Array Transforms public API and parsing

This includes the new FIRFieldValue sentinels, the FSTUserDataConverter code to parse them into internal ArrayTransform operations for use in an FSTTransformMutation, and some sanity testing in FSTMutationTests.

I still need to implement FSTTransformMutation support for local application and serialization (and then integration tests).

1 files changed, 23 insertions, 0 deletions

diff --git a/Firestore/Source/Public/FIRFieldValue.h b/Firestore/Source/Public/FIRFieldValue.h
index 11a0da0..d896587 100644
--- a/Firestore/Source/Public/FIRFieldValue.h
+++ b/Firestore/Source/Public/FIRFieldValue.h
@@ -38,6 +38,29 @@ NS_SWIFT_NAME(FieldValue)
  */
 + (instancetype)fieldValueForServerTimestamp NS_SWIFT_NAME(serverTimestamp());
 
+/**
+ * Returns a special value that can be used with setData() or updateData() that tells the server to
+ * union the given elements with any array value that already exists on the server. Each
+ * specified element that doesn't already exist in the array will be added to the end. If the
+ * field being modified is not already an array it will be overwritten with an array containing
+ * exactly the specified elements.
+ *
+ * @param elements The elements to union into the array.
+ * @return The FieldValue sentinel for use in a call to setData() or updateData().
+ */
++ (instancetype)fieldValueForArrayUnion:(NSArray<id> *)elements NS_SWIFT_NAME(arrayUnion(_:));
+
+/**
+ * Returns a special value that can be used with setData() or updateData() that tells the server to
+ * remove the given elements from any array value that already exists on the server. All
+ * instances of each element specified will be removed from the array. If the field being
+ * modified is not already an array it will be overwritten with an empty array.
+ *
+ * @param elements The elements to remove from the array.
+ * @return The FieldValue sentinel for use in a call to setData() or updateData().
+ */
++ (instancetype)fieldValueForArrayRemove:(NSArray<id> *)elements NS_SWIFT_NAME(arrayRemove(_:));
+
 @end
 
 NS_ASSUME_NONNULL_END