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1//===-- JSONTest.cpp - JSON unit tests --------------------------*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "llvm/Support/JSON.h"10#include "llvm/Support/raw_ostream.h"11#include "llvm/Testing/Support/Error.h"12 13#include "gmock/gmock.h"14#include "gtest/gtest.h"15 16namespace llvm {17namespace json {18 19namespace {20 21std::string s(const Value &E) { return llvm::formatv("{0}", E).str(); }22std::string sp(const Value &E) { return llvm::formatv("{0:2}", E).str(); }23 24TEST(JSONTest, Types) {25  EXPECT_EQ("true", s(true));26  EXPECT_EQ("null", s(nullptr));27  EXPECT_EQ("2.5", s(2.5));28  EXPECT_EQ(R"("foo")", s("foo"));29  EXPECT_EQ("[1,2,3]", s({1, 2, 3}));30  EXPECT_EQ(R"({"x":10,"y":20})", s(Object{{"x", 10}, {"y", 20}}));31 32#ifdef NDEBUG33  EXPECT_EQ(R"("��")", s("\xC0\x80"));34  EXPECT_EQ(R"({"��":0})", s(Object{{"\xC0\x80", 0}}));35#else36  EXPECT_DEATH(s("\xC0\x80"), "Invalid UTF-8");37  EXPECT_DEATH(s(Object{{"\xC0\x80", 0}}), "Invalid UTF-8");38#endif39}40 41TEST(JSONTest, Constructors) {42  // Lots of edge cases around empty and singleton init lists.43  EXPECT_EQ("[[[3]]]", s({{{3}}}));44  EXPECT_EQ("[[[]]]", s({{{}}}));45  EXPECT_EQ("[[{}]]", s({{Object{}}}));46  EXPECT_EQ(R"({"A":{"B":{}}})", s(Object{{"A", Object{{"B", Object{}}}}}));47  EXPECT_EQ(R"({"A":{"B":{"X":"Y"}}})",48            s(Object{{"A", Object{{"B", Object{{"X", "Y"}}}}}}));49  EXPECT_EQ("null", s(std::optional<double>()));50  EXPECT_EQ("2.5", s(std::optional<double>(2.5)));51  EXPECT_EQ("[[2.5,null]]", s(std::vector<std::vector<std::optional<double>>>{52                                {2.5, std::nullopt}}));53}54 55TEST(JSONTest, StringOwnership) {56  char X[] = "Hello";57  Value Alias = static_cast<const char *>(X);58  X[1] = 'a';59  EXPECT_EQ(R"("Hallo")", s(Alias));60 61  std::string Y = "Hello";62  Value Copy = Y;63  Y[1] = 'a';64  EXPECT_EQ(R"("Hello")", s(Copy));65}66 67TEST(JSONTest, CanonicalOutput) {68  // Objects are sorted (but arrays aren't)!69  EXPECT_EQ(R"({"a":1,"b":2,"c":3})", s(Object{{"a", 1}, {"c", 3}, {"b", 2}}));70  EXPECT_EQ(R"(["a","c","b"])", s({"a", "c", "b"}));71  EXPECT_EQ("3", s(3.0));72}73 74TEST(JSONTest, Escaping) {75  std::string Test = {76      0,                    // Strings may contain nulls.77      '\b',   '\f',         // Have mnemonics, but we escape numerically.78      '\r',   '\n',   '\t', // Escaped with mnemonics.79      'S',    '\"',   '\\', // Printable ASCII characters.80      '\x7f',               // Delete is not escaped.81      '\xce', '\x94',       // Non-ASCII UTF-8 is not escaped.82  };83 84  std::string TestString = R"("\u0000\u0008\u000c\r\n\tS\"\\)"85                           "\x7f\xCE\x94\"";86 87  EXPECT_EQ(TestString, s(Test));88 89  EXPECT_EQ(R"({"object keys are\nescaped":true})",90            s(Object{{"object keys are\nescaped", true}}));91}92 93TEST(JSONTest, PrettyPrinting) {94  const char Str[] = R"({95  "empty_array": [],96  "empty_object": {},97  "full_array": [98    1,99    null100  ],101  "full_object": {102    "nested_array": [103      {104        "property": "value"105      }106    ]107  }108})";109 110  EXPECT_EQ(Str, sp(Object{111                     {"empty_object", Object{}},112                     {"empty_array", {}},113                     {"full_array", {1, nullptr}},114                     {"full_object",115                      Object{116                          {"nested_array",117                           {Object{118                               {"property", "value"},119                           }}},120                      }},121                 }));122}123 124TEST(JSONTest, Array) {125  Array A{1, 2};126  A.emplace_back(3);127  A.emplace(++A.begin(), 0);128  A.push_back(4);129  A.insert(++++A.begin(), 99);130 131  EXPECT_EQ(A.size(), 6u);132  EXPECT_EQ(R"([1,0,99,2,3,4])", s(std::move(A)));133}134 135TEST(JSONTest, Object) {136  Object O{{"a", 1}, {"b", 2}, {"c", 3}};137  EXPECT_TRUE(O.try_emplace("d", 4).second);138  EXPECT_FALSE(O.try_emplace("a", 4).second);139 140  auto D = O.find("d");141  EXPECT_NE(D, O.end());142  auto E = O.find("e");143  EXPECT_EQ(E, O.end());144 145  O.erase("b");146  O.erase(D);147  EXPECT_EQ(O.size(), 2u);148  EXPECT_EQ(R"({"a":1,"c":3})", s(std::move(O)));149}150 151TEST(JSONTest, Parse) {152  auto Compare = [](llvm::StringRef S, Value Expected) {153    if (auto E = parse(S)) {154      // Compare both string forms and with operator==, in case we have bugs.155      EXPECT_EQ(*E, Expected);156      EXPECT_EQ(sp(*E), sp(Expected));157    } else {158      handleAllErrors(E.takeError(), [S](const llvm::ErrorInfoBase &E) {159        FAIL() << "Failed to parse JSON >>> " << S << " <<<: " << E.message();160      });161    }162  };163 164  Compare(R"(true)", true);165  Compare(R"(false)", false);166  Compare(R"(null)", nullptr);167 168  Compare(R"(42)", 42);169  Compare(R"(2.5)", 2.5);170  Compare(R"(2e50)", 2e50);171  Compare(R"(1.2e3456789)", std::numeric_limits<double>::infinity());172 173  Compare(R"("foo")", "foo");174  Compare(R"("\"\\\b\f\n\r\t")", "\"\\\b\f\n\r\t");175  Compare(R"("\u0000")", llvm::StringRef("\0", 1));176  Compare("\"\x7f\"", "\x7f");177  Compare(R"("\ud801\udc37")", // UTF-16 surrogate pair escape.178          /*U+10437*/ "\xf0\x90\x90\xb7");179  Compare("\"\xE2\x82\xAC\xF0\x9D\x84\x9E\"", // UTF-8180          /*U+20AC U+1D11E*/ "\xe2\x82\xac\xf0\x9d\x84\x9e");181  Compare(182      // Invalid unicode.183      R"("LoneLeading=\ud801, LoneTrailing=\udc01, LeadLeadTrail=\ud801\ud801\udc37")",184      "LoneLeading=" /*U+FFFD*/ "\xef\xbf\xbd, "185      "LoneTrailing=" /*U+FFFD*/ "\xef\xbf\xbd, "186      "LeadLeadTrail=" /*U+FFFD U+10437*/ "\xef\xbf\xbd\xf0\x90\x90\xb7");187 188  Compare(R"({"":0,"":0})", Object{{"", 0}});189  Compare(R"({"obj":{},"arr":[]})", Object{{"obj", Object{}}, {"arr", {}}});190  Compare(R"({"\n":{"\u0000":[[[[]]]]}})",191          Object{{"\n", Object{192                            {llvm::StringRef("\0", 1), {{{{}}}}},193                        }}});194  Compare("\r[\n\t] ", {});195}196 197TEST(JSONTest, ParseErrors) {198  auto ExpectErr = [](llvm::StringRef Msg, llvm::StringRef S) {199    if (auto E = parse(S)) {200      // Compare both string forms and with operator==, in case we have bugs.201      FAIL() << "Parsed JSON >>> " << S << " <<< but wanted error: " << Msg;202    } else {203      handleAllErrors(E.takeError(), [S, Msg](const llvm::ErrorInfoBase &E) {204        EXPECT_THAT(E.message(), testing::HasSubstr(std::string(Msg))) << S;205      });206    }207  };208  ExpectErr("Unexpected EOF", "");209  ExpectErr("Unexpected EOF", "[");210  ExpectErr("Text after end of document", "[][]");211  ExpectErr("Invalid JSON value (false?)", "fuzzy");212  ExpectErr("Expected , or ]", "[2?]");213  ExpectErr("Expected object key", "{a:2}");214  ExpectErr("Expected : after object key", R"({"a",2})");215  ExpectErr("Expected , or } after object property", R"({"a":2 "b":3})");216  ExpectErr("Invalid JSON value", R"([&%!])");217  ExpectErr("Invalid JSON value (number?)", "1e1.0");218  ExpectErr("Unterminated string", R"("abc\"def)");219  ExpectErr("Control character in string", "\"abc\ndef\"");220  ExpectErr("Invalid escape sequence", R"("\030")");221  ExpectErr("Invalid \\u escape sequence", R"("\usuck")");222  ExpectErr("[3:3, byte=19]", R"({223  "valid": 1,224  invalid: 2225})");226  ExpectErr("Invalid UTF-8 sequence", "\"\xC0\x80\""); // WTF-8 null227}228 229// Direct tests of isUTF8 and fixUTF8. Internal uses are also tested elsewhere.230TEST(JSONTest, UTF8) {231  for (const char *Valid : {232           "this is ASCII text",233           "thïs tëxt häs BMP chäräctërs",234           "𐌶𐌰L𐌾𐍈 C𐍈𐌼𐌴𐍃",235       }) {236    EXPECT_TRUE(isUTF8(Valid)) << Valid;237    EXPECT_EQ(fixUTF8(Valid), Valid);238  }239  for (auto Invalid : std::vector<std::pair<const char *, const char *>>{240           {"lone trailing \x81\x82 bytes", "lone trailing �� bytes"},241           {"missing trailing \xD0 bytes", "missing trailing � bytes"},242           {"truncated character \xD0", "truncated character �"},243           {"not \xC1\x80 the \xE0\x9f\xBF shortest \xF0\x83\x83\x83 encoding",244            "not �� the ��� shortest ���� encoding"},245           {"too \xF9\x80\x80\x80\x80 long", "too ����� long"},246           {"surrogate \xED\xA0\x80 invalid \xF4\x90\x80\x80",247            "surrogate ��� invalid ����"}}) {248    EXPECT_FALSE(isUTF8(Invalid.first)) << Invalid.first;249    EXPECT_EQ(fixUTF8(Invalid.first), Invalid.second);250  }251}252 253TEST(JSONTest, Inspection) {254  llvm::Expected<Value> Doc = parse(R"(255    {256      "null": null,257      "boolean": false,258      "number": 2.78,259      "string": "json",260      "array": [null, true, 3.14, "hello", [1,2,3], {"time": "arrow"}],261      "object": {"fruit": "banana"}262    }263  )");264  EXPECT_TRUE(!!Doc);265 266  Object *O = Doc->getAsObject();267  ASSERT_TRUE(O);268 269  EXPECT_FALSE(O->getNull("missing"));270  EXPECT_FALSE(O->getNull("boolean"));271  EXPECT_TRUE(O->getNull("null"));272 273  EXPECT_EQ(O->getNumber("number"), std::optional<double>(2.78));274  EXPECT_FALSE(O->getInteger("number"));275  EXPECT_EQ(O->getString("string"), std::optional<llvm::StringRef>("json"));276  ASSERT_FALSE(O->getObject("missing"));277  ASSERT_FALSE(O->getObject("array"));278  ASSERT_TRUE(O->getObject("object"));279  EXPECT_EQ(*O->getObject("object"), (Object{{"fruit", "banana"}}));280 281  Array *A = O->getArray("array");282  ASSERT_TRUE(A);283  EXPECT_EQ((*A)[1].getAsBoolean(), std::optional<bool>(true));284  ASSERT_TRUE((*A)[4].getAsArray());285  EXPECT_EQ(*(*A)[4].getAsArray(), (Array{1, 2, 3}));286  EXPECT_EQ((*(*A)[4].getAsArray())[1].getAsInteger(),287            std::optional<int64_t>(2));288  int I = 0;289  for (Value &E : *A) {290    if (I++ == 5) {291      ASSERT_TRUE(E.getAsObject());292      EXPECT_EQ(E.getAsObject()->getString("time"),293                std::optional<llvm::StringRef>("arrow"));294    } else295      EXPECT_FALSE(E.getAsObject());296  }297}298 299// Verify special integer handling - we try to preserve exact int64 values.300TEST(JSONTest, Integers) {301  struct {302    const char *Desc;303    Value Val;304    const char *Str;305    std::optional<int64_t> AsInt;306    std::optional<double> AsNumber;307  } TestCases[] = {308    {309        "Non-integer. Stored as double, not convertible.",310        double{1.5},311        "1.5",312        std::nullopt,313        1.5,314    },315 316    {317        "Integer, not exact double. Stored as int64, convertible.",318        int64_t{0x4000000000000001},319        "4611686018427387905",320        int64_t{0x4000000000000001},321        double{0x4000000000000000},322    },323 324    {325        "Negative integer, not exact double. Stored as int64, convertible.",326        int64_t{-0x4000000000000001},327        "-4611686018427387905",328        int64_t{-0x4000000000000001},329        double{-0x4000000000000000},330    },331 332      // PR46470,333      // https://developercommunity.visualstudio.com/content/problem/1093399/incorrect-result-when-printing-6917529027641081856.html334#if !defined(_MSC_VER) || _MSC_VER < 1926335    {336        "Dynamically exact integer. Stored as double, convertible.",337        double{0x6000000000000000},338        "6.9175290276410819e+18",339        int64_t{0x6000000000000000},340        double{0x6000000000000000},341    },342#endif343 344    {345        "Dynamically integer, >64 bits. Stored as double, not convertible.",346        1.5 * double{0x8000000000000000},347        "1.3835058055282164e+19",348        std::nullopt,349        1.5 * double{0x8000000000000000},350    },351  };352  for (const auto &T : TestCases) {353    EXPECT_EQ(T.Str, s(T.Val)) << T.Desc;354    llvm::Expected<Value> Doc = parse(T.Str);355    EXPECT_TRUE(!!Doc) << T.Desc;356    EXPECT_EQ(Doc->getAsInteger(), T.AsInt) << T.Desc;357    EXPECT_EQ(Doc->getAsNumber(), T.AsNumber) << T.Desc;358    EXPECT_EQ(T.Val, *Doc) << T.Desc;359    EXPECT_EQ(T.Str, s(*Doc)) << T.Desc;360  }361}362 363// Verify uint64_t type.364TEST(JSONTest, U64Integers) {365  Value Val = uint64_t{3100100100};366  uint64_t Var = 3100100100;367  EXPECT_EQ(Val, Var);368 369  Val = uint64_t{std::numeric_limits<uint64_t>::max()};370  Var = std::numeric_limits<uint64_t>::max();371  EXPECT_EQ(Val, Var);372 373  // Test the parse() part.374  {375    const char *Str = "4611686018427387905";376    llvm::Expected<Value> Doc = parse(Str);377 378    EXPECT_TRUE(!!Doc);379    EXPECT_EQ(Doc->getAsInteger(), int64_t{4611686018427387905});380    EXPECT_EQ(Doc->getAsUINT64(), uint64_t{4611686018427387905});381  }382 383  {384    const char *Str = "-78278238238328222";385    llvm::Expected<Value> Doc = parse(Str);386 387    EXPECT_TRUE(!!Doc);388    EXPECT_EQ(Doc->getAsInteger(), int64_t{-78278238238328222});389    EXPECT_EQ(Doc->getAsUINT64(), std::nullopt);390  }391 392  // Test with the largest 64 signed int.393  {394    const char *Str = "9223372036854775807";395    llvm::Expected<Value> Doc = parse(Str);396 397    EXPECT_TRUE(!!Doc);398    EXPECT_EQ(Doc->getAsInteger(), int64_t{9223372036854775807});399    EXPECT_EQ(Doc->getAsUINT64(), uint64_t{9223372036854775807});400  }401 402  // Test with the largest 64 unsigned int.403  {404    const char *Str = "18446744073709551615";405    llvm::Expected<Value> Doc = parse(Str);406 407    EXPECT_TRUE(!!Doc);408    EXPECT_EQ(Doc->getAsInteger(), std::nullopt);409    EXPECT_EQ(Doc->getAsUINT64(), uint64_t{18446744073709551615u});410  }411 412  // Test with a number that is too big for 64 bits.413  {414    const char *Str = "184467440737095516150";415    llvm::Expected<Value> Doc = parse(Str);416 417    EXPECT_TRUE(!!Doc);418    EXPECT_EQ(Doc->getAsInteger(), std::nullopt);419    EXPECT_EQ(Doc->getAsUINT64(), std::nullopt);420    // The number was parsed as a double.421    EXPECT_TRUE(!!Doc->getAsNumber());422  }423 424  // Test with a negative number that is too small for 64 bits.425  {426    const char *Str = "-18446744073709551615";427    llvm::Expected<Value> Doc = parse(Str);428 429    EXPECT_TRUE(!!Doc);430    EXPECT_EQ(Doc->getAsInteger(), std::nullopt);431    EXPECT_EQ(Doc->getAsUINT64(), std::nullopt);432    // The number was parsed as a double.433    EXPECT_TRUE(!!Doc->getAsNumber());434  }435  // Test with a large number that is malformed.436  {437    const char *Str = "184467440737095516150.12.12";438    llvm::Expected<Value> Doc = parse(Str);439 440    EXPECT_EQ("[1:27, byte=27]: Invalid JSON value (number?)",441              llvm::toString(Doc.takeError()));442  }443}444 445template <typename T> void checkCppIntegers() {446  Value Val = T{10};447  T Var = 10;448  EXPECT_EQ(Val, Var);449 450  Val = T{std::numeric_limits<T>::max()};451  Var = std::numeric_limits<T>::max();452  EXPECT_EQ(Val, Var);453 454  Val = T{std::numeric_limits<T>::min()};455  Var = std::numeric_limits<T>::min();456  EXPECT_EQ(Val, Var);457}458 459// Test that underlying C++ integer types behave as expected.460TEST(JSONTest, CppIntegers) {461  checkCppIntegers<char>();462  checkCppIntegers<signed char>();463  checkCppIntegers<unsigned char>();464 465  checkCppIntegers<short>();466  checkCppIntegers<unsigned short>();467 468  checkCppIntegers<int>();469  checkCppIntegers<unsigned int>();470 471  checkCppIntegers<long>();472  checkCppIntegers<unsigned long>();473 474  checkCppIntegers<long long>();475  checkCppIntegers<unsigned long long>();476}477 478// Sample struct with typical JSON-mapping rules.479struct CustomStruct {480  CustomStruct() : B(false) {}481  CustomStruct(std::string S, std::optional<int> I, bool B)482      : S(S), I(I), B(B) {}483  std::string S;484  std::optional<int> I;485  bool B;486};487inline bool operator==(const CustomStruct &L, const CustomStruct &R) {488  return L.S == R.S && L.I == R.I && L.B == R.B;489}490inline llvm::raw_ostream &operator<<(llvm::raw_ostream &OS,491                                     const CustomStruct &S) {492  return OS << "(" << S.S << ", " << (S.I ? std::to_string(*S.I) : "None")493            << ", " << S.B << ")";494}495bool fromJSON(const Value &E, CustomStruct &R, Path P) {496  ObjectMapper O(E, P);497  return O && O.map("str", R.S) && O.map("int", R.I) &&498         O.mapOptional("bool", R.B);499}500 501static std::string errorContext(const Value &V, const Path::Root &R) {502  std::string Context;503  llvm::raw_string_ostream OS(Context);504  R.printErrorContext(V, OS);505  return Context;506}507 508TEST(JSONTest, Deserialize) {509  std::map<std::string, std::vector<CustomStruct>> R;510  CustomStruct ExpectedStruct = {"foo", 42, true};511  std::map<std::string, std::vector<CustomStruct>> Expected;512  Value J = Object{{"foo", Array{513                               Object{514                                   {"str", "foo"},515                                   {"int", 42},516                                   {"bool", true},517                                   {"unknown", "ignored"},518                               },519                               Object{{"str", "bar"}},520                           }}};521  Expected["foo"] = {522      CustomStruct("foo", 42, true),523      CustomStruct("bar", std::nullopt, false),524  };525  Path::Root Root("CustomStruct");526  ASSERT_TRUE(fromJSON(J, R, Root));527  EXPECT_EQ(R, Expected);528 529  (*J.getAsObject()->getArray("foo"))[0] = 123;530  ASSERT_FALSE(fromJSON(J, R, Root));531  EXPECT_EQ("expected object at CustomStruct.foo[0]",532            toString(Root.getError()));533  const char *ExpectedDump = R"({534  "foo": [535    /* error: expected object */536    123,537    { ... }538  ]539})";540  EXPECT_EQ(ExpectedDump, errorContext(J, Root));541 542  CustomStruct V;543  EXPECT_FALSE(fromJSON(nullptr, V, Root));544  EXPECT_EQ("expected object when parsing CustomStruct",545            toString(Root.getError()));546 547  EXPECT_FALSE(fromJSON(Object{}, V, Root));548  EXPECT_EQ("missing value at CustomStruct.str", toString(Root.getError()));549 550  EXPECT_FALSE(fromJSON(Object{{"str", 1}}, V, Root));551  EXPECT_EQ("expected string at CustomStruct.str", toString(Root.getError()));552 553  // std::optional<T> must parse as the correct type if present.554  EXPECT_FALSE(fromJSON(Object{{"str", "1"}, {"int", "string"}}, V, Root));555  EXPECT_EQ("expected integer at CustomStruct.int", toString(Root.getError()));556 557  // mapOptional must parse as the correct type if present.558  EXPECT_FALSE(fromJSON(Object{{"str", "1"}, {"bool", "string"}}, V, Root));559  EXPECT_EQ("expected boolean at CustomStruct.bool", toString(Root.getError()));560}561 562TEST(JSONTest, ParseDeserialize) {563  auto E = parse<std::vector<CustomStruct>>(R"json(564    [{"str": "foo", "int": 42}, {"int": 42}]565  )json");566  EXPECT_THAT_EXPECTED(E, FailedWithMessage("missing value at (root)[1].str"));567 568  E = parse<std::vector<CustomStruct>>(R"json(569    [{"str": "foo", "int": 42}, {"str": "bar"}570  )json");571  EXPECT_THAT_EXPECTED(572      E,573      FailedWithMessage("[3:2, byte=50]: Expected , or ] after array element"));574 575  E = parse<std::vector<CustomStruct>>(R"json(576    [{"str": "foo", "int": 42}]577  )json");578  EXPECT_THAT_EXPECTED(E, Succeeded());579  EXPECT_THAT(*E, testing::SizeIs(1));580}581 582TEST(JSONTest, Stream) {583  auto StreamStuff = [](unsigned Indent) {584    std::string S;585    llvm::raw_string_ostream OS(S);586    OStream J(OS, Indent);587    J.comment("top*/level");588    J.object([&] {589      J.attributeArray("foo", [&] {590        J.value(nullptr);591        J.comment("element");592        J.value(42.5);593        J.arrayBegin();594        J.value(43);595        J.arrayEnd();596        J.rawValue([](raw_ostream &OS) { OS << "'unverified\nraw value'"; });597      });598      J.comment("attribute");599      J.attributeBegin("bar");600      J.comment("attribute value");601      J.objectBegin();602      J.objectEnd();603      J.attributeEnd();604      J.attribute("baz", "xyz");605    });606    return S;607  };608 609  const char *Plain =610      R"(/*top* /level*/{"foo":[null,/*element*/42.5,[43],'unverified611raw value'],/*attribute*/"bar":/*attribute value*/{},"baz":"xyz"})";612  EXPECT_EQ(Plain, StreamStuff(0));613  const char *Pretty = R"(/* top* /level */614{615  "foo": [616    null,617    /* element */618    42.5,619    [620      43621    ],622    'unverified623raw value'624  ],625  /* attribute */626  "bar": /* attribute value */ {},627  "baz": "xyz"628})";629  EXPECT_EQ(Pretty, StreamStuff(2));630}631 632TEST(JSONTest, Path) {633  Path::Root R("foo");634  Path P = R, A = P.field("a"), B = P.field("b");635  P.report("oh no");636  EXPECT_THAT_ERROR(R.getError(), FailedWithMessage("oh no when parsing foo"));637  A.index(1).field("c").index(2).report("boom");638  EXPECT_THAT_ERROR(R.getError(), FailedWithMessage("boom at foo.a[1].c[2]"));639  B.field("d").field("e").report("bam");640  EXPECT_THAT_ERROR(R.getError(), FailedWithMessage("bam at foo.b.d.e"));641 642  Value V = Object{643      {"a", Array{42}},644      {"b",645       Object{{"d",646               Object{647                   {"e", Array{1, Object{{"x", "y"}}}},648                   {"f", "a moderately long string: 48 characters in total"},649               }}}},650  };651  const char *Expected = R"({652  "a": [ ... ],653  "b": {654    "d": {655      "e": /* error: bam */ [656        1,657        { ... }658      ],659      "f": "a moderately long string: 48 characte..."660    }661  }662})";663  EXPECT_EQ(Expected, errorContext(V, R));664}665 666} // namespace667} // namespace json668} // namespace llvm669