nix-super/tests/unit/libutil/canon-path.cc
John Ericson d17e1d9737 Purify CanonPath
The core `CanonPath` constructors were using `absPath`, but `absPath` in
some situations does IO which is not appropriate. It turns out that
these constructors avoided those situations, and thus were pure, but it
was far from obvious this was the case.

To remedy the situation, abstract the core algorithm from `canonPath` to
use separately in `CanonPath` without any IO. No we know by-construction
that those constructors are pure.

That leaves `CanonPath::fromCWD` as the only operation which uses IO /
is impure. Add docs on it, and `CanonPath` as a whole, explaining the
situation.

This is also necessary to support Windows paths on windows without
messing up `CanonPath`. But, I think it is good even without that.

Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
2024-02-16 09:47:25 -05:00

180 lines
5.9 KiB
C++

#include "canon-path.hh"
#include <gtest/gtest.h>
namespace nix {
TEST(CanonPath, basic) {
{
CanonPath p("/");
ASSERT_EQ(p.abs(), "/");
ASSERT_EQ(p.rel(), "");
ASSERT_EQ(p.baseName(), std::nullopt);
ASSERT_EQ(p.dirOf(), std::nullopt);
ASSERT_FALSE(p.parent());
}
{
CanonPath p("/foo//");
ASSERT_EQ(p.abs(), "/foo");
ASSERT_EQ(p.rel(), "foo");
ASSERT_EQ(*p.baseName(), "foo");
ASSERT_EQ(*p.dirOf(), ""); // FIXME: do we want this?
ASSERT_EQ(p.parent()->abs(), "/");
}
{
CanonPath p("foo/bar");
ASSERT_EQ(p.abs(), "/foo/bar");
ASSERT_EQ(p.rel(), "foo/bar");
ASSERT_EQ(*p.baseName(), "bar");
ASSERT_EQ(*p.dirOf(), "/foo");
ASSERT_EQ(p.parent()->abs(), "/foo");
}
{
CanonPath p("foo//bar/");
ASSERT_EQ(p.abs(), "/foo/bar");
ASSERT_EQ(p.rel(), "foo/bar");
ASSERT_EQ(*p.baseName(), "bar");
ASSERT_EQ(*p.dirOf(), "/foo");
}
}
TEST(CanonPath, from_existing) {
CanonPath p0("foo//bar/");
{
CanonPath p("/baz//quux/", p0);
ASSERT_EQ(p.abs(), "/baz/quux");
ASSERT_EQ(p.rel(), "baz/quux");
ASSERT_EQ(*p.baseName(), "quux");
ASSERT_EQ(*p.dirOf(), "/baz");
}
{
CanonPath p("baz//quux/", p0);
ASSERT_EQ(p.abs(), "/foo/bar/baz/quux");
ASSERT_EQ(p.rel(), "foo/bar/baz/quux");
ASSERT_EQ(*p.baseName(), "quux");
ASSERT_EQ(*p.dirOf(), "/foo/bar/baz");
}
}
TEST(CanonPath, pop) {
CanonPath p("foo/bar/x");
ASSERT_EQ(p.abs(), "/foo/bar/x");
p.pop();
ASSERT_EQ(p.abs(), "/foo/bar");
p.pop();
ASSERT_EQ(p.abs(), "/foo");
p.pop();
ASSERT_EQ(p.abs(), "/");
}
TEST(CanonPath, removePrefix) {
CanonPath p1("foo/bar");
CanonPath p2("foo/bar/a/b/c");
ASSERT_EQ(p2.removePrefix(p1).abs(), "/a/b/c");
ASSERT_EQ(p1.removePrefix(p1).abs(), "/");
ASSERT_EQ(p1.removePrefix(CanonPath("/")).abs(), "/foo/bar");
}
TEST(CanonPath, iter) {
{
CanonPath p("a//foo/bar//");
std::vector<std::string_view> ss;
for (auto & c : p) ss.push_back(c);
ASSERT_EQ(ss, std::vector<std::string_view>({"a", "foo", "bar"}));
}
{
CanonPath p("/");
std::vector<std::string_view> ss;
for (auto & c : p) ss.push_back(c);
ASSERT_EQ(ss, std::vector<std::string_view>());
}
}
TEST(CanonPath, concat) {
{
CanonPath p1("a//foo/bar//");
CanonPath p2("xyzzy/bla");
ASSERT_EQ((p1 / p2).abs(), "/a/foo/bar/xyzzy/bla");
}
{
CanonPath p1("/");
CanonPath p2("/a/b");
ASSERT_EQ((p1 / p2).abs(), "/a/b");
}
{
CanonPath p1("/a/b");
CanonPath p2("/");
ASSERT_EQ((p1 / p2).abs(), "/a/b");
}
{
CanonPath p("/foo/bar");
ASSERT_EQ((p / "x").abs(), "/foo/bar/x");
}
{
CanonPath p("/");
ASSERT_EQ((p / "foo" / "bar").abs(), "/foo/bar");
}
}
TEST(CanonPath, within) {
ASSERT_TRUE(CanonPath("foo").isWithin(CanonPath("foo")));
ASSERT_FALSE(CanonPath("foo").isWithin(CanonPath("bar")));
ASSERT_FALSE(CanonPath("foo").isWithin(CanonPath("fo")));
ASSERT_TRUE(CanonPath("foo/bar").isWithin(CanonPath("foo")));
ASSERT_FALSE(CanonPath("foo").isWithin(CanonPath("foo/bar")));
ASSERT_TRUE(CanonPath("/foo/bar/default.nix").isWithin(CanonPath("/")));
ASSERT_TRUE(CanonPath("/").isWithin(CanonPath("/")));
}
TEST(CanonPath, sort) {
ASSERT_FALSE(CanonPath("foo") < CanonPath("foo"));
ASSERT_TRUE (CanonPath("foo") < CanonPath("foo/bar"));
ASSERT_TRUE (CanonPath("foo/bar") < CanonPath("foo!"));
ASSERT_FALSE(CanonPath("foo!") < CanonPath("foo"));
ASSERT_TRUE (CanonPath("foo") < CanonPath("foo!"));
}
TEST(CanonPath, allowed) {
std::set<CanonPath> allowed {
CanonPath("foo/bar"),
CanonPath("foo!"),
CanonPath("xyzzy"),
CanonPath("a/b/c"),
};
ASSERT_TRUE (CanonPath("foo/bar").isAllowed(allowed));
ASSERT_TRUE (CanonPath("foo/bar/bla").isAllowed(allowed));
ASSERT_TRUE (CanonPath("foo").isAllowed(allowed));
ASSERT_FALSE(CanonPath("bar").isAllowed(allowed));
ASSERT_FALSE(CanonPath("bar/a").isAllowed(allowed));
ASSERT_TRUE (CanonPath("a").isAllowed(allowed));
ASSERT_TRUE (CanonPath("a/b").isAllowed(allowed));
ASSERT_TRUE (CanonPath("a/b/c").isAllowed(allowed));
ASSERT_TRUE (CanonPath("a/b/c/d").isAllowed(allowed));
ASSERT_TRUE (CanonPath("a/b/c/d/e").isAllowed(allowed));
ASSERT_FALSE(CanonPath("a/b/a").isAllowed(allowed));
ASSERT_FALSE(CanonPath("a/b/d").isAllowed(allowed));
ASSERT_FALSE(CanonPath("aaa").isAllowed(allowed));
ASSERT_FALSE(CanonPath("zzz").isAllowed(allowed));
ASSERT_TRUE (CanonPath("/").isAllowed(allowed));
}
TEST(CanonPath, makeRelative) {
CanonPath d("/foo/bar");
ASSERT_EQ(d.makeRelative(CanonPath("/foo/bar")), ".");
ASSERT_EQ(d.makeRelative(CanonPath("/foo")), "..");
ASSERT_EQ(d.makeRelative(CanonPath("/")), "../..");
ASSERT_EQ(d.makeRelative(CanonPath("/foo/bar/xyzzy")), "xyzzy");
ASSERT_EQ(d.makeRelative(CanonPath("/foo/bar/xyzzy/bla")), "xyzzy/bla");
ASSERT_EQ(d.makeRelative(CanonPath("/foo/xyzzy/bla")), "../xyzzy/bla");
ASSERT_EQ(d.makeRelative(CanonPath("/xyzzy/bla")), "../../xyzzy/bla");
}
}