From e9cd70e143d6cbe8ba9a9bbb320c34f658c8a264 Mon Sep 17 00:00:00 2001
From: Frank Lin <github@linshuang.info>
Date: Fri, 3 Jul 2026 16:56:44 -0700
Subject: [PATCH] Add librime OpenCC compatibility tests

Protect librime's existing OpenCC integration by covering GetConversionChain access, exact word expansion, and prefix fallback threading through conversion chains.
---
 src/ConfigTest.cpp | 144 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 144 insertions(+)

diff --git a/src/ConfigTest.cpp b/src/ConfigTest.cpp
index 71e20db9d..7d1fd3de4 100644
--- a/src/ConfigTest.cpp
+++ b/src/ConfigTest.cpp
@@ -19,6 +19,7 @@
 #include <fstream>
 #include <filesystem>
 #include <memory>
+#include <set>
 #include <string_view>
 #include <utility>
 #include <vector>
@@ -33,10 +34,12 @@
 #include "ConfigTestBase.hpp"
 #include "ConversionChain.hpp"
 #include "Converter.hpp"
+#include "Dict.hpp"
 #include "Segments.hpp"
 #include "Exception.hpp"
 #include "ResourceProvider.hpp"
 #include "TestUtilsUTF8.hpp"
+#include "UTF8Util.hpp"
 
 namespace opencc {
 namespace {
@@ -188,6 +191,78 @@ std::string InlineSingleStepConfig(const std::string& segmentationEntries,
          "}\n";
 }
 
+std::string ChainConfig(const std::vector<std::string>& dicts) {
+  std::string config =
+      "{\n"
+      "  \"name\": \"Rime Compatibility Test\",\n"
+      "  \"conversion_chain\": [\n";
+  for (size_t i = 0; i < dicts.size(); i++) {
+    config +=
+        "    {\n"
+        "      \"dict\": " +
+        dicts[i] +
+        "\n"
+        "    }";
+    config += (i + 1 == dicts.size()) ? "\n" : ",\n";
+  }
+  config +=
+      "  ]\n"
+      "}\n";
+  return config;
+}
+
+bool ConvertWordLikeRime(const ConversionChainPtr& chain,
+                         const std::string& input,
+                         std::vector<std::string>* converted) {
+  std::vector<std::string> current{input};
+  bool hasExactMatch = false;
+
+  const auto AddIfNew = [](const std::string& value,
+                           std::vector<std::string>* values,
+                           std::set<std::string>* seen) {
+    if (seen->insert(value).second) {
+      values->push_back(value);
+    }
+  };
+
+  for (const ConversionPtr& conversion : chain->GetConversions()) {
+    const DictPtr dict = conversion->GetDict();
+    std::vector<std::string> next;
+    std::set<std::string> seen;
+
+    for (const std::string& word : current) {
+      const Optional<const DictEntry*> exact = dict->Match(word);
+      if (!exact.IsNull()) {
+        hasExactMatch = true;
+        for (const std::string& value : exact.Get()->Values()) {
+          AddIfNew(value, &next, &seen);
+        }
+        continue;
+      }
+
+      std::string fallback;
+      for (const char* pstr = word.c_str(); *pstr != '\0';) {
+        const Optional<const DictEntry*> prefix = dict->MatchPrefix(pstr);
+        size_t matchedLength;
+        if (prefix.IsNull()) {
+          matchedLength = UTF8Util::NextCharLength(pstr);
+          fallback.append(pstr, matchedLength);
+        } else {
+          matchedLength = prefix.Get()->KeyLength();
+          fallback += prefix.Get()->GetDefault();
+        }
+        pstr += matchedLength;
+      }
+      AddIfNew(fallback, &next, &seen);
+    }
+
+    current = std::move(next);
+  }
+
+  *converted = current;
+  return hasExactMatch;
+}
+
 std::string FindOcd2DictionaryDir(const std::string& configTestDirPath) {
   std::vector<fs::path> candidates;
   if (!PACKAGE_DATA_DIRECTORY.empty()) {
@@ -1060,10 +1135,79 @@ TEST_F(ConfigTest, NormalizationGetConversionChainIsNonNull) {
   const ConverterPtr conv = c.NewFromString(config, CONFIG_TEST_DIR_PATH);
   const ConversionChainPtr chain = conv->GetConversionChain();
   ASSERT_NE(nullptr, chain);
+  const std::list<ConversionPtr> conversions = chain->GetConversions();
+  ASSERT_FALSE(conversions.empty());
+  ASSERT_NE(nullptr, conversions.front()->GetDict());
+  EXPECT_FALSE(conversions.front()->GetDict()->Match(utf8("乙")).IsNull());
+  EXPECT_TRUE(conversions.front()->GetDict()->Match(utf8("甲")).IsNull());
+
   // Verify it is the main chain: 乙 → 丙 (not the normalization chain 甲 → 乙).
   const SegmentsPtr result = chain->Convert(SegmentsPtr(new Segments{utf8("乙")}));
   ASSERT_EQ(1u, result->Length());
   EXPECT_EQ(utf8("丙"), result->At(0));
 }
 
+TEST_F(ConfigTest, RimeConvertWordExactExpansionThreadsThroughChain) {
+  const fs::path tempDir = MakeTempDir("opencc-rime-exact-expansion-test");
+  WriteFile(tempDir / "first.txt", utf8("里\t裏 里 哩\n"));
+
+  const std::string config = ChainConfig({
+      "{\"type\": \"text\", \"file\": \"first.txt\"}",
+      "{\n"
+      "        \"type\": \"inline\",\n"
+      "        \"entries\": {\"裏\": \"裡\"}\n"
+      "      }",
+  });
+  Config c;
+  const ConverterPtr conv = c.NewFromString(config, PathString(tempDir));
+
+  std::vector<std::string> converted;
+  EXPECT_TRUE(ConvertWordLikeRime(conv->GetConversionChain(), utf8("里"),
+                                  &converted));
+  EXPECT_EQ((std::vector<std::string>{utf8("裡"), utf8("里"), utf8("哩")}),
+            converted);
+
+  fs::remove_all(tempDir);
+}
+
+TEST_F(ConfigTest, RimeConvertWordPartialFallbackContinuesToNextStage) {
+  const std::string config = ChainConfig({
+      "{\n"
+      "        \"type\": \"inline\",\n"
+      "        \"entries\": {\"内\": \"內\"}\n"
+      "      }",
+      "{\n"
+      "        \"type\": \"inline\",\n"
+      "        \"entries\": {\"內存\": \"記憶體\"}\n"
+      "      }",
+  });
+  Config c;
+  const ConverterPtr conv = c.NewFromString(config, CONFIG_TEST_DIR_PATH);
+
+  std::vector<std::string> converted;
+  EXPECT_TRUE(ConvertWordLikeRime(conv->GetConversionChain(), utf8("内存"),
+                                  &converted));
+  EXPECT_EQ((std::vector<std::string>{utf8("記憶體")}), converted);
+}
+
+TEST_F(ConfigTest, RimeConvertWordReturnsFalseWithoutAnyExactMatch) {
+  const std::string config = ChainConfig({
+      "{\n"
+      "        \"type\": \"inline\",\n"
+      "        \"entries\": {\"a\": \"A\"}\n"
+      "      }",
+      "{\n"
+      "        \"type\": \"inline\",\n"
+      "        \"entries\": {\"z\": \"Z\"}\n"
+      "      }",
+  });
+  Config c;
+  const ConverterPtr conv = c.NewFromString(config, CONFIG_TEST_DIR_PATH);
+
+  std::vector<std::string> converted;
+  EXPECT_FALSE(ConvertWordLikeRime(conv->GetConversionChain(), "abc",
+                                   &converted));
+  EXPECT_EQ((std::vector<std::string>{"Abc"}), converted);
+}
+
 } // namespace opencc