LibTest/core/RegExp/Pattern_semantics/firstMatch_Disjunction_A01_t01.dart

/*
 * Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 * for details. All rights reserved. Use of this source code is governed by a
 * BSD-style license that can be found in the LICENSE file.
 */
/**
 * @assertion 15.10.2.3: The | regular expression operator separates two
 *            alternatives. The pattern first tries to match the left
 *            Alternative (followed by the sequel of the regular expression); if
 *            it fails, it tries to match the right Disjunction (followed by the
 *            sequel of the regular expression). If the left Alternative, the
 *            right Disjunction, and the sequel all have choice points, all
 *            choices in the sequel are tried before moving on to the next
 *            choice in the left Alternative. If choices in the left Alternative
 *            are exhausted, the right Disjunction is tried instead of the left
 *            Alternative. Any capturing parentheses inside a portion of the
 *            pattern skipped by | produce undefined values instead of Strings.
 * @description Checks that a valid disjunction pattern works as described and that the captured groups have correct values.
 * @3rdparty sputnik-v1:S15.10.2.3_A1_T1.js-S15.10.2.3_A1_T17.js
 * @author rodionov
 * @note We're assuming JS's undefined values are translated to nulls in Dart.
 * @needsreview
 * @reviewer msyabro
 */
import "../../../../Utils/expect.dart";
 

main() {
  check("a|ab", "abc");
  check("\\d{3}|[a-z]{4}", "2, 12 and of course repeat 12");
  checkNeg("\\d{3}|[a-z]{4}", "2, 12 and 23 AND 0.00.1");
  check("ab|cd|ef", "AEKFCD", ignoreCase: true);
  checkNeg("ab|cd|ef", "AEKFCD");
  check("11111|111", "1111111111111111");
  check("xyz|...", "abc");
  check("(ab|cd)+|ef",                  "AEKFCD",       ignoreCase:true,  expectedGroups:["CD", "CD"]);
  check("(ab|cd)+|ef",                  "AEKFCDab",     ignoreCase:true,  expectedGroups:["CDab", "ab"]);
  check("(ab|cd)+|ef",                  "AEKeFCDab",    ignoreCase:true,  expectedGroups:["eF", null]);
  check("(.)..|abc",                    "abc",          expectedGroups:["abc", "a"]);
  check(".+: gr(a|e)y",                 "color: grey",  expectedGroups:["color: grey", "e"]);
  check("(Rob)|(Bob)|(Robert)|(Bobby)", "Hi Bob",       expectedGroups:["Bob", null, "Bob", null, null]);
  check("()|",                          "",             expectedGroups:["", ""]);
  check("|()",                          "",             expectedGroups:["", null]);
  check("((a)|(ab))((c)|(bc))",         "abc",          expectedGroups:["abc", "a", "a", null, "bc", null, "bc"]);
  check("((a)|(b))c",                   "aebc",         expectedGroups:["bc", "b", null, "b"]);
}

void check(String pattern, String str, {bool multiLine: false, bool ignoreCase: false,
    List<String> expectedGroups: null}) {
  RegExp re = new RegExp(pattern, multiLine: multiLine, caseSensitive: !ignoreCase);
  Match fm = re.firstMatch(str);
  if(null == fm) {
    Expect.fail("\"$pattern\" !~ \"$str\"");
  }
  if(null != expectedGroups) {
    Expect.equals(expectedGroups.length, fm.groupCount + 1);
    
    for(int i = 0; i <= fm.groupCount; i++) {
      String expGr = expectedGroups[i];
      String actGr = fm.group(i);
      if(expGr != actGr) {
        Expect.fail("Mismatch at group $i: \"$expGr\" expected instead of \"$actGr\"");
      }
    }
  }
}

void checkNeg(String pattern, String str) {
  RegExp re = new RegExp(pattern);
  if(null != re.firstMatch(str)) {
    Expect.fail("\"$pattern\" ~ \"$str\"");
  }
}