Improve List.of backport implementations to match spec
Also update tests to cover behavior mandated by the spec.
Test: tools/test.py --no-internal -v *BackportJava9Test*
Change-Id: I656dc60177aff5f7e66190f5139a3e7fa98976c0
diff --git a/src/test/examplesJava9/backport/ListBackportJava9Main.java b/src/test/examplesJava9/backport/ListBackportJava9Main.java
index 9ad147f..88d20ab 100644
--- a/src/test/examplesJava9/backport/ListBackportJava9Main.java
+++ b/src/test/examplesJava9/backport/ListBackportJava9Main.java
@@ -8,7 +8,7 @@
public class ListBackportJava9Main {
- public static void main(String[] args) throws Exception {
+ public static void main(String[] args) {
testOf0();
testOf1();
testOf2();
@@ -17,50 +17,114 @@
private static void testOf0() {
List<Object> ofObject = List.of();
+ assertEquals(0, ofObject.size());
+ assertMutationNotAllowed(ofObject);
+
List<Integer> ofInteger = List.of();
- assertTrue(ofObject instanceof List);
- assertTrue(ofObject.size() == 0);
- assertTrue(ofInteger instanceof List);
- assertTrue(ofInteger.size() == 0);
+ assertEquals(0, ofInteger.size());
+ assertMutationNotAllowed(ofObject);
}
private static void testOf1() {
- List<Object> ofObject = List.of(new Object());
+ Object anObject = new Object();
+ List<Object> ofObject = List.of(anObject);
+ assertEquals(1, ofObject.size());
+ assertSame(anObject, ofObject.get(0));
+ assertMutationNotAllowed(ofObject);
+
List<Integer> ofInteger = List.of(1);
- assertTrue(ofObject instanceof List);
- assertTrue(ofObject.size() == 1);
- assertTrue(ofInteger instanceof List);
- assertTrue(ofInteger.size() == 1);
+ assertEquals(1, ofInteger.size());
+ assertEquals(1, ofInteger.get(0));
+
+ try {
+ List.of((Object) null);
+ throw new AssertionError();
+ } catch (NullPointerException expected) {
+ }
}
private static void testOf2() {
- List<Object> ofObject = List.of(new Object(), new Object());
+ Object anObject0 = new Object();
+ Object anObject1 = new Object();
+ List<Object> ofObject = List.of(anObject0, anObject1);
+ assertEquals(2, ofObject.size());
+ assertSame(anObject0, ofObject.get(0));
+ assertSame(anObject1, ofObject.get(1));
+ assertMutationNotAllowed(ofObject);
+
List<Integer> ofInteger = List.of(1, 2);
- List<Object> ofMixed = List.of(new Object(), 1);
- assertTrue(ofObject instanceof List);
- assertTrue(ofObject.size() == 2);
- assertTrue(ofInteger instanceof List);
- assertTrue(ofInteger.size() == 2);
- assertTrue(ofMixed instanceof List);
- assertTrue(ofMixed.size() == 2);
+ assertEquals(2, ofInteger.size());
+ assertEquals(1, ofInteger.get(0));
+ assertEquals(2, ofInteger.get(1));
+
+ List<Object> ofMixed = List.of(anObject0, 1);
+ assertEquals(2, ofMixed.size());
+ assertSame(anObject0, ofMixed.get(0));
+ assertEquals(1, ofMixed.get(1));
+ assertMutationNotAllowed(ofMixed);
+
+ try {
+ List.of(1, null);
+ throw new AssertionError();
+ } catch (NullPointerException expected) {
+ }
}
private static void testOf10() {
- Object e = new Object();
- List<Object> ofObject = List.of(e, e, e, e, e, e, e, e, e, e);
+ Object anObject0 = new Object();
+ Object anObject6 = new Object();
+ Object anObject9 = new Object();
+ List<Object> ofObject =
+ List.of(anObject0, new Object(), new Object(), new Object(), new Object(), new Object(),
+ anObject6, new Object(), new Object(), anObject9);
+ assertEquals(10, ofObject.size());
+ assertSame(anObject0, ofObject.get(0));
+ assertSame(anObject6, ofObject.get(6));
+ assertSame(anObject9, ofObject.get(9));
+ assertMutationNotAllowed(ofObject);
+
List<Integer> ofInteger = List.of(0, 1, 2, 3, 4, 5, 6, 7, 8, 9);
- List<Object> ofMixed = List.of(0, 1, 2, 3, 4, 5, 6, 7, 8, e);
- assertTrue(ofObject instanceof List);
- assertTrue(ofObject.size() == 10);
- assertTrue(ofInteger instanceof List);
- assertTrue(ofInteger.size() == 10);
- assertTrue(ofMixed instanceof List);
- assertTrue(ofMixed.size() == 10);
+ assertEquals(10, ofInteger.size());
+ assertEquals(0, ofInteger.get(0));
+ assertEquals(6, ofInteger.get(6));
+ assertEquals(9, ofInteger.get(9));
+
+ List<Object> ofMixed = List.of(0, 1, 2, 3, 4, 5, 6, 7, 8, anObject9);
+ assertEquals(10, ofMixed.size());
+ assertEquals(0, ofMixed.get(0));
+ assertEquals(6, ofMixed.get(6));
+ assertSame(anObject9, ofMixed.get(9));
+ assertMutationNotAllowed(ofMixed);
+
+ try {
+ List.of(0, 1, 2, 3, 4, 5, 6, 7, 8, null);
+ throw new AssertionError();
+ } catch (NullPointerException expected) {
+ }
}
- private static void assertTrue(boolean value) {
- if (!value) {
- throw new AssertionError("Expected <true> but was <false>");
+ private static void assertMutationNotAllowed(List<Object> ofObject) {
+ try {
+ ofObject.add(new Object());
+ throw new AssertionError();
+ } catch (UnsupportedOperationException expected) {
+ }
+ try {
+ ofObject.set(0, new Object());
+ throw new AssertionError();
+ } catch (UnsupportedOperationException expected) {
+ }
+ }
+
+ private static void assertSame(Object expected, Object actual) {
+ if (expected != actual) {
+ throw new AssertionError("Expected <" + expected + "> but was <" + actual + ">");
+ }
+ }
+
+ private static void assertEquals(Object expected, Object actual) {
+ if (expected != actual && !expected.equals(actual)) {
+ throw new AssertionError("Expected <" + expected + "> but was <" + actual + ">");
}
}
}
