fix: Do not escape regex in d2:validatePattern [DHIS2-21359]

build.gradle.kts

@@ -11,7 +11,7 @@ repositories {
     mavenCentral()
 }
 
-version = "1.4.1-SNAPSHOT"
+version = "1.4.2-SNAPSHOT"
 group = "org.hisp.dhis.lib.expression"
 
 if (project.hasProperty("removeSnapshotSuffix")) {
@@ -107,4 +107,4 @@ sonarqube {
 
 tasks.named("sonar").configure {
     dependsOn(":koverXmlReport")
-}
+}

src/commonMain/kotlin/org/hisp/dhis/lib/expression/ast/Nodes.kt

@@ -356,6 +356,45 @@ object Nodes {
                 }
                 return str.toString()
             }
+
+            /**
+             * Processes a raw expression-string value for use as a regex pattern on all platforms.
+             *
+             * Strips backslashes from expression-level escapes (e.g. \' -> ', \ -> ' ')
+             * but preserves standard regex escapes (\d, \w, \s, \uXXXX, etc.) so the
+             * regex engine receives them intact. In particular, \- is kept as \- so that
+             * a hyphen inside a character class is treated as a literal and cannot form an
+             * unintended range. Both Java and JS unicode-mode regex accept \-.
+             */
+            internal fun decodeToRegex(rawValue: String): String {
+                if (rawValue.indexOf('\\') < 0) return rawValue
+                val str = StringBuilder()
+                val chars = rawValue.toCharArray()
+                var i = 0
+                while (i < chars.size) {
+                    val c = chars[i++]
+                    if (c != '\\' || i >= chars.size) {
+                        str.append(c)
+                        continue
+                    }
+                    val next = chars[i++]
+                    when (next) {
+                        't', 'n', 'r', 'f', 'b',
+                        '\\', '^', '$', '.', '*', '+', '?', '(', ')', '[', ']', '{', '}', '|',
+                        '-', 'd', 'D', 'w', 'W', 's', 'S', 'B', 'p', 'P' -> str.append('\\').append(next)
+                        'u' -> {
+                            str.append('\\').append('u')
+                            repeat(4) { if (i < chars.size) str.append(chars[i++]) }
+                        }
+                        'x' -> {
+                            str.append('\\').append('x')
+                            repeat(2) { if (i < chars.size) str.append(chars[i++]) }
+                        }
+                        else -> str.append(next)
+                    }
+                }
+                return str.toString()
+            }
         }
     }
 

src/commonMain/kotlin/org/hisp/dhis/lib/expression/eval/Calculator.kt

@@ -2,6 +2,7 @@ package org.hisp.dhis.lib.expression.eval
 
 import kotlinx.datetime.LocalDate
 import org.hisp.dhis.lib.expression.ast.*
+import org.hisp.dhis.lib.expression.ast.Nodes.Utf8StringNode
 import org.hisp.dhis.lib.expression.ast.UnaryOperator.Companion.negate
 import org.hisp.dhis.lib.expression.spi.*
 
@@ -139,7 +140,7 @@ internal class Calculator(
                 evalToInteger(fn.child(2)))
             NamedFunction.d2_validatePattern -> functions.d2_validatePattern(
                 evalToString(fn.child(0)),
-                evalToString(fn.child(1)))
+                evalToRawString(fn.child(1)))
             NamedFunction.d2_weeksBetween -> functions.d2_weeksBetween(
                 evalToDate(fn.child(0)),
                 evalToDate(fn.child(1)))
@@ -301,6 +302,15 @@ internal class Calculator(
         return eval(node, "String", Typed::toStringTypeCoercion)
     }
 
+    private fun evalToRawString(node: Node<*>): String? {
+        return when (node.getType()) {
+            NodeType.STRING -> Utf8StringNode.decodeToRegex(node.getRawValue())
+            NodeType.ARGUMENT -> evalToRawString(node.child(0))
+            NodeType.PAR -> evalToRawString(node.child(0))
+            else -> evalToString(node)
+        }
+    }
+
     fun evalToBoolean(node: Node<*>): Boolean? {
         return eval(node, "Boolean", Typed::toBooleanTypeCoercion)
     }

src/commonTest/kotlin/org/hisp/dhis/lib/expression/function/ValidatePatternTest.kt

@@ -29,15 +29,17 @@ internal class ValidatePatternTest {
     fun testValidatePattern_Match() {
         assertTrue(evaluate("d2:validatePattern(\"124\", \"[0-9]+\")"))
         assertTrue(evaluate("d2:validatePattern(\"12x4\", \"[0-9x]+\")"))
+        assertTrue(evaluate("d2:validatePattern(\"John\",(\"[a-zA-Z0-9À-ȕ\\'\\-\\‘\\`\\’\\ ]+\"))"))
     }
 
     @Test
     fun testValidatePattern_NoMatch() {
         assertFalse(evaluate("d2:validatePattern(\"12x4\", \"[0-9]+\")"))
         assertFalse(evaluate("d2:validatePattern(\"ab0\", \"[0-9x]+\")"))
+        assertFalse(evaluate("d2:validatePattern(\"Иван\",(\"[a-zA-Z0-9À-ȕ\\'\\-\\‘\\`\\’\\ ]+\"))"))
     }
 
     private fun evaluate(expression: String): Boolean {
         return Expression(expression, ExpressionMode.RULE_ENGINE_ACTION).evaluate() as Boolean
     }
-}
+}