Rename StorageMap::exists to ::contains_key (Resolves #4839) (#4847)

* rename StorageMap::exists(key) to ::contains_key(key)

* bump impl_version

substrate/frame/support/src/storage/generator/double_map.rs

@@ -110,7 +110,7 @@ where
 		Self::storage_double_map_final_key(k1, k2)
 	}
 
-	fn exists<KArg1, KArg2>(k1: KArg1, k2: KArg2) -> bool
+	fn contains_key<KArg1, KArg2>(k1: KArg1, k2: KArg2) -> bool
 	where
 		KArg1: EncodeLike<K1>,
 		KArg2: EncodeLike<K2>,

substrate/frame/support/src/storage/generator/linked_map.rs

@@ -326,7 +326,7 @@ where
 
 	type Enumerator = Enumerator<K, V, G::KeyFormat>;
 
-	fn exists<KeyArg: EncodeLike<K>>(key: KeyArg) -> bool {
+	fn contains_key<KeyArg: EncodeLike<K>>(key: KeyArg) -> bool {
 		unhashed::exists(Self::storage_linked_map_final_key(key).as_ref())
 	}
 

substrate/frame/support/src/storage/generator/map.rs

@@ -95,7 +95,7 @@ impl<K: FullEncode, V: FullCodec, G: StorageMap<K, V>> storage::StorageMap<K, V>
 		}
 	}
 
-	fn exists<KeyArg: EncodeLike<K>>(key: KeyArg) -> bool {
+	fn contains_key<KeyArg: EncodeLike<K>>(key: KeyArg) -> bool {
 		unhashed::exists(Self::storage_map_final_key(key).as_ref())
 	}
 

substrate/frame/support/src/storage/mod.rs

@@ -126,7 +126,7 @@ pub trait StorageMap<K: FullEncode, V: FullCodec> {
 	fn hashed_key_for<KeyArg: EncodeLike<K>>(key: KeyArg) -> Vec<u8>;
 
 	/// Does the value (explicitly) exist in storage?
-	fn exists<KeyArg: EncodeLike<K>>(key: KeyArg) -> bool;
+	fn contains_key<KeyArg: EncodeLike<K>>(key: KeyArg) -> bool;
 
 	/// Load the value associated with the given key from the map.
 	fn get<KeyArg: EncodeLike<K>>(key: KeyArg) -> Self::Query;
@@ -176,7 +176,7 @@ pub trait StorageMap<K: FullEncode, V: FullCodec> {
 	/// `T` is required to implement `Codec::DecodeLength`.
 	///
 	/// Note that `0` is returned as the default value if no encoded value exists at the given key.
-	/// Therefore, this function cannot be used as a sign of _existence_. use the `::exists()`
+	/// Therefore, this function cannot be used as a sign of _existence_. use the `::contains_key()`
 	/// function for this purpose.
 	fn decode_len<KeyArg: EncodeLike<K>>(key: KeyArg) -> Result<usize, &'static str>
 		where V: codec::DecodeLength + Len;
@@ -196,7 +196,7 @@ pub trait StorageLinkedMap<K: FullCodec, V: FullCodec> {
 	type Enumerator: Iterator<Item = (K, V)>;
 
 	/// Does the value (explicitly) exist in storage?
-	fn exists<KeyArg: EncodeLike<K>>(key: KeyArg) -> bool;
+	fn contains_key<KeyArg: EncodeLike<K>>(key: KeyArg) -> bool;
 
 	/// Load the value associated with the given key from the map.
 	fn get<KeyArg: EncodeLike<K>>(key: KeyArg) -> Self::Query;
@@ -227,7 +227,7 @@ pub trait StorageLinkedMap<K: FullCodec, V: FullCodec> {
 	/// `T` is required to implement `Codec::DecodeLength`.
 	///
 	/// Note that `0` is returned as the default value if no encoded value exists at the given key.
-	/// Therefore, this function cannot be used as a sign of _existence_. use the `::exists()`
+	/// Therefore, this function cannot be used as a sign of _existence_. use the `::contains_key()`
 	/// function for this purpose.
 	fn decode_len<KeyArg: EncodeLike<K>>(key: KeyArg) -> Result<usize, &'static str>
 		where V: codec::DecodeLength + Len;
@@ -270,7 +270,7 @@ pub trait StorageDoubleMap<K1: FullEncode, K2: FullEncode, V: FullCodec> {
 		KArg1: EncodeLike<K1>,
 		KArg2: EncodeLike<K2>;
 
-	fn exists<KArg1, KArg2>(k1: KArg1, k2: KArg2) -> bool
+	fn contains_key<KArg1, KArg2>(k1: KArg1, k2: KArg2) -> bool
 	where
 		KArg1: EncodeLike<K1>,
 		KArg2: EncodeLike<K2>;
@@ -348,7 +348,7 @@ pub trait StorageDoubleMap<K1: FullEncode, K2: FullEncode, V: FullCodec> {
 	/// `V` is required to implement `Codec::DecodeLength`.
 	///
 	/// Note that `0` is returned as the default value if no encoded value exists at the given key.
-	/// Therefore, this function cannot be used as a sign of _existence_. use the `::exists()`
+	/// Therefore, this function cannot be used as a sign of _existence_. use the `::contains_key()`
 	/// function for this purpose.
 	fn decode_len<KArg1, KArg2>(key1: KArg1, key2: KArg2) -> Result<usize, &'static str>
 		where

substrate/frame/support/test/tests/instance.rs

@@ -348,8 +348,8 @@ fn storage_with_instance_basic_operation() {
 		assert_eq!(Value::get(), 0);
 
 		let key = 1;
-		assert_eq!(Map::exists(0), true);
-		assert_eq!(Map::exists(key), false);
+		assert_eq!(Map::contains_key(0), true);
+		assert_eq!(Map::contains_key(key), false);
 		Map::insert(key, 1);
 		assert_eq!(Map::get(key), 1);
 		assert_eq!(Map::take(key), 1);
@@ -357,11 +357,11 @@ fn storage_with_instance_basic_operation() {
 		Map::mutate(key, |a| *a=2);
 		assert_eq!(Map::get(key), 2);
 		Map::remove(key);
-		assert_eq!(Map::exists(key), false);
+		assert_eq!(Map::contains_key(key), false);
 		assert_eq!(Map::get(key), 0);
 
-		assert_eq!(LinkedMap::exists(0), true);
-		assert_eq!(LinkedMap::exists(key), false);
+		assert_eq!(LinkedMap::contains_key(0), true);
+		assert_eq!(LinkedMap::contains_key(key), false);
 		LinkedMap::insert(key, vec![1]);
 		assert_eq!(LinkedMap::enumerate().count(), 2);
 		assert_eq!(LinkedMap::get(key), vec![1]);
@@ -373,17 +373,17 @@ fn storage_with_instance_basic_operation() {
 		assert_eq!(LinkedMap::get(key), vec![2]);
 		LinkedMap::remove(key);
 		assert_eq!(LinkedMap::enumerate().count(), 1);
-		assert_eq!(LinkedMap::exists(key), false);
+		assert_eq!(LinkedMap::contains_key(key), false);
 		assert_eq!(LinkedMap::get(key), vec![]);
-		assert_eq!(LinkedMap::exists(key), false);
+		assert_eq!(LinkedMap::contains_key(key), false);
 		assert_eq!(LinkedMap::enumerate().count(), 1);
 		LinkedMap::insert(key, &vec![1]);
 		assert_eq!(LinkedMap::enumerate().count(), 2);
 
 		let key1 = 1;
 		let key2 = 1;
-		assert_eq!(DoubleMap::exists(&0, &0), true);
-		assert_eq!(DoubleMap::exists(&key1, &key2), false);
+		assert_eq!(DoubleMap::contains_key(&0, &0), true);
+		assert_eq!(DoubleMap::contains_key(&key1, &key2), false);
 		DoubleMap::insert(&key1, &key2, &1);
 		assert_eq!(DoubleMap::get(&key1, &key2), 1);
 		assert_eq!(DoubleMap::take(&key1, &key2), 1);