Merge pull request #5 from slu-it/conditions

Replaced direct use of Predicate with own Condition subclass

Author: Axel Schüssler

documentation/chapters/conditions.md

@@ -1,11 +1,12 @@
 [Home](../README.md)
 
 # The Conditions Utility Class
-The utility class `Conditions` provides several factory methods for creating `Predicate` instances.
-These can be (re-)used in the following sub-systems:
+The utility class `Conditions` provides several factory methods for creating `Condition` instances.
+These are specialized subclasses of Java 8's `Predicate` interface and can be used in the following sub-systems:
 
-- Filtering a streams of page fragments
-- Conditions for wait operations
+- Waiting: `@Wait` and `Wait.until(..)`
+- Post Construct Assertions: `@PostConstructMustBe(...)`
+- Filtering of `PageFragement` Streams
 
 ```java
 // ad-hoc finding of page fragments with filter
@@ -14,8 +15,6 @@ browser.findMany(".textfield").filter(Conditions.is(Conditions.visible()));
 Wait.until(textField).has(Conditions.text("foo"));
 ```
 
-Since all of these implement Java's `Predicate` interface it is easy to create your own conditions if need be.
-
 ## Syntax
 
 Conditions are designed to be readable. They take a lot of inspiration from Hamecrest's `Matcher` and AssertJ's fluent API.

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/Condition.java

@@ -0,0 +1,36 @@
+package info.novatec.testit.webtester.conditions;
+
+import java.util.Objects;
+import java.util.function.Predicate;
+
+
+/**
+ * A condition is a special form of {@link Predicate}.
+ * <p>
+ * It is used in WebTester's API  in order to allow for the extension with additional features in the future.
+ *
+ * @param <T> the type of the input to the predicate
+ * @see Predicate
+ * @see Conditions
+ * @since 2.0
+ */
+public interface Condition<T> extends Predicate<T> {
+
+    @Override
+    default Condition<T> negate() {
+        return (t) -> !test(t);
+    }
+
+    @Override
+    default Condition<T> and(Predicate<? super T> other) {
+        Objects.requireNonNull(other);
+        return (t) -> test(t) && other.test(t);
+    }
+
+    @Override
+    default Condition<T> or(Predicate<? super T> other) {
+        Objects.requireNonNull(other);
+        return (t) -> test(t) || other.test(t);
+    }
+
+}

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/Conditions.java

@@ -1,7 +1,6 @@
 package info.novatec.testit.webtester.conditions;
 
 import java.util.Collection;
-import java.util.function.Predicate;
 
 import info.novatec.testit.webtester.conditions.pagefragments.Attribute;
 import info.novatec.testit.webtester.conditions.pagefragments.AttributeWithValue;
@@ -36,16 +35,16 @@ private Conditions() {
 
     /* syntax */
 
-    public static <T> Is<T> is(Predicate<T> predicate) {
-        return new Is<>(predicate);
+    public static <T> Is<T> is(Condition<T> condition) {
+        return new Is<>(condition);
     }
 
-    public static <T> Has<T> has(Predicate<T> predicate) {
-        return new Has<>(predicate);
+    public static <T> Has<T> has(Condition<T> condition) {
+        return new Has<>(condition);
     }
 
-    public static <T> Not<T> not(Predicate<T> predicate) {
-        return new Not<>(predicate);
+    public static <T> Not<T> not(Condition<T> condition) {
+        return new Not<>(condition);
     }
 
     /* other */

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/pagefragments/Attribute.java

@@ -1,17 +1,17 @@
 package info.novatec.testit.webtester.conditions.pagefragments;
 
-import java.util.function.Predicate;
-
+import info.novatec.testit.webtester.conditions.Condition;
 import info.novatec.testit.webtester.pagefragments.PageFragment;
 
 
 /**
- * {@link Predicate} to be used in order to check if a specific attribute of a {@link PageFragment page fragment} is present.
+ * {@link Condition} to be used in order to check if a specific attribute of a {@link PageFragment page fragment} is present.
  *
+ * @see Condition
  * @see PageFragment#getAttribute(String)
  * @since 2.0
  */
-public class Attribute implements Predicate<PageFragment> {
+public class Attribute implements Condition<PageFragment> {
 
     private final String attributeName;
 

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/pagefragments/AttributeWithValue.java

@@ -1,19 +1,20 @@
 package info.novatec.testit.webtester.conditions.pagefragments;
 
 import java.util.Objects;
-import java.util.function.Predicate;
 
+import info.novatec.testit.webtester.conditions.Condition;
 import info.novatec.testit.webtester.pagefragments.PageFragment;
 
 
 /**
- * {@link Predicate} to be used in order to check if a specific attribute of a {@link PageFragment page fragment} has a
+ * {@link Condition} to be used in order to check if a specific attribute of a {@link PageFragment page fragment} has a
  * certain value.
  *
+ * @see Condition
  * @see PageFragment#getAttribute(String)
  * @since 2.0
  */
-public class AttributeWithValue implements Predicate<PageFragment> {
+public class AttributeWithValue implements Condition<PageFragment> {
 
     private final String attributeName;
     private final String expectedValue;

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/pagefragments/Disabled.java

@@ -1,17 +1,17 @@
 package info.novatec.testit.webtester.conditions.pagefragments;
 
-import java.util.function.Predicate;
-
+import info.novatec.testit.webtester.conditions.Condition;
 import info.novatec.testit.webtester.pagefragments.PageFragment;
 
 
 /**
- * {@link Predicate} to be used in order to check if a {@link PageFragment page fragment} is disabled.
+ * {@link Condition} to be used in order to check if a {@link PageFragment page fragment} is disabled.
  *
+ * @see Condition
  * @see PageFragment#isDisabled()
  * @since 2.0
  */
-public class Disabled implements Predicate<PageFragment> {
+public class Disabled implements Condition<PageFragment> {
 
     @Override
     public boolean test(PageFragment canBeDisabled) {

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/pagefragments/Editable.java

@@ -1,21 +1,21 @@
 package info.novatec.testit.webtester.conditions.pagefragments;
 
-import java.util.function.Predicate;
-
+import info.novatec.testit.webtester.conditions.Condition;
 import info.novatec.testit.webtester.pagefragments.PageFragment;
 
 
 /**
- * {@link Predicate} to be used in order to check if a {@link PageFragment page fragment} is 'editable'.
+ * {@link Condition} to be used in order to check if a {@link PageFragment page fragment} is 'editable'.
  * <p>
  * A page fragment is considered editable if it is present, visible, enabled and NOT read-only.
  *
+ * @see Condition
  * @see ReadOnly
  * @see Enabled
  * @see Visible
  * @since 2.0
  */
-public class Editable implements Predicate<PageFragment> {
+public class Editable implements Condition<PageFragment> {
 
     private final Present present = new Present();
     private final Visible visible = new Visible();

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/pagefragments/Enabled.java

@@ -1,17 +1,17 @@
 package info.novatec.testit.webtester.conditions.pagefragments;
 
-import java.util.function.Predicate;
-
+import info.novatec.testit.webtester.conditions.Condition;
 import info.novatec.testit.webtester.pagefragments.PageFragment;
 
 
 /**
- * {@link Predicate} to be used in order to check if a {@link PageFragment page fragment} is enabled.
+ * {@link Condition} to be used in order to check if a {@link PageFragment page fragment} is enabled.
  *
+ * @see Condition
  * @see PageFragment#isEnabled()
  * @since 2.0
  */
-public class Enabled implements Predicate<PageFragment> {
+public class Enabled implements Condition<PageFragment> {
 
     @Override
     public boolean test(PageFragment canBeDisabled) {

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/pagefragments/Interactable.java

@@ -1,21 +1,21 @@
 package info.novatec.testit.webtester.conditions.pagefragments;
 
-import java.util.function.Predicate;
-
+import info.novatec.testit.webtester.conditions.Condition;
 import info.novatec.testit.webtester.pagefragments.PageFragment;
 
 
 /**
- * {@link Predicate} to be used in order to check if a {@link PageFragment page fragment} is interactable.
+ * {@link Condition} to be used in order to check if a {@link PageFragment page fragment} is interactable.
  * <p>
  * A page fragment is considered interactable if it is present, visible and enabled.
  *
+ * @see Condition
  * @see Present
  * @see Visible
  * @see Enabled
  * @since 2.0
  */
-public class Interactable implements Predicate<PageFragment> {
+public class Interactable implements Condition<PageFragment> {
 
     private final Present present = new Present();
     private final Visible visible = new Visible();

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/pagefragments/Invisible.java

@@ -1,17 +1,17 @@
 package info.novatec.testit.webtester.conditions.pagefragments;
 
-import java.util.function.Predicate;
-
+import info.novatec.testit.webtester.conditions.Condition;
 import info.novatec.testit.webtester.pagefragments.PageFragment;
 
 
 /**
- * {@link Predicate} to be used in order to check if a {@link PageFragment page fragment} is invisible.
+ * {@link Condition} to be used in order to check if a {@link PageFragment page fragment} is invisible.
  *
+ * @see Condition
  * @see PageFragment#isVisible()
  * @since 2.0
  */
-public class Invisible implements Predicate<PageFragment> {
+public class Invisible implements Condition<PageFragment> {
 
     private Visible visible = new Visible();
 

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/pagefragments/Present.java

@@ -1,17 +1,17 @@
 package info.novatec.testit.webtester.conditions.pagefragments;
 
-import java.util.function.Predicate;
-
+import info.novatec.testit.webtester.conditions.Condition;
 import info.novatec.testit.webtester.pagefragments.PageFragment;
 
 
 /**
- * {@link Predicate} to be used in order to check if a {@link PageFragment page fragment} is present.
+ * {@link Condition} to be used in order to check if a {@link PageFragment page fragment} is present.
  *
+ * @see Condition
  * @see PageFragment#isPresent()
  * @since 2.0
  */
-public class Present implements Predicate<PageFragment> {
+public class Present implements Condition<PageFragment> {
 
     @Override
     public boolean test(PageFragment pageFragment) {

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/pagefragments/PresentAndVisible.java

@@ -1,18 +1,18 @@
 package info.novatec.testit.webtester.conditions.pagefragments;
 
-import java.util.function.Predicate;
-
+import info.novatec.testit.webtester.conditions.Condition;
 import info.novatec.testit.webtester.pagefragments.PageFragment;
 
 
 /**
- * {@link Predicate} to be used in order to check if a {@link PageFragment page fragment} is present and visible.
+ * {@link Condition} to be used in order to check if a {@link PageFragment page fragment} is present and visible.
  *
+ * @see Condition
  * @see Present
  * @see Visible
  * @since 2.0
  */
-public class PresentAndVisible implements Predicate<PageFragment> {
+public class PresentAndVisible implements Condition<PageFragment> {
 
     private final Visible visible = new Visible();
     private final Present present = new Present();

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/pagefragments/ReadOnly.java

@@ -1,20 +1,20 @@
 package info.novatec.testit.webtester.conditions.pagefragments;
 
-import java.util.function.Predicate;
-
+import info.novatec.testit.webtester.conditions.Condition;
 import info.novatec.testit.webtester.pagefragments.PageFragment;
 
 
 /**
- * {@link Predicate} to be used in order to check if a {@link PageFragment page fragment} is 'read-only'.
+ * {@link Condition} to be used in order to check if a {@link PageFragment page fragment} is 'read-only'.
  * I.g. read-only elements are input elements which are locked against value change but can still be edited.
  * <p>
  * This condition is true in case the 'readonly' attribute is either 'true' (HTML) or 'readonly' (XHTML).
  *
+ * @see Condition
  * @see PageFragment#getAttribute(String)
  * @since 2.0
  */
-public class ReadOnly implements Predicate<PageFragment> {
+public class ReadOnly implements Condition<PageFragment> {
 
     @Override
     public boolean test(PageFragment pageFragment) {

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/pagefragments/Selected.java

@@ -1,20 +1,20 @@
 package info.novatec.testit.webtester.conditions.pagefragments;
 
-import java.util.function.Predicate;
-
+import info.novatec.testit.webtester.conditions.Condition;
 import info.novatec.testit.webtester.pagefragments.PageFragment;
 import info.novatec.testit.webtester.pagefragments.traits.Selectable;
 
 
 /**
- * {@link Predicate} to be used in order to check if the {@link Selectable selectable} {@link PageFragment page fragment} is
+ * {@link Condition} to be used in order to check if the {@link Selectable selectable} {@link PageFragment page fragment} is
  * selected.
  *
+ * @see Condition
  * @see Selectable
  * @see Selectable#isSelected()
  * @since 2.0
  */
-public class Selected implements Predicate<Selectable> {
+public class Selected implements Condition<Selectable> {
 
     @Override
     public boolean test(Selectable selectable) {

webtester-core/src/main/java/info/novatec/testit/webtester/conditions/pagefragments/SelectedIndex.java

@@ -1,18 +1,18 @@
 package info.novatec.testit.webtester.conditions.pagefragments;
 
-import java.util.function.Predicate;
-
+import info.novatec.testit.webtester.conditions.Condition;
 import info.novatec.testit.webtester.pagefragments.SingleSelect;
 
 
 /**
- * {@link Predicate} to be used in order to check if a {@link SingleSelect single-select} has a certain selected index.
+ * {@link Condition} to be used in order to check if a {@link SingleSelect single-select} has a certain selected index.
  *
+ * @see Condition
  * @see SingleSelect
  * @see SingleSelect#getSelectionIndex()
  * @since 2.0
  */
-public class SelectedIndex implements Predicate<SingleSelect> {
+public class SelectedIndex implements Condition<SingleSelect> {
 
     private final Integer expectedIndex;