Replace RE2 import with a dependency

third_party/re2/re2/testing/string_generator_test.cc

-// Copyright 2008 The RE2 Authors.  All Rights Reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Test StringGenerator.
-
-#include <stdlib.h>
-#include <string>
-#include <vector>
-#include "util/test.h"
-#include "re2/testing/string_generator.h"
-#include "re2/testing/regexp_generator.h"
-
-namespace re2 {
-
-// Returns i to the e.
-static int64 IntegerPower(int i, int e) {
-  int64 p = 1;
-  while (e-- > 0)
-    p *= i;
-  return p;
-}
-
-// Checks that for given settings of the string generator:
-//   * it generates strings that are non-decreasing in length.
-//   * strings of the same length are sorted in alphabet order.
-//   * it doesn't generate the same string twice.
-//   * it generates the right number of strings.
-//
-// If all of these hold, the StringGenerator is behaving.
-// Assumes that the alphabet is sorted, so that the generated
-// strings can just be compared lexicographically.
-static void RunTest(int len, string alphabet, bool donull) {
-  StringGenerator g(len, Explode(alphabet));
-
-  int n = 0;
-  int last_l = -1;
-  string last_s;
-
-  if (donull) {
-    g.GenerateNULL();
-    EXPECT_TRUE(g.HasNext());
-    StringPiece sp = g.Next();
-    EXPECT_EQ(sp.data(), static_cast<const char*>(NULL));
-    EXPECT_EQ(sp.size(), 0);
-  }
-
-  while (g.HasNext()) {
-    string s = g.Next().as_string();
-    n++;
-
-    // Check that all characters in s appear in alphabet.
-    for (const char *p = s.c_str(); *p != '\0'; ) {
-      Rune r;
-      p += chartorune(&r, p);
-      EXPECT_TRUE(utfrune(alphabet.c_str(), r) != NULL);
-    }
-
-    // Check that string is properly ordered w.r.t. previous string.
-    int l = utflen(s.c_str());
-    EXPECT_LE(l, len);
-    if (last_l < l) {
-      last_l = l;
-    } else {
-      EXPECT_EQ(last_l, l);
-      EXPECT_LT(last_s, s);
-    }
-    last_s = s;
-  }
-
-  // Check total string count.
-  int64 m = 0;
-  int alpha = utflen(alphabet.c_str());
-  if (alpha == 0)  // Degenerate case.
-    len = 0;
-  for (int i = 0; i <= len; i++)
-    m += IntegerPower(alpha, i);
-  EXPECT_EQ(n, m);
-}
-
-TEST(StringGenerator, NoLength) {
-  RunTest(0, "abc", false);
-}
-
-TEST(StringGenerator, NoLengthNoAlphabet) {
-  RunTest(0, "", false);
-}
-
-TEST(StringGenerator, NoAlphabet) {
-  RunTest(5, "", false);
-}
-
-TEST(StringGenerator, Simple) {
-  RunTest(3, "abc", false);
-}
-
-TEST(StringGenerator, UTF8) {
-  RunTest(4, "abc\xE2\x98\xBA", false);
-}
-
-TEST(StringGenerator, GenNULL) {
-  RunTest(0, "abc", true);
-  RunTest(0, "", true);
-  RunTest(5, "", true);
-  RunTest(3, "abc", true);
-  RunTest(4, "abc\xE2\x98\xBA", true);
-}
-
-}  // namespace re2