Add a utility function to rewrite path strings relative to a subdirectory

4 files changed, 102 insertions, 1 deletions

diff --git a/src/utils/cpp/TARGETS b/src/utils/cpp/TARGETS
index 8a7f8dff..fda8f473 100644
--- a/src/utils/cpp/TARGETS
+++ b/src/utils/cpp/TARGETS
@@ -48,6 +48,12 @@
   , "hdrs": ["path.hpp"]
   , "stage": ["src", "utils", "cpp"]
   }
+, "path_rebase":
+  { "type": ["@", "rules", "CC", "library"]
+  , "name": ["path_rebase"]
+  , "hdrs": ["path_rebase.hpp"]
+  , "stage": ["src", "utils", "cpp"]
+  }
 , "vector":
   { "type": ["@", "rules", "CC", "library"]
   , "name": ["vector"]
diff --git a/src/utils/cpp/path_rebase.hpp b/src/utils/cpp/path_rebase.hpp
new file mode 100644
index 00000000..25b99724
--- /dev/null
+++ b/src/utils/cpp/path_rebase.hpp
@@ -0,0 +1,39 @@
+// Copyright 2024 Huawei Cloud Computing Technology Co., Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef INCLUDED_SRC_UTILS_CPP_PATH_REBASE_HPP
+#define INCLUDED_SRC_UTILS_CPP_PATH_REBASE_HPP
+
+#include <filesystem>
+#include <string>
+#include <vector>
+
+[[nodiscard]] static inline auto RebasePathStringRelativeTo(
+    const std::string& base,
+    const std::string& path) -> std::string {
+    return std::filesystem::path(path).lexically_relative(base).string();
+}
+
+[[nodiscard]] static inline auto RebasePathStringsRelativeTo(
+    const std::string& base,
+    const std::vector<std::string>& paths) -> std::vector<std::string> {
+    std::vector<std::string> result{};
+    result.reserve(paths.size());
+    for (auto const& path : paths) {
+        result.emplace_back(RebasePathStringRelativeTo(base, path));
+    }
+    return result;
+}
+
+#endif
diff --git a/test/utils/cpp/TARGETS b/test/utils/cpp/TARGETS
index 5d7809c4..1678fdda 100644
--- a/test/utils/cpp/TARGETS
+++ b/test/utils/cpp/TARGETS
@@ -9,6 +9,17 @@
     ]
   , "stage": ["test", "utils", "cpp"]
   }
+, "path_rebase":
+  { "type": ["@", "rules", "CC/test", "test"]
+  , "name": ["path_rebase"]
+  , "srcs": ["path_rebase.test.cpp"]
+  , "private-deps":
+    [ ["@", "catch2", "", "catch2"]
+    , ["", "catch-main"]
+    , ["@", "src", "src/utils/cpp", "path_rebase"]
+    ]
+  , "stage": ["test", "utils", "cpp"]
+  }
 , "file_locking":
   { "type": ["@", "rules", "CC/test", "test"]
   , "name": ["file_locking"]
@@ -37,6 +48,6 @@
 , "TESTS":
   { "type": "install"
   , "tainted": ["test"]
-  , "deps": ["path", "file_locking", "prefix"]
+  , "deps": ["path", "path_rebase", "file_locking", "prefix"]
   }
 }
diff --git a/test/utils/cpp/path_rebase.test.cpp b/test/utils/cpp/path_rebase.test.cpp
new file mode 100644
index 00000000..79a13fb5
--- /dev/null
+++ b/test/utils/cpp/path_rebase.test.cpp
@@ -0,0 +1,45 @@
+// Copyright 2024 Huawei Cloud Computing Technology Co., Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "catch2/catch_test_macros.hpp"
+#include "src/utils/cpp/path_rebase.hpp"
+
+TEST_CASE("rebase", "[path_rebase]") {
+    CHECK(RebasePathStringRelativeTo("work", "work/foo/bar") == "foo/bar");
+    CHECK(RebasePathStringRelativeTo("work", "work/foo") == "foo");
+    CHECK(RebasePathStringRelativeTo("work", "work") == ".");
+    CHECK(RebasePathStringRelativeTo("work", "other/foo.txt") ==
+          "../other/foo.txt");
+    CHECK(RebasePathStringRelativeTo("work/foo", "foo.txt") == "../../foo.txt");
+    CHECK(RebasePathStringRelativeTo("work/foo", "work/foo/bar") == "bar");
+    CHECK(RebasePathStringRelativeTo("work/foo", "work/foo") == ".");
+    CHECK(RebasePathStringRelativeTo("work/foo", "work") == "..");
+}
+
+TEST_CASE("no change", "[path_rebase]") {
+    CHECK(RebasePathStringRelativeTo("", "work/foo/bar") == "work/foo/bar");
+    CHECK(RebasePathStringRelativeTo(".", "work/foo/bar") == "work/foo/bar");
+    CHECK(RebasePathStringRelativeTo("", ".") == ".");
+    CHECK(RebasePathStringRelativeTo("", "") == ".");
+}
+
+TEST_CASE("vector rebse", "[path_rebase]") {
+    std::vector<std::string> input{
+        "work/foo.txt", "work/bar/baz.txt", "other/out.txt"};
+    auto output = RebasePathStringsRelativeTo("work", input);
+    REQUIRE(output.size() == 3);
+    CHECK(output[0] == "foo.txt");
+    CHECK(output[1] == "bar/baz.txt");
+    CHECK(output[2] == "../other/out.txt");
+}