Add errors example (stellar#138)

brson · Oct 7, 2022 · 6cc2f11 · 6cc2f11
1 parent b084f9c
commit 6cc2f11
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diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -20,6 +20,7 @@ members = [
     "timelock",
     "token",
     "logging",
+    "errors",
 ]
 
 [profile.release-with-logs]

diff --git a/errors/Cargo.toml b/errors/Cargo.toml
@@ -0,0 +1,20 @@
+[package]
+name = "soroban-errors-contract"
+version = "0.0.0"
+authors = ["Stellar Development Foundation <[email protected]>"]
+license = "Apache-2.0"
+edition = "2021"
+publish = false
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+doctest = false
+
+[features]
+testutils = ["soroban-sdk/testutils"]
+
+[dependencies]
+soroban-sdk = "0.1.0"
+
+[dev_dependencies]
+soroban-sdk = { version = "0.1.0", features = ["testutils"] }
diff --git a/errors/src/lib.rs b/errors/src/lib.rs
@@ -0,0 +1,46 @@
+#![no_std]
+use soroban_sdk::{contracterror, contractimpl, log, symbol, Env, Symbol};
+
+#[contracterror]
+#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[repr(u32)]
+pub enum Error {
+    LimitReached = 1,
+}
+
+const COUNTER: Symbol = symbol!("COUNTER");
+const MAX: u32 = 10;
+
+pub struct IncrementContract;
+
+#[contractimpl]
+impl IncrementContract {
+    /// Increment increments an internal counter, and returns the value. Errors
+    /// if the value is attempted to be incremented past 10.
+    pub fn increment(env: Env) -> Result<u32, Error> {
+        // Get the current count.
+        let mut count: u32 = env
+            .data()
+            .get(COUNTER)
+            .unwrap_or(Ok(0)) // If no value set, assume 0.
+            .unwrap(); // Panic if the value of COUNTER is not u32.
+        log!(&env, "count: {}", count);
+
+        // Increment the count.
+        count += 1;
+
+        // Check if the count exceeds the max.
+        if count <= MAX {
+            // Save the count.
+            env.data().set(COUNTER, count);
+
+            // Return the count to the caller.
+            Ok(count)
+        } else {
+            // Return an error if the max is exceeded.
+            Err(Error::LimitReached)
+        }
+    }
+}
+
+mod test;
diff --git a/errors/src/test.rs b/errors/src/test.rs
@@ -0,0 +1,47 @@
+#![cfg(test)]
+
+use super::*;
+use soroban_sdk::{testutils::Logger, Env};
+
+extern crate std;
+
+#[test]
+fn test() {
+    let env = Env::default();
+    let contract_id = env.register_contract(None, IncrementContract);
+    let client = IncrementContractClient::new(&env, &contract_id);
+
+    assert_eq!(client.try_increment(), Ok(Ok(1)));
+    assert_eq!(client.try_increment(), Ok(Ok(2)));
+    assert_eq!(client.try_increment(), Ok(Ok(3)));
+    assert_eq!(client.try_increment(), Ok(Ok(4)));
+    assert_eq!(client.try_increment(), Ok(Ok(5)));
+    assert_eq!(client.try_increment(), Ok(Ok(6)));
+    assert_eq!(client.try_increment(), Ok(Ok(7)));
+    assert_eq!(client.try_increment(), Ok(Ok(8)));
+    assert_eq!(client.try_increment(), Ok(Ok(9)));
+    assert_eq!(client.try_increment(), Ok(Ok(10)));
+    assert_eq!(client.try_increment(), Err(Ok(Error::LimitReached)));
+
+    std::println!("{}", env.logger().all().join("\n"));
+}
+
+#[test]
+#[should_panic(expected = "Status(ContractError(1))")]
+fn test_panic() {
+    let env = Env::default();
+    let contract_id = env.register_contract(None, IncrementContract);
+    let client = IncrementContractClient::new(&env, &contract_id);
+
+    assert_eq!(client.increment(), 1);
+    assert_eq!(client.increment(), 2);
+    assert_eq!(client.increment(), 3);
+    assert_eq!(client.increment(), 4);
+    assert_eq!(client.increment(), 5);
+    assert_eq!(client.increment(), 6);
+    assert_eq!(client.increment(), 7);
+    assert_eq!(client.increment(), 8);
+    assert_eq!(client.increment(), 9);
+    assert_eq!(client.increment(), 10);
+    client.increment();
+}