Fix null handling for collection conditions

docs/release_notes.adoc

@@ -11,6 +11,7 @@ include::include.adoc[]
 
 === Misc
 * Add support for <<extensions.adoc#extension-store,keeping state in extensions>>
+* Fix bad error message for collection conditions, when one of the operands is `null`
 
 == 2.4-M1 (2022-11-30)
 

spock-core/src/main/java/org/spockframework/runtime/SpockRuntime.java

@@ -1,17 +1,16 @@
 /*
- * Copyright 2009 the original author or authors.
+ * Copyright 2023 the original author or authors.
  *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
  *
- *     https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
  */
 
 package org.spockframework.runtime;
@@ -269,9 +268,16 @@ void verify(ErrorCollector errorCollector, @Nullable List<Object> values, @Nulla
         // we have a mismatch, so add false for the result
         // due to the way the ValueRecorder works, we have two (n/a) values at the end, so we need to skip them
         values.add(values.size() - 2, false);
+      } else if (left == null || right == null) {
+        values.set(idxActual, left);
+        values.set(idxExpected, right);
+        if (left == null && right == null) {
+          return;
+        }
+        values.set(3, false);
       } else {
-        Pattern pattern = Pattern.compile(right.toString());
-        java.util.regex.Matcher matcher = pattern.matcher(left.toString());
+        Pattern pattern = Pattern.compile(String.valueOf(right));
+        java.util.regex.Matcher matcher = pattern.matcher(String.valueOf(left));
 
         values.set(idxActual, left);
         values.set(idxExpected, right);

spock-specs/src/test/groovy/org/spockframework/smoke/condition/ConditionEvaluation.groovy

@@ -1,17 +1,16 @@
 /*
- * Copyright 2008 the original author or authors.
+ * Copyright 2023 the original author or authors.
  *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
  *
- *     https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
  */
 
 package org.spockframework.smoke.condition
@@ -20,13 +19,14 @@ import org.opentest4j.AssertionFailedError
 import org.spockframework.EmbeddedSpecification
 import org.spockframework.runtime.ConditionFailedWithExceptionError
 import org.spockframework.runtime.ConditionNotSatisfiedError
-
-import spock.lang.Issue
+import org.spockframework.specs.extension.Snapshot
+import org.spockframework.specs.extension.Snapshotter
 import spock.lang.FailsWith
+import spock.lang.Issue
 
+import static java.lang.Integer.MAX_VALUE
 import static java.lang.Math.max
 import static java.lang.Math.min
-import static java.lang.Integer.MAX_VALUE
 import static java.lang.Thread.State.BLOCKED
 
 /**
@@ -389,6 +389,60 @@ class ConditionEvaluation extends EmbeddedSpecification {
     [aType, bType] << ['int[]', 'Integer[]', 'List', 'Queue', 'Deque'].with { [it, it] }.combinations()
   }
 
+  def "collection conditions work with nulls"(@Snapshot Snapshotter snapshotter) {
+    when:
+    runner.runFeatureBody("""
+        given:
+        def a = ${aType}
+        def b = ${bType}
+        expect:
+        a =~ b
+        """)
+    then:
+    ConditionNotSatisfiedError e = thrown()
+    snapshotter.assertThat(e.message).matchesSnapshot()
+
+    where:
+    aType   | bType
+    '"str"' | 'null'
+    '[1]'   | 'null'
+    'null'  | '[1]'
+    'null'  | '"str"'
+  }
+
+  def "strict collection conditions work with nulls"(@Snapshot Snapshotter snapshotter) {
+    when:
+    runner.runFeatureBody("""
+        given:
+        def a = ${aType}
+        def b = ${bType}
+        expect:
+        a ==~ b
+        """)
+    then:
+    ConditionNotSatisfiedError e = thrown()
+    snapshotter.assertThat(e.message).matchesSnapshot()
+
+    where:
+    aType  | bType
+    '"str"' | 'null'
+    '[1]'   | 'null'
+    'null'  | '[1]'
+    'null'  | '"str"'
+  }
+
+  def "collection conditions work with null equality"() {
+    given:
+    def a = null
+    def b = null
+
+    expect:
+    null ==~ null
+    null =~ null
+    a ==~ b
+    a =~ b
+  }
+
   @FailsWith(ConditionFailedWithExceptionError)
   def "regular implicit condition"() {
     expect:

spock-specs/src/test/resources/org/spockframework/smoke/condition/ConditionEvaluation__collection_conditions_work_with_nulls_[0].txt

@@ -0,0 +1,7 @@
+Condition not satisfied:
+
+a =~ b
+| |  |
+| |  null
+| false
+str

spock-specs/src/test/resources/org/spockframework/smoke/condition/ConditionEvaluation__collection_conditions_work_with_nulls_[1].txt

@@ -0,0 +1,7 @@
+Condition not satisfied:
+
+a =~ b
+| |  |
+| |  null
+| false
+[1]

spock-specs/src/test/resources/org/spockframework/smoke/condition/ConditionEvaluation__collection_conditions_work_with_nulls_[2].txt

@@ -0,0 +1,7 @@
+Condition not satisfied:
+
+a =~ b
+| |  |
+| |  [1]
+| false
+null

spock-specs/src/test/resources/org/spockframework/smoke/condition/ConditionEvaluation__collection_conditions_work_with_nulls_[3].txt

@@ -0,0 +1,7 @@
+Condition not satisfied:
+
+a =~ b
+| |  |
+| |  str
+| false
+null

spock-specs/src/test/resources/org/spockframework/smoke/condition/ConditionEvaluation__strict_collection_conditions_work_with_nulls_[0].txt

@@ -0,0 +1,7 @@
+Condition not satisfied:
+
+a ==~ b
+| |   |
+| |   null
+| false
+str

spock-specs/src/test/resources/org/spockframework/smoke/condition/ConditionEvaluation__strict_collection_conditions_work_with_nulls_[1].txt

@@ -0,0 +1,7 @@
+Condition not satisfied:
+
+a ==~ b
+| |   |
+| |   null
+| false
+[1]

spock-specs/src/test/resources/org/spockframework/smoke/condition/ConditionEvaluation__strict_collection_conditions_work_with_nulls_[2].txt

@@ -0,0 +1,7 @@
+Condition not satisfied:
+
+a ==~ b
+| |   |
+| |   [1]
+| false
+null

spock-specs/src/test/resources/org/spockframework/smoke/condition/ConditionEvaluation__strict_collection_conditions_work_with_nulls_[3].txt

@@ -0,0 +1,7 @@
+Condition not satisfied:
+
+a ==~ b
+| |   |
+| |   str
+| false
+null