Add requireIfPresent validator (#60)

Fix #57.

Author: jpraet

belgif-rest-problem-validator/src/main/java/io/github/belgif/rest/problem/validation/RequestValidator.java

@@ -357,6 +357,18 @@ public <T> RequestValidator require(Input<T> input) {
         return this;
     }
 
+    /**
+     * Validate that all the given inputs are present when the given target input is present.
+     *
+     * @param target the target input
+     * @param inputs the inputs that are required when the target input is present
+     * @return this RequestValidator
+     */
+    public RequestValidator requireIfPresent(Input<?> target, Input<?>... inputs) {
+        validators.add(new RequiredIfPresentValidator(target, Arrays.asList(inputs)));
+        return this;
+    }
+
     /**
      * Conditionally register input validators.
      *

belgif-rest-problem-validator/src/main/java/io/github/belgif/rest/problem/validation/RequiredIfPresentValidator.java

@@ -0,0 +1,31 @@
+package io.github.belgif.rest.problem.validation;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+
+import io.github.belgif.rest.problem.api.Input;
+import io.github.belgif.rest.problem.api.InputValidationIssue;
+import io.github.belgif.rest.problem.api.InputValidationIssues;
+
+/**
+ * Validate that all the given inputs are present when the given target input is present.
+ */
+class RequiredIfPresentValidator extends AbstractMultiInputValidator<Object> {
+
+    private final Input<?> target;
+
+    RequiredIfPresentValidator(Input<?> target, List<Input<?>> inputs) {
+        super(inputs);
+        this.target = target;
+    }
+
+    @Override
+    public Optional<InputValidationIssue> validate() {
+        if (target.getValue() != null && getInputValueStream().anyMatch(Objects::isNull)) {
+            return Optional.of(InputValidationIssues.requiredInputsIfPresent(target, getInputs()));
+        }
+        return Optional.empty();
+    }
+
+}

belgif-rest-problem-validator/src/test/java/io/github/belgif/rest/problem/validation/RequestValidatorTest.java

@@ -380,6 +380,24 @@ void requireInvalid() {
                 InputValidationIssues.requiredInput(QUERY, "require"));
     }
 
+    @Test
+    void requireIfPresentValid() {
+        assertValid(new RequestValidator().requireIfPresent(Input.query("target", "ok"),
+                Input.query("a", "ok"), Input.query("b", "ok")));
+        assertValid(new RequestValidator().requireIfPresent(Input.query("target", null),
+                Input.query("a", "ok"), Input.query("b", "ok")));
+        assertValid(new RequestValidator().requireIfPresent(Input.query("target", null),
+                Input.query("a", null), Input.query("b", "ok")));
+    }
+
+    @Test
+    void requireIfPresentInvalid() {
+        assertInvalid(new RequestValidator().requireIfPresent(Input.query("target", "ok"),
+                Input.query("a", null), Input.query("b", "ok")),
+                InputValidationIssues.requiredInputsIfPresent(Input.query("target", "ok"),
+                        Arrays.asList(Input.query("a", null), Input.query("b", "ok"))));
+    }
+
     @Test
     void whenValid() {
         assertValid(new RequestValidator().when(false, validator -> validator.reject(Input.query("reject", "nok"))));

belgif-rest-problem-validator/src/test/java/io/github/belgif/rest/problem/validation/RequiredIfPresentValidatorTest.java

@@ -0,0 +1,37 @@
+package io.github.belgif.rest.problem.validation;
+
+import static org.assertj.core.api.Assertions.*;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import io.github.belgif.rest.problem.api.Input;
+import io.github.belgif.rest.problem.api.InputValidationIssues;
+
+class RequiredIfPresentValidatorTest {
+
+    @Test
+    void okTargetNotPresent() {
+        assertThat(new RequiredIfPresentValidator(Input.query("x", null),
+                Arrays.asList(Input.query("a", "value"), Input.query("b", null)))
+                        .validate()).isEmpty();
+    }
+
+    @Test
+    void okTargetPresent() {
+        assertThat(new RequiredIfPresentValidator(Input.query("x", "value"),
+                Arrays.asList(Input.query("a", "value"), Input.query("b", "ok")))
+                        .validate()).isEmpty();
+    }
+
+    @Test
+    void nok() {
+        Input<?> target = Input.query("x", "value");
+        List<Input<?>> inputs = Arrays.asList(Input.query("a", "value"), Input.query("b", null));
+        assertThat(new RequiredIfPresentValidator(target, inputs).validate()).contains(
+                InputValidationIssues.requiredInputsIfPresent(target, inputs));
+    }
+
+}

belgif-rest-problem/src/main/java/io/github/belgif/rest/problem/api/InputValidationIssues.java

@@ -120,6 +120,18 @@ public static InputValidationIssue requiredInput(InEnum in, String name) {
                 .in(in, name, null);
     }
 
+    public static InputValidationIssue requiredInputsIfPresent(Input<?> target, List<Input<?>> inputs) {
+        InputValidationIssue issue =
+                new InputValidationIssue(ISSUE_TYPE_REQUIRED_INPUT, "Input is required in this context")
+                        .detail(String.format("All of these inputs must be present if %s is present: %s",
+                                target.getName(), getJoinedNames(inputs)));
+        issue.addInput(target);
+        for (Input<?> input : inputs) {
+            issue.addInput(input);
+        }
+        return issue;
+    }
+
     public static InputValidationIssue replacedSsin(InEnum in, String name, String ssin, String newSsin) {
         return new InputValidationIssue(ISSUE_TYPE_REPLACED_SSIN, "SSIN has been replaced, use new SSIN")
                 .detail(String.format("SSIN %s has been replaced by %s", ssin, newSsin))

belgif-rest-problem/src/test/java/io/github/belgif/rest/problem/api/InputValidationIssuesTest.java

@@ -141,6 +141,19 @@ void requiredInput() {
         assertThat(issue).extracting("href", "inputs", "additionalProperties").allMatch(this::isEmpty);
     }
 
+    @Test
+    void requiredInputsIfPresent() {
+        Input<?> target = Input.query("x", "value");
+        List<Input<?>> inputs = Arrays.asList(Input.query("a", null), Input.query("b", "value"));
+        InputValidationIssue issue = InputValidationIssues.requiredInputsIfPresent(target, inputs);
+        assertThat(issue.getType()).hasToString("urn:problem-type:cbss:input-validation:requiredInput");
+        assertThat(issue.getTitle()).isEqualTo("Input is required in this context");
+        assertThat(issue.getDetail()).isEqualTo("All of these inputs must be present if x is present: a, b");
+        assertThat(issue.getInputs()).contains(target).containsAll(inputs);
+        assertThat(issue).extracting("href", "in", "name", "value", "additionalProperties")
+                .allMatch(this::isEmpty);
+    }
+
     @Test
     void replacedSsin() {
         InputValidationIssue issue =

src/main/asciidoc/index.adoc

@@ -34,6 +34,10 @@ The library consists of these modules:
 
 * Removed deprecated InvalidParamProblem: use InputValidationProblem, which supports both the legacy invalidParams[] and the new issues[] structure
 
+*belgif-rest-problem-validator:*
+
+* Added requireIfPresent check for validating input(s) that must be present when a given target input is present
+
 === Version 0.3
 
 *belgif-rest-problem:*