GROOVY-6766: collectEntries misleading error message
diff --git a/src/main/org/codehaus/groovy/runtime/DefaultGroovyMethods.java b/src/main/org/codehaus/groovy/runtime/DefaultGroovyMethods.java
index 5f2c0aa..f0b0a55 100644
--- a/src/main/org/codehaus/groovy/runtime/DefaultGroovyMethods.java
+++ b/src/main/org/codehaus/groovy/runtime/DefaultGroovyMethods.java
@@ -2647,6 +2647,10 @@
* assert [a:1, b:2].collectEntries( [30:'C'] ) { key, value ->
* [(value*10): key.toUpperCase()] } == [10:'A', 20:'B', 30:'C']
* </pre>
+ * Note: When using the list-style of result, the behavior is '<code>def (key, value) = listResultFromClosure</code>'.
+ * While we strongly discourage using a list of size other than 2, Groovy's normal semantics apply in this case;
+ * throwing away elements after the second one and using null for the key or value for the case of a shortened list.
+ * If your collector Map doesn't support null keys or values, you might get a runtime error, e.g. NullPointerException or IllegalArgumentException.
*
* @param self a Map
* @param collector the Map into which the transformed entries are put
@@ -2671,6 +2675,10 @@
* assert [a:1, b:2].collectEntries { key, value ->
* [(value*10): key.toUpperCase()] } == [10:'A', 20:'B']
* </pre>
+ * Note: When using the list-style of result, the behavior is '<code>def (key, value) = listResultFromClosure</code>'.
+ * While we strongly discourage using a list of size other than 2, Groovy's normal semantics apply in this case;
+ * throwing away elements after the second one and using null for the key or value for the case of a shortened list.
+ * If your Map doesn't support null keys or values, you might get a runtime error, e.g. NullPointerException or IllegalArgumentException.
*
* @param self a Map
* @param transform the closure used for transforming, which can take one (Map.Entry) or two (key, value) parameters and
@@ -2717,6 +2725,9 @@
* // collect letters with index using map style
* assert (0..2).collectEntries { index -> [(index): letters[index]] } == [0:'a', 1:'b', 2:'c']
* </pre>
+ * Note: When using the list-style of result, the behavior is '<code>def (key, value) = listResultFromClosure</code>'.
+ * While we strongly discourage using a list of size other than 2, Groovy's normal semantics apply in this case;
+ * throwing away elements after the second one and using null for the key or value for the case of a shortened list.
*
* @param self an Iterable
* @param transform the closure used for transforming, which has an item from self as the parameter and
@@ -2809,6 +2820,10 @@
* assert (0..2).collectEntries( [4:'d'] ) { index ->
* [(index+1): letters[index]] } == [1:'a', 2:'b', 3:'c', 4:'d']
* </pre>
+ * Note: When using the list-style of result, the behavior is '<code>def (key, value) = listResultFromClosure</code>'.
+ * While we strongly discourage using a list of size other than 2, Groovy's normal semantics apply in this case;
+ * throwing away elements after the second one and using null for the key or value for the case of a shortened list.
+ * If your collector Map doesn't support null keys or values, you might get a runtime error, e.g. NullPointerException or IllegalArgumentException.
*
* @param self an Iterable
* @param collector the Map into which the transformed entries are put
@@ -2871,6 +2886,10 @@
* assert nums.collectEntries( [4:'d'] ) { index ->
* [(index+1): letters[index]] } == [1:'a', 2:'b', 3:'c', 4:'d']
* </pre>
+ * Note: When using the list-style of result, the behavior is '<code>def (key, value) = listResultFromClosure</code>'.
+ * While we strongly discourage using a list of size other than 2, Groovy's normal semantics apply in this case;
+ * throwing away elements after the second one and using null for the key or value for the case of a shortened list.
+ * If your collector Map doesn't support null keys or values, you might get a runtime error, e.g. NullPointerException or IllegalArgumentException.
*
* @param self an Object array
* @param collector the Map into which the transformed entries are put
@@ -2909,6 +2928,9 @@
* // collect letters with index using map style
* assert nums.collectEntries { index -> [(index): letters[index]] } == [0:'a', 1:'b', 2:'c']
* </pre>
+ * Note: When using the list-style of result, the behavior is '<code>def (key, value) = listResultFromClosure</code>'.
+ * While we strongly discourage using a list of size other than 2, Groovy's normal semantics apply in this case;
+ * throwing away elements after the second one and using null for the key or value for the case of a shortened list.
*
* @param self a Collection
* @param transform the closure used for transforming, which has an item from self as the parameter and
@@ -2936,9 +2958,12 @@
private static <K, V> void addEntry(Map<K, V> result, Object newEntry) {
if (newEntry instanceof Map) {
leftShift(result, (Map)newEntry);
- } else if (newEntry instanceof List && ((List)newEntry).size() == 2) {
+ } else if (newEntry instanceof List) {
List list = (List) newEntry;
- leftShift(result, new MapEntry(list.get(0), list.get(1)));
+ // def (key, value) == list
+ Object key = list.size() == 0 ? null : list.get(0);
+ Object value = list.size() <= 1 ? null : list.get(1);
+ leftShift(result, new MapEntry(key, value));
} else {
// TODO: enforce stricter behavior?
// given Map.Entry is an interface, we get a proxy which gives us lots
diff --git a/src/test/groovy/GroovyMethodsTest.groovy b/src/test/groovy/GroovyMethodsTest.groovy
index a7fafdf..6a2fd77 100644
--- a/src/test/groovy/GroovyMethodsTest.groovy
+++ b/src/test/groovy/GroovyMethodsTest.groovy
@@ -1173,10 +1173,13 @@
assert map == [a: 'A', b: 'B', c: 'C']
}
- void testArrayContains() {
- String[] vowels = ['a', 'e', 'i', 'o', 'u']
- assert vowels.contains('u')
- assert !vowels.contains('x')
+ void testCollectEntriesListFallbackCases() {
+ assert [[[1,'a'], [2,'b'], [3]].collectEntries(),
+ [[1,'a'], [2,'b'], []].collectEntries(),
+ [[1,'a'], [2,'b'], [3, 'c', 42]].collectEntries()] == [[1:'a', 2:'b', 3:null], [1:'a', 2:'b', (null):null], [1:'a', 2:'b', 3:'c']]
+ shouldFail(NullPointerException) {
+ [[1, 'a'], [3]].collectEntries(new Hashtable())
+ }
}
void testListTakeWhile() {
