Feat: handle pattern annotation (#193)

Co-authored-by: Jérôme Vanderstichelen <[email protected]>

Author: jervds

restdocs-api-spec-jsonschema/src/main/kotlin/com/epages/restdocs/apispec/jsonschema/ConstraintResolver.kt

@@ -24,12 +24,18 @@ internal object ConstraintResolver {
 
     private const val SIZE_CONSTRAINT = "javax.validation.constraints.Size"
 
+    private const val PATTERN_CONSTRAINT = "javax.validation.constraints.Pattern"
+
     internal fun maybeMinSizeArray(fieldDescriptor: FieldDescriptor?) = fieldDescriptor?.maybeSizeConstraint()?.let { it.configuration["min"] as? Int }
 
     internal fun maybeMaxSizeArray(fieldDescriptor: FieldDescriptor?) = fieldDescriptor?.maybeSizeConstraint()?.let { it.configuration["max"] as? Int }
 
     private fun FieldDescriptor.maybeSizeConstraint() = findConstraints(this).firstOrNull { SIZE_CONSTRAINT == it.name }
 
+    internal fun maybePattern(fieldDescriptor: FieldDescriptor?) = fieldDescriptor?.maybePatternConstraint()?.let { it.configuration["pattern"] as? String }
+
+    private fun FieldDescriptor.maybePatternConstraint() = findConstraints(this).firstOrNull { PATTERN_CONSTRAINT == it.name }
+
     internal fun minLengthString(fieldDescriptor: FieldDescriptor): Int? {
         return findConstraints(fieldDescriptor)
             .firstOrNull { constraint ->

restdocs-api-spec-jsonschema/src/main/kotlin/com/epages/restdocs/apispec/jsonschema/JsonSchemaFromFieldDescriptorsGenerator.kt

@@ -4,6 +4,7 @@ import com.epages.restdocs.apispec.jsonschema.ConstraintResolver.isRequired
 import com.epages.restdocs.apispec.jsonschema.ConstraintResolver.maxLengthString
 import com.epages.restdocs.apispec.jsonschema.ConstraintResolver.maybeMaxSizeArray
 import com.epages.restdocs.apispec.jsonschema.ConstraintResolver.maybeMinSizeArray
+import com.epages.restdocs.apispec.jsonschema.ConstraintResolver.maybePattern
 import com.epages.restdocs.apispec.jsonschema.ConstraintResolver.minLengthString
 import com.epages.restdocs.apispec.model.Attributes
 import com.epages.restdocs.apispec.model.FieldDescriptor
@@ -233,9 +234,7 @@ class JsonSchemaFromFieldDescriptorsGenerator {
                 "array" -> ArraySchema.builder().applyConstraints(this).allItemSchema(arrayItemsSchema())
                 "boolean" -> BooleanSchema.builder()
                 "number" -> NumberSchema.builder()
-                "string" -> StringSchema.builder()
-                    .minLength(minLengthString(this))
-                    .maxLength(maxLengthString(this))
+                "string" -> StringSchema.builder().applyConstraints(this)
                 "enum" -> CombinedSchema.oneOf(
                     listOf(
                         StringSchema.builder().build(),
@@ -282,6 +281,12 @@ class JsonSchemaFromFieldDescriptorsGenerator {
     }
 }
 
+private fun StringSchema.Builder.applyConstraints(fieldDescriptor: FieldDescriptor) = apply {
+    minLength(minLengthString(fieldDescriptor))
+    maxLength(maxLengthString(fieldDescriptor))
+    maybePattern(fieldDescriptor)?.let { pattern(it) }
+}
+
 private fun ArraySchema.Builder.applyConstraints(fieldDescriptor: FieldDescriptor?) = apply {
     minItems(maybeMinSizeArray(fieldDescriptor))
     maxItems(maybeMaxSizeArray(fieldDescriptor))

restdocs-api-spec-jsonschema/src/test/kotlin/com/epages/restdocs/apispec/jsonschema/JsonSchemaFromFieldDescriptorsGeneratorTest.kt

@@ -24,6 +24,7 @@ import org.json.JSONObject
 import org.junit.jupiter.api.Test
 import java.io.IOException
 import java.util.Collections.emptyMap
+import java.util.regex.Pattern
 import javax.validation.constraints.NotNull
 
 class JsonSchemaFromFieldDescriptorsGeneratorTest {
@@ -49,6 +50,12 @@ class JsonSchemaFromFieldDescriptorsGeneratorTest {
         then(objectSchema.propertySchemas["id"]).isInstanceOf(StringSchema::class.java)
         then(objectSchema.requiredProperties).contains("id")
 
+        then(objectSchema.definesProperty("pattern")).isTrue
+        then(objectSchema.propertySchemas["pattern"]).isInstanceOf(StringSchema::class.java)
+        val patternSchema = objectSchema.propertySchemas["pattern"] as StringSchema
+        then(patternSchema.pattern.pattern()).isEqualTo("[a-z]")
+
+
         then(objectSchema.definesProperty("shippingAddress")).isTrue()
         val shippingAddressSchema = objectSchema.propertySchemas["shippingAddress"]!!
         then(shippingAddressSchema).isInstanceOf(ObjectSchema::class.java)
@@ -116,7 +123,8 @@ class JsonSchemaFromFieldDescriptorsGeneratorTest {
                             "value": 1
                         }
                     ]
-                }
+                },
+                "pattern": "a"
             }
             """.trimIndent()
         )
@@ -578,6 +586,15 @@ class JsonSchemaFromFieldDescriptorsGeneratorTest {
                 )
             )
 
+        val patternConstraint =
+            Attributes(
+                listOf(
+                    Constraint(
+                        "javax.validation.constraints.Pattern",
+                        mapOf("pattern" to "[a-z]")
+                    )
+                )
+            )
         fieldDescriptors = listOf(
             FieldDescriptor(
                 "id",
@@ -638,6 +655,12 @@ class JsonSchemaFromFieldDescriptorsGeneratorTest {
                         )
                     )
                 )
+            ),
+            FieldDescriptor(
+                "pattern",
+                "some",
+                "STRING",
+                attributes = patternConstraint
             )
         )
     }