fix(cli): make config-path absolute

.changeset/bumpy-months-draw.md

@@ -0,0 +1,7 @@
+---
+"@biomejs/biome": patch
+---
+
+Fixed [#7390](https://github.com/biomejs/biome/issues/7390), where Biome couldn't apply the correct configuration passed via `--config-path`.
+
+If you have multiple **root** configuration files, running any command with `--config-path` will now apply the chosen configuration file.

crates/biome_cli/src/cli_options.rs

@@ -3,7 +3,7 @@ use crate::logging::LoggingKind;
 use biome_configuration::ConfigurationPathHint;
 use biome_diagnostics::Severity;
 use bpaf::Bpaf;
-use camino::Utf8PathBuf;
+use camino::{Utf8Path, Utf8PathBuf};
 use std::fmt::{Display, Formatter};
 use std::str::FromStr;
 
@@ -100,13 +100,20 @@ pub struct CliOptions {
 
 impl CliOptions {
     /// Computes the [ConfigurationPathHint] based on the options passed by the user
-    pub(crate) fn as_configuration_path_hint(&self) -> ConfigurationPathHint {
+    pub(crate) fn as_configuration_path_hint(
+        &self,
+        working_directory: &Utf8Path,
+    ) -> ConfigurationPathHint {
         match self.config_path.as_ref() {
             None => ConfigurationPathHint::default(),
             Some(path) => {
                 let path = Utf8PathBuf::from(path);
                 let path = path.strip_prefix("./").unwrap_or(&path);
-                ConfigurationPathHint::FromUser(path.to_path_buf())
+                if path.is_absolute() {
+                    ConfigurationPathHint::FromUser(path.to_path_buf())
+                } else {
+                    ConfigurationPathHint::FromUser(working_directory.join(path))
+                }
             }
         }
     }

crates/biome_cli/src/commands/mod.rs

@@ -939,8 +939,9 @@ pub(crate) trait CommandRunner: Sized {
         workspace: &dyn Workspace,
         cli_options: &CliOptions,
     ) -> Result<ConfiguredWorkspace, CliDiagnostic> {
+        let working_dir = fs.working_directory().unwrap_or_default();
         // Load configuration
-        let configuration_path_hint = cli_options.as_configuration_path_hint();
+        let configuration_path_hint = cli_options.as_configuration_path_hint(working_dir.as_path());
         let loaded_configuration = load_configuration(fs, configuration_path_hint)?;
         if self.should_validate_configuration_diagnostics() {
             validate_configuration_diagnostics(
@@ -961,7 +962,6 @@ pub(crate) trait CommandRunner: Sized {
 
         let execution = self.get_execution(cli_options, console, workspace)?;
 
-        let working_dir = fs.working_directory().unwrap_or_default();
         let root_configuration_dir = configuration_dir_path
             .clone()
             .unwrap_or_else(|| working_dir.clone());