chore(mysql): fix linting issues from Phase 5

- cspell: add USERINFO, userinfo, CSPRNG, plainpassword to project-words.txt
- clippy: use map_or_else instead of map().unwrap_or_else() in tracker_core_section.rs
- clippy: backtick MySQL and SQLite in doc comments (doc_markdown)
- clippy: add #[allow(clippy::too_many_arguments)] to new_with_mysql
- clippy: change mysql_host and host from String to &str (needless_pass_by_value)
- clippy: add # Panics section to generate_random_password docs
- clippy: replace redundant closures with char::is_uppercase/is_lowercase
- rustfmt: run cargo fmt
- docs: mark Phase 5 and all acceptance criteria as complete in issue torrust#410

Author: josecelano

docs/issues/410-bug-multiple-mysql-configuration-issues.md

@@ -313,10 +313,10 @@ Tasks are ordered from simplest to most complex.
 
 ### Phase 5: Linting and pre-commit
 
-- [ ] Run linters: `cargo run --bin linter all`
-- [ ] Run pre-commit: `./scripts/pre-commit.sh`
+- [x] Run linters: `cargo run --bin linter all`
+- [x] Run pre-commit: `./scripts/pre-commit.sh`
 
-> **Status**: Phases 1–4 complete and committed. Phase 5 pending.
+> **Status**: Phases 1–5 complete and committed.
 
 ## Acceptance Criteria
 
@@ -326,7 +326,7 @@ Tasks are ordered from simplest to most complex.
 
 **Quality Checks**:
 
-- [ ] Pre-commit checks pass: `./scripts/pre-commit.sh`
+- [x] Pre-commit checks pass: `./scripts/pre-commit.sh`
 
 **Task-Specific Criteria — Bug 3 (reserved username)**:
 
@@ -365,7 +365,7 @@ Tasks are ordered from simplest to most complex.
       a valid, correctly encoded DSN in the `.env` file (verified with `tracker_p@ss!word#1`)
 - [x] A MySQL password with only alphanumeric characters is rendered unchanged
 - [x] `MysqlTemplateConfig` no longer exists in `tracker_config/context.rs`
-- [ ] `cargo machete` reports no unused dependencies
+- [x] `cargo machete` reports no unused dependencies
 
 ## Manual E2E Verification Test
 

project-words.txt

@@ -540,6 +540,10 @@ zcat
 zeroize
 zoneinfo
 zstd
+CSPRNG
+USERINFO
+plainpassword
+userinfo
 Émojis
 значение
 ключ

src/application/command_handlers/create/config/tracker/tracker_core_section.rs

@@ -94,8 +94,7 @@ impl TryFrom<DatabaseSection> for DatabaseConfig {
                 root_password,
             } => {
                 let root_password = root_password
-                    .map(|p| Password::from(p.as_str()))
-                    .unwrap_or_else(generate_random_password);
+                    .map_or_else(generate_random_password, |p| Password::from(p.as_str()));
                 let config = MysqlConfig::new(
                     host,
                     port,

src/application/services/rendering/docker_compose.rs

@@ -107,7 +107,7 @@ impl DockerComposeTemplateRenderingService {
             DatabaseConfig::Mysql(mysql_config) => self.create_mysql_contexts(
                 admin_token.to_string(),
                 tracker,
-                mysql_config.host().to_string(),
+                mysql_config.host(),
                 mysql_config.port(),
                 mysql_config.database_name().to_string(),
                 mysql_config.username().to_string(),
@@ -215,7 +215,7 @@ impl DockerComposeTemplateRenderingService {
         &self,
         admin_token: String,
         tracker: TrackerServiceContext,
-        host: String,
+        host: &str,
         port: u16,
         database_name: String,
         username: String,

src/domain/tracker/config/core/database/mysql.rs

@@ -19,7 +19,7 @@ pub enum MysqlConfigError {
     /// Username cannot be empty
     #[error("MySQL username cannot be empty")]
     EmptyUsername,
-    /// Username `root` is reserved by the MySQL Docker image
+    /// Username `root` is reserved by the `MySQL` Docker image
     #[error("MySQL username \"root\" is reserved and cannot be used as the app database username")]
     ReservedUsername,
 }

src/infrastructure/templating/docker_compose/template/wrappers/env/context.rs

@@ -12,7 +12,7 @@ use serde::Serialize;
 
 use crate::infrastructure::templating::TemplateMetadata;
 
-/// Characters that must be percent-encoded in the userinfo (user/password) part of a MySQL DSN URL.
+/// Characters that must be percent-encoded in the userinfo (user/password) part of a `MySQL` DSN URL.
 ///
 /// Encodes delimiters that have structural meaning in the URL authority component:
 /// - `@` — userinfo/host separator
@@ -45,9 +45,9 @@ pub struct TrackerServiceConfig {
     /// Database driver type ("sqlite3" or "mysql")
     /// Controls which config template the container entrypoint uses
     pub database_driver: String,
-    /// Percent-encoded MySQL DSN for `TORRUST_TRACKER_CONFIG_OVERRIDE_CORE__DATABASE__PATH`
+    /// Percent-encoded `MySQL` DSN for `TORRUST_TRACKER_CONFIG_OVERRIDE_CORE__DATABASE__PATH`
     ///
-    /// Only populated when MySQL is configured; `None` for SQLite.
+    /// Only populated when `MySQL` is configured; `None` for `SQLite`.
     /// Username and password are percent-encoded with `NON_ALPHANUMERIC` to handle
     /// URL-reserved characters (e.g. `@`, `+`, `/`, `:`).
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -171,21 +171,22 @@ impl EnvContext {
     ///     "tracker_db".to_string(),
     ///     "tracker_user".to_string(),
     ///     "user_pass".to_string(),
-    ///     "mysql".to_string(),
+    ///     "mysql",
     ///     3306,
     /// );
     /// assert_eq!(context.tracker.database_driver, "mysql");
     /// assert!(context.mysql.is_some());
     /// ```
     #[must_use]
+    #[allow(clippy::too_many_arguments)]
     pub fn new_with_mysql(
         metadata: TemplateMetadata,
         tracker_api_admin_token: String,
         mysql_root_password: String,
         mysql_database: String,
         mysql_user: String,
         mysql_password: String,
-        mysql_host: String,
+        mysql_host: &str,
         mysql_port: u16,
     ) -> Self {
         let encoded_user = utf8_percent_encode(&mysql_user, &USERINFO_ENCODE).to_string();
@@ -321,7 +322,7 @@ mod tests {
             "tracker_db".to_string(),
             "tracker_user".to_string(),
             "user_pass".to_string(),
-            "mysql".to_string(),
+            "mysql",
             3306,
         );
 
@@ -358,7 +359,7 @@ mod tests {
             "db".to_string(),
             "user".to_string(),
             "pass".to_string(),
-            "mysql".to_string(),
+            "mysql",
             3306,
         );
 
@@ -387,7 +388,7 @@ mod tests {
             "tracker_db".to_string(),
             "tracker_user".to_string(),
             "user_pass".to_string(),
-            "mysql".to_string(),
+            "mysql",
             3306,
         );
 
@@ -411,7 +412,7 @@ mod tests {
             "tracker".to_string(),
             "tracker_user".to_string(),
             "p@ss:w/ord+1".to_string(),
-            "mysql".to_string(),
+            "mysql",
             3306,
         );
 
@@ -434,7 +435,7 @@ mod tests {
             "tracker".to_string(),
             "tracker_user".to_string(),
             "plainpassword123".to_string(),
-            "mysql".to_string(),
+            "mysql",
             3306,
         );
 

src/shared/mod.rs

@@ -19,6 +19,8 @@ pub use command::{CommandError, CommandExecutor, CommandResult};
 pub use domain_name::{DomainName, DomainNameError};
 pub use email::{Email, EmailError};
 pub use error::{ErrorKind, Traceable};
-pub use secrets::{ApiToken, ExposeSecret, Password, PlainApiToken, PlainPassword, generate_random_password};
+pub use secrets::{
+    generate_random_password, ApiToken, ExposeSecret, Password, PlainApiToken, PlainPassword,
+};
 pub use service_endpoint::{InvalidServiceEndpointUrl, ServiceEndpoint};
 pub use username::{Username, UsernameError};

src/shared/secrets/random.rs

@@ -1,8 +1,8 @@
 //! Cryptographically random password generation
 
-use rand::Rng as _;
 use rand::seq::IndexedRandom as _;
 use rand::seq::SliceRandom as _;
+use rand::Rng as _;
 
 use super::password::Password;
 
@@ -25,11 +25,16 @@ fn full_charset() -> Vec<u8> {
 ///   reseeded — suitable for secrets in rand 0.9 (direct `OsRng` no longer
 ///   implements the high-level `Rng` trait required by `choose`/`shuffle`)
 /// - `choose`: avoids modulo bias — uniform distribution
-/// - Explicit class inclusion: satisfies MySQL `validate_password` MEDIUM policy
+/// - Explicit class inclusion: satisfies `MySQL` `validate_password` MEDIUM policy
 /// - Shuffle: removes structural bias from fixed positions
 ///
 /// The generated password is 32 characters long and always contains at least
 /// one lowercase letter, one uppercase letter, one digit, and one symbol.
+///
+/// # Panics
+///
+/// Panics if any character set constant is empty, which cannot happen in practice
+/// as they are defined as non-empty byte string literals.
 #[must_use]
 pub fn generate_random_password() -> Password {
     let mut rng = rand::rng();
@@ -78,12 +83,11 @@ mod tests {
             let s = pwd.expose_secret();
 
             assert_eq!(s.len(), 32, "password must be 32 characters");
-            assert!(s.chars().any(|c| c.is_uppercase()), "must contain uppercase");
-            assert!(s.chars().any(|c| c.is_lowercase()), "must contain lowercase");
+            assert!(s.chars().any(char::is_uppercase), "must contain uppercase");
+            assert!(s.chars().any(char::is_lowercase), "must contain lowercase");
             assert!(s.chars().any(|c| c.is_ascii_digit()), "must contain digit");
             assert!(
-                s.chars()
-                    .any(|c| "!@#$%^&*()-_=+[]{}<>?".contains(c)),
+                s.chars().any(|c| "!@#$%^&*()-_=+[]{}<>?".contains(c)),
                 "must contain symbol"
             );
             assert!(s.is_ascii(), "must be ASCII (safe in .env files and shell)");