rabestro · June 15, 2023 15:44 · Jun 15, 2023 · Jun 15, 2023
diff --git a/FlipFlopSpec.groovy b/FlipFlopSpec.groovy
@@ -0,0 +1,21 @@
+class FlipFlopPredicateSpec extends Specification {
+
+    def 'the flip-flop predicate returns false until the first condition is met'() {
+
+        given: 'the flip-flop left and right side predicates'
+        def leftSide = 'ON'::equals
+        def rightSide = 'OFF'::equals
+
+        when: 'we create a flip-flop predicate'
+        def flipFlop = FlipFlopPredicate.flipFlop(leftSide, rightSide)
+
+        then: 'the result is false while the left side is not met'
+        flipFlop.test('A') == false
+
+        then: 'the result is true when the left side is met'
+        flipFlop.test('ON') == true
+
+        then: 'the result is true until the right side is met'
+        flipFlop.test('A') == true
+    }
+}
diff --git a/CopilotTest.java b/CopilotTest.java
@@ -0,0 +1,21 @@
+package com.epam.flipflop;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import java.util.function.Predicate;
+
+class CopilotTest {
+   @Test
+   void testFlipFlop() {
+      var flipFlop = new FlipFlop<Integer>(x -> x % 2 == 0, x -> x % 3 == 0);
+
+      assertTrue(flipFlop.test(2));
+      assertTrue(flipFlop.test(3));
+      assertTrue(flipFlop.test(4));
+      assertTrue(flipFlop.test(6));
+      assertFalse(flipFlop.test(9));
+      assertTrue(flipFlop.test(10));
+   }
+}
diff --git a/FlipFlopPredicate.java b/FlipFlopPredicate.java
@@ -0,0 +1,21 @@
+package org.epam.flipflop;
+
+import java.util.function.Predicate;
+
+public final class FlipFlopPredicate<T> implements Predicate<T> {
+    private boolean state;
+    private final Predicate<T> lhs;
+    private final Predicate<T> rhs;
+
+    public FlipFlopPredicate(Predicate<T> leftHandSide, Predicate<T> rightHandSide) {
+        this.lhs = leftHandSide;
+        this.rhs = rightHandSide;
+    }
+
+    @Override
+    public boolean test(T value) {
+        var result = state || lhs.test(value);
+        state = result && !rhs.test(value);
+        return result;
+    }
+}
diff --git a/FlipFlopPredicateTest.java b/FlipFlopPredicateTest.java
@@ -0,0 +1,54 @@
+package com.epam.flipflop;
+
+import org.junit.jupiter.api.DisplayNameGeneration;
+import org.junit.jupiter.api.DisplayNameGenerator;
+import org.junit.jupiter.api.Test;
+
+import java.util.function.Predicate;
+import java.util.stream.Stream;
+
+import static com.epam.flipflop.FlipFlopPredicate.flipFlop;
+import static org.assertj.core.api.Assertions.assertThat;
+
+
+@DisplayNameGeneration(DisplayNameGenerator.ReplaceUnderscores.class)
+class FlipFlopPredicate2Test {
+
+   @Test
+   void extract_all_javadoc_by_flip_flop_predicate() {
+      // sample test data
+      var sampleSourceCode = """
+            package sample;
+            /**
+             * Multiline javadoc
+             */
+            void someMethod() {}
+
+            // single-line comment
+
+            /** single-line javadoc */
+
+            /*
+             * Multiline comment
+             */
+            """;
+
+      // given
+      Predicate<String> javaDocOpen = line -> line.startsWith("/**");
+      Predicate<String> javaDocClose = line -> line.endsWith("*/");
+
+      // when
+      var javaDocsLines = sampleSourceCode
+            .lines()
+            .filter(flipFlop(javaDocOpen, javaDocClose));
+
+      // then
+      assertThat(javaDocsLines)
+            .as("JavaDoc comments extracted from the source code")
+            .containsExactly(
+                  "/**",
+                  " * Multiline javadoc",
+                  " */",
+                  "/** single-line javadoc */");
+   }
+}