Merge pull request #3 from emlagowski/feature/integer_validations

Added integer validations.

README.md

@@ -10,12 +10,73 @@
 <!-- ![Sonar Test Count](https://img.shields.io/sonar/total_tests/io.github.emlagowski:validify?server=https%3A%2F%2Fsonarcloud.io&sonarVersion=8.2&style=for-the-badge) -->
 <!-- ![Sonar Tests](https://img.shields.io/sonar/tests/io.github.emlagowski:validify?compact_message&server=https%3A%2F%2Fsonarcloud.io&style=for-the-badge) -->
 
-This library purpose is to make validation process more straightforward. 
-It helps to validate objects and keep information about errors occurred during validation.
+The main purpose of this library is to provide a simple way to create more complicated validations and to accurately return information about errors that occurred during the validation.
+The secondary goal is to not use any external dependencies.
 
-## Usage example
+## Available validations
 
-You can combine multiple validators with logical operators like 'AND' and 'OR'. 
+At this moment some factory classes provides few out-of-the box self-explanatory (I hope so) validations.
+
+```shell script
+CoreValidations
+  - lengthIsEqual
+  - lengthInRange
+  - matches
+  - allCharactersAreDigits
+  - isEmpty
+  - isNotEmpty
+  - is
+  - isIn
+  - startsWith
+  - endsWith
+IntegerValidations
+  - valueInRange
+```
+
+### Custom validation
+
+Creating custom validations is as simple as implementing `io.github.emlagowski.validify.Validation` functional interface. 
+It have to return `ValidationResult` and to do that methods `ValidationsResult.valid()` and `ValidationResult invalid(String message, Object... args)` can be used.
+
+Example of providing custom validation with implementing Validation interface.
+
+```java
+public class IntegerValueInRangeValidation implements Validation<Integer> {
+
+    private final Integer min;
+    private final Integer max;
+
+    public IntegerValueInRangeValidation(Integer min, Integer max) {
+        this.min = min;
+        this.max = max;
+    }
+
+    @Override
+    public ValidationResult apply(Integer value) {
+        return Optional.ofNullable(value)
+                .filter(v -> min <= v && v <= max)
+                .map(v -> ValidationResult.valid())
+                .orElseGet(() -> ValidationResult.invalid("Value '%s' should be in the range [%d, %d]", value, min, max));
+    }
+}
+```
+
+Or it can be even shorter if you would use lambda expression like
+
+```java
+public static Validation<Integer> valueInRange(int min, int max) {
+    return value -> Optional.ofNullable(value)
+            .filter(v -> min <= v && v <= max)
+            .map(v -> ValidationResult.valid())
+            .orElseGet(() -> ValidationResult.invalid("Value '%s' should be in the range [%d, %d]", value, min, max));
+}
+```
+
+## Validation API
+
+On all Validations you can use `and` and `or` methods to combine them into one Validation.
+
+### Usage example
 
 Example below shows how to achieve validation that checks if 
 (value is 1-2 length string with only digits characters)
@@ -46,3 +107,9 @@ Length of 'value that not apply' not in range [1, 2]
 'value that not apply' is not 'N/A'
 'value that not apply' is not in [A, B, C]
 ```
+
+### More examples
+
+For more examples please see `examples` module or tests inside the `validify-core` module.
+
+

examples/src/main/java/io/github/emlagowski/validify/IntegerValueInRangeValidation.java

@@ -0,0 +1,22 @@
+package io.github.emlagowski.validify;
+
+import java.util.Optional;
+
+public class IntegerValueInRangeValidation implements Validation<Integer> {
+
+    private final Integer min;
+    private final Integer max;
+
+    public IntegerValueInRangeValidation(Integer min, Integer max) {
+        this.min = min;
+        this.max = max;
+    }
+
+    @Override
+    public ValidationResult apply(Integer value) {
+        return Optional.ofNullable(value)
+                .filter(v -> min <= v && v <= max)
+                .map(v -> ValidationResult.valid())
+                .orElseGet(() -> ValidationResult.invalid("Value '%s' should be in the range [%d, %d]", value, min, max));
+    }
+}

validify-core/pom.xml

@@ -12,7 +12,6 @@
     <artifactId>validify-core</artifactId>
 
     <properties>
-        <sonar.projectKey>emlagowski_validify</sonar.projectKey>
         <sonar.tests>src/test/groovy</sonar.tests>
     </properties>
 

validify-core/src/main/java/io/github/emlagowski/validify/IntegerValidations.java

@@ -0,0 +1,18 @@
+package io.github.emlagowski.validify;
+
+import java.util.Optional;
+
+public class IntegerValidations {
+
+    private IntegerValidations() {
+        // utility class
+    }
+
+    public static Validation<Integer> valueInRange(int min, int max) {
+        return value -> Optional.ofNullable(value)
+                .filter(v -> min <= v && v <= max)
+                .map(v -> ValidationResult.valid())
+                .orElseGet(() -> ValidationResult.invalid("Value '%s' should be in the range [%d, %d]", value, min, max));
+    }
+
+}

validify-core/src/main/java/io/github/emlagowski/validify/Validation.java

@@ -2,6 +2,7 @@
 
 import java.util.function.Function;
 
+@FunctionalInterface
 public interface Validation<T> extends Function<T, ValidationResult> {
 
     default Validation<T> and(Validation<T> other) {

validify-core/src/test/groovy/io/github/emlagowski/validify/ValueInRangeTest.groovy

@@ -0,0 +1,38 @@
+package io.github.emlagowski.validify
+
+import spock.lang.Specification
+import spock.lang.Unroll
+
+class ValueInRangeTest extends Specification {
+
+    @Unroll
+    def 'validation should check if value #value is between #min and #max and result with success=#expectedSuccess'() {
+        when:
+        def result = IntegerValidations.valueInRange(min, max).apply(value)
+
+        then:
+        expectedSuccess == result.success
+        messages == result.messages.size()
+
+        where:
+        value | min | max || expectedSuccess | messages
+        0     | 0   | 1   || true            | 0
+        1     | 0   | 1   || true            | 0
+        2     | 0   | 1   || false           | 1
+        2     | 100 | 200 || false           | 1
+        -3    | -5  | 5   || true            | 0
+        null  | -5  | 5   || false           | 1
+    }
+
+    def 'return message has all important information'() {
+        when:
+        def result = IntegerValidations.valueInRange(1, 2).apply(15)
+
+        then:
+        result.messages.size() == 1
+        result.messages.first().message.contains("1")
+        result.messages.first().message.contains("2")
+        result.messages.first().message.contains("15")
+    }
+
+}