feat: add serial_test dependency and update tests for serial execution

Cargo.lock

@@ -627,6 +627,7 @@ dependencies = [
  "migration",
  "sea-orm",
  "serde",
+ "serial_test",
  "temp-env",
  "thiserror 2.0.12",
  "tracing-actix-web",
@@ -2803,12 +2804,27 @@ version = "1.0.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
 
+[[package]]
+name = "scc"
+version = "2.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "22b2d775fb28f245817589471dd49c5edf64237f4a19d10ce9a92ff4651a27f4"
+dependencies = [
+ "sdd",
+]
+
 [[package]]
 name = "scopeguard"
 version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
 
+[[package]]
+name = "sdd"
+version = "3.0.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "584e070911c7017da6cb2eb0788d09f43d789029b5877d3e5ecc8acf86ceee21"
+
 [[package]]
 name = "sea-bae"
 version = "0.2.1"
@@ -3024,6 +3040,31 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serial_test"
+version = "3.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b258109f244e1d6891bf1053a55d63a5cd4f8f4c30cf9a1280989f80e7a1fa9"
+dependencies = [
+ "futures",
+ "log",
+ "once_cell",
+ "parking_lot",
+ "scc",
+ "serial_test_derive",
+]
+
+[[package]]
+name = "serial_test_derive"
+version = "3.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d69265a08751de7844521fd15003ae0a888e035773ba05695c5c759a6f89eef"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.100",
+]
+
 [[package]]
 name = "sha1"
 version = "0.10.6"

crates/backend/Cargo.toml

@@ -31,6 +31,7 @@ dotenvy = "0.15"
 
 [dev-dependencies]
 temp-env = "*"
+serial_test = "*"
 
 [features]
 serve = []

crates/backend/src/main.rs

@@ -120,10 +120,12 @@ fn build_database_url() -> String {
 #[cfg(test)]
 mod tests {
     use std::env;
+    use serial_test::serial;
     use super::*;
     use temp_env::{with_var, with_vars};
 
     #[test]
+    #[serial]
     fn build_database_url_with_defaults() {
         with_vars(
             [
@@ -141,6 +143,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn build_database_url_with_all_vars() {
         with_vars(
             [
@@ -162,6 +165,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     #[should_panic(expected = "DB_HOST must be set in .env")]
     fn build_database_url_missing_host_panics() {
         with_var("DB_HOST", None::<&str>, || {
@@ -170,6 +174,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn connect_to_redis_database_with_defaults() {
         with_vars(
             [
@@ -193,6 +198,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn connect_to_redis_database_with_custom_port() {
         with_vars(
             [
@@ -217,6 +223,7 @@ mod tests {
     }
 
     #[test]
+    #[serial]
     fn check_if_no_env_variables_are_loaded_from_environment_file() {
         assert_eq!(env::var("DB_NAME"), Err(env::VarError::NotPresent));
         assert_eq!(env::var("DB_USER"), Err(env::VarError::NotPresent));