• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // Copyright 2017 The Abseil Authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //      https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 #include "absl/strings/string_view.h"
16 
17 #include <stdlib.h>
18 
19 #include <cstddef>
20 #include <cstdlib>
21 #include <cstring>
22 #include <iomanip>
23 #include <ios>
24 #include <iterator>
25 #include <limits>
26 #include <map>
27 #include <memory>
28 #include <sstream>
29 #include <string>
30 #include <type_traits>
31 #include <utility>
32 
33 #include "gtest/gtest.h"
34 #include "absl/base/config.h"
35 
36 #if defined(ABSL_HAVE_STD_STRING_VIEW) || defined(__ANDROID__)
37 // We don't control the death messaging when using std::string_view.
38 // Android assert messages only go to system log, so death tests cannot inspect
39 // the message for matching.
40 #define ABSL_EXPECT_DEATH_IF_SUPPORTED(statement, regex) \
41   EXPECT_DEATH_IF_SUPPORTED(statement, ".*")
42 #else
43 #define ABSL_EXPECT_DEATH_IF_SUPPORTED(statement, regex) \
44   EXPECT_DEATH_IF_SUPPORTED(statement, regex)
45 #endif
46 
47 namespace {
48 
49 // A minimal allocator that uses malloc().
50 template <typename T>
51 struct Mallocator {
52   typedef T value_type;
53   typedef size_t size_type;
54   typedef ptrdiff_t difference_type;
55   typedef T* pointer;
56   typedef const T* const_pointer;
57   typedef T& reference;
58   typedef const T& const_reference;
59 
max_size__anonbb075c750111::Mallocator60   size_type max_size() const {
61     return size_t(std::numeric_limits<size_type>::max()) / sizeof(value_type);
62   }
63   template <typename U>
64   struct rebind {
65     typedef Mallocator<U> other;
66   };
67   Mallocator() = default;
68   template <class U>
Mallocator__anonbb075c750111::Mallocator69   Mallocator(const Mallocator<U>&) {}  // NOLINT(runtime/explicit)
70 
allocate__anonbb075c750111::Mallocator71   T* allocate(size_t n) { return static_cast<T*>(std::malloc(n * sizeof(T))); }
deallocate__anonbb075c750111::Mallocator72   void deallocate(T* p, size_t) { std::free(p); }
73 };
74 template <typename T, typename U>
operator ==(const Mallocator<T> &,const Mallocator<U> &)75 bool operator==(const Mallocator<T>&, const Mallocator<U>&) {
76   return true;
77 }
78 template <typename T, typename U>
operator !=(const Mallocator<T> &,const Mallocator<U> &)79 bool operator!=(const Mallocator<T>&, const Mallocator<U>&) {
80   return false;
81 }
82 
TEST(StringViewTest,Ctor)83 TEST(StringViewTest, Ctor) {
84   {
85     // Null.
86     absl::string_view s10;
87     EXPECT_TRUE(s10.data() == nullptr);
88     EXPECT_EQ(0u, s10.length());
89   }
90 
91   {
92     // const char* without length.
93     const char* hello = "hello";
94     absl::string_view s20(hello);
95     EXPECT_TRUE(s20.data() == hello);
96     EXPECT_EQ(5u, s20.length());
97 
98     // const char* with length.
99     absl::string_view s21(hello, 4);
100     EXPECT_TRUE(s21.data() == hello);
101     EXPECT_EQ(4u, s21.length());
102 
103     // Not recommended, but valid C++
104     absl::string_view s22(hello, 6);
105     EXPECT_TRUE(s22.data() == hello);
106     EXPECT_EQ(6u, s22.length());
107   }
108 
109   {
110     // std::string.
111     std::string hola = "hola";
112     absl::string_view s30(hola);
113     EXPECT_TRUE(s30.data() == hola.data());
114     EXPECT_EQ(4u, s30.length());
115 
116     // std::string with embedded '\0'.
117     hola.push_back('\0');
118     hola.append("h2");
119     hola.push_back('\0');
120     absl::string_view s31(hola);
121     EXPECT_TRUE(s31.data() == hola.data());
122     EXPECT_EQ(8u, s31.length());
123   }
124 
125   {
126     using mstring =
127         std::basic_string<char, std::char_traits<char>, Mallocator<char>>;
128     mstring str1("BUNGIE-JUMPING!");
129     const mstring str2("SLEEPING!");
130 
131     absl::string_view s1(str1);
132     s1.remove_prefix(strlen("BUNGIE-JUM"));
133 
134     absl::string_view s2(str2);
135     s2.remove_prefix(strlen("SLEE"));
136 
137     EXPECT_EQ(s1, s2);
138     EXPECT_EQ(s1, "PING!");
139   }
140 
141   // TODO(mec): absl::string_view(const absl::string_view&);
142 }
143 
TEST(StringViewTest,Swap)144 TEST(StringViewTest, Swap) {
145   absl::string_view a("a");
146   absl::string_view b("bbb");
147   EXPECT_TRUE(noexcept(a.swap(b)));
148   a.swap(b);
149   EXPECT_EQ(a, "bbb");
150   EXPECT_EQ(b, "a");
151   a.swap(b);
152   EXPECT_EQ(a, "a");
153   EXPECT_EQ(b, "bbb");
154 }
155 
TEST(StringViewTest,STLComparator)156 TEST(StringViewTest, STLComparator) {
157   std::string s1("foo");
158   std::string s2("bar");
159   std::string s3("baz");
160 
161   absl::string_view p1(s1);
162   absl::string_view p2(s2);
163   absl::string_view p3(s3);
164 
165   typedef std::map<absl::string_view, int> TestMap;
166   TestMap map;
167 
168   map.insert(std::make_pair(p1, 0));
169   map.insert(std::make_pair(p2, 1));
170   map.insert(std::make_pair(p3, 2));
171   EXPECT_EQ(map.size(), 3u);
172 
173   TestMap::const_iterator iter = map.begin();
174   EXPECT_EQ(iter->second, 1);
175   ++iter;
176   EXPECT_EQ(iter->second, 2);
177   ++iter;
178   EXPECT_EQ(iter->second, 0);
179   ++iter;
180   EXPECT_TRUE(iter == map.end());
181 
182   TestMap::iterator new_iter = map.find("zot");
183   EXPECT_TRUE(new_iter == map.end());
184 
185   new_iter = map.find("bar");
186   EXPECT_TRUE(new_iter != map.end());
187 
188   map.erase(new_iter);
189   EXPECT_EQ(map.size(), 2u);
190 
191   iter = map.begin();
192   EXPECT_EQ(iter->second, 2);
193   ++iter;
194   EXPECT_EQ(iter->second, 0);
195   ++iter;
196   EXPECT_TRUE(iter == map.end());
197 }
198 
199 #define COMPARE(result, op, x, y)                                      \
200   EXPECT_EQ(result, absl::string_view((x)) op absl::string_view((y))); \
201   EXPECT_EQ(result, absl::string_view((x)).compare(absl::string_view((y))) op 0)
202 
TEST(StringViewTest,ComparisonOperators)203 TEST(StringViewTest, ComparisonOperators) {
204   COMPARE(true, ==, "",   "");
205   COMPARE(true, ==, "", absl::string_view());
206   COMPARE(true, ==, absl::string_view(), "");
207   COMPARE(true, ==, "a",  "a");
208   COMPARE(true, ==, "aa", "aa");
209   COMPARE(false, ==, "a",  "");
210   COMPARE(false, ==, "",   "a");
211   COMPARE(false, ==, "a",  "b");
212   COMPARE(false, ==, "a",  "aa");
213   COMPARE(false, ==, "aa", "a");
214 
215   COMPARE(false, !=, "",   "");
216   COMPARE(false, !=, "a",  "a");
217   COMPARE(false, !=, "aa", "aa");
218   COMPARE(true, !=, "a",  "");
219   COMPARE(true, !=, "",   "a");
220   COMPARE(true, !=, "a",  "b");
221   COMPARE(true, !=, "a",  "aa");
222   COMPARE(true, !=, "aa", "a");
223 
224   COMPARE(true, <, "a",  "b");
225   COMPARE(true, <, "a",  "aa");
226   COMPARE(true, <, "aa", "b");
227   COMPARE(true, <, "aa", "bb");
228   COMPARE(false, <, "a",  "a");
229   COMPARE(false, <, "b",  "a");
230   COMPARE(false, <, "aa", "a");
231   COMPARE(false, <, "b",  "aa");
232   COMPARE(false, <, "bb", "aa");
233 
234   COMPARE(true, <=, "a",  "a");
235   COMPARE(true, <=, "a",  "b");
236   COMPARE(true, <=, "a",  "aa");
237   COMPARE(true, <=, "aa", "b");
238   COMPARE(true, <=, "aa", "bb");
239   COMPARE(false, <=, "b",  "a");
240   COMPARE(false, <=, "aa", "a");
241   COMPARE(false, <=, "b",  "aa");
242   COMPARE(false, <=, "bb", "aa");
243 
244   COMPARE(false, >=, "a",  "b");
245   COMPARE(false, >=, "a",  "aa");
246   COMPARE(false, >=, "aa", "b");
247   COMPARE(false, >=, "aa", "bb");
248   COMPARE(true, >=, "a",  "a");
249   COMPARE(true, >=, "b",  "a");
250   COMPARE(true, >=, "aa", "a");
251   COMPARE(true, >=, "b",  "aa");
252   COMPARE(true, >=, "bb", "aa");
253 
254   COMPARE(false, >, "a",  "a");
255   COMPARE(false, >, "a",  "b");
256   COMPARE(false, >, "a",  "aa");
257   COMPARE(false, >, "aa", "b");
258   COMPARE(false, >, "aa", "bb");
259   COMPARE(true, >, "b",  "a");
260   COMPARE(true, >, "aa", "a");
261   COMPARE(true, >, "b",  "aa");
262   COMPARE(true, >, "bb", "aa");
263 }
264 
TEST(StringViewTest,ComparisonOperatorsByCharacterPosition)265 TEST(StringViewTest, ComparisonOperatorsByCharacterPosition) {
266   std::string x;
267   for (size_t i = 0; i < 256; i++) {
268     x += 'a';
269     std::string y = x;
270     COMPARE(true, ==, x, y);
271     for (size_t j = 0; j < i; j++) {
272       std::string z = x;
273       z[j] = 'b';       // Differs in position 'j'
274       COMPARE(false, ==, x, z);
275       COMPARE(true, <, x, z);
276       COMPARE(true, >, z, x);
277       if (j + 1 < i) {
278         z[j + 1] = 'A';  // Differs in position 'j+1' as well
279         COMPARE(false, ==, x, z);
280         COMPARE(true, <, x, z);
281         COMPARE(true, >, z, x);
282         z[j + 1] = 'z';  // Differs in position 'j+1' as well
283         COMPARE(false, ==, x, z);
284         COMPARE(true, <, x, z);
285         COMPARE(true, >, z, x);
286       }
287     }
288   }
289 }
290 #undef COMPARE
291 
292 // Sadly, our users often confuse std::string::npos with
293 // absl::string_view::npos; So much so that we test here that they are the same.
294 // They need to both be unsigned, and both be the maximum-valued integer of
295 // their type.
296 
297 template <typename T>
298 struct is_type {
299   template <typename U>
same__anonbb075c750111::is_type300   static bool same(U) {
301     return false;
302   }
same__anonbb075c750111::is_type303   static bool same(T) { return true; }
304 };
305 
TEST(StringViewTest,NposMatchesStdStringView)306 TEST(StringViewTest, NposMatchesStdStringView) {
307   EXPECT_EQ(absl::string_view::npos, std::string::npos);
308 
309   EXPECT_TRUE(is_type<size_t>::same(absl::string_view::npos));
310   EXPECT_FALSE(is_type<size_t>::same(""));
311 
312   // Make sure absl::string_view::npos continues to be a header constant.
313   char test[absl::string_view::npos & 1] = {0};
314   EXPECT_EQ(0, test[0]);
315 }
316 
TEST(StringViewTest,STL1)317 TEST(StringViewTest, STL1) {
318   const absl::string_view a("abcdefghijklmnopqrstuvwxyz");
319   const absl::string_view b("abc");
320   const absl::string_view c("xyz");
321   const absl::string_view d("foobar");
322   const absl::string_view e;
323   std::string temp("123");
324   temp += '\0';
325   temp += "456";
326   const absl::string_view f(temp);
327 
328   EXPECT_EQ(a[6], 'g');
329   EXPECT_EQ(b[0], 'a');
330   EXPECT_EQ(c[2], 'z');
331   EXPECT_EQ(f[3], '\0');
332   EXPECT_EQ(f[5], '5');
333 
334   EXPECT_EQ(*d.data(), 'f');
335   EXPECT_EQ(d.data()[5], 'r');
336   EXPECT_TRUE(e.data() == nullptr);
337 
338   EXPECT_EQ(*a.begin(), 'a');
339   EXPECT_EQ(*(b.begin() + 2), 'c');
340   EXPECT_EQ(*(c.end() - 1), 'z');
341 
342   EXPECT_EQ(*a.rbegin(), 'z');
343   EXPECT_EQ(*(b.rbegin() + 2), 'a');
344   EXPECT_EQ(*(c.rend() - 1), 'x');
345   EXPECT_TRUE(a.rbegin() + 26 == a.rend());
346 
347   EXPECT_EQ(a.size(), 26u);
348   EXPECT_EQ(b.size(), 3u);
349   EXPECT_EQ(c.size(), 3u);
350   EXPECT_EQ(d.size(), 6u);
351   EXPECT_EQ(e.size(), 0u);
352   EXPECT_EQ(f.size(), 7u);
353 
354   EXPECT_TRUE(!d.empty());
355   EXPECT_TRUE(d.begin() != d.end());
356   EXPECT_TRUE(d.begin() + 6 == d.end());
357 
358   EXPECT_TRUE(e.empty());
359   EXPECT_TRUE(e.begin() == e.end());
360 
361   char buf[4] = { '%', '%', '%', '%' };
362   EXPECT_EQ(a.copy(buf, 4), 4u);
363   EXPECT_EQ(buf[0], a[0]);
364   EXPECT_EQ(buf[1], a[1]);
365   EXPECT_EQ(buf[2], a[2]);
366   EXPECT_EQ(buf[3], a[3]);
367   EXPECT_EQ(a.copy(buf, 3, 7), 3u);
368   EXPECT_EQ(buf[0], a[7]);
369   EXPECT_EQ(buf[1], a[8]);
370   EXPECT_EQ(buf[2], a[9]);
371   EXPECT_EQ(buf[3], a[3]);
372   EXPECT_EQ(c.copy(buf, 99), 3u);
373   EXPECT_EQ(buf[0], c[0]);
374   EXPECT_EQ(buf[1], c[1]);
375   EXPECT_EQ(buf[2], c[2]);
376   EXPECT_EQ(buf[3], a[3]);
377 #ifdef ABSL_HAVE_EXCEPTIONS
378   EXPECT_THROW(a.copy(buf, 1, 27), std::out_of_range);
379 #else
380   ABSL_EXPECT_DEATH_IF_SUPPORTED(a.copy(buf, 1, 27), "absl::string_view::copy");
381 #endif
382 }
383 
384 // Separated from STL1() because some compilers produce an overly
385 // large stack frame for the combined function.
TEST(StringViewTest,STL2)386 TEST(StringViewTest, STL2) {
387   const absl::string_view a("abcdefghijklmnopqrstuvwxyz");
388   const absl::string_view b("abc");
389   const absl::string_view c("xyz");
390   absl::string_view d("foobar");
391   const absl::string_view e;
392   const absl::string_view f(
393       "123"
394       "\0"
395       "456",
396       7);
397 
398   d = absl::string_view();
399   EXPECT_EQ(d.size(), 0u);
400   EXPECT_TRUE(d.empty());
401   EXPECT_TRUE(d.data() == nullptr);
402   EXPECT_TRUE(d.begin() == d.end());
403 
404   EXPECT_EQ(a.find(b), 0u);
405   EXPECT_EQ(a.find(b, 1), absl::string_view::npos);
406   EXPECT_EQ(a.find(c), 23u);
407   EXPECT_EQ(a.find(c, 9), 23u);
408   EXPECT_EQ(a.find(c, absl::string_view::npos), absl::string_view::npos);
409   EXPECT_EQ(b.find(c), absl::string_view::npos);
410   EXPECT_EQ(b.find(c, absl::string_view::npos), absl::string_view::npos);
411   EXPECT_EQ(a.find(d), 0u);
412   EXPECT_EQ(a.find(e), 0u);
413   EXPECT_EQ(a.find(d, 12), 12u);
414   EXPECT_EQ(a.find(e, 17), 17u);
415   absl::string_view g("xx not found bb");
416   EXPECT_EQ(a.find(g), absl::string_view::npos);
417   // empty string nonsense
418   EXPECT_EQ(d.find(b), absl::string_view::npos);
419   EXPECT_EQ(e.find(b), absl::string_view::npos);
420   EXPECT_EQ(d.find(b, 4), absl::string_view::npos);
421   EXPECT_EQ(e.find(b, 7), absl::string_view::npos);
422 
423   size_t empty_search_pos = std::string().find(std::string());
424   EXPECT_EQ(d.find(d), empty_search_pos);
425   EXPECT_EQ(d.find(e), empty_search_pos);
426   EXPECT_EQ(e.find(d), empty_search_pos);
427   EXPECT_EQ(e.find(e), empty_search_pos);
428   EXPECT_EQ(d.find(d, 4), std::string().find(std::string(), 4));
429   EXPECT_EQ(d.find(e, 4), std::string().find(std::string(), 4));
430   EXPECT_EQ(e.find(d, 4), std::string().find(std::string(), 4));
431   EXPECT_EQ(e.find(e, 4), std::string().find(std::string(), 4));
432 
433   EXPECT_EQ(a.find('a'), 0u);
434   EXPECT_EQ(a.find('c'), 2u);
435   EXPECT_EQ(a.find('z'), 25u);
436   EXPECT_EQ(a.find('$'), absl::string_view::npos);
437   EXPECT_EQ(a.find('\0'), absl::string_view::npos);
438   EXPECT_EQ(f.find('\0'), 3u);
439   EXPECT_EQ(f.find('3'), 2u);
440   EXPECT_EQ(f.find('5'), 5u);
441   EXPECT_EQ(g.find('o'), 4u);
442   EXPECT_EQ(g.find('o', 4), 4u);
443   EXPECT_EQ(g.find('o', 5), 8u);
444   EXPECT_EQ(a.find('b', 5), absl::string_view::npos);
445   // empty string nonsense
446   EXPECT_EQ(d.find('\0'), absl::string_view::npos);
447   EXPECT_EQ(e.find('\0'), absl::string_view::npos);
448   EXPECT_EQ(d.find('\0', 4), absl::string_view::npos);
449   EXPECT_EQ(e.find('\0', 7), absl::string_view::npos);
450   EXPECT_EQ(d.find('x'), absl::string_view::npos);
451   EXPECT_EQ(e.find('x'), absl::string_view::npos);
452   EXPECT_EQ(d.find('x', 4), absl::string_view::npos);
453   EXPECT_EQ(e.find('x', 7), absl::string_view::npos);
454 
455   EXPECT_EQ(a.find(b.data(), 1, 0), 1u);
456   EXPECT_EQ(a.find(c.data(), 9, 0), 9u);
457   EXPECT_EQ(a.find(c.data(), absl::string_view::npos, 0),
458             absl::string_view::npos);
459   EXPECT_EQ(b.find(c.data(), absl::string_view::npos, 0),
460             absl::string_view::npos);
461   // empty string nonsense
462   EXPECT_EQ(d.find(b.data(), 4, 0), absl::string_view::npos);
463   EXPECT_EQ(e.find(b.data(), 7, 0), absl::string_view::npos);
464 
465   EXPECT_EQ(a.find(b.data(), 1), absl::string_view::npos);
466   EXPECT_EQ(a.find(c.data(), 9), 23u);
467   EXPECT_EQ(a.find(c.data(), absl::string_view::npos), absl::string_view::npos);
468   EXPECT_EQ(b.find(c.data(), absl::string_view::npos), absl::string_view::npos);
469   // empty string nonsense
470   EXPECT_EQ(d.find(b.data(), 4), absl::string_view::npos);
471   EXPECT_EQ(e.find(b.data(), 7), absl::string_view::npos);
472 
473   EXPECT_EQ(a.rfind(b), 0u);
474   EXPECT_EQ(a.rfind(b, 1), 0u);
475   EXPECT_EQ(a.rfind(c), 23u);
476   EXPECT_EQ(a.rfind(c, 22), absl::string_view::npos);
477   EXPECT_EQ(a.rfind(c, 1), absl::string_view::npos);
478   EXPECT_EQ(a.rfind(c, 0), absl::string_view::npos);
479   EXPECT_EQ(b.rfind(c), absl::string_view::npos);
480   EXPECT_EQ(b.rfind(c, 0), absl::string_view::npos);
481   EXPECT_EQ(a.rfind(d), std::string(a).rfind(std::string()));
482   EXPECT_EQ(a.rfind(e), std::string(a).rfind(std::string()));
483   EXPECT_EQ(a.rfind(d, 12), 12u);
484   EXPECT_EQ(a.rfind(e, 17), 17u);
485   EXPECT_EQ(a.rfind(g), absl::string_view::npos);
486   EXPECT_EQ(d.rfind(b), absl::string_view::npos);
487   EXPECT_EQ(e.rfind(b), absl::string_view::npos);
488   EXPECT_EQ(d.rfind(b, 4), absl::string_view::npos);
489   EXPECT_EQ(e.rfind(b, 7), absl::string_view::npos);
490   // empty string nonsense
491   EXPECT_EQ(d.rfind(d, 4), std::string().rfind(std::string()));
492   EXPECT_EQ(e.rfind(d, 7), std::string().rfind(std::string()));
493   EXPECT_EQ(d.rfind(e, 4), std::string().rfind(std::string()));
494   EXPECT_EQ(e.rfind(e, 7), std::string().rfind(std::string()));
495   EXPECT_EQ(d.rfind(d), std::string().rfind(std::string()));
496   EXPECT_EQ(e.rfind(d), std::string().rfind(std::string()));
497   EXPECT_EQ(d.rfind(e), std::string().rfind(std::string()));
498   EXPECT_EQ(e.rfind(e), std::string().rfind(std::string()));
499 
500   EXPECT_EQ(g.rfind('o'), 8u);
501   EXPECT_EQ(g.rfind('q'), absl::string_view::npos);
502   EXPECT_EQ(g.rfind('o', 8), 8u);
503   EXPECT_EQ(g.rfind('o', 7), 4u);
504   EXPECT_EQ(g.rfind('o', 3), absl::string_view::npos);
505   EXPECT_EQ(f.rfind('\0'), 3u);
506   EXPECT_EQ(f.rfind('\0', 12), 3u);
507   EXPECT_EQ(f.rfind('3'), 2u);
508   EXPECT_EQ(f.rfind('5'), 5u);
509   // empty string nonsense
510   EXPECT_EQ(d.rfind('o'), absl::string_view::npos);
511   EXPECT_EQ(e.rfind('o'), absl::string_view::npos);
512   EXPECT_EQ(d.rfind('o', 4), absl::string_view::npos);
513   EXPECT_EQ(e.rfind('o', 7), absl::string_view::npos);
514 
515   EXPECT_EQ(a.rfind(b.data(), 1, 0), 1u);
516   EXPECT_EQ(a.rfind(c.data(), 22, 0), 22u);
517   EXPECT_EQ(a.rfind(c.data(), 1, 0), 1u);
518   EXPECT_EQ(a.rfind(c.data(), 0, 0), 0u);
519   EXPECT_EQ(b.rfind(c.data(), 0, 0), 0u);
520   EXPECT_EQ(d.rfind(b.data(), 4, 0), 0u);
521   EXPECT_EQ(e.rfind(b.data(), 7, 0), 0u);
522 }
523 
524 // Continued from STL2
TEST(StringViewTest,STL2FindFirst)525 TEST(StringViewTest, STL2FindFirst) {
526   const absl::string_view a("abcdefghijklmnopqrstuvwxyz");
527   const absl::string_view b("abc");
528   const absl::string_view c("xyz");
529   absl::string_view d("foobar");
530   const absl::string_view e;
531   const absl::string_view f(
532       "123"
533       "\0"
534       "456",
535       7);
536   absl::string_view g("xx not found bb");
537 
538   d = absl::string_view();
539   EXPECT_EQ(a.find_first_of(b), 0u);
540   EXPECT_EQ(a.find_first_of(b, 0), 0u);
541   EXPECT_EQ(a.find_first_of(b, 1), 1u);
542   EXPECT_EQ(a.find_first_of(b, 2), 2u);
543   EXPECT_EQ(a.find_first_of(b, 3), absl::string_view::npos);
544   EXPECT_EQ(a.find_first_of(c), 23u);
545   EXPECT_EQ(a.find_first_of(c, 23), 23u);
546   EXPECT_EQ(a.find_first_of(c, 24), 24u);
547   EXPECT_EQ(a.find_first_of(c, 25), 25u);
548   EXPECT_EQ(a.find_first_of(c, 26), absl::string_view::npos);
549   EXPECT_EQ(g.find_first_of(b), 13u);
550   EXPECT_EQ(g.find_first_of(c), 0u);
551   EXPECT_EQ(a.find_first_of(f), absl::string_view::npos);
552   EXPECT_EQ(f.find_first_of(a), absl::string_view::npos);
553   // empty string nonsense
554   EXPECT_EQ(a.find_first_of(d), absl::string_view::npos);
555   EXPECT_EQ(a.find_first_of(e), absl::string_view::npos);
556   EXPECT_EQ(d.find_first_of(b), absl::string_view::npos);
557   EXPECT_EQ(e.find_first_of(b), absl::string_view::npos);
558   EXPECT_EQ(d.find_first_of(d), absl::string_view::npos);
559   EXPECT_EQ(e.find_first_of(d), absl::string_view::npos);
560   EXPECT_EQ(d.find_first_of(e), absl::string_view::npos);
561   EXPECT_EQ(e.find_first_of(e), absl::string_view::npos);
562 
563   EXPECT_EQ(a.find_first_not_of(b), 3u);
564   EXPECT_EQ(a.find_first_not_of(c), 0u);
565   EXPECT_EQ(b.find_first_not_of(a), absl::string_view::npos);
566   EXPECT_EQ(c.find_first_not_of(a), absl::string_view::npos);
567   EXPECT_EQ(f.find_first_not_of(a), 0u);
568   EXPECT_EQ(a.find_first_not_of(f), 0u);
569   EXPECT_EQ(a.find_first_not_of(d), 0u);
570   EXPECT_EQ(a.find_first_not_of(e), 0u);
571   // empty string nonsense
572   EXPECT_EQ(a.find_first_not_of(d), 0u);
573   EXPECT_EQ(a.find_first_not_of(e), 0u);
574   EXPECT_EQ(a.find_first_not_of(d, 1), 1u);
575   EXPECT_EQ(a.find_first_not_of(e, 1), 1u);
576   EXPECT_EQ(a.find_first_not_of(d, a.size() - 1), a.size() - 1);
577   EXPECT_EQ(a.find_first_not_of(e, a.size() - 1), a.size() - 1);
578   EXPECT_EQ(a.find_first_not_of(d, a.size()), absl::string_view::npos);
579   EXPECT_EQ(a.find_first_not_of(e, a.size()), absl::string_view::npos);
580   EXPECT_EQ(a.find_first_not_of(d, absl::string_view::npos),
581             absl::string_view::npos);
582   EXPECT_EQ(a.find_first_not_of(e, absl::string_view::npos),
583             absl::string_view::npos);
584   EXPECT_EQ(d.find_first_not_of(a), absl::string_view::npos);
585   EXPECT_EQ(e.find_first_not_of(a), absl::string_view::npos);
586   EXPECT_EQ(d.find_first_not_of(d), absl::string_view::npos);
587   EXPECT_EQ(e.find_first_not_of(d), absl::string_view::npos);
588   EXPECT_EQ(d.find_first_not_of(e), absl::string_view::npos);
589   EXPECT_EQ(e.find_first_not_of(e), absl::string_view::npos);
590 
591   absl::string_view h("====");
592   EXPECT_EQ(h.find_first_not_of('='), absl::string_view::npos);
593   EXPECT_EQ(h.find_first_not_of('=', 3), absl::string_view::npos);
594   EXPECT_EQ(h.find_first_not_of('\0'), 0u);
595   EXPECT_EQ(g.find_first_not_of('x'), 2u);
596   EXPECT_EQ(f.find_first_not_of('\0'), 0u);
597   EXPECT_EQ(f.find_first_not_of('\0', 3), 4u);
598   EXPECT_EQ(f.find_first_not_of('\0', 2), 2u);
599   // empty string nonsense
600   EXPECT_EQ(d.find_first_not_of('x'), absl::string_view::npos);
601   EXPECT_EQ(e.find_first_not_of('x'), absl::string_view::npos);
602   EXPECT_EQ(d.find_first_not_of('\0'), absl::string_view::npos);
603   EXPECT_EQ(e.find_first_not_of('\0'), absl::string_view::npos);
604 }
605 
606 // Continued from STL2
TEST(StringViewTest,STL2FindLast)607 TEST(StringViewTest, STL2FindLast) {
608   const absl::string_view a("abcdefghijklmnopqrstuvwxyz");
609   const absl::string_view b("abc");
610   const absl::string_view c("xyz");
611   absl::string_view d("foobar");
612   const absl::string_view e;
613   const absl::string_view f(
614       "123"
615       "\0"
616       "456",
617       7);
618   absl::string_view g("xx not found bb");
619   absl::string_view h("====");
620   absl::string_view i("56");
621 
622   d = absl::string_view();
623   EXPECT_EQ(h.find_last_of(a), absl::string_view::npos);
624   EXPECT_EQ(g.find_last_of(a), g.size() - 1);
625   EXPECT_EQ(a.find_last_of(b), 2u);
626   EXPECT_EQ(a.find_last_of(c), a.size() - 1);
627   EXPECT_EQ(f.find_last_of(i), 6u);
628   EXPECT_EQ(a.find_last_of('a'), 0u);
629   EXPECT_EQ(a.find_last_of('b'), 1u);
630   EXPECT_EQ(a.find_last_of('z'), 25u);
631   EXPECT_EQ(a.find_last_of('a', 5), 0u);
632   EXPECT_EQ(a.find_last_of('b', 5), 1u);
633   EXPECT_EQ(a.find_last_of('b', 0), absl::string_view::npos);
634   EXPECT_EQ(a.find_last_of('z', 25), 25u);
635   EXPECT_EQ(a.find_last_of('z', 24), absl::string_view::npos);
636   EXPECT_EQ(f.find_last_of(i, 5), 5u);
637   EXPECT_EQ(f.find_last_of(i, 6), 6u);
638   EXPECT_EQ(f.find_last_of(a, 4), absl::string_view::npos);
639   // empty string nonsense
640   EXPECT_EQ(f.find_last_of(d), absl::string_view::npos);
641   EXPECT_EQ(f.find_last_of(e), absl::string_view::npos);
642   EXPECT_EQ(f.find_last_of(d, 4), absl::string_view::npos);
643   EXPECT_EQ(f.find_last_of(e, 4), absl::string_view::npos);
644   EXPECT_EQ(d.find_last_of(d), absl::string_view::npos);
645   EXPECT_EQ(d.find_last_of(e), absl::string_view::npos);
646   EXPECT_EQ(e.find_last_of(d), absl::string_view::npos);
647   EXPECT_EQ(e.find_last_of(e), absl::string_view::npos);
648   EXPECT_EQ(d.find_last_of(f), absl::string_view::npos);
649   EXPECT_EQ(e.find_last_of(f), absl::string_view::npos);
650   EXPECT_EQ(d.find_last_of(d, 4), absl::string_view::npos);
651   EXPECT_EQ(d.find_last_of(e, 4), absl::string_view::npos);
652   EXPECT_EQ(e.find_last_of(d, 4), absl::string_view::npos);
653   EXPECT_EQ(e.find_last_of(e, 4), absl::string_view::npos);
654   EXPECT_EQ(d.find_last_of(f, 4), absl::string_view::npos);
655   EXPECT_EQ(e.find_last_of(f, 4), absl::string_view::npos);
656 
657   EXPECT_EQ(a.find_last_not_of(b), a.size() - 1);
658   EXPECT_EQ(a.find_last_not_of(c), 22u);
659   EXPECT_EQ(b.find_last_not_of(a), absl::string_view::npos);
660   EXPECT_EQ(b.find_last_not_of(b), absl::string_view::npos);
661   EXPECT_EQ(f.find_last_not_of(i), 4u);
662   EXPECT_EQ(a.find_last_not_of(c, 24), 22u);
663   EXPECT_EQ(a.find_last_not_of(b, 3), 3u);
664   EXPECT_EQ(a.find_last_not_of(b, 2), absl::string_view::npos);
665   // empty string nonsense
666   EXPECT_EQ(f.find_last_not_of(d), f.size() - 1);
667   EXPECT_EQ(f.find_last_not_of(e), f.size() - 1);
668   EXPECT_EQ(f.find_last_not_of(d, 4), 4u);
669   EXPECT_EQ(f.find_last_not_of(e, 4), 4u);
670   EXPECT_EQ(d.find_last_not_of(d), absl::string_view::npos);
671   EXPECT_EQ(d.find_last_not_of(e), absl::string_view::npos);
672   EXPECT_EQ(e.find_last_not_of(d), absl::string_view::npos);
673   EXPECT_EQ(e.find_last_not_of(e), absl::string_view::npos);
674   EXPECT_EQ(d.find_last_not_of(f), absl::string_view::npos);
675   EXPECT_EQ(e.find_last_not_of(f), absl::string_view::npos);
676   EXPECT_EQ(d.find_last_not_of(d, 4), absl::string_view::npos);
677   EXPECT_EQ(d.find_last_not_of(e, 4), absl::string_view::npos);
678   EXPECT_EQ(e.find_last_not_of(d, 4), absl::string_view::npos);
679   EXPECT_EQ(e.find_last_not_of(e, 4), absl::string_view::npos);
680   EXPECT_EQ(d.find_last_not_of(f, 4), absl::string_view::npos);
681   EXPECT_EQ(e.find_last_not_of(f, 4), absl::string_view::npos);
682 
683   EXPECT_EQ(h.find_last_not_of('x'), h.size() - 1);
684   EXPECT_EQ(h.find_last_not_of('='), absl::string_view::npos);
685   EXPECT_EQ(b.find_last_not_of('c'), 1u);
686   EXPECT_EQ(h.find_last_not_of('x', 2), 2u);
687   EXPECT_EQ(h.find_last_not_of('=', 2), absl::string_view::npos);
688   EXPECT_EQ(b.find_last_not_of('b', 1), 0u);
689   // empty string nonsense
690   EXPECT_EQ(d.find_last_not_of('x'), absl::string_view::npos);
691   EXPECT_EQ(e.find_last_not_of('x'), absl::string_view::npos);
692   EXPECT_EQ(d.find_last_not_of('\0'), absl::string_view::npos);
693   EXPECT_EQ(e.find_last_not_of('\0'), absl::string_view::npos);
694 }
695 
696 // Continued from STL2
TEST(StringViewTest,STL2Substr)697 TEST(StringViewTest, STL2Substr) {
698   const absl::string_view a("abcdefghijklmnopqrstuvwxyz");
699   const absl::string_view b("abc");
700   const absl::string_view c("xyz");
701   absl::string_view d("foobar");
702   const absl::string_view e;
703 
704   d = absl::string_view();
705   EXPECT_EQ(a.substr(0, 3), b);
706   EXPECT_EQ(a.substr(23), c);
707   EXPECT_EQ(a.substr(23, 3), c);
708   EXPECT_EQ(a.substr(23, 99), c);
709   EXPECT_EQ(a.substr(0), a);
710   EXPECT_EQ(a.substr(), a);
711   EXPECT_EQ(a.substr(3, 2), "de");
712   // empty string nonsense
713   EXPECT_EQ(d.substr(0, 99), e);
714   // use of npos
715   EXPECT_EQ(a.substr(0, absl::string_view::npos), a);
716   EXPECT_EQ(a.substr(23, absl::string_view::npos), c);
717   // throw exception
718 #ifdef ABSL_HAVE_EXCEPTIONS
719   EXPECT_THROW((void)a.substr(99, 2), std::out_of_range);
720 #else
721   ABSL_EXPECT_DEATH_IF_SUPPORTED((void)a.substr(99, 2),
722                                  "absl::string_view::substr");
723 #endif
724 }
725 
TEST(StringViewTest,TruncSubstr)726 TEST(StringViewTest, TruncSubstr) {
727   const absl::string_view hi("hi");
728   EXPECT_EQ("", absl::ClippedSubstr(hi, 0, 0));
729   EXPECT_EQ("h", absl::ClippedSubstr(hi, 0, 1));
730   EXPECT_EQ("hi", absl::ClippedSubstr(hi, 0));
731   EXPECT_EQ("i", absl::ClippedSubstr(hi, 1));
732   EXPECT_EQ("", absl::ClippedSubstr(hi, 2));
733   EXPECT_EQ("", absl::ClippedSubstr(hi, 3));  // truncation
734   EXPECT_EQ("", absl::ClippedSubstr(hi, 3, 2));  // truncation
735 }
736 
TEST(StringViewTest,UTF8)737 TEST(StringViewTest, UTF8) {
738   std::string utf8 = "\u00E1";
739   std::string utf8_twice = utf8 + " " + utf8;
740   size_t utf8_len = strlen(utf8.data());
741   EXPECT_EQ(utf8_len, absl::string_view(utf8_twice).find_first_of(" "));
742   EXPECT_EQ(utf8_len, absl::string_view(utf8_twice).find_first_of(" \t"));
743 }
744 
TEST(StringViewTest,FindConformance)745 TEST(StringViewTest, FindConformance) {
746   struct {
747     std::string haystack;
748     std::string needle;
749   } specs[] = {
750     {"", ""},
751     {"", "a"},
752     {"a", ""},
753     {"a", "a"},
754     {"a", "b"},
755     {"aa", ""},
756     {"aa", "a"},
757     {"aa", "b"},
758     {"ab", "a"},
759     {"ab", "b"},
760     {"abcd", ""},
761     {"abcd", "a"},
762     {"abcd", "d"},
763     {"abcd", "ab"},
764     {"abcd", "bc"},
765     {"abcd", "cd"},
766     {"abcd", "abcd"},
767   };
768   for (const auto& s : specs) {
769     SCOPED_TRACE(s.haystack);
770     SCOPED_TRACE(s.needle);
771     std::string st = s.haystack;
772     absl::string_view sp = s.haystack;
773     for (size_t i = 0; i <= sp.size(); ++i) {
774       size_t pos = (i == sp.size()) ? absl::string_view::npos : i;
775       SCOPED_TRACE(pos);
776       EXPECT_EQ(sp.find(s.needle, pos),
777                 st.find(s.needle, pos));
778       EXPECT_EQ(sp.rfind(s.needle, pos),
779                 st.rfind(s.needle, pos));
780       EXPECT_EQ(sp.find_first_of(s.needle, pos),
781                 st.find_first_of(s.needle, pos));
782       EXPECT_EQ(sp.find_first_not_of(s.needle, pos),
783                 st.find_first_not_of(s.needle, pos));
784       EXPECT_EQ(sp.find_last_of(s.needle, pos),
785                 st.find_last_of(s.needle, pos));
786       EXPECT_EQ(sp.find_last_not_of(s.needle, pos),
787                 st.find_last_not_of(s.needle, pos));
788     }
789   }
790 }
791 
TEST(StringViewTest,Remove)792 TEST(StringViewTest, Remove) {
793   absl::string_view a("foobar");
794   std::string s1("123");
795   s1 += '\0';
796   s1 += "456";
797   absl::string_view e;
798   std::string s2;
799 
800   // remove_prefix
801   absl::string_view c(a);
802   c.remove_prefix(3);
803   EXPECT_EQ(c, "bar");
804   c = a;
805   c.remove_prefix(0);
806   EXPECT_EQ(c, a);
807   c.remove_prefix(c.size());
808   EXPECT_EQ(c, e);
809 
810   // remove_suffix
811   c = a;
812   c.remove_suffix(3);
813   EXPECT_EQ(c, "foo");
814   c = a;
815   c.remove_suffix(0);
816   EXPECT_EQ(c, a);
817   c.remove_suffix(c.size());
818   EXPECT_EQ(c, e);
819 }
820 
TEST(StringViewTest,Set)821 TEST(StringViewTest, Set) {
822   absl::string_view a("foobar");
823   absl::string_view empty;
824   absl::string_view b;
825 
826   // set
827   b = absl::string_view("foobar", 6);
828   EXPECT_EQ(b, a);
829   b = absl::string_view("foobar", 0);
830   EXPECT_EQ(b, empty);
831   b = absl::string_view("foobar", 7);
832   EXPECT_NE(b, a);
833 
834   b = absl::string_view("foobar");
835   EXPECT_EQ(b, a);
836 }
837 
TEST(StringViewTest,FrontBack)838 TEST(StringViewTest, FrontBack) {
839   static const char arr[] = "abcd";
840   const absl::string_view csp(arr, 4);
841   EXPECT_EQ(&arr[0], &csp.front());
842   EXPECT_EQ(&arr[3], &csp.back());
843 }
844 
TEST(StringViewTest,FrontBackSingleChar)845 TEST(StringViewTest, FrontBackSingleChar) {
846   static const char c = 'a';
847   const absl::string_view csp(&c, 1);
848   EXPECT_EQ(&c, &csp.front());
849   EXPECT_EQ(&c, &csp.back());
850 }
851 
TEST(StringViewTest,FrontBackEmpty)852 TEST(StringViewTest, FrontBackEmpty) {
853 #ifndef ABSL_USES_STD_STRING_VIEW
854 #if !defined(NDEBUG) || ABSL_OPTION_HARDENED
855   // Abseil's string_view implementation has debug assertions that check that
856   // front() and back() are not called on an empty string_view.
857   absl::string_view sv;
858   ABSL_EXPECT_DEATH_IF_SUPPORTED(sv.front(), "");
859   ABSL_EXPECT_DEATH_IF_SUPPORTED(sv.back(), "");
860 #endif
861 #endif
862 }
863 
864 // `std::string_view::string_view(const char*)` calls
865 // `std::char_traits<char>::length(const char*)` to get the string length. In
866 // libc++, it doesn't allow `nullptr` in the constexpr context, with the error
867 // "read of dereferenced null pointer is not allowed in a constant expression".
868 // At run time, the behavior of `std::char_traits::length()` on `nullptr` is
869 // undefined by the standard and usually results in crash with libc++.
870 // GCC also started rejected this in libstdc++ starting in GCC9.
871 // In MSVC, creating a constexpr string_view from nullptr also triggers an
872 // "unevaluable pointer value" error. This compiler implementation conforms
873 // to the standard, but `absl::string_view` implements a different
874 // behavior for historical reasons. We work around tests that construct
875 // `string_view` from `nullptr` when using libc++.
876 #if !defined(ABSL_USES_STD_STRING_VIEW) ||                    \
877     (!(defined(_GLIBCXX_RELEASE) && _GLIBCXX_RELEASE >= 9) && \
878      !defined(_LIBCPP_VERSION) && !defined(_MSC_VER))
879 #define ABSL_HAVE_STRING_VIEW_FROM_NULLPTR 1
880 #endif
881 
TEST(StringViewTest,NULLInput)882 TEST(StringViewTest, NULLInput) {
883   absl::string_view s;
884   EXPECT_EQ(s.data(), nullptr);
885   EXPECT_EQ(s.size(), 0u);
886 
887 #ifdef ABSL_HAVE_STRING_VIEW_FROM_NULLPTR
888   s = absl::string_view(nullptr);
889   EXPECT_EQ(s.data(), nullptr);
890   EXPECT_EQ(s.size(), 0u);
891 
892   // .ToString() on a absl::string_view with nullptr should produce the empty
893   // string.
894   EXPECT_EQ("", std::string(s));
895 #endif  // ABSL_HAVE_STRING_VIEW_FROM_NULLPTR
896 }
897 
TEST(StringViewTest,Comparisons2)898 TEST(StringViewTest, Comparisons2) {
899   // The `compare` member has 6 overloads (v: string_view, s: const char*):
900   //  (1) compare(v)
901   //  (2) compare(pos1, count1, v)
902   //  (3) compare(pos1, count1, v, pos2, count2)
903   //  (4) compare(s)
904   //  (5) compare(pos1, count1, s)
905   //  (6) compare(pos1, count1, s, count2)
906 
907   absl::string_view abc("abcdefghijklmnopqrstuvwxyz");
908 
909   // check comparison operations on strings longer than 4 bytes.
910   EXPECT_EQ(abc, absl::string_view("abcdefghijklmnopqrstuvwxyz"));
911   EXPECT_EQ(abc.compare(absl::string_view("abcdefghijklmnopqrstuvwxyz")), 0);
912 
913   EXPECT_LT(abc, absl::string_view("abcdefghijklmnopqrstuvwxzz"));
914   EXPECT_LT(abc.compare(absl::string_view("abcdefghijklmnopqrstuvwxzz")), 0);
915 
916   EXPECT_GT(abc, absl::string_view("abcdefghijklmnopqrstuvwxyy"));
917   EXPECT_GT(abc.compare(absl::string_view("abcdefghijklmnopqrstuvwxyy")), 0);
918 
919   // The "substr" variants of `compare`.
920   absl::string_view digits("0123456789");
921   auto npos = absl::string_view::npos;
922 
923   // Taking string_view
924   EXPECT_EQ(digits.compare(3, npos, absl::string_view("3456789")), 0);  // 2
925   EXPECT_EQ(digits.compare(3, 4, absl::string_view("3456")), 0);        // 2
926   EXPECT_EQ(digits.compare(10, 0, absl::string_view()), 0);             // 2
927   EXPECT_EQ(digits.compare(3, 4, absl::string_view("0123456789"), 3, 4),
928             0);  // 3
929   EXPECT_LT(digits.compare(3, 4, absl::string_view("0123456789"), 3, 5),
930             0);  // 3
931   EXPECT_LT(digits.compare(0, npos, absl::string_view("0123456789"), 3, 5),
932             0);  // 3
933   // Taking const char*
934   EXPECT_EQ(digits.compare(3, 4, "3456"), 0);                 // 5
935   EXPECT_EQ(digits.compare(3, npos, "3456789"), 0);           // 5
936   EXPECT_EQ(digits.compare(10, 0, ""), 0);                    // 5
937   EXPECT_EQ(digits.compare(3, 4, "0123456789", 3, 4), 0);     // 6
938   EXPECT_LT(digits.compare(3, 4, "0123456789", 3, 5), 0);     // 6
939   EXPECT_LT(digits.compare(0, npos, "0123456789", 3, 5), 0);  // 6
940 }
941 
TEST(StringViewTest,At)942 TEST(StringViewTest, At) {
943   absl::string_view abc = "abc";
944   EXPECT_EQ(abc.at(0), 'a');
945   EXPECT_EQ(abc.at(1), 'b');
946   EXPECT_EQ(abc.at(2), 'c');
947 #ifdef ABSL_HAVE_EXCEPTIONS
948   EXPECT_THROW((void)abc.at(3), std::out_of_range);
949 #else
950   ABSL_EXPECT_DEATH_IF_SUPPORTED((void)abc.at(3), "absl::string_view::at");
951 #endif
952 }
953 
954 #if ABSL_INTERNAL_CPLUSPLUS_LANG >= 202002L
TEST(StringViewTest,StartsWith)955 TEST(StringViewTest, StartsWith) {
956   const absl::string_view a("foobar");
957   const absl::string_view b("123\0abc", 7);
958   const absl::string_view e;
959   EXPECT_TRUE(a.starts_with(a));
960   EXPECT_TRUE(a.starts_with("foo"));
961   EXPECT_TRUE(a.starts_with('f'));
962   EXPECT_TRUE(a.starts_with(e));
963   EXPECT_TRUE(b.starts_with(b));
964   EXPECT_TRUE(b.starts_with('1'));
965   EXPECT_TRUE(b.starts_with(e));
966   EXPECT_TRUE(e.starts_with(""));
967   EXPECT_FALSE(a.starts_with(b));
968   EXPECT_FALSE(b.starts_with(a));
969   EXPECT_FALSE(e.starts_with(a));
970   EXPECT_FALSE(a.starts_with('r'));
971   EXPECT_FALSE(a.starts_with('\0'));
972   EXPECT_FALSE(e.starts_with('r'));
973   EXPECT_FALSE(e.starts_with('\0'));
974 
975   // Test that constexpr compiles.
976   constexpr absl::string_view kFooBar("foobar");
977   constexpr absl::string_view kFoo("foo");
978   constexpr absl::string_view kBar("bar");
979   constexpr bool k1 = kFooBar.starts_with(kFoo);
980   EXPECT_TRUE(k1);
981   constexpr bool k2 = kFooBar.starts_with(kBar);
982   EXPECT_FALSE(k2);
983   constexpr bool k3 = kFooBar.starts_with('f');
984   EXPECT_TRUE(k3);
985   constexpr bool k4 = kFooBar.starts_with("fo");
986   EXPECT_TRUE(k4);
987 }
988 
TEST(StringViewTest,EndsWith)989 TEST(StringViewTest, EndsWith) {
990   const absl::string_view a("foobar");
991   const absl::string_view b("123\0abc", 7);
992   const absl::string_view e;
993   EXPECT_TRUE(a.ends_with(a));
994   EXPECT_TRUE(a.ends_with('r'));
995   EXPECT_TRUE(a.ends_with("bar"));
996   EXPECT_TRUE(a.ends_with(e));
997   EXPECT_TRUE(b.ends_with(b));
998   EXPECT_TRUE(b.ends_with('c'));
999   EXPECT_TRUE(b.ends_with(e));
1000   EXPECT_TRUE(e.ends_with(""));
1001   EXPECT_FALSE(a.ends_with(b));
1002   EXPECT_FALSE(b.ends_with(a));
1003   EXPECT_FALSE(e.ends_with(a));
1004   EXPECT_FALSE(a.ends_with('f'));
1005   EXPECT_FALSE(a.ends_with('\0'));
1006   EXPECT_FALSE(e.ends_with('r'));
1007   EXPECT_FALSE(e.ends_with('\0'));
1008 
1009   // Test that constexpr compiles.
1010   constexpr absl::string_view kFooBar("foobar");
1011   constexpr absl::string_view kFoo("foo");
1012   constexpr absl::string_view kBar("bar");
1013   constexpr bool k1 = kFooBar.ends_with(kFoo);
1014   EXPECT_FALSE(k1);
1015   constexpr bool k2 = kFooBar.ends_with(kBar);
1016   EXPECT_TRUE(k2);
1017   constexpr bool k3 = kFooBar.ends_with('r');
1018   EXPECT_TRUE(k3);
1019   constexpr bool k4 = kFooBar.ends_with("ar");
1020   EXPECT_TRUE(k4);
1021 }
1022 #endif  // ABSL_INTERNAL_CPLUSPLUS_LANG >= 202002L
1023 
1024 struct MyCharAlloc : std::allocator<char> {};
1025 
TEST(StringViewTest,ExplicitConversionOperator)1026 TEST(StringViewTest, ExplicitConversionOperator) {
1027   absl::string_view sp = "hi";
1028   EXPECT_EQ(sp, std::string(sp));
1029 }
1030 
TEST(StringViewTest,NullSafeStringView)1031 TEST(StringViewTest, NullSafeStringView) {
1032   {
1033     absl::string_view s = absl::NullSafeStringView(nullptr);
1034     EXPECT_EQ(nullptr, s.data());
1035     EXPECT_EQ(0u, s.size());
1036     EXPECT_EQ(absl::string_view(), s);
1037   }
1038   {
1039     static const char kHi[] = "hi";
1040     absl::string_view s = absl::NullSafeStringView(kHi);
1041     EXPECT_EQ(kHi, s.data());
1042     EXPECT_EQ(strlen(kHi), s.size());
1043     EXPECT_EQ(absl::string_view("hi"), s);
1044   }
1045 }
1046 
TEST(StringViewTest,ConstexprNullSafeStringView)1047 TEST(StringViewTest, ConstexprNullSafeStringView) {
1048   {
1049     constexpr absl::string_view s = absl::NullSafeStringView(nullptr);
1050     EXPECT_EQ(nullptr, s.data());
1051     EXPECT_EQ(0u, s.size());
1052     EXPECT_EQ(absl::string_view(), s);
1053   }
1054 #if !defined(_MSC_VER) || _MSC_VER >= 1910
1055   // MSVC 2017+ is required for good constexpr string_view support.
1056   // See the implementation of `absl::string_view::StrlenInternal()`.
1057   {
1058     static constexpr char kHi[] = "hi";
1059     absl::string_view s = absl::NullSafeStringView(kHi);
1060     EXPECT_EQ(kHi, s.data());
1061     EXPECT_EQ(strlen(kHi), s.size());
1062     EXPECT_EQ(absl::string_view("hi"), s);
1063   }
1064   {
1065     constexpr absl::string_view s = absl::NullSafeStringView("hello");
1066     EXPECT_EQ(s.size(), 5u);
1067     EXPECT_EQ("hello", s);
1068   }
1069 #endif
1070 }
1071 
TEST(StringViewTest,ConstexprCompiles)1072 TEST(StringViewTest, ConstexprCompiles) {
1073   constexpr absl::string_view sp;
1074 #ifdef ABSL_HAVE_STRING_VIEW_FROM_NULLPTR
1075   constexpr absl::string_view cstr(nullptr);
1076 #endif
1077   constexpr absl::string_view cstr_len("cstr", 4);
1078 
1079 #if defined(ABSL_USES_STD_STRING_VIEW)
1080   // In libstdc++ (as of 7.2), `std::string_view::string_view(const char*)`
1081   // calls `std::char_traits<char>::length(const char*)` to get the string
1082   // length, but it is not marked constexpr yet. See GCC bug:
1083   // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78156
1084   // Also, there is a LWG issue that adds constexpr to length() which was just
1085   // resolved 2017-06-02. See
1086   // http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2232
1087   // TODO(zhangxy): Update the condition when libstdc++ adopts the constexpr
1088   // length().
1089 #if !defined(__GLIBCXX__)
1090 #define ABSL_HAVE_CONSTEXPR_STRING_VIEW_FROM_CSTR 1
1091 #endif  // !__GLIBCXX__
1092 
1093 #else  // ABSL_USES_STD_STRING_VIEW
1094 
1095 // This duplicates the check for __builtin_strlen in the header.
1096 #if ABSL_HAVE_BUILTIN(__builtin_strlen) || \
1097     (defined(__GNUC__) && !defined(__clang__))
1098 #define ABSL_HAVE_CONSTEXPR_STRING_VIEW_FROM_CSTR 1
1099 #elif defined(__GNUC__)  // GCC or clang
1100 #error GCC/clang should have constexpr string_view.
1101 #endif
1102 
1103 // MSVC 2017+ should be able to construct a constexpr string_view from a cstr.
1104 #if defined(_MSC_VER) && _MSC_VER >= 1910
1105 #define ABSL_HAVE_CONSTEXPR_STRING_VIEW_FROM_CSTR 1
1106 #endif
1107 
1108 #endif  // ABSL_USES_STD_STRING_VIEW
1109 
1110 #ifdef ABSL_HAVE_CONSTEXPR_STRING_VIEW_FROM_CSTR
1111   constexpr absl::string_view cstr_strlen("foo");
1112   EXPECT_EQ(cstr_strlen.length(), 3u);
1113   constexpr absl::string_view cstr_strlen2 = "bar";
1114   EXPECT_EQ(cstr_strlen2, "bar");
1115 
1116 #if ABSL_HAVE_BUILTIN(__builtin_memcmp) || \
1117     (defined(__GNUC__) && !defined(__clang__))
1118 #define ABSL_HAVE_CONSTEXPR_STRING_VIEW_COMPARISON 1
1119 #endif
1120 #ifdef ABSL_HAVE_CONSTEXPR_STRING_VIEW_COMPARISON
1121   constexpr absl::string_view foo = "foo";
1122   constexpr absl::string_view bar = "bar";
1123   constexpr bool foo_eq_bar = foo == bar;
1124   constexpr bool foo_ne_bar = foo != bar;
1125   constexpr bool foo_lt_bar = foo < bar;
1126   constexpr bool foo_le_bar = foo <= bar;
1127   constexpr bool foo_gt_bar = foo > bar;
1128   constexpr bool foo_ge_bar = foo >= bar;
1129   constexpr int foo_compare_bar = foo.compare(bar);
1130   EXPECT_FALSE(foo_eq_bar);
1131   EXPECT_TRUE(foo_ne_bar);
1132   EXPECT_FALSE(foo_lt_bar);
1133   EXPECT_FALSE(foo_le_bar);
1134   EXPECT_TRUE(foo_gt_bar);
1135   EXPECT_TRUE(foo_ge_bar);
1136   EXPECT_GT(foo_compare_bar, 0);
1137 #endif
1138 #endif
1139 
1140 #if !defined(__clang__) || 3 < __clang_major__ || \
1141   (3 == __clang_major__ && 4 < __clang_minor__)
1142   // older clang versions (< 3.5) complain that:
1143   //   "cannot perform pointer arithmetic on null pointer"
1144   constexpr absl::string_view::iterator const_begin_empty = sp.begin();
1145   constexpr absl::string_view::iterator const_end_empty = sp.end();
1146   EXPECT_EQ(const_begin_empty, const_end_empty);
1147 
1148 #ifdef ABSL_HAVE_STRING_VIEW_FROM_NULLPTR
1149   constexpr absl::string_view::iterator const_begin_nullptr = cstr.begin();
1150   constexpr absl::string_view::iterator const_end_nullptr = cstr.end();
1151   EXPECT_EQ(const_begin_nullptr, const_end_nullptr);
1152 #endif  // ABSL_HAVE_STRING_VIEW_FROM_NULLPTR
1153 #endif  // !defined(__clang__) || ...
1154 
1155   constexpr absl::string_view::iterator const_begin = cstr_len.begin();
1156   constexpr absl::string_view::iterator const_end = cstr_len.end();
1157   constexpr absl::string_view::size_type const_size = cstr_len.size();
1158   constexpr absl::string_view::size_type const_length = cstr_len.length();
1159   static_assert(const_begin + const_size == const_end,
1160                 "pointer arithmetic check");
1161   static_assert(const_begin + const_length == const_end,
1162                 "pointer arithmetic check");
1163 #ifndef _MSC_VER
1164   // MSVC has bugs doing constexpr pointer arithmetic.
1165   // https://developercommunity.visualstudio.com/content/problem/482192/bad-pointer-arithmetic-in-constepxr-2019-rc1-svc1.html
1166   EXPECT_EQ(const_begin + const_size, const_end);
1167   EXPECT_EQ(const_begin + const_length, const_end);
1168 #endif
1169 
1170   constexpr bool isempty = sp.empty();
1171   EXPECT_TRUE(isempty);
1172 
1173   constexpr const char c = cstr_len[2];
1174   EXPECT_EQ(c, 't');
1175 
1176   constexpr const char cfront = cstr_len.front();
1177   constexpr const char cback = cstr_len.back();
1178   EXPECT_EQ(cfront, 'c');
1179   EXPECT_EQ(cback, 'r');
1180 
1181   constexpr const char* np = sp.data();
1182   constexpr const char* cstr_ptr = cstr_len.data();
1183   EXPECT_EQ(np, nullptr);
1184   EXPECT_NE(cstr_ptr, nullptr);
1185 
1186   constexpr size_t sp_npos = sp.npos;
1187   EXPECT_EQ(sp_npos, static_cast<size_t>(-1));
1188 }
1189 
ConstexprMethodsHelper()1190 constexpr char ConstexprMethodsHelper() {
1191 #if defined(__cplusplus) && __cplusplus >= 201402L
1192   absl::string_view str("123", 3);
1193   str.remove_prefix(1);
1194   str.remove_suffix(1);
1195   absl::string_view bar;
1196   str.swap(bar);
1197   return bar.front();
1198 #else
1199   return '2';
1200 #endif
1201 }
1202 
TEST(StringViewTest,ConstexprMethods)1203 TEST(StringViewTest, ConstexprMethods) {
1204   // remove_prefix, remove_suffix, swap
1205   static_assert(ConstexprMethodsHelper() == '2', "");
1206 
1207   // substr
1208   constexpr absl::string_view foobar("foobar", 6);
1209   constexpr absl::string_view foo = foobar.substr(0, 3);
1210   constexpr absl::string_view bar = foobar.substr(3);
1211   EXPECT_EQ(foo, "foo");
1212   EXPECT_EQ(bar, "bar");
1213 }
1214 
TEST(StringViewTest,Noexcept)1215 TEST(StringViewTest, Noexcept) {
1216   EXPECT_TRUE((std::is_nothrow_constructible<absl::string_view,
1217                                              const std::string&>::value));
1218   EXPECT_TRUE((std::is_nothrow_constructible<absl::string_view,
1219                                              const std::string&>::value));
1220   EXPECT_TRUE(std::is_nothrow_constructible<absl::string_view>::value);
1221   constexpr absl::string_view sp;
1222   EXPECT_TRUE(noexcept(sp.begin()));
1223   EXPECT_TRUE(noexcept(sp.end()));
1224   EXPECT_TRUE(noexcept(sp.cbegin()));
1225   EXPECT_TRUE(noexcept(sp.cend()));
1226   EXPECT_TRUE(noexcept(sp.rbegin()));
1227   EXPECT_TRUE(noexcept(sp.rend()));
1228   EXPECT_TRUE(noexcept(sp.crbegin()));
1229   EXPECT_TRUE(noexcept(sp.crend()));
1230   EXPECT_TRUE(noexcept(sp.size()));
1231   EXPECT_TRUE(noexcept(sp.length()));
1232   EXPECT_TRUE(noexcept(sp.empty()));
1233   EXPECT_TRUE(noexcept(sp.data()));
1234   EXPECT_TRUE(noexcept(sp.compare(sp)));
1235   EXPECT_TRUE(noexcept(sp.find(sp)));
1236   EXPECT_TRUE(noexcept(sp.find('f')));
1237   EXPECT_TRUE(noexcept(sp.rfind(sp)));
1238   EXPECT_TRUE(noexcept(sp.rfind('f')));
1239   EXPECT_TRUE(noexcept(sp.find_first_of(sp)));
1240   EXPECT_TRUE(noexcept(sp.find_first_of('f')));
1241   EXPECT_TRUE(noexcept(sp.find_last_of(sp)));
1242   EXPECT_TRUE(noexcept(sp.find_last_of('f')));
1243   EXPECT_TRUE(noexcept(sp.find_first_not_of(sp)));
1244   EXPECT_TRUE(noexcept(sp.find_first_not_of('f')));
1245   EXPECT_TRUE(noexcept(sp.find_last_not_of(sp)));
1246   EXPECT_TRUE(noexcept(sp.find_last_not_of('f')));
1247 }
1248 
TEST(StringViewTest,BoundsCheck)1249 TEST(StringViewTest, BoundsCheck) {
1250 #ifndef ABSL_USES_STD_STRING_VIEW
1251 #if !defined(NDEBUG) || ABSL_OPTION_HARDENED
1252   // Abseil's string_view implementation has bounds-checking in debug mode.
1253   absl::string_view h = "hello";
1254   ABSL_EXPECT_DEATH_IF_SUPPORTED(h[5], "");
1255   ABSL_EXPECT_DEATH_IF_SUPPORTED(h[static_cast<size_t>(-1)], "");
1256 #endif
1257 #endif
1258 }
1259 
TEST(ComparisonOpsTest,StringCompareNotAmbiguous)1260 TEST(ComparisonOpsTest, StringCompareNotAmbiguous) {
1261   EXPECT_EQ("hello", std::string("hello"));
1262   EXPECT_LT("hello", std::string("world"));
1263 }
1264 
TEST(ComparisonOpsTest,HeterogeneousStringViewEquals)1265 TEST(ComparisonOpsTest, HeterogeneousStringViewEquals) {
1266   EXPECT_EQ(absl::string_view("hello"), std::string("hello"));
1267   EXPECT_EQ("hello", absl::string_view("hello"));
1268 }
1269 
TEST(FindOneCharTest,EdgeCases)1270 TEST(FindOneCharTest, EdgeCases) {
1271   absl::string_view a("xxyyyxx");
1272 
1273   // Set a = "xyyyx".
1274   a.remove_prefix(1);
1275   a.remove_suffix(1);
1276 
1277   EXPECT_EQ(0u, a.find('x'));
1278   EXPECT_EQ(0u, a.find('x', 0));
1279   EXPECT_EQ(4u, a.find('x', 1));
1280   EXPECT_EQ(4u, a.find('x', 4));
1281   EXPECT_EQ(absl::string_view::npos, a.find('x', 5));
1282 
1283   EXPECT_EQ(4u, a.rfind('x'));
1284   EXPECT_EQ(4u, a.rfind('x', 5));
1285   EXPECT_EQ(4u, a.rfind('x', 4));
1286   EXPECT_EQ(0u, a.rfind('x', 3));
1287   EXPECT_EQ(0u, a.rfind('x', 0));
1288 
1289   // Set a = "yyy".
1290   a.remove_prefix(1);
1291   a.remove_suffix(1);
1292 
1293   EXPECT_EQ(absl::string_view::npos, a.find('x'));
1294   EXPECT_EQ(absl::string_view::npos, a.rfind('x'));
1295 }
1296 
1297 #ifndef ABSL_HAVE_THREAD_SANITIZER  // Allocates too much memory for tsan.
TEST(HugeStringView,TwoPointTwoGB)1298 TEST(HugeStringView, TwoPointTwoGB) {
1299   if (sizeof(size_t) <= 4)
1300     return;
1301   // Try a huge string piece.
1302   const size_t size = size_t{2200} * 1000 * 1000;
1303   std::string s(size, 'a');
1304   absl::string_view sp(s);
1305   EXPECT_EQ(size, sp.length());
1306   sp.remove_prefix(1);
1307   EXPECT_EQ(size - 1, sp.length());
1308   sp.remove_suffix(2);
1309   EXPECT_EQ(size - 1 - 2, sp.length());
1310 }
1311 #endif  // ABSL_HAVE_THREAD_SANITIZER
1312 
1313 #if !defined(NDEBUG) && !defined(ABSL_USES_STD_STRING_VIEW)
TEST(NonNegativeLenTest,NonNegativeLen)1314 TEST(NonNegativeLenTest, NonNegativeLen) {
1315   ABSL_EXPECT_DEATH_IF_SUPPORTED(
1316       absl::string_view("xyz", static_cast<size_t>(-1)), "len <= kMaxSize");
1317 }
1318 
TEST(LenExceedsMaxSizeTest,LenExceedsMaxSize)1319 TEST(LenExceedsMaxSizeTest, LenExceedsMaxSize) {
1320   auto max_size = absl::string_view().max_size();
1321 
1322   // This should construct ok (although the view itself is obviously invalid).
1323   absl::string_view ok_view("", max_size);
1324 
1325   // Adding one to the max should trigger an assertion.
1326   ABSL_EXPECT_DEATH_IF_SUPPORTED(absl::string_view("", max_size + 1),
1327                                  "len <= kMaxSize");
1328 }
1329 #endif  // !defined(NDEBUG) && !defined(ABSL_USES_STD_STRING_VIEW)
1330 
1331 class StringViewStreamTest : public ::testing::Test {
1332  public:
1333   // Set negative 'width' for right justification.
1334   template <typename T>
Pad(const T & s,int width,char fill=0)1335   std::string Pad(const T& s, int width, char fill = 0) {
1336     std::ostringstream oss;
1337     if (fill != 0) {
1338       oss << std::setfill(fill);
1339     }
1340     if (width < 0) {
1341       width = -width;
1342       oss << std::right;
1343     }
1344     oss << std::setw(width) << s;
1345     return oss.str();
1346   }
1347 };
1348 
TEST_F(StringViewStreamTest,Padding)1349 TEST_F(StringViewStreamTest, Padding) {
1350   std::string s("hello");
1351   absl::string_view sp(s);
1352   for (int w = -64; w < 64; ++w) {
1353     SCOPED_TRACE(w);
1354     EXPECT_EQ(Pad(s, w), Pad(sp, w));
1355   }
1356   for (int w = -64; w < 64; ++w) {
1357     SCOPED_TRACE(w);
1358     EXPECT_EQ(Pad(s, w, '#'), Pad(sp, w, '#'));
1359   }
1360 }
1361 
TEST_F(StringViewStreamTest,ResetsWidth)1362 TEST_F(StringViewStreamTest, ResetsWidth) {
1363   // Width should reset after one formatted write.
1364   // If we weren't resetting width after formatting the string_view,
1365   // we'd have width=5 carrying over to the printing of the "]",
1366   // creating "[###hi####]".
1367   std::string s = "hi";
1368   absl::string_view sp = s;
1369   {
1370     std::ostringstream oss;
1371     oss << "[" << std::setfill('#') << std::setw(5) << s << "]";
1372     ASSERT_EQ("[###hi]", oss.str());
1373   }
1374   {
1375     std::ostringstream oss;
1376     oss << "[" << std::setfill('#') << std::setw(5) << sp << "]";
1377     EXPECT_EQ("[###hi]", oss.str());
1378   }
1379 }
1380 
1381 }  // namespace
1382