From: Joel Rosdahl <joel@rosdahl.net>
Date: Tue, 11 Nov 2025 19:09:42 +0000 (+0100)
Subject: enhance: Add util::SimpleJsonParser
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=74e48c17ed4c23aac378c6f598d38d62be66001d;p=thirdparty%2Fccache.git

enhance: Add util::SimpleJsonParser
---

diff --git a/src/ccache/util/CMakeLists.txt b/src/ccache/util/CMakeLists.txt
index 7fe6c1fb..494457be 100644
--- a/src/ccache/util/CMakeLists.txt
+++ b/src/ccache/util/CMakeLists.txt
@@ -13,6 +13,7 @@ set(
   file.cpp
   filelock.cpp
   filesystem.cpp
+  json.cpp
   lockfile.cpp
   logging.cpp
   longlivedlockfilemanager.cpp
diff --git a/src/ccache/util/json.cpp b/src/ccache/util/json.cpp
new file mode 100644
index 00000000..676fad5d
--- /dev/null
+++ b/src/ccache/util/json.cpp
@@ -0,0 +1,364 @@
+// Copyright (C) 2025 Joel Rosdahl and other contributors
+//
+// See doc/authors.adoc for a complete list of contributors.
+//
+// This program is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3 of the License, or (at your option)
+// any later version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+// more details.
+//
+// You should have received a copy of the GNU General Public License along with
+// this program; if not, write to the Free Software Foundation, Inc., 51
+// Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+#include "json.hpp"
+
+#include <ccache/util/format.hpp>
+#include <ccache/util/string.hpp>
+
+namespace {
+
+struct ParseState
+{
+  std::string_view doc;
+  size_t pos;
+};
+
+void
+skip_whitespace(ParseState& state)
+{
+  while (state.pos < state.doc.size() && util::is_space(state.doc[state.pos])) {
+    ++state.pos;
+  }
+}
+
+tl::expected<std::string, std::string>
+parse_string(ParseState& state)
+{
+  if (state.pos >= state.doc.size() || state.doc[state.pos] != '"') {
+    return tl::unexpected("Expected string");
+  }
+  ++state.pos; // Skip opening '"'
+
+  std::string result;
+  while (state.pos < state.doc.size()) {
+    char ch = state.doc[state.pos];
+
+    if (ch == '"') {
+      ++state.pos; // Skip closing '"'
+      return result;
+    }
+
+    if (ch == '\\') {
+      ++state.pos;
+      if (state.pos >= state.doc.size()) {
+        return tl::unexpected("Unexpected end of string");
+      }
+
+      char escaped = state.doc[state.pos];
+      switch (escaped) {
+      case '"':
+      case '\\':
+      case '/':
+        result += escaped;
+        break;
+      case 'b':
+        result += '\b';
+        break;
+      case 'f':
+        result += '\f';
+        break;
+      case 'n':
+        result += '\n';
+        break;
+      case 'r':
+        result += '\r';
+        break;
+      case 't':
+        result += '\t';
+        break;
+      case 'u':
+        return tl::unexpected("\\uXXXX escape sequences are not supported");
+      default:
+        return tl::unexpected(FMT("Unknown escape sequence: \\{}", escaped));
+      }
+      ++state.pos;
+    } else {
+      result += ch;
+      ++state.pos;
+    }
+  }
+
+  return tl::unexpected("Unterminated string");
+}
+
+void
+skip_primitive(ParseState& state)
+{
+  // Skip numbers, true, false, null
+  while (state.pos < state.doc.size()) {
+    char ch = state.doc[state.pos];
+    if (util::is_space(ch) || ch == ',' || ch == '}' || ch == ']') {
+      break;
+    }
+    ++state.pos;
+  }
+}
+
+tl::expected<void, std::string>
+skip_array(ParseState& state)
+{
+  if (state.pos >= state.doc.size() || state.doc[state.pos] != '[') {
+    return tl::unexpected("Expected array");
+  }
+  ++state.pos; // Skip '['
+
+  int depth = 1;
+  while (state.pos < state.doc.size() && depth > 0) {
+    char ch = state.doc[state.pos];
+    if (ch == '"') {
+      auto str_result = parse_string(state); // Parse and discard
+      if (!str_result) {
+        return tl::unexpected(str_result.error());
+      }
+    } else if (ch == '[') {
+      ++depth;
+      ++state.pos;
+    } else if (ch == ']') {
+      --depth;
+      ++state.pos;
+    } else {
+      ++state.pos;
+    }
+  }
+
+  if (depth != 0) {
+    return tl::unexpected("Unterminated array");
+  }
+  return {};
+}
+
+tl::expected<void, std::string>
+skip_object(ParseState& state)
+{
+  if (state.pos >= state.doc.size() || state.doc[state.pos] != '{') {
+    return tl::unexpected("Expected object");
+  }
+  ++state.pos; // Skip '{'
+
+  int depth = 1;
+  while (state.pos < state.doc.size() && depth > 0) {
+    char ch = state.doc[state.pos];
+    if (ch == '"') {
+      auto str_result = parse_string(state); // Parse and discard
+      if (!str_result) {
+        return tl::unexpected(str_result.error());
+      }
+    } else if (ch == '{') {
+      ++depth;
+      ++state.pos;
+    } else if (ch == '}') {
+      --depth;
+      ++state.pos;
+    } else {
+      ++state.pos;
+    }
+  }
+
+  if (depth != 0) {
+    return tl::unexpected("Unterminated object");
+  }
+  return {};
+}
+
+tl::expected<void, std::string>
+skip_value(ParseState& state)
+{
+  if (state.pos >= state.doc.size()) {
+    return tl::unexpected("Unexpected end of document");
+  }
+
+  char ch = state.doc[state.pos];
+
+  if (ch == '"') {
+    auto str_result = parse_string(state); // Parse and discard
+    if (!str_result) {
+      return tl::unexpected(str_result.error());
+    }
+  } else if (ch == '{') {
+    auto obj_result = skip_object(state);
+    if (!obj_result) {
+      return tl::unexpected(obj_result.error());
+    }
+  } else if (ch == '[') {
+    auto arr_result = skip_array(state);
+    if (!arr_result) {
+      return tl::unexpected(arr_result.error());
+    }
+  } else if (ch == 't' || ch == 'f' || ch == 'n' || ch == '-'
+             || util::is_digit(ch)) {
+    skip_primitive(state);
+  } else {
+    return tl::unexpected(FMT("Unexpected character: '{}'", ch));
+  }
+  return {};
+}
+
+tl::expected<void, std::string>
+navigate_to_key(ParseState& state, std::string_view key)
+{
+  if (state.pos >= state.doc.size() || state.doc[state.pos] != '{') {
+    return tl::unexpected("Expected object");
+  }
+  ++state.pos; // Skip '{'
+
+  while (true) {
+    skip_whitespace(state);
+
+    if (state.pos >= state.doc.size()) {
+      return tl::unexpected(FMT("Key '{}' not found", key));
+    }
+
+    if (state.doc[state.pos] == '}') {
+      return tl::unexpected(FMT("Key '{}' not found", key));
+    }
+
+    if (state.doc[state.pos] != '"') {
+      return tl::unexpected("Expected string key");
+    }
+    auto current_key_result = parse_string(state);
+    if (!current_key_result) {
+      return tl::unexpected(current_key_result.error());
+    }
+
+    skip_whitespace(state);
+    if (state.pos >= state.doc.size() || state.doc[state.pos] != ':') {
+      return tl::unexpected("Expected ':' after key");
+    }
+    ++state.pos; // Skip ':'
+
+    skip_whitespace(state);
+
+    if (*current_key_result == key) {
+      return {}; // Found the key, state.pos is now at the value
+    }
+
+    auto skip_result = skip_value(state);
+    if (!skip_result) {
+      return tl::unexpected(skip_result.error());
+    }
+
+    skip_whitespace(state);
+    if (state.pos < state.doc.size() && state.doc[state.pos] == ',') {
+      ++state.pos; // Skip comma
+    }
+  }
+}
+
+tl::expected<std::vector<std::string>, std::string>
+parse_string_array(ParseState& state)
+{
+  if (state.pos >= state.doc.size() || state.doc[state.pos] != '[') {
+    return tl::unexpected("Expected array");
+  }
+  ++state.pos; // Skip '['
+
+  std::vector<std::string> result;
+
+  while (true) {
+    skip_whitespace(state);
+
+    if (state.pos >= state.doc.size()) {
+      return tl::unexpected("Unterminated array");
+    }
+
+    if (state.doc[state.pos] == ']') {
+      ++state.pos; // Skip ']'
+      return result;
+    }
+
+    if (state.doc[state.pos] != '"') {
+      return tl::unexpected("Expected string in array");
+    }
+
+    auto str_result = parse_string(state);
+    if (!str_result) {
+      return tl::unexpected(str_result.error());
+    }
+    result.push_back(*str_result);
+
+    skip_whitespace(state);
+
+    if (state.pos >= state.doc.size()) {
+      return tl::unexpected("Unterminated array");
+    }
+
+    if (state.doc[state.pos] == ',') {
+      ++state.pos; // Skip comma
+    } else if (state.doc[state.pos] != ']') {
+      return tl::unexpected("Expected ',' or ']' in array");
+    }
+  }
+}
+
+} // namespace
+
+namespace util {
+
+SimpleJsonParser::SimpleJsonParser(std::string_view document)
+  : m_document(document)
+{
+}
+
+tl::expected<std::vector<std::string>, std::string>
+SimpleJsonParser::get_string_array(std::string_view filter) const
+{
+  if (filter.empty() || filter[0] != '.') {
+    return tl::unexpected("Invalid filter: must start with '.'");
+  }
+
+  // Parse filter path, e.g. ".Data.Includes" -> ["Data", "Includes"].
+  auto path = split_into_views(filter.substr(1), ".");
+  if (path.empty()) {
+    return tl::unexpected("Empty filter path");
+  }
+
+  ParseState state{m_document, 0};
+  skip_whitespace(state);
+
+  if (state.pos >= state.doc.size() || state.doc[state.pos] != '{') {
+    return tl::unexpected("Expected object at root");
+  }
+
+  // Navigate through nested objects.
+  for (size_t i = 0; i < path.size() - 1; ++i) {
+    auto nav_result = navigate_to_key(state, path[i]);
+    if (!nav_result) {
+      return tl::unexpected(nav_result.error());
+    }
+    skip_whitespace(state);
+    if (state.pos >= state.doc.size() || state.doc[state.pos] != '{') {
+      return tl::unexpected(FMT("Expected object for key '{}'", path[i]));
+    }
+  }
+
+  // Navigate to the final key which should contain an array.
+  auto nav_result = navigate_to_key(state, path.back());
+  if (!nav_result) {
+    return tl::unexpected(nav_result.error());
+  }
+  skip_whitespace(state);
+
+  if (state.pos >= state.doc.size() || state.doc[state.pos] != '[') {
+    return tl::unexpected(FMT("Expected array for key '{}'", path.back()));
+  }
+
+  return parse_string_array(state);
+}
+
+} // namespace util
diff --git a/src/ccache/util/json.hpp b/src/ccache/util/json.hpp
new file mode 100644
index 00000000..4b7f9e5e
--- /dev/null
+++ b/src/ccache/util/json.hpp
@@ -0,0 +1,48 @@
+// Copyright (C) 2025 Joel Rosdahl and other contributors
+//
+// See doc/authors.adoc for a complete list of contributors.
+//
+// This program is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3 of the License, or (at your option)
+// any later version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+// more details.
+//
+// You should have received a copy of the GNU General Public License along with
+// this program; if not, write to the Free Software Foundation, Inc., 51
+// Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+#pragma once
+
+#include <tl/expected.hpp>
+
+#include <string>
+#include <string_view>
+#include <vector>
+
+namespace util {
+
+// Simple JSON parser that is tailored for parsing MSVC's /sourceDependencies
+// files.
+//
+// Does not support \uXXXX escapes and lots of other things.
+class SimpleJsonParser
+{
+public:
+  explicit SimpleJsonParser(std::string_view document);
+
+  // Extract array of strings from the document. `filter` is a jq-like filter
+  // (e.g. ".Data.Includes") that locates the string array to extract. The
+  // filter syntax currently only supports nested objects.
+  tl::expected<std::vector<std::string>, std::string>
+  get_string_array(std::string_view filter) const;
+
+private:
+  std::string_view m_document;
+};
+
+} // namespace util
diff --git a/unittest/CMakeLists.txt b/unittest/CMakeLists.txt
index 98e9fdc8..84dbe706 100644
--- a/unittest/CMakeLists.txt
+++ b/unittest/CMakeLists.txt
@@ -28,6 +28,7 @@ set(
   test_util_exec.cpp
   test_util_expected.cpp
   test_util_file.cpp
+  test_util_json.cpp
   test_util_lockfile.cpp
   test_util_path.cpp
   test_util_string.cpp
diff --git a/unittest/test_util_json.cpp b/unittest/test_util_json.cpp
new file mode 100644
index 00000000..558484af
--- /dev/null
+++ b/unittest/test_util_json.cpp
@@ -0,0 +1,344 @@
+// Copyright (C) 2025 Joel Rosdahl and other contributors
+//
+// See doc/authors.adoc for a complete list of contributors.
+//
+// This program is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3 of the License, or (at your option)
+// any later version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+// more details.
+//
+// You should have received a copy of the GNU General Public License along with
+// this program; if not, write to the Free Software Foundation, Inc., 51
+// Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+#include "testutil.hpp"
+
+#include <ccache/context.hpp>
+#include <ccache/util/json.hpp>
+
+#include <doctest/doctest.h>
+
+TEST_SUITE_BEGIN("json");
+
+TEST_CASE("SimpleJsonParser")
+{
+  SUBCASE("Parse MSVC /sourceDependencies file")
+  {
+    std::string json = R"({
+  "Version": "1.1",
+  "Data": {
+    "Source": "C:\\path\\to\\source.cpp",
+    "ProvidedModule": "",
+    "Includes": [
+      "C:\\path\\to\\header\"with\"quotes.h",
+      "C:\\path\\to\\header\\with\\backslashes.h",
+      "C:\\日本語\\header1.h"
+    ]
+  }
+})";
+
+    util::SimpleJsonParser parser(json);
+    auto includes = parser.get_string_array(".Data.Includes");
+    REQUIRE(includes);
+    REQUIRE(includes->size() == 3);
+    CHECK((*includes)[0] == "C:\\path\\to\\header\"with\"quotes.h");
+    CHECK((*includes)[1] == "C:\\path\\to\\header\\with\\backslashes.h");
+    CHECK((*includes)[2] == "C:\\日本語\\header1.h");
+  }
+
+  SUBCASE("Empty array")
+  {
+    std::string json = R"({
+  "Data": {
+    "Includes": []
+  }
+})";
+
+    util::SimpleJsonParser parser(json);
+    auto includes = parser.get_string_array(".Data.Includes");
+    REQUIRE(includes);
+    CHECK(includes->empty());
+  }
+
+  SUBCASE("Single element array")
+  {
+    std::string json = R"({
+  "Data": {
+    "Includes": ["single.h"]
+  }
+})";
+
+    util::SimpleJsonParser parser(json);
+    auto includes = parser.get_string_array(".Data.Includes");
+    REQUIRE(includes);
+    REQUIRE(includes->size() == 1);
+    CHECK((*includes)[0] == "single.h");
+  }
+
+  SUBCASE("Array with whitespace variations")
+  {
+    std::string json = R"({
+"Data":{"Includes":["a.h"  ,  "b.h","c.h"]}
+})";
+
+    util::SimpleJsonParser parser(json);
+    auto includes = parser.get_string_array(".Data.Includes");
+    REQUIRE(includes);
+    REQUIRE(includes->size() == 3);
+    CHECK((*includes)[0] == "a.h");
+    CHECK((*includes)[1] == "b.h");
+    CHECK((*includes)[2] == "c.h");
+  }
+
+  SUBCASE("Escape sequences")
+  {
+    std::string json = R"({
+  "Data": {
+    "Includes": [
+      "path\\with\\backslashes",
+      "string\"with\"quotes",
+      "line1\nline2",
+      "tab\tseparated",
+      "carriage\rreturn",
+      "form\ffeed",
+      "back\bspace",
+      "forward/slash"
+    ]
+  }
+})";
+
+    util::SimpleJsonParser parser(json);
+    auto includes = parser.get_string_array(".Data.Includes");
+    REQUIRE(includes);
+    REQUIRE(includes->size() == 8);
+    CHECK((*includes)[0] == "path\\with\\backslashes");
+    CHECK((*includes)[1] == "string\"with\"quotes");
+    CHECK((*includes)[2] == "line1\nline2");
+    CHECK((*includes)[3] == "tab\tseparated");
+    CHECK((*includes)[4] == "carriage\rreturn");
+    CHECK((*includes)[5] == "form\ffeed");
+    CHECK((*includes)[6] == "back\bspace");
+    CHECK((*includes)[7] == "forward/slash");
+  }
+
+  SUBCASE("UTF-8 characters")
+  {
+    std::string json = R"({
+  "Data": {
+    "Includes": [
+      "日本語.h",
+      "中文.cpp",
+      "한글.hpp",
+      "emoji😀.c",
+      "Ελληνικά.h"
+    ]
+  }
+})";
+
+    util::SimpleJsonParser parser(json);
+    auto includes = parser.get_string_array(".Data.Includes");
+    REQUIRE(includes);
+    REQUIRE(includes->size() == 5);
+    CHECK((*includes)[0] == "日本語.h");
+    CHECK((*includes)[1] == "中文.cpp");
+    CHECK((*includes)[2] == "한글.hpp");
+    CHECK((*includes)[3] == "emoji😀.c");
+    CHECK((*includes)[4] == "Ελληνικά.h");
+  }
+
+  SUBCASE("Nested objects")
+  {
+    std::string json = R"({
+  "Level1": {
+    "Level2": {
+      "Level3": {
+        "Files": ["deep.h"]
+      }
+    }
+  }
+})";
+
+    util::SimpleJsonParser parser(json);
+    auto files = parser.get_string_array(".Level1.Level2.Level3.Files");
+    REQUIRE(files);
+    REQUIRE(files->size() == 1);
+    CHECK((*files)[0] == "deep.h");
+  }
+
+  SUBCASE("Object with multiple keys")
+  {
+    std::string json = R"({
+  "Version": "1.0",
+  "Data": {
+    "Source": "main.cpp",
+    "Includes": ["header.h"],
+    "Flags": ["-O2", "-Wall"]
+  }
+})";
+
+    util::SimpleJsonParser parser(json);
+    auto includes = parser.get_string_array(".Data.Includes");
+    REQUIRE(includes);
+    REQUIRE(includes->size() == 1);
+    CHECK((*includes)[0] == "header.h");
+
+    util::SimpleJsonParser parser2(json);
+    auto flags = parser2.get_string_array(".Data.Flags");
+    REQUIRE(flags);
+    REQUIRE(flags->size() == 2);
+    CHECK((*flags)[0] == "-O2");
+    CHECK((*flags)[1] == "-Wall");
+  }
+
+  SUBCASE("Skip non-target values")
+  {
+    std::string json = R"({
+  "Other": {
+    "NestedArray": [1, 2, 3],
+    "NestedObject": {"key": "value"}
+  },
+  "Data": {
+    "Includes": ["target.h"]
+  }
+})";
+
+    util::SimpleJsonParser parser(json);
+    auto includes = parser.get_string_array(".Data.Includes");
+    REQUIRE(includes);
+    REQUIRE(includes->size() == 1);
+    CHECK((*includes)[0] == "target.h");
+  }
+
+  SUBCASE("Empty strings in array")
+  {
+    std::string json = R"({
+  "Data": {
+    "Includes": ["", "file.h", ""]
+  }
+})";
+
+    util::SimpleJsonParser parser(json);
+    auto includes = parser.get_string_array(".Data.Includes");
+    REQUIRE(includes);
+    REQUIRE(includes->size() == 3);
+    CHECK((*includes)[0] == "");
+    CHECK((*includes)[1] == "file.h");
+    CHECK((*includes)[2] == "");
+  }
+
+  SUBCASE("Error: Invalid filter (no leading dot)")
+  {
+    std::string json = R"({"Data": {"Includes": []}})";
+    util::SimpleJsonParser parser(json);
+    auto result = parser.get_string_array("Data.Includes");
+    CHECK(!result);
+    CHECK(result.error() == "Invalid filter: must start with '.'");
+  }
+
+  SUBCASE("Error: Invalid filter (empty)")
+  {
+    std::string json = R"({"Data": {"Includes": []}})";
+    util::SimpleJsonParser parser(json);
+    auto result = parser.get_string_array("");
+    CHECK(!result);
+    CHECK(result.error() == "Invalid filter: must start with '.'");
+  }
+
+  SUBCASE("Error: Key not found")
+  {
+    std::string json = R"({"Data": {"Other": []}})";
+    util::SimpleJsonParser parser(json);
+    auto result = parser.get_string_array(".Data.Includes");
+    CHECK(!result);
+    CHECK(result.error().find("not found") != std::string::npos);
+  }
+
+  SUBCASE("Error: Not an array")
+  {
+    std::string json = R"({"Data": {"Includes": "not-an-array"}})";
+    util::SimpleJsonParser parser(json);
+    auto result = parser.get_string_array(".Data.Includes");
+    CHECK(!result);
+    CHECK(result.error().find("Expected array") != std::string::npos);
+  }
+
+  SUBCASE("Error: Not an object")
+  {
+    std::string json = R"({"Data": "not-an-object"})";
+    util::SimpleJsonParser parser(json);
+    auto result = parser.get_string_array(".Data.Includes");
+    CHECK(!result);
+    CHECK(result.error().find("Expected object") != std::string::npos);
+  }
+
+  SUBCASE("Error: Unterminated string")
+  {
+    std::string json = R"({"Data": {"Includes": ["unterminated]}})";
+    util::SimpleJsonParser parser(json);
+    auto result = parser.get_string_array(".Data.Includes");
+    CHECK(!result);
+    CHECK(result.error() == "Unterminated string");
+  }
+
+  SUBCASE("Error: Unterminated array")
+  {
+    std::string json = R"({"Data": {"Includes": ["file.h")";
+    util::SimpleJsonParser parser(json);
+    auto result = parser.get_string_array(".Data.Includes");
+    CHECK(!result);
+    CHECK(result.error() == "Unterminated array");
+  }
+
+  SUBCASE("Error: Invalid escape sequence")
+  {
+    std::string json = R"({"Data": {"Includes": ["invalid\xescape"]}})";
+    util::SimpleJsonParser parser(json);
+    auto result = parser.get_string_array(".Data.Includes");
+    CHECK(!result);
+    CHECK(result.error().find("Unknown escape sequence") != std::string::npos);
+  }
+
+  SUBCASE("Error: \\uXXXX escape sequence not supported")
+  {
+    std::string json = R"({"Data": {"Includes": ["unicode\u0041char"]}})";
+    util::SimpleJsonParser parser(json);
+    auto result = parser.get_string_array(".Data.Includes");
+    CHECK(!result);
+    CHECK(result.error() == "\\uXXXX escape sequences are not supported");
+  }
+
+  SUBCASE("Error: \\uXXXX in nested object")
+  {
+    std::string json =
+      R"({"Data": {"Key": "value\u1234", "Includes": ["file.h"]}})";
+    util::SimpleJsonParser parser(json);
+    auto result = parser.get_string_array(".Data.Includes");
+    CHECK(!result);
+    CHECK(result.error() == "\\uXXXX escape sequences are not supported");
+  }
+
+  SUBCASE("Error: Root is not an object")
+  {
+    std::string json = R"(["array", "at", "root"])";
+    util::SimpleJsonParser parser(json);
+    auto result = parser.get_string_array(".Data.Includes");
+    CHECK(!result);
+    CHECK(result.error() == "Expected object at root");
+  }
+
+  SUBCASE("Error: Non-string element in array")
+  {
+    std::string json = R"({"Data": {"Includes": ["file.h", 123]}})";
+    util::SimpleJsonParser parser(json);
+    auto result = parser.get_string_array(".Data.Includes");
+    CHECK(!result);
+    CHECK(result.error() == "Expected string in array");
+  }
+}
+
+TEST_SUITE_END();