fix(task): resolve vars from subdirectory configs for monorepo tasks

e2e/tasks/test_task_monorepo_vars

@@ -0,0 +1,69 @@
+#!/usr/bin/env bash
+# Test that monorepo tasks properly load [vars] from subdirectory configs
+export MISE_EXPERIMENTAL=1
+
+# Create monorepo root config with vars
+cat <<EOF >mise.toml
+experimental_monorepo_root = true
+
+[monorepo]
+config_roots = ["infra/stacks/*"]
+
+[vars]
+ROOT_VAR = "root_value"
+SHARED_VAR = "from_root"
+
+[tasks.root-greet]
+run = 'echo "ROOT_VAR={{vars.ROOT_VAR}} SHARED_VAR={{vars.SHARED_VAR}}"'
+EOF
+
+# Create subdirectory config with its own vars and tasks
+mkdir -p infra/stacks/gcp
+cat <<EOF >infra/stacks/gcp/mise.toml
+[vars]
+GCP_VAR = "gcp_value"
+SHARED_VAR = "from_gcp"
+
+[tasks.greet]
+run = 'echo "GCP_VAR={{vars.GCP_VAR}} SHARED_VAR={{vars.SHARED_VAR}} ROOT_VAR={{vars.ROOT_VAR}}"'
+
+[tasks.greet-dev]
+run = 'echo "DEV_VAR={{vars.DEV_VAR}} SHARED_VAR={{vars.SHARED_VAR}}"'
+EOF
+
+# Create MISE_ENV-specific config for the subdirectory
+cat <<EOF >infra/stacks/gcp/mise.dev.toml
+[vars]
+DEV_VAR = "dev_value"
+SHARED_VAR = "from_gcp_dev"
+EOF
+
+# Test 1: Root task sees root vars
+echo "=== Test 1: Root task sees root vars ==="
+unset MISE_ENV
+output=$(mise run //:root-greet)
+echo "$output"
+assert_contains "echo '$output'" "ROOT_VAR=root_value"
+assert_contains "echo '$output'" "SHARED_VAR=from_root"
+
+# Test 2: Subdirectory task sees its own vars, inherits root vars, and overrides shared vars
+echo "=== Test 2: Subdirectory task var resolution ==="
+unset MISE_ENV
+output=$(mise run '//infra/stacks/gcp:greet')
+echo "$output"
+# Core bug fix: subdirectory vars are loaded
+assert_contains "echo '$output'" "GCP_VAR=gcp_value"
+# Subdirectory vars override root vars of the same name
+assert_contains "echo '$output'" "SHARED_VAR=from_gcp"
+# Subdirectory task still inherits root vars it doesn't override
+assert_contains "echo '$output'" "ROOT_VAR=root_value"
+
+# Test 3: Subdirectory task with MISE_ENV sees env-specific vars
+echo "=== Test 3: MISE_ENV-specific vars in subdirectory ==="
+output=$(MISE_ENV=dev mise run '//infra/stacks/gcp:greet-dev')
+echo "$output"
+assert_contains "echo '$output'" "DEV_VAR=dev_value"
+# MISE_ENV vars should override base vars
+assert_contains "echo '$output'" "SHARED_VAR=from_gcp_dev"
+
+echo "=== All tests passed! ==="

src/task/mod.rs

@@ -691,6 +691,17 @@ impl Task {
         config: &Arc<Config>,
         cwd: Option<PathBuf>,
         env: &EnvMap,
+    ) -> Result<(usage::Spec, Vec<String>)> {
+        self.parse_usage_spec_with_vars(config, cwd, env, None)
+            .await
+    }
+
+    pub async fn parse_usage_spec_with_vars(
+        &self,
+        config: &Arc<Config>,
+        cwd: Option<PathBuf>,
+        env: &EnvMap,
+        extra_vars: Option<IndexMap<String, String>>,
     ) -> Result<(usage::Spec, Vec<String>)> {
         let (mut spec, scripts) = if let Some(file) = self.file_path(config).await? {
             let spec = usage::Spec::parse_script(&file)
@@ -704,7 +715,7 @@ impl Task {
             (spec, vec![])
         } else {
             let scripts_only = self.run_script_strings();
-            let (scripts, spec) = TaskScriptParser::new(cwd)
+            let (scripts, spec) = Self::make_script_parser(cwd, extra_vars)
                 .parse_run_scripts(config, self, &scripts_only, env)
                 .await?;
             (spec, scripts)
@@ -713,6 +724,17 @@ impl Task {
         Ok((spec, scripts))
     }
 
+    fn make_script_parser(
+        cwd: Option<PathBuf>,
+        extra_vars: Option<IndexMap<String, String>>,
+    ) -> TaskScriptParser {
+        let parser = TaskScriptParser::new(cwd);
+        match extra_vars {
+            Some(vars) => parser.with_extra_vars(vars),
+            None => parser,
+        }
+    }
+
     /// Parse usage spec for display purposes without expensive environment rendering
     pub async fn parse_usage_spec_for_display(&self, config: &Arc<Config>) -> Result<usage::Spec> {
         let dir = self.dir(config).await?;
@@ -741,11 +763,14 @@ impl Task {
         cwd: Option<PathBuf>,
         args: &[String],
         env: &EnvMap,
+        extra_vars: Option<IndexMap<String, String>>,
     ) -> Result<Vec<(String, Vec<String>)>> {
-        let (spec, scripts) = self.parse_usage_spec(config, cwd.clone(), env).await?;
+        let (spec, scripts) = self
+            .parse_usage_spec_with_vars(config, cwd.clone(), env, extra_vars.clone())
+            .await?;
         if has_any_args_defined(&spec) {
             let scripts_only = self.run_script_strings();
-            let scripts = TaskScriptParser::new(cwd)
+            let scripts = Self::make_script_parser(cwd, extra_vars)
                 .parse_run_scripts_with_args(config, self, &scripts_only, env, args, &spec)
                 .await?;
             Ok(scripts.into_iter().map(|s| (s, vec![])).collect())