xref: /llvm-project/llvm/unittests/Support/JSONTest.cpp (revision 77bab2a6f37af918a9133d1bb15551bd351b291e)
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-exception
6 //
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 
16 namespace llvm {
17 namespace json {
18 
19 namespace {
20 
21 std::string s(const Value &E) { return llvm::formatv("{0}", E).str(); }
22 std::string sp(const Value &E) { return llvm::formatv("{0:2}", E).str(); }
23 
24 TEST(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 NDEBUG
33   EXPECT_EQ(R"("��")", s("\xC0\x80"));
34   EXPECT_EQ(R"({"��":0})", s(Object{{"\xC0\x80", 0}}));
35 #else
36   EXPECT_DEATH(s("\xC0\x80"), "Invalid UTF-8");
37   EXPECT_DEATH(s(Object{{"\xC0\x80", 0}}), "Invalid UTF-8");
38 #endif
39 }
40 
41 TEST(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 
55 TEST(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 
67 TEST(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 
74 TEST(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 
93 TEST(JSONTest, PrettyPrinting) {
94   const char Str[] = R"({
95   "empty_array": [],
96   "empty_object": {},
97   "full_array": [
98     1,
99     null
100   ],
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 
124 TEST(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 
135 TEST(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 
151 TEST(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-8
180           /*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 
197 TEST(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: 2
225 })");
226   ExpectErr("Invalid UTF-8 sequence", "\"\xC0\x80\""); // WTF-8 null
227 }
228 
229 // Direct tests of isUTF8 and fixUTF8. Internal uses are also tested elsewhere.
230 TEST(JSONTest, UTF8) {
231   for (const char *Valid : {
232            "this is ASCII text",
233            "thïs tëxt häs BMP chäräctërs",
234            "����L���� C��������",
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 
253 TEST(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     } else
295       EXPECT_FALSE(E.getAsObject());
296   }
297 }
298 
299 // Verify special integer handling - we try to preserve exact int64 values.
300 TEST(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.html
334 #if !defined(_MSC_VER) || _MSC_VER < 1926
335     {
336         "Dynamically exact integer. Stored as double, convertible.",
337         double{0x6000000000000000},
338         "6.9175290276410819e+18",
339         int64_t{0x6000000000000000},
340         double{0x6000000000000000},
341     },
342 #endif
343 
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.
364 TEST(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 
445 template <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.
460 TEST(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.
479 struct 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 };
487 inline bool operator==(const CustomStruct &L, const CustomStruct &R) {
488   return L.S == R.S && L.I == R.I && L.B == R.B;
489 }
490 inline 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 }
495 bool 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 
501 static 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 
508 TEST(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 
562 TEST(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 
582 TEST(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],'unverified
611 raw 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       43
621     ],
622     'unverified
623 raw value'
624   ],
625   /* attribute */
626   "bar": /* attribute value */ {},
627   "baz": "xyz"
628 })";
629   EXPECT_EQ(Pretty, StreamStuff(2));
630 }
631 
632 TEST(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 } // namespace
667 } // namespace json
668 } // namespace llvm
669