Create Envs, a factory for making mock Envs

Author: webmaster128

packages/std/src/testing/mock.rs

@@ -392,17 +392,110 @@ fn validate_length(bytes: &[u8]) -> StdResult<()> {
 /// // `env3` is one block and 5.5 seconds later
 /// ```
 pub fn mock_env() -> Env {
-    let contract_addr = MockApi::default().addr_make("cosmos2contract");
-    Env {
-        block: BlockInfo {
-            height: 12_345,
-            time: Timestamp::from_nanos(1_571_797_419_879_305_533),
-            chain_id: "cosmos-testnet-14002".to_string(),
-        },
-        transaction: Some(TransactionInfo { index: 3 }),
-        contract: ContractInfo {
-            address: contract_addr,
-        },
+    let mut envs = Envs::new(BECH32_PREFIX);
+    envs.make()
+}
+
+/// A factory type that stores chain information such as bech32 prefix and can make mock `Env`s from there.
+///
+/// It increments height for each mock call and block time by 5 seconds but is otherwise dumb.
+///
+/// In contrast to using `mock_env`, the bech32 prefix must always be specified.
+///
+/// ## Examples
+///
+/// Typical usage
+///
+/// ```
+/// # use cosmwasm_std::Timestamp;
+/// use cosmwasm_std::testing::Envs;
+///
+/// let mut envs = Envs::new("food");
+///
+/// let env = envs.make();
+/// assert_eq!(env.contract.address.as_str(), "food1jpev2csrppg792t22rn8z8uew8h3sjcpglcd0qv9g8gj8ky922ts74yrjj");
+/// assert_eq!(env.block.height, 12_345);
+/// assert_eq!(env.block.time, Timestamp::from_nanos(1_571_797_419_879_305_533));
+///
+/// let env = envs.make();
+/// assert_eq!(env.contract.address.as_str(), "food1jpev2csrppg792t22rn8z8uew8h3sjcpglcd0qv9g8gj8ky922ts74yrjj");
+/// assert_eq!(env.block.height, 12_346);
+/// assert_eq!(env.block.time, Timestamp::from_nanos(1_571_797_424_879_305_533));
+///
+/// let env = envs.make();
+/// assert_eq!(env.contract.address.as_str(), "food1jpev2csrppg792t22rn8z8uew8h3sjcpglcd0qv9g8gj8ky922ts74yrjj");
+/// assert_eq!(env.block.height, 12_347);
+/// assert_eq!(env.block.time, Timestamp::from_nanos(1_571_797_429_879_305_533));
+/// ```
+///
+/// Or use with iterator
+///
+/// ```
+/// # use cosmwasm_std::Timestamp;
+/// use cosmwasm_std::testing::Envs;
+///
+/// let mut envs = Envs::new("food");
+///
+/// for (index, env) in envs.take(100).enumerate() {
+///     assert_eq!(env.contract.address.as_str(), "food1jpev2csrppg792t22rn8z8uew8h3sjcpglcd0qv9g8gj8ky922ts74yrjj");
+///     assert_eq!(env.block.height, 12_345 + index as u64);
+///     assert_eq!(env.block.time, Timestamp::from_nanos(1_571_797_419_879_305_533).plus_seconds((index*5) as u64));
+/// }
+/// ```
+pub struct Envs {
+    contract_address: Addr,
+    last_height: u64,
+    last_time: Timestamp,
+    envs_produced: u64,
+}
+
+impl Envs {
+    pub fn new(
+        bech32_prefix: &'static str, /* static due to MockApi's Copy requirement. No better idea for now. */
+    ) -> Self {
+        let api = MockApi::default().with_prefix(bech32_prefix);
+        Envs {
+            // Default values here for compatibility with old `mock_env` function. They could be changed to anything else if there is a good reason.
+            contract_address: api.addr_make("cosmos2contract"),
+            last_height: 12_344,
+            last_time: Timestamp::from_nanos(1_571_797_419_879_305_533).minus_seconds(5),
+            envs_produced: 0,
+        }
+    }
+
+    pub fn make(&mut self) -> Env {
+        let height = self.last_height + 1;
+        let time = self.last_time.plus_seconds(5);
+
+        self.last_height = height;
+        self.last_time = time;
+        self.envs_produced += 1;
+
+        Env {
+            block: BlockInfo {
+                height,
+                time,
+                chain_id: "cosmos-testnet-14002".to_string(),
+            },
+            transaction: Some(TransactionInfo { index: 3 }),
+            contract: ContractInfo {
+                address: self.contract_address.clone(),
+            },
+        }
+    }
+}
+
+// The iterator implementation can produce 1 million envs and then stops for no good reason.
+impl Iterator for Envs {
+    type Item = Env;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.envs_produced < 1_000_000 {
+            let item = self.make();
+            Some(item)
+        } else {
+            None
+        }
     }
 }
 
@@ -1285,6 +1378,71 @@ mod tests {
         )
     }
 
+    #[test]
+    fn envs_works() {
+        let mut envs = Envs::new("food");
+
+        let env = envs.make();
+        assert_eq!(
+            env.contract.address.as_str(),
+            "food1jpev2csrppg792t22rn8z8uew8h3sjcpglcd0qv9g8gj8ky922ts74yrjj"
+        );
+        assert_eq!(env.block.height, 12_345);
+        assert_eq!(
+            env.block.time,
+            Timestamp::from_nanos(1_571_797_419_879_305_533)
+        );
+
+        let env = envs.make();
+        assert_eq!(
+            env.contract.address.as_str(),
+            "food1jpev2csrppg792t22rn8z8uew8h3sjcpglcd0qv9g8gj8ky922ts74yrjj"
+        );
+        assert_eq!(env.block.height, 12_346);
+        assert_eq!(
+            env.block.time,
+            Timestamp::from_nanos(1_571_797_424_879_305_533)
+        );
+
+        let env = envs.make();
+        assert_eq!(
+            env.contract.address.as_str(),
+            "food1jpev2csrppg792t22rn8z8uew8h3sjcpglcd0qv9g8gj8ky922ts74yrjj"
+        );
+        assert_eq!(env.block.height, 12_347);
+        assert_eq!(
+            env.block.time,
+            Timestamp::from_nanos(1_571_797_429_879_305_533)
+        );
+    }
+
+    #[test]
+    fn envs_implements_iteratorworks() {
+        let envs = Envs::new("food");
+
+        let result: Vec<_> = envs.into_iter().take(5).collect();
+
+        assert_eq!(
+            result[0].contract.address.as_str(),
+            "food1jpev2csrppg792t22rn8z8uew8h3sjcpglcd0qv9g8gj8ky922ts74yrjj"
+        );
+        assert_eq!(result[0].block.height, 12_345);
+        assert_eq!(
+            result[0].block.time,
+            Timestamp::from_nanos(1_571_797_419_879_305_533)
+        );
+
+        assert_eq!(
+            result[4].contract.address.as_str(),
+            "food1jpev2csrppg792t22rn8z8uew8h3sjcpglcd0qv9g8gj8ky922ts74yrjj"
+        );
+        assert_eq!(result[4].block.height, 12_349);
+        assert_eq!(
+            result[4].block.time,
+            Timestamp::from_nanos(1_571_797_439_879_305_533)
+        );
+    }
+
     #[test]
     fn addr_validate_works() {
         // default prefix is 'cosmwasm'

packages/std/src/testing/mod.rs

@@ -21,7 +21,7 @@ pub use mock::DistributionQuerier;
 pub use mock::StakingQuerier;
 pub use mock::{
     mock_dependencies, mock_dependencies_with_balance, mock_dependencies_with_balances, mock_env,
-    mock_wasmd_attr, BankQuerier, MockApi, MockQuerier, MockQuerierCustomHandlerResult,
+    mock_wasmd_attr, BankQuerier, Envs, MockApi, MockQuerier, MockQuerierCustomHandlerResult,
     MOCK_CONTRACT_ADDR,
 };
 #[cfg(feature = "stargate")]