fix(test): prevent panic when .env is absent

The `dotenv!` macro panics if no file named `.env` is present in the
workspace root.  Use `dotenv::var` function instead.

Author: Jean-Pierre de Villiers

.github/workflows/rust-workspace-test.yaml

@@ -52,6 +52,8 @@ jobs:
       -
         name: cargo test
         uses: MarcoPolo/cargo@a527bf4d534717ff4424a84446c5d710f8833139
+        env:
+          ALGORAND_MNEMONIC: ${{ secrets.TEST_ALGORAND_MNEMONIC }}
         with:
           working-directory: rust-workspace
           command: test

rust-workspace/Cargo.lock

@@ -17,6 +17,6 @@ url = { version = "2.2", features = ["serde"] }
 zeroize = { version = "1.5", features = ["zeroize_derive"] }
 
 [dev-dependencies]
-dotenv_codegen = "0.15"
+dotenv = { version = "0.15" }
 tokio = { version = "1.18", default-features = false, features = ["macros", "rt"] }
 mockall = "0.11"

rust-workspace/crates/ntc-asset-manager/Cargo.toml

@@ -1,4 +1,3 @@
-use dotenv_codegen::dotenv;
 use ntc_asset_manager::{
     algorand::Address,
     algorand::{Account, Algod, AlgonautAlgod},
@@ -10,13 +9,12 @@ use std::str::FromStr;
 
 static ALGO_ENDPOINT: &str = "https://node.testnet.algoexplorerapi.io/";
 static ALGO_API_TOKEN: [char; 64] = ['a'; 64];
-static ALGORAND_MNEMONIC: &str = dotenv!("ALGORAND_MNEMONIC");
 
 #[tokio::test]
 async fn create_new_drt() {
     let api_token: String = ALGO_API_TOKEN.iter().collect();
     let algod = Algod(AlgonautAlgod::new(ALGO_ENDPOINT, &api_token).unwrap());
-    let secret = Secret::from_str(ALGORAND_MNEMONIC).unwrap();
+    let secret = Secret::from_str(&dotenv::var("ALGORAND_MNEMONIC").unwrap()).unwrap();
     let account = Account::from_secret(secret).unwrap();
 
     let note = AsaNote {