Combining a SpEL expression and a $regex filter triggers a PatternSyntaxException [DATAMONGO-2119]

[spring-projects-issues]

Lucas Cimon opened DATAMONGO-2119 and commented

Hi.

I created a PR providing an example here: https://github.com/spring-projects/spring-data-mongodb/pull/616/files

Here is the main code snippet:

@Query("{ 'key.lastname' : { '$regex' : ?#{[0].lastname} }")
Person findByPersonLastnameRegex(Person key);

When ran, the test triggers the following stack trace:

 java.lang.IllegalArgumentException: Dangling meta character '?' near index 0
?expr0
^	at org.springframework.data.mongodb.repository.query.StringBasedMongoQueryUnitTests.createQueryForMethod(StringBasedMongoQueryUnitTests.java:614)
	at org.springframework.data.mongodb.repository.query.StringBasedMongoQueryUnitTests.shouldAllowCombinationOfSpELAndRegex(StringBasedMongoQueryUnitTests.java:505)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:79)
	at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:85)
	at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:39)
	at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.util.regex.PatternSyntaxException: Dangling meta character '?' near index 0
?expr0
^
	at java.util.regex.Pattern.error(Pattern.java:1955)
	at java.util.regex.Pattern.sequence(Pattern.java:2123)
	at java.util.regex.Pattern.expr(Pattern.java:1996)
	at java.util.regex.Pattern.compile(Pattern.java:1696)
	at java.util.regex.Pattern.<init>(Pattern.java:1351)
	at java.util.regex.Pattern.compile(Pattern.java:1054)
	at com.mongodb.util.JSONCallback.objectDone(JSONCallback.java:105)
	at com.mongodb.util.JSONParser.parseObject(JSON.java:275)
	at com.mongodb.util.JSONParser.parse(JSON.java:228)
	at com.mongodb.util.JSONParser.parseObject(JSON.java:264)
	at com.mongodb.util.JSONParser.parse(JSON.java:228)
	at com.mongodb.util.JSONParser.parse(JSON.java:156)
	at com.mongodb.util.JSON.parse(JSON.java:98)
	at com.mongodb.util.JSON.parse(JSON.java:79)
	at org.springframework.data.mongodb.repository.query.StringBasedMongoQuery$ParameterBindingParser.parseAndCollectParameterBindingsFromQueryIntoBindings(StringBasedMongoQuery.java:228)
	at org.springframework.data.mongodb.repository.query.StringBasedMongoQuery.<init>(StringBasedMongoQuery.java:96)
	at org.springframework.data.mongodb.repository.query.StringBasedMongoQuery.<init>(StringBasedMongoQuery.java:75)
	at org.springframework.data.mongodb.repository.query.StringBasedMongoQueryUnitTests.createQueryForMethod(StringBasedMongoQueryUnitTests.java:611)
	... 28 more

It seems to me that SpEL expression and the $regex filter are incompatible.
Is that right ?
The documentation implies this should work.

Regards

---

Affects: 2.0.11 (Kay SR11), 2.1.2 (Lovelace SR2)

Referenced from: pull request #621

Backported to: 2.1.3 (Lovelace SR3), 2.0.12 (Kay SR12)

[spring-projects-issues]

Lucas Cimon commented

Actually there was already some code testing the combination of a SpEL expression and a $regex: shouldAllowPlaceholderReuseInQuotedValue

But it did not use an array that contains all the arguments, to quote the terminology of the SpringData MongoDB doc

[spring-projects-issues]

Mark Paluch commented

Regex and SpEL expressions are currently not supported. This is, because we're using MongoDB's JSON parser to parse the query. The parser creates a Pattern object from the given payload and so it fails.

We should be able to do something about that