Regex support for missing predefined character classes and negated character classes by lmasroca · Pull Request #1474 · WebFuzzing/EvoMaster

lmasroca · 2026-03-17T16:44:11Z

Added Java/JS support for negated character classes
Added Java support for missing predefined character classes escapes (\v, \H, etc.) and POSIX character classes (\p{Lower}, etc.)

…\v, \V, \h, \H)

… etc.)

…nal-pr-lmasroca

…omplement for predefined character classes

…al-pr-lmasroca

…mization

…rrently fails otherwise

…al-pr-lmasroca

…nal-pr-lmasroca

…as CI currently fails otherwise" This reverts commit 56a7462.

core/src/main/antlr4/org/evomaster/core/parser/RegexJava.g4

core/src/main/kotlin/org/evomaster/core/search/gene/regex/CharacterRangeRxGene.kt

core/src/main/kotlin/org/evomaster/core/search/service/Randomness.kt

core/src/test/kotlin/org/evomaster/core/search/gene/GeneSamplerForTests.kt

…ts.kt

lmasroca · 2026-03-20T13:33:16Z

Looking into this failing check, the test generates a SqlCompositeGene which contains a ChoiceGene which contains an ArrayGene which starts empty but its template contains SqlForeignKeyGene. This generates no problems as long as the array is empty, but as soon as the array gets a random element everything stops being globally valid (in this case the new element, SqlForeignKeyGene is not globally valid as none of its parents in the chain are an SqlAction). The test filters globally invalid genes before randomizing but not after.

This happens on GeneRandomizedTest during verifyCopyValueFrom. We could add a globally valid check after randomization the same way it is done with printable checks, this makes the test pass. However, I am not sure if there should be checks in place to make this chain invalid even before randomizing instead.

    private fun verifyCopyValueFrom(
        mutable: List<Gene>,
        rand: Randomness
    ) {
        val printable = mutable.filter { it.isGloballyValid() && it.isPrintable() }

        printable.forEach { root ->

            val x = root.copy()
            val sx = x.getValueAsRawString()

            val y = x.copy().apply { randomize(rand, true) }
            if(!y.isPrintable()){ // we could add a globally valid check here the same way we filter before
                return@forEach
            }
            val sy = y.getValueAsRawString()

jgaleotti · 2026-03-24T13:42:43Z

CI is passing. I think this is ready for Andrea's review.

arcuri82 · 2026-03-25T09:38:28Z

...s/spring/spring-rest-openapi-v3/src/main/resources/static/openapi-dto-reflective-assert.yaml

                - aDouble
                - aFloat
                - aBoolean
+                - aNullableString


why this change?
@Pgarrett you wrote this file, isn't it? what is your opinion on this change?

Yes I did, it seemed one of the fields was not being generated in the test and thus causing the test to fail in the reflective assertions

No concern on my side

arcuri82 · 2026-03-25T09:42:28Z

core/src/main/antlr4/org/evomaster/core/parser/RegexJava.g4

 | HexEscapeSequence
 | UnicodeEscapeSequence
 | OctalEscapeSequence
+ | 'p' BRACE_open PosixCharacterClassLabel BRACE_close


add comment that this is specific to Java... possible also add link where \p is explained

\p is allowed in javascript also but only when certain flags are enabled. There is no flag support for Java/JS yet.

arcuri82 · 2026-03-25T09:43:23Z

core/src/main/antlr4/org/evomaster/core/parser/RegexJava.g4

 //| IdentityEscape
 ;

+fragment PosixCharacterClassLabel


provide reference link from where those values were taken from. recall the comments at the top of this file

arcuri82 · 2026-03-25T09:44:49Z

core/src/main/antlr4/org/evomaster/core/parser/RegexJava.g4

 fragment CharacterClassEscape
- //one of d D s S w W
- : [dDsSwW]
+ //one of d D s S w W v V h H


as v V h H are non-standard, and specific to Java, add a comment to explain them here

arcuri82 · 2026-03-25T09:52:34Z

core/src/main/kotlin/org/evomaster/core/search/gene/regex/CharacterRangeRxGene.kt

+        // this limits the character class complements to 0xffff instead of allowing up to 0x10ffff, but values over
+        // 0xffff are not permitted on Char as they need 2 Chars to be represented; to allow this, we would need to
+        // use String or Int in every possible step as methods which return a single Char cannot return these characters
+        if(negated) internalRanges.add(CharacterRange(Character.MIN_VALUE,Character.MAX_VALUE))


always use {} for blocks, even if single statement inside

arcuri82 · 2026-03-25T11:17:17Z

core/src/main/kotlin/org/evomaster/core/search/service/Randomness.kt

    companion object {
        private val log: Logger = LoggerFactory.getLogger(Randomness::class.java)
+
+        private fun stringToListOfCharPairs(s: String) : List<CharacterRange> {


rather stringToListOfCharacterRanges ?

arcuri82 · 2026-03-25T11:20:05Z

core/src/main/kotlin/org/evomaster/core/search/service/Randomness.kt

+    private val digitSet = listOf(CharacterRange('0', '9'))
+    private val asciiLetterSet = listOf(CharacterRange('a', 'z'), CharacterRange('A', 'Z'))
+    private val wordSet = listOf(CharacterRange('_', '_')) + asciiLetterSet + digitSet
+    private val spaceSet = stringToListOfCharPairs(" \t\r\n\u000C\u000b")


explain in a comment what \u000C\u000b are...
also notice that, in some cases, we explicitely skipped some special characters because escaping in the generating test files is bit buggy (need fixing... but never had time)

arcuri82 · 2026-03-25T11:22:16Z

core/src/main/kotlin/org/evomaster/core/search/service/Randomness.kt

+    private val verticalSpaceSet = stringToListOfCharPairs("\n\u000B\u000C\r\u0085\u2028\u2029")
+    private val punctuationSet = stringToListOfCharPairs("""!"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~""")
+
+    private val digitCharClass = CharacterRangeRxGene(false, digitSet)


should not have references to a gene (ie CharacterRangeRxGene) here in this package, as it can have architectural side-effects in the long run... whatever logic needs to be re-used, should be refactored and extracted outside of gene

Before these changes there were no references to genes here, but character classes values were sampled from here. The possible values came from strings defined on this file, which provided some basic functionality but missed several characters from predefined character classes. Trying to get these predefined character classes working with these missing characters I implemented them by changing code here. I see now how this could be an issue.

So to fix this, the predefined character classes definitions should be in CharacterClassEscapeRxGene, then with each randomize instead of using Randomness.nextX() we just call CharacterRangeRxGene.randomize(...) by making each CharacterClassEscapeRxGene hold the CharacterRangeRxGene which represents it? Then restore the previous method of getting Randomness.nextWordChar(), etc. (regarding previous comment about skipping some special characters as escaping in the generating test files)

arcuri82 · 2026-03-25T11:25:07Z

core/src/main/kotlin/org/evomaster/core/search/service/Randomness.kt

        return set[random.nextInt(set.length)]
    }

+    fun nextFromCharClass(cc: CharacterRangeRxGene) : Char{


maybe you could introduce a new MultiCharacterRange and move out some of business logic of CharacterRangeRxGene into it (which then would use MultiCharacterRange internally)

arcuri82 · 2026-03-25T11:26:59Z

core/src/main/kotlin/org/evomaster/core/search/service/Randomness.kt

+        cc.randomize(this, false)
+        val k = cc.value
+        // is it necessary to log this?
+        log.trace("nextFromCharClass(): {}", k)


yes... we have tests for determinism that check those trace logs. eg look at runAndCheckDeterminism()

…aracterClassEscapeRxGene.kt, restore old Randomness.kt

…sary

…al-pr-lmasroca

…acterRangeRxGene.kt to new class src/main/kotlin/org/evomaster/core/utils/MultiCharacterRange

lmasroca and others added 24 commits October 22, 2025 17:12

added Java support for missing predefined character classes escapes (…

8c03d8b

…\v, \V, \h, \H)

added Java support for POSIX character classes (\p{Lower}, \p{Print},…

147d40c

… etc.)

Merge remote-tracking branch 'origin/external-pr-lmasroca' into exter…

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…nal-pr-lmasroca

Merge remote-tracking branch 'origin/master' into external-pr-lmasroca

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Merge remote-tracking branch 'origin/master' into external-pr-lmasroca

8db3796

added a comment

fa88731

Regex support for negated character classes, improved and optimized c…

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…omplement for predefined character classes

Merge remote-tracking branch 'origin/master' into external-pr-lmasroca

5ce41e2

Merge remote-tracking branch 'origin/master' into external-pr-lmasroca

75385cf

Merge remote-tracking branch 'origin/master' into external-pr-lmasroca

bc91846

added some comments

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Merge remote-tracking branch 'origin/master' into external-pr-lmasroca

1c7861c

trying a fix

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Merge remote-tracking branch 'refs/remotes/origin/master' into extern…

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…al-pr-lmasroca

increasing iterations for an e2e test to account for changes in rando…

897f04b

…mization

Merge remote-tracking branch 'origin/master' into external-pr-lmasroca

19b336c

Disabled dto for TaintNestedEMTest from openapi-v2 E2E tests as CI cu…

56a7462

…rrently fails otherwise

Merge remote-tracking branch 'refs/remotes/origin/master' into extern…

a0d3ea9

…al-pr-lmasroca

Merge remote-tracking branch 'origin/master' into external-pr-lmasroca

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Merge remote-tracking branch 'origin/master' into external-pr-lmasroca

bd9a0f1

Add required field to spec

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Merge remote-tracking branch 'origin/master' into external-pr-lmasroca

7c851fc

Merge remote-tracking branch 'origin/external-pr-lmasroca' into exter…

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…nal-pr-lmasroca

Revert "Disabled dto for TaintNestedEMTest from openapi-v2 E2E tests …

e9780d9

…as CI currently fails otherwise" This reverts commit 56a7462.

lmasroca requested a review from jgaleotti March 17, 2026 16:44

jgaleotti requested changes Mar 17, 2026

View reviewed changes

lmasroca added 3 commits March 18, 2026 14:04

Requested changes pt.1

fededcf

Requested changes pt.2

9822f49

Merge remote-tracking branch 'origin/master' into external-pr-lmasroca

09cf21d

lmasroca commented Mar 18, 2026

View reviewed changes

core/src/test/kotlin/org/evomaster/core/search/gene/GeneSamplerForTests.kt Outdated Show resolved Hide resolved

lmasroca added 2 commits March 19, 2026 11:30

Merge remote-tracking branch 'origin/master' into external-pr-lmasroca

7327816

Solved TODO related to negated character classes in GeneSamplerForTes…

719c148

…ts.kt

lmasroca requested a review from jgaleotti March 19, 2026 14:51

lmasroca added 2 commits March 20, 2026 11:08

Merge remote-tracking branch 'origin/master' into external-pr-lmasroca

02fcfc4

Increasing iterations for e2e test

fc407bf

jgaleotti approved these changes Mar 24, 2026

View reviewed changes

jgaleotti requested a review from arcuri82 March 24, 2026 13:44

arcuri82 requested changes Mar 25, 2026

View reviewed changes

lmasroca added 6 commits March 26, 2026 14:12

Requested changes

abefd64

Moved CharacterRange class to src/main/kotlin/org/evomaster/core/utils

f848529

Moved predefined character class definitions from Randomness.kt to Ch…

0c881c0

…aracterClassEscapeRxGene.kt, restore old Randomness.kt

Reversed iterations increase as new changes made the increase unneces…

bfb0aca

…sary

Merge remote-tracking branch 'refs/remotes/origin/master' into extern…

9ba041d

…al-pr-lmasroca

Moved some logic regarding the construction of valid ranges from Char…

2c114aa

…acterRangeRxGene.kt to new class src/main/kotlin/org/evomaster/core/utils/MultiCharacterRange

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lmasroca commented Mar 17, 2026

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lmasroca commented Mar 20, 2026

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arcuri82 Mar 25, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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arcuri82 Mar 25, 2026 •

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