Escape $ for JavaPoet

Author: yevhenii-nadtochii

java-tests/validating/src/testFixtures/kotlin/io/spine/validation/assertions/Assertions.kt

@@ -37,6 +37,7 @@ import io.kotest.matchers.string.shouldContain
 import io.spine.type.toJson
 import io.spine.validate.ConstraintViolation
 import io.spine.validate.ValidationException
+import io.spine.validate.text.format
 import org.junit.jupiter.api.Assertions.assertDoesNotThrow
 import org.junit.jupiter.api.Assertions.assertThrows
 import org.junit.jupiter.api.Assertions.fail
@@ -89,8 +90,7 @@ fun assertViolation(
         .contains(field)
 
     val violation = violations.atField(field)
-
-    violation.msgFormat shouldContain errorMessagePart
+    violation.message.format() shouldContain errorMessagePart
 }
 
 /**

java-tests/vanilla/src/test/kotlin/io/spine/validation/java/IsRequiredSpec.kt

@@ -31,6 +31,7 @@ import com.google.protobuf.Message
 import io.spine.testing.TestValues.randomString
 import io.spine.validate.NonValidated
 import io.spine.validate.Validate.violationsOf
+import io.spine.validate.text.format
 import io.spine.validation.java.given.Fish
 import io.spine.validation.java.given.Meal
 import io.spine.validation.java.given.Sauce
@@ -50,7 +51,7 @@ internal class IsRequiredSpec {
         val violations = violationsOf(message)
         assertThat(violations)
             .hasSize(1)
-        assertThat(violations[0]!!.msgFormat)
+        assertThat(violations[0]!!.message.format())
             .contains("choice")
     }
 

java/src/main/kotlin/io/spine/validation/java/DistributingGenerator.kt

@@ -98,7 +98,10 @@ internal class DistributingGenerator(
             addModifiers(Modifier.PRIVATE)
             returns(violationsType)
             addCode(body)
-        }.toString()
+        }
+            .toString() // `MethodSpec` cannot be directly added to `CodeBloc`.
+            .replace("$", "$$") // We need to escape `$` symbols,
+                                                  // which can be present in error templates.
 
         return otherMembers.toBuilder()
             .add(groupingMethod)