) {
ASSERT_EQ(getNameFromURL(parseURL("path:/home/user/project")), "project");
ASSERT_EQ(getNameFromURL(parseURL("path:~/repos/nixpkgs#packages.x86_64-linux.hello")), "hello");
ASSERT_EQ(getNameFromURL(parseURL("path:.#nonStandardAttr.mylaptop")), "nonStandardAttr.mylaptop");
ASSERT_EQ(getNameFromURL(parseURL("path:./repos/myflake#nonStandardAttr.mylaptop")), "nonStandardAttr.mylaptop");
ASSERT_EQ(getNameFromURL(parseURL("path:./nixpkgs#packages.x86_64-linux.complex^bin,man")), "complex");
ASSERT_EQ(getNameFromURL(parseURL("path:./myproj#packages.x86_64-linux.default^*")), "myproj");
ASSERT_EQ(getNameFromURL(parseURL("github:NixOS/nixpkgs#packages.x86_64-linux.hello")), "hello");
ASSERT_EQ(getNameFromURL(parseURL("github:NixOS/nixpkgs#hello")), "hello");
ASSERT_EQ(getNameFromURL(parseURL("github:NixOS/nix#packages.x86_64-linux.default")), "nix");
ASSERT_EQ(getNameFromURL(parseURL("github:NixOS/nix#")), "nix");
ASSERT_EQ(getNameFromURL(parseURL("github:NixOS/nix")), "nix");
ASSERT_EQ(getNameFromURL(parseURL("github:cachix/devenv/main#packages.x86_64-linux.default")), "devenv");
ASSERT_EQ(getNameFromURL(parseURL("github:edolstra/nix-warez?rev=1234&dir=blender&ref=master")), "blender");
ASSERT_EQ(getNameFromURL(parseURL("gitlab:NixOS/nixpkgs#packages.x86_64-linux.hello")), "hello");
ASSERT_EQ(getNameFromURL(parseURL("gitlab:NixOS/nixpkgs#hello")), "hello");
ASSERT_EQ(getNameFromURL(parseURL("gitlab:NixOS/nix#packages.x86_64-linux.default")), "nix");
ASSERT_EQ(getNameFromURL(parseURL("gitlab:NixOS/nix#")), "nix");
ASSERT_EQ(getNameFromURL(parseURL("gitlab:NixOS/nix")), "nix");
ASSERT_EQ(getNameFromURL(parseURL("gitlab:cachix/devenv/main#packages.x86_64-linux.default")), "devenv");
ASSERT_EQ(getNameFromURL(parseURL("sourcehut:NixOS/nixpkgs#packages.x86_64-linux.hello")), "hello");
ASSERT_EQ(getNameFromURL(parseURL("sourcehut:NixOS/nixpkgs#hello")), "hello");
ASSERT_EQ(getNameFromURL(parseURL("sourcehut:NixOS/nix#packages.x86_64-linux.default")), "nix");
ASSERT_EQ(getNameFromURL(parseURL("sourcehut:NixOS/nix#")), "nix");
ASSERT_EQ(getNameFromURL(parseURL("sourcehut:NixOS/nix")), "nix");
ASSERT_EQ(getNameFromURL(parseURL("sourcehut:cachix/devenv/main#packages.x86_64-linux.default")), "devenv");
ASSERT_EQ(getNameFromURL(parseURL("git://github.com/edolstra/dwarffs")), "dwarffs");
ASSERT_EQ(getNameFromURL(parseURL("git://github.com/edolstra/nix-warez?dir=blender")), "blender");
ASSERT_EQ(getNameFromURL(parseURL("git+file:///home/user/project")), "project");
ASSERT_EQ(getNameFromURL(parseURL("git+file:///home/user/project?ref=fa1e2d23a22")), "project");
ASSERT_EQ(getNameFromURL(parseURL("git+ssh://git@github.com/someuser/my-repo#")), "my-repo");
ASSERT_EQ(getNameFromURL(parseURL("git+git://github.com/someuser/my-repo?rev=v1.2.3")), "my-repo");
ASSERT_EQ(getNameFromURL(parseURL("git+ssh:///home/user/project?dir=subproject&rev=v2.4")), "subproject");
ASSERT_EQ(getNameFromURL(parseURL("git+http://not-even-real#packages.x86_64-linux.hello")), "hello");
ASSERT_EQ(getNameFromURL(parseURL("git+https://not-even-real#packages.aarch64-darwin.hello")), "hello");
ASSERT_EQ(getNameFromURL(parseURL("tarball+http://github.com/NixOS/nix/archive/refs/tags/2.18.1#packages.x86_64-linux.jq")), "jq");
ASSERT_EQ(getNameFromURL(parseURL("tarball+https://github.com/NixOS/nix/archive/refs/tags/2.18.1#packages.x86_64-linux.hg")), "hg");
ASSERT_EQ(getNameFromURL(parseURL("tarball+file:///home/user/Downloads/nixpkgs-2.18.1#packages.aarch64-darwin.ripgrep")), "ripgrep");
ASSERT_EQ(getNameFromURL(parseURL("https://github.com/NixOS/nix/archive/refs/tags/2.18.1.tar.gz#packages.x86_64-linux.pv")), "pv");
ASSERT_EQ(getNameFromURL(parseURL("http://github.com/NixOS/nix/archive/refs/tags/2.18.1.tar.gz#packages.x86_64-linux.pv")), "pv");
ASSERT_EQ(getNameFromURL(parseURL("file:///home/user/project?ref=fa1e2d23a22")), "project");
ASSERT_EQ(getNameFromURL(parseURL("file+file:///home/user/project?ref=fa1e2d23a22")), "project");
ASSERT_EQ(getNameFromURL(parseURL("file+http://not-even-real#packages.x86_64-linux.hello")), "hello");
ASSERT_EQ(getNameFromURL(parseURL("file+http://gitfantasy.com/org/user/notaflake")), "notaflake");
ASSERT_EQ(getNameFromURL(parseURL("file+https://not-even-real#packages.aarch64-darwin.hello")), "hello");
ASSERT_EQ(getNameFromURL(parseURL("https://www.github.com/")), std::nullopt);
ASSERT_EQ(getNameFromURL(parseURL("path:.")), std::nullopt);
ASSERT_EQ(getNameFromURL(parseURL("file:.#")), std::nullopt);
ASSERT_EQ(getNameFromURL(parseURL("path:.#packages.x86_64-linux.default")), std::nullopt);
ASSERT_EQ(getNameFromURL(parseURL("path:.#packages.x86_64-linux.default^*")), std::nullopt);
}
}

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@ -52,6 +52,7 @@ libutil_tests_sources = files(
'libutil/suggestions.cc',
'libutil/tests.cc',
'libutil/url.cc',
'libutil/url-name.cc',
'libutil/xml-writer.cc',
)