fix(test): address Codex round-14 findings

Real-tool resolution runs from the step cwd, so relative PATH entries
resolve exactly as the child sees them (after-steps included). The
migrator omits only the ROOT steps.json/snap.txt; a project file with the
same name in a subdirectory carries over. Windows global provisioning
copies vp-shim.exe beside vp.exe when the source build has one, so
trampoline-creating cases (vp env setup) work.

Claude-Session: https://claude.ai/code/session_01NRgjMi2Vus3iJctudGEWPT

Author: fengmk2

crates/vite_cli_snapshots/tests/cli_snapshots/flavor.rs

@@ -268,6 +268,15 @@ pub fn provision(flavor: Flavor, run_root: &Path) -> Result<FlavorRuntime, Strin
             for name in ["vp", "vpr", "vpx"] {
                 install_tool(&bin_dir, name, &vp)?;
             }
+            // Windows `vp env setup` looks for the trampoline template
+            // (vp-shim.exe) beside vp.exe; carry it over when the source
+            // build has one, so shim-creating cases work.
+            #[cfg(windows)]
+            if let Some(shim) = vp.parent().map(|dir| dir.join("vp-shim.exe"))
+                && shim.is_file()
+            {
+                let _ = std::fs::copy(&shim, bin_dir.join("vp-shim.exe"));
+            }
             Some(repo_root().join("packages/cli/dist"))
         }
         Flavor::Local => {
@@ -298,6 +307,7 @@ impl FlavorRuntime {
         &self,
         program: &str,
         case_path: &std::ffi::OsStr,
+        cwd: &Path,
     ) -> Result<PathBuf, String> {
         match program {
             "vp" | "vpr" | "vpx" | "oxfmt" | "oxlint" => {
@@ -306,14 +316,14 @@ impl FlavorRuntime {
                 // on that PATH too, so this is a pure precedence rule; the
                 // direct bin-dir lookup below only remains as the fallback
                 // for cases that override PATH entirely.
-                if let Ok(found) = which::which_in(program, Some(case_path), PathBuf::from(".")) {
+                if let Ok(found) = which::which_in(program, Some(case_path), cwd) {
                     return Ok(found);
                 }
                 self.bin_dir_tool(program)
             }
             "vpt" => self.bin_dir_tool(program),
             "node" | "git" | "npm" | "pnpm" | "yarn" | "bun" => {
-                which::which_in(program, Some(case_path), PathBuf::from("."))
+                which::which_in(program, Some(case_path), cwd)
                     .map_err(|e| format!("`{program}` not found on the case PATH: {e}"))
             }
             other => Err(format!(

crates/vite_cli_snapshots/tests/cli_snapshots/main.rs

@@ -702,11 +702,12 @@ fn run_case(
             step_env_override = env;
             &step_env_override
         };
-        // Resolution honors a per-step PATH override, so steps testing shims
-        // or custom prefixes run exactly the tool the child would see.
+        // Resolution honors a per-step PATH override and runs from the step
+        // cwd (relative PATH entries resolve as the child would see them),
+        // so shim and custom-prefix steps run exactly the child's tool.
         let step_path = step_env.get("PATH").cloned().unwrap_or_else(|| case_path.clone());
-        let program = runtime.resolve_program(&argv[0], &step_path)?;
         let step_cwd = stage.join(step.cwd().unwrap_or(case.cwd.as_str()));
+        let program = runtime.resolve_program(&argv[0], &step_path, &step_cwd)?;
         let timeout = step.timeout();
 
         let (termination_state, raw_output) = if step.tty() {
@@ -910,12 +911,13 @@ fn run_case(
             &after_env_override
         };
         let after_path = after_env.get("PATH").cloned().unwrap_or_else(|| case_path.clone());
-        if let Ok(program) = runtime.resolve_program(&argv[0], &after_path) {
+        let after_cwd = stage.join(step.cwd().unwrap_or(case.cwd.as_str()));
+        if let Ok(program) = runtime.resolve_program(&argv[0], &after_path, &after_cwd) {
             let mut cmd = std::process::Command::new(program);
             cmd.args(&argv[1..])
                 .env_clear()
                 .envs(after_env)
-                .current_dir(stage.join(step.cwd().unwrap_or(case.cwd.as_str())))
+                .current_dir(&after_cwd)
                 .stdin(std::process::Stdio::null())
                 .stdout(std::process::Stdio::null())
                 .stderr(std::process::Stdio::null());

packages/tools/src/migrate-snap-tests.ts

@@ -576,12 +576,15 @@ function migrateCase(
   // Write the fixture: everything except steps.json and snap.txt carries over.
   const fixtureDir = path.join(outDir, newName);
   fs.mkdirSync(fixtureDir, { recursive: true });
+  // Only the ROOT metadata files are omitted; a project file that happens
+  // to be named snap.txt or steps.json in a subdirectory carries over.
+  const rootMetadata = new Set([
+    path.resolve(caseDir, 'steps.json'),
+    path.resolve(caseDir, 'snap.txt'),
+  ]);
   fs.cpSync(caseDir, fixtureDir, {
     recursive: true,
-    filter: (src) => {
-      const base = path.basename(src);
-      return base !== 'steps.json' && base !== 'snap.txt';
-    },
+    filter: (src) => !rootMetadata.has(path.resolve(src)),
   });
   fs.writeFileSync(path.join(fixtureDir, 'snapshots.toml'), `${lines.join('\n')}\n`);
   return report;