feat: allow for specifying path of root turbo.json (#9087)

### Description

Allow for setting the root `turbo.json` path via
`--root-turbo-json=path/to/my.json` or
`TURBO_ROOT_TURBO_JSON=path/to/my.json`. This option is not compatible
with watch mode.

Reviewing this PR should be done commit-wise, there's a lot of
prefactoring before the final commit that implements the actual feature.

Major changes as part of prefactor:
- We parse `turbo.json` based on absolute paths instead of repo root
relative ones. This allows us to read a `turbo.json` from wherever a
user wants
- Moved the reading of a trace generated `turbo.json` outside of the
primary `turbo.json` reading logic and into `TaskAccess`
- Changed ordering of how `config` layering happens instead of ordering
them from least to most significant and always choosing a present value,
we now go from most to least significant and only choose a value if we
do not already have a value for it. This is necessary as we now have a
config option (`TURBO_ROOT_TURBO_JSON`) that alters a less significant
config source (`turbo.json`).
 - Move config sources out of `config.rs`
- We are now lazy with evaluating our config sources. This allows us to
change the path of the `turbo.json` we read after partial evaluation of
config sources

### Testing Instructions

Existing unit tests for the refactors.
Manual testing of the traced config logic.
Integration test for new feature.

---------

Co-authored-by: Nicholas Yang <[email protected]>

Author: chris-olszewski

crates/turborepo-lib/src/cli/mod.rs

@@ -222,6 +222,10 @@ pub struct Args {
     /// should be used.
     #[clap(long, global = true)]
     pub dangerously_disable_package_manager_check: bool,
+    /// Use the `turbo.json` located at the provided path instead of one at the
+    /// root of the repository.
+    #[clap(long, global = true)]
+    pub root_turbo_json: Option<Utf8PathBuf>,
     #[clap(flatten, next_help_heading = "Run Arguments")]
     // DO NOT MAKE THIS VISIBLE
     // This is explicitly set to None in `run`

crates/turborepo-lib/src/commands/link.rs

@@ -569,7 +569,7 @@ mod test {
 
     use anyhow::Result;
     use tempfile::{NamedTempFile, TempDir};
-    use turbopath::{AbsoluteSystemPathBuf, AnchoredSystemPath};
+    use turbopath::AbsoluteSystemPathBuf;
     use turborepo_ui::ColorConfig;
     use turborepo_vercel_api_mock::start_test_server;
 
@@ -609,7 +609,7 @@ mod test {
         let port = port_scanner::request_open_port().unwrap();
         let handle = tokio::spawn(start_test_server(port));
         let mut base = CommandBase {
-            global_config_path: Some(
+            override_global_config_path: Some(
                 AbsoluteSystemPathBuf::try_from(user_config_file.path().to_path_buf()).unwrap(),
             ),
             repo_root: repo_root.clone(),
@@ -675,7 +675,7 @@ mod test {
         let port = port_scanner::request_open_port().unwrap();
         let handle = tokio::spawn(start_test_server(port));
         let mut base = CommandBase {
-            global_config_path: Some(
+            override_global_config_path: Some(
                 AbsoluteSystemPathBuf::try_from(user_config_file.path().to_path_buf()).unwrap(),
             ),
             repo_root: repo_root.clone(),
@@ -712,11 +712,7 @@ mod test {
 
         // verify space id is added to turbo.json
         let turbo_json_contents = fs::read_to_string(&turbo_json_file).unwrap();
-        let turbo_json = RawTurboJson::parse(
-            &turbo_json_contents,
-            AnchoredSystemPath::new("turbo.json").unwrap(),
-        )
-        .unwrap();
+        let turbo_json = RawTurboJson::parse(&turbo_json_contents, "turbo.json").unwrap();
         assert_eq!(
             turbo_json.experimental_spaces.unwrap().id.unwrap(),
             turborepo_vercel_api_mock::EXPECTED_SPACE_ID.into()

crates/turborepo-lib/src/commands/mod.rs

@@ -32,8 +32,7 @@ pub(crate) mod unlink;
 pub struct CommandBase {
     pub repo_root: AbsoluteSystemPathBuf,
     pub color_config: ColorConfig,
-    #[cfg(test)]
-    pub global_config_path: Option<AbsoluteSystemPathBuf>,
+    pub override_global_config_path: Option<AbsoluteSystemPathBuf>,
     config: OnceCell<ConfigurationOptions>,
     args: Args,
     version: &'static str,
@@ -50,16 +49,14 @@ impl CommandBase {
             repo_root,
             color_config,
             args,
-            #[cfg(test)]
-            global_config_path: None,
+            override_global_config_path: None,
             config: OnceCell::new(),
             version,
         }
     }
 
-    #[cfg(test)]
-    pub fn with_global_config_path(mut self, path: AbsoluteSystemPathBuf) -> Self {
-        self.global_config_path = Some(path);
+    pub fn with_override_global_config_path(mut self, path: AbsoluteSystemPathBuf) -> Self {
+        self.override_global_config_path = Some(path);
         self
     }
 
@@ -119,6 +116,13 @@ impl CommandBase {
                             .and_then(|args| args.cache_dir.clone())
                     }),
             )
+            .with_root_turbo_json_path(
+                self.args
+                    .root_turbo_json
+                    .clone()
+                    .map(AbsoluteSystemPathBuf::from_cwd)
+                    .transpose()?,
+            )
             .build()
     }
 
@@ -129,7 +133,7 @@ impl CommandBase {
     // Getting all of the paths.
     fn global_config_path(&self) -> Result<AbsoluteSystemPathBuf, ConfigError> {
         #[cfg(test)]
-        if let Some(global_config_path) = self.global_config_path.clone() {
+        if let Some(global_config_path) = self.override_global_config_path.clone() {
             return Ok(global_config_path);
         }
 

crates/turborepo-lib/src/commands/prune.rs

@@ -449,7 +449,7 @@ impl<'a> Prune<'a> {
             Err(e) => return Err(e.into()),
         };
 
-        let turbo_json = RawTurboJson::parse(&turbo_json_contents, anchored_turbo_path)?;
+        let turbo_json = RawTurboJson::parse(&turbo_json_contents, anchored_turbo_path.as_str())?;
 
         let pruned_turbo_json = turbo_json.prune_tasks(workspaces);
         new_turbo_path.create_with_contents(serde_json::to_string_pretty(&pruned_turbo_json)?)?;