fix: synthetic tasks inherit parent task's cache config (#150)

# Synthetic tasks (e.g., `vp lint` → `oxlint`) now respect the parent task's cache configuration

Synthetic tasks (e.g., `vp lint` → `oxlint`) now respect the parent
task's cache configuration instead of always enabling their own cache.
Cache is enabled only when both parent and synthetic want it, and
parent settings like `passThroughEnvs` are properly propagated.

- Add `ParentCacheConfig` enum (None/Disabled/Inherited) to represent
  parent cache state passed to synthetic task planning
- Add `resolve_synthetic_cache_config` to merge parent and synthetic
  cache configs with clear precedence rules
- Change `EnvConfig.pass_through_envs` from `Arc<[Str]>` to
  `FxHashSet<Str>` for natural deduplication during merge
- Sort pass-through envs for deterministic cache fingerprinting
- Add `synthetic-cache-disabled` test fixture with 6 cases covering
  disabled scripts, disabled tasks, enabled tasks, env inheritance,
  and expanded query task independence

Author: branchseer

crates/vite_task_graph/src/config/mod.rs

@@ -51,16 +51,19 @@ impl ResolvedTaskOptions {
         let cache_config = match user_options.cache_config {
             UserCacheConfig::Disabled { cache: MustBe!(false) } => None,
             UserCacheConfig::Enabled { cache: _, enabled_cache_config } => {
-                let mut pass_through_envs =
-                    enabled_cache_config.pass_through_envs.unwrap_or_default();
+                let mut pass_through_envs: FxHashSet<Str> = enabled_cache_config
+                    .pass_through_envs
+                    .unwrap_or_default()
+                    .into_iter()
+                    .collect();
                 pass_through_envs.extend(DEFAULT_PASSTHROUGH_ENVS.iter().copied().map(Str::from));
                 Some(CacheConfig {
                     env_config: EnvConfig {
                         fingerprinted_envs: enabled_cache_config
                             .envs
                             .map(|e| e.into_vec().into_iter().collect())
                             .unwrap_or_default(),
-                        pass_through_envs: pass_through_envs.into(),
+                        pass_through_envs,
                     },
                 })
             }
@@ -69,17 +72,17 @@ impl ResolvedTaskOptions {
     }
 }
 
-#[derive(Debug, Serialize)]
+#[derive(Debug, Clone, Serialize)]
 pub struct CacheConfig {
     pub env_config: EnvConfig,
 }
 
-#[derive(Debug, Serialize)]
+#[derive(Debug, Clone, Serialize)]
 pub struct EnvConfig {
     /// environment variable names to be fingerprinted and passed to the task, with defaults populated
     pub fingerprinted_envs: FxHashSet<Str>,
     /// environment variable names to be passed to the task without fingerprinting, with defaults populated
-    pub pass_through_envs: Arc<[Str]>,
+    pub pass_through_envs: FxHashSet<Str>,
 }
 
 #[derive(Debug, thiserror::Error)]

crates/vite_task_plan/src/envs.rs

@@ -121,8 +121,12 @@ impl EnvFingerprints {
 
         Ok(Self {
             fingerprinted_envs,
-            // Save pass_through_envs names as-is, so any changes to it will invalidate the cache
-            pass_through_env_config: Arc::clone(&env_config.pass_through_envs),
+            // Save pass_through_envs names sorted for deterministic cache fingerprinting
+            pass_through_env_config: {
+                let mut sorted: Vec<Str> = env_config.pass_through_envs.iter().cloned().collect();
+                sorted.sort();
+                sorted.into()
+            },
         })
     }
 }
@@ -194,9 +198,7 @@ mod tests {
     fn create_env_config(fingerprinted: &[&str], pass_through: &[&str]) -> EnvConfig {
         EnvConfig {
             fingerprinted_envs: fingerprinted.iter().map(|s| Str::from(*s)).collect(),
-            pass_through_envs: Arc::from(
-                pass_through.iter().map(|s| Str::from(*s)).collect::<Vec<_>>(),
-            ),
+            pass_through_envs: pass_through.iter().map(|s| Str::from(*s)).collect(),
         }
     }
 

crates/vite_task_plan/src/lib.rs

@@ -16,7 +16,7 @@ pub use error::{Error, TaskPlanErrorKind};
 use execution_graph::ExecutionGraph;
 use in_process::InProcessExecution;
 pub use path_env::{get_path_env, prepend_path_env};
-use plan::{plan_query_request, plan_synthetic_request};
+use plan::{ParentCacheConfig, plan_query_request, plan_synthetic_request};
 use plan_request::{PlanRequest, SyntheticPlanRequest};
 use rustc_hash::FxHashMap;
 use serde::{Serialize, ser::SerializeMap as _};
@@ -230,6 +230,7 @@ impl ExecutionPlan {
                     synthetic_plan_request,
                     None,
                     cwd,
+                    ParentCacheConfig::None,
                 )
                 .with_empty_call_stack()?;
                 ExecutionItemKind::Leaf(LeafExecutionKind::Spawn(execution))
@@ -256,6 +257,7 @@ impl ExecutionPlan {
             synthetic_plan_request,
             Some(execution_cache_key),
             cwd,
+            ParentCacheConfig::None,
         )
         .with_empty_call_stack()?;
         Ok(Self { root_node: ExecutionItemKind::Leaf(LeafExecutionKind::Spawn(execution)) })

crates/vite_task_plan/src/plan.rs

@@ -18,7 +18,10 @@ use vite_shell::try_parse_as_and_list;
 use vite_str::Str;
 use vite_task_graph::{
     TaskNodeIndex,
-    config::{ResolvedTaskOptions, user::UserTaskOptions},
+    config::{
+        CacheConfig, ResolvedTaskOptions,
+        user::{UserCacheConfig, UserTaskOptions},
+    },
 };
 
 use crate::{
@@ -199,12 +202,21 @@ async fn plan_task_as_execution_node(
                 }
                 // Synthetic task (from CommandHandler)
                 Some(PlanRequest::Synthetic(synthetic_plan_request)) => {
+                    let parent_cache_config = task_node
+                        .resolved_config
+                        .resolved_options
+                        .cache_config
+                        .as_ref()
+                        .map_or(ParentCacheConfig::Disabled, |config| {
+                            ParentCacheConfig::Inherited(config.clone())
+                        });
                     let spawn_execution = plan_synthetic_request(
                         context.workspace_path(),
                         &and_item.envs,
                         synthetic_plan_request,
                         Some(task_execution_cache_key),
                         &cwd,
+                        parent_cache_config,
                     )
                     .with_plan_context(&context)?;
                     ExecutionItemKind::Leaf(LeafExecutionKind::Spawn(spawn_execution))
@@ -298,26 +310,91 @@ async fn plan_task_as_execution_node(
     Ok(TaskExecution { task_display: task_node.task_display.clone(), items })
 }
 
+/// Cache configuration inherited from the parent task that contains a synthetic command.
+///
+/// When a synthetic task (e.g., `vp lint` expanding to `oxlint`) appears inside a
+/// user-defined task's script, the parent task's cache configuration should constrain
+/// the synthetic task's caching behavior.
+pub enum ParentCacheConfig {
+    /// No parent task (top-level synthetic command like `vp lint` run directly).
+    /// The synthetic task uses its own default cache configuration.
+    None,
+
+    /// Parent task has caching disabled (`cache: false` or `cacheScripts` not enabled).
+    /// The synthetic task should also have caching disabled.
+    Disabled,
+
+    /// Parent task has caching enabled with this configuration.
+    /// The synthetic task inherits this config, merged with its own additions.
+    Inherited(CacheConfig),
+}
+
+/// Resolves the effective cache configuration for a synthetic task by combining
+/// the parent task's cache config with the synthetic command's own additions.
+///
+/// Synthetic tasks (e.g., `vp lint` → `oxlint`) may declare their own cache-related
+/// env requirements (e.g., `pass_through_envs` for env-test). When a parent task
+/// exists, its cache config takes precedence:
+/// - If the parent disables caching, the synthetic task is also uncached.
+/// - If the parent enables caching but the synthetic disables it, caching is disabled.
+/// - If both parent and synthetic enable caching, the synthetic inherits the parent's
+///   env config and merges in any additional envs the synthetic command needs.
+/// - If there is no parent (top-level invocation), the synthetic task's own
+///   [`UserCacheConfig`] is resolved with defaults.
+fn resolve_synthetic_cache_config(
+    parent: ParentCacheConfig,
+    synthetic_cache_config: UserCacheConfig,
+    cwd: &Arc<AbsolutePath>,
+) -> Option<CacheConfig> {
+    match parent {
+        ParentCacheConfig::None => {
+            // Top-level: resolve from synthetic's own config
+            ResolvedTaskOptions::resolve(
+                UserTaskOptions {
+                    cache_config: synthetic_cache_config,
+                    cwd_relative_to_package: None,
+                    depends_on: None,
+                },
+                cwd,
+            )
+            .cache_config
+        }
+        ParentCacheConfig::Disabled => Option::None,
+        ParentCacheConfig::Inherited(mut parent_config) => {
+            // Cache is enabled only if both parent and synthetic want it.
+            // Merge synthetic's additions into parent's config.
+            match synthetic_cache_config {
+                UserCacheConfig::Disabled { .. } => Option::None,
+                UserCacheConfig::Enabled { enabled_cache_config, .. } => {
+                    if let Some(extra_envs) = enabled_cache_config.envs {
+                        parent_config.env_config.fingerprinted_envs.extend(extra_envs.into_vec());
+                    }
+                    if let Some(extra_pts) = enabled_cache_config.pass_through_envs {
+                        parent_config.env_config.pass_through_envs.extend(extra_pts);
+                    }
+                    Some(parent_config)
+                }
+            }
+        }
+    }
+}
+
 #[expect(clippy::result_large_err, reason = "TaskPlanErrorKind is large for diagnostics")]
 pub fn plan_synthetic_request(
     workspace_path: &Arc<AbsolutePath>,
     prefix_envs: &BTreeMap<Str, Str>,
     synthetic_plan_request: SyntheticPlanRequest,
     execution_cache_key: Option<ExecutionCacheKey>,
     cwd: &Arc<AbsolutePath>,
+    parent_cache_config: ParentCacheConfig,
 ) -> Result<SpawnExecution, TaskPlanErrorKind> {
     let SyntheticPlanRequest { program, args, cache_config, envs } = synthetic_plan_request;
 
     let program_path = which(&program, &envs, cwd).map_err(TaskPlanErrorKind::ProgramNotFound)?;
-    let resolved_options = ResolvedTaskOptions::resolve(
-        UserTaskOptions {
-            cache_config,
-            // cwd_relative_to_package and depends_on don't make sense for synthetic tasks.
-            cwd_relative_to_package: None,
-            depends_on: None,
-        },
-        cwd,
-    );
+    let resolved_cache_config =
+        resolve_synthetic_cache_config(parent_cache_config, cache_config, cwd);
+    let resolved_options =
+        ResolvedTaskOptions { cwd: Arc::clone(cwd), cache_config: resolved_cache_config };
 
     plan_spawn_execution(
         workspace_path,

crates/vite_task_plan/src/plan_request.rs

@@ -18,6 +18,19 @@ pub struct ScriptCommand {
     pub cwd: Arc<AbsolutePath>,
 }
 
+impl ScriptCommand {
+    /// Convert this `ScriptCommand` to a `SyntheticPlanRequest` with the given `cache_config`.
+    #[must_use]
+    pub fn to_synthetic_plan_request(&self, cache_config: UserCacheConfig) -> SyntheticPlanRequest {
+        SyntheticPlanRequest {
+            program: Arc::from(OsStr::new(&self.program)),
+            args: self.args.clone(),
+            cache_config,
+            envs: self.envs.clone(),
+        }
+    }
+}
+
 #[derive(Debug)]
 pub struct PlanOptions {
     pub extra_args: Arc<[Str]>,

crates/vite_task_plan/tests/plan_snapshots/fixtures/synthetic-cache-disabled/package.json

@@ -0,0 +1,7 @@
+{
+  "name": "@test/synthetic-cache-disabled",
+  "scripts": {
+    "lint": "vp lint",
+    "run-build-cache-false": "vp run build"
+  }
+}

crates/vite_task_plan/tests/plan_snapshots/fixtures/synthetic-cache-disabled/snapshots.toml

@@ -0,0 +1,23 @@
+[[plan]]
+name = "script without cacheScripts defaults to no cache"
+args = ["run", "lint"]
+
+[[plan]]
+name = "task with cache false disables synthetic cache"
+args = ["run", "lint-no-cache"]
+
+[[plan]]
+name = "task with cache true enables synthetic cache"
+args = ["run", "lint-with-cache"]
+
+[[plan]]
+name = "task passThroughEnvs inherited by synthetic"
+args = ["run", "lint-with-pass-through-envs"]
+
+[[plan]]
+name = "parent cache false does not affect expanded query tasks"
+args = ["run", "run-build-no-cache"]
+
+[[plan]]
+name = "script cache false does not affect expanded synthetic cache"
+args = ["run", "run-build-cache-false"]

crates/vite_task_plan/tests/plan_snapshots/fixtures/synthetic-cache-disabled/snapshots/query - parent cache false does not affect expanded query tasks.snap

@@ -0,0 +1,112 @@
+---
+source: crates/vite_task_plan/tests/plan_snapshots/main.rs
+expression: "&plan_json"
+input_file: crates/vite_task_plan/tests/plan_snapshots/fixtures/synthetic-cache-disabled
+---
+{
+  "root_node": {
+    "Expanded": [
+      {
+        "key": [
+          "<workspace>/",
+          "run-build-no-cache"
+        ],
+        "node": {
+          "task_display": {
+            "package_name": "@test/synthetic-cache-disabled",
+            "task_name": "run-build-no-cache",
+            "package_path": "<workspace>/"
+          },
+          "items": [
+            {
+              "execution_item_display": {
+                "task_display": {
+                  "package_name": "@test/synthetic-cache-disabled",
+                  "task_name": "run-build-no-cache",
+                  "package_path": "<workspace>/"
+                },
+                "command": "vp run build",
+                "and_item_index": null,
+                "cwd": "<workspace>/"
+              },
+              "kind": {
+                "Expanded": [
+                  {
+                    "key": [
+                      "<workspace>/",
+                      "build"
+                    ],
+                    "node": {
+                      "task_display": {
+                        "package_name": "@test/synthetic-cache-disabled",
+                        "task_name": "build",
+                        "package_path": "<workspace>/"
+                      },
+                      "items": [
+                        {
+                          "execution_item_display": {
+                            "task_display": {
+                              "package_name": "@test/synthetic-cache-disabled",
+                              "task_name": "build",
+                              "package_path": "<workspace>/"
+                            },
+                            "command": "vp lint",
+                            "and_item_index": null,
+                            "cwd": "<workspace>/"
+                          },
+                          "kind": {
+                            "Leaf": {
+                              "Spawn": {
+                                "cache_metadata": {
+                                  "spawn_fingerprint": {
+                                    "cwd": "",
+                                    "program_fingerprint": {
+                                      "OutsideWorkspace": {
+                                        "program_name": "oxlint"
+                                      }
+                                    },
+                                    "args": [],
+                                    "env_fingerprints": {
+                                      "fingerprinted_envs": {},
+                                      "pass_through_env_config": [
+                                        "<default pass-through envs>"
+                                      ]
+                                    },
+                                    "fingerprint_ignores": null
+                                  },
+                                  "execution_cache_key": {
+                                    "UserTask": {
+                                      "task_name": "build",
+                                      "and_item_index": 0,
+                                      "extra_args": [],
+                                      "package_path": ""
+                                    }
+                                  }
+                                },
+                                "spawn_command": {
+                                  "program_path": "<tools>/node_modules/.bin/oxlint",
+                                  "args": [],
+                                  "all_envs": {
+                                    "NO_COLOR": "1",
+                                    "PATH": "<workspace>/node_modules/.bin:<tools>/node_modules/.bin"
+                                  },
+                                  "cwd": "<workspace>/"
+                                }
+                              }
+                            }
+                          }
+                        }
+                      ]
+                    },
+                    "neighbors": []
+                  }
+                ]
+              }
+            }
+          ]
+        },
+        "neighbors": []
+      }
+    ]
+  }
+}