diff --git a/tests/fixtures/fake_test_runner.rs b/tests/fixtures/fake_test_runner.rs
new file mode 100644
index 0000000000..cc2f25a3ba
--- /dev/null
+++ b/tests/fixtures/fake_test_runner.rs
@@ -0,0 +1,32 @@
+//! Native fake for CLI routing tests: records the executable and argument vector
+//! without requiring Node, a shell, a package registry, or installed JS runners.
+use std::env;
+use std::fs::OpenOptions;
+use std::io::Write;
+
+fn main() {
+    let executable = env::current_exe().expect("current executable");
+    let name = executable.file_stem().expect("executable name");
+    let mut trace = OpenOptions::new()
+        .create(true)
+        .append(true)
+        .open(env::var_os("RTK_TEST_TRACE").expect("trace path"))
+        .expect("open trace");
+    writeln!(trace, "{}", name.to_string_lossy()).expect("record executable");
+    for arg in env::args().skip(1) {
+        writeln!(trace, "{arg}").expect("record argument");
+    }
+    writeln!(trace, "END").expect("record invocation end");
+    std::io::stdout()
+        .write_all(env::var("RTK_TEST_STDOUT").unwrap_or_default().as_bytes())
+        .expect("write stdout");
+    std::io::stderr()
+        .write_all(env::var("RTK_TEST_STDERR").unwrap_or_default().as_bytes())
+        .expect("write stderr");
+    std::process::exit(
+        env::var("RTK_TEST_EXIT")
+            .expect("exit code")
+            .parse()
+            .expect("numeric exit code"),
+    );
+}
diff --git a/tests/framework_test_routing_test.rs b/tests/framework_test_routing_test.rs
new file mode 100644
index 0000000000..7007eaecd1
--- /dev/null
+++ b/tests/framework_test_routing_test.rs
@@ -0,0 +1,245 @@
+//! Exercise the public CLI, package-manager selection, spawn and output wiring.
+//! A native Rust fake runs on Unix and Windows; no JS tools or downloads are used.
+use std::fs;
+use std::path::Path;
+use std::process::{Command, Output};
+use std::sync::LazyLock;
+
+mod common;
+
+const PASS_JSON: &str =
+    r#"{"numTotalTests":2,"numPassedTests":2,"numFailedTests":0,"testResults":[]}"#;
+const FAIL_JSON: &str = r#"{"numTotalTests":1,"numPassedTests":0,"numFailedTests":1,"testResults":[{"name":"src/fail.test.ts","assertionResults":[{"fullName":"fails deliberately","status":"failed","failureMessages":["expected true, got false"]}]}]}"#;
+
+// Compile once using the same Rust toolchain required to run the test suite.
+// Keep bytes rather than a TempDir in a static so the compiler's scratch files
+// are cleaned up, and every fixture owns its own executables.
+static FAKE_RUNNER: LazyLock<Vec<u8>> = LazyLock::new(|| {
+    let dir = tempfile::tempdir().expect("compiler scratch directory");
+    let output = dir
+        .path()
+        .join(format!("fake{}", std::env::consts::EXE_SUFFIX));
+    let result = Command::new(std::env::var_os("RUSTC").unwrap_or_else(|| "rustc".into()))
+        .arg(Path::new(env!("CARGO_MANIFEST_DIR")).join("tests/fixtures/fake_test_runner.rs"))
+        .args(["--edition=2024", "--deny", "warnings", "-o"])
+        .arg(&output)
+        .output()
+        .expect("compile native fake runner");
+    assert!(
+        result.status.success(),
+        "compile fake runner: {}",
+        String::from_utf8_lossy(&result.stderr)
+    );
+    fs::read(output).expect("read native fake runner")
+});
+
+struct Fixture {
+    dir: tempfile::TempDir,
+}
+
+impl Fixture {
+    fn new(direct_tools: bool, lockfile: Option<&str>) -> Self {
+        let dir = tempfile::tempdir().expect("fixture directory");
+        let bin = dir.path().join("bin");
+        fs::create_dir(&bin).expect("fixture bin");
+        // Install all runner fakes so choosing the wrong one is observable too.
+        let mut names = vec!["pnpm", "yarn", "npx", "bunx"];
+        if direct_tools {
+            names.extend(["vitest", "jest"]);
+        }
+        for name in names {
+            let path = bin.join(format!("{name}{}", std::env::consts::EXE_SUFFIX));
+            fs::write(&path, &*FAKE_RUNNER).expect("write fake executable");
+            #[cfg(unix)]
+            {
+                use std::os::unix::fs::PermissionsExt;
+                fs::set_permissions(path, fs::Permissions::from_mode(0o755))
+                    .expect("make fake executable");
+            }
+        }
+        if let Some(lockfile) = lockfile {
+            fs::write(dir.path().join(lockfile), "").expect("write lockfile");
+        }
+        Self { dir }
+    }
+
+    fn run(&self, args: &[&str], stdout: &str, stderr: &str, exit: i32) -> Output {
+        common::rtk_command()
+            .args(args)
+            .current_dir(self.dir.path())
+            // No inherited PATH: an installed runner must never defeat the fake
+            // or cause these tests to execute/download real JavaScript packages.
+            .env("PATH", self.dir.path().join("bin"))
+            .env("PATHEXT", ".EXE")
+            .env("NO_COLOR", "1")
+            .env("RTK_TEST_TRACE", self.dir.path().join("trace"))
+            .env("RTK_TEST_STDOUT", stdout)
+            .env("RTK_TEST_STDERR", stderr)
+            .env("RTK_TEST_EXIT", exit.to_string())
+            .output()
+            .expect("run rtk")
+    }
+
+    fn assert_invocation(&self, expected: &[&str]) {
+        let trace = fs::read_to_string(self.dir.path().join("trace")).expect("read spawn trace");
+        let expected: Vec<_> = expected.iter().copied().chain(["END"]).collect();
+        assert_eq!(trace.lines().collect::<Vec<_>>(), expected);
+    }
+}
+
+fn framework_args(framework: &str) -> Vec<&str> {
+    match framework {
+        "vitest" => vec!["run", "--reporter=json"],
+        "jest" => vec!["--no-watch", "--json"],
+        _ => panic!("unknown test framework"),
+    }
+}
+
+#[test]
+fn cli_dispatches_each_framework_to_its_own_executable_and_arguments() {
+    for framework in ["vitest", "jest"] {
+        // A lockfile must not displace a runner already available on PATH.
+        let fixture = Fixture::new(true, Some("pnpm-lock.yaml"));
+        let user_args = ["src/has space.test.ts", "-t", "works with spaces"];
+        let args: Vec<_> = [framework].into_iter().chain(user_args).collect();
+        let out = fixture.run(&args, PASS_JSON, "", 0);
+        let mut expected = vec![framework];
+        expected.extend(framework_args(framework));
+        expected.extend(user_args);
+        fixture.assert_invocation(&expected);
+        assert_eq!(out.status.code(), Some(0));
+        assert_eq!(out.stdout, b"PASS (2) FAIL (0)\n");
+        assert!(out.stderr.is_empty());
+    }
+}
+
+#[test]
+fn missing_framework_uses_the_projects_package_manager_without_fetching() {
+    for (lockfile, prefix) in [
+        (Some("pnpm-lock.yaml"), vec!["pnpm", "exec", "--"]),
+        (Some("yarn.lock"), vec!["yarn", "exec", "--"]),
+        (Some("bun.lock"), vec!["npx", "--no-install", "--"]),
+        (None, vec!["npx", "--no-install", "--"]),
+    ] {
+        for framework in ["vitest", "jest"] {
+            let fixture = Fixture::new(false, lockfile);
+            let out = fixture.run(&[framework, "src/a.test.ts"], PASS_JSON, "", 0);
+            let mut expected = prefix.clone();
+            expected.push(framework);
+            expected.extend(framework_args(framework));
+            expected.push("src/a.test.ts");
+            fixture.assert_invocation(&expected);
+            assert_eq!(out.status.code(), Some(0));
+            assert_eq!(out.stdout, b"PASS (2) FAIL (0)\n");
+            assert!(out.stderr.is_empty());
+        }
+    }
+}
+
+#[test]
+fn explicit_vitest_reporter_reaches_the_spawn_and_bypasses_parsing() {
+    let verbose =
+        " ✓ src/a.test.ts > keeps this test name\n\n Tests  2 passed (2)\n Duration  10ms\n";
+    let json_line = format!("{PASS_JSON}\n");
+    for (reporter, raw, expected_stdout) in [
+        (vec!["--reporter=verbose"], verbose, verbose),
+        (vec!["--reporter", "verbose"], verbose, verbose),
+        // An explicitly requested JSON report must also remain JSON.
+        (vec!["--reporter=json"], PASS_JSON, json_line.as_str()),
+    ] {
+        let fixture = Fixture::new(true, None);
+        let mut args = vec!["vitest", "src/a.test.ts"];
+        args.extend(&reporter);
+        let out = fixture.run(&args, raw, "", 0);
+        let mut expected = vec!["vitest", "run", "src/a.test.ts"];
+        expected.extend(&reporter);
+        fixture.assert_invocation(&expected);
+        assert_eq!(out.status.code(), Some(0));
+        // Terminated reports stay byte-exact; only a missing final newline is added.
+        assert_eq!(out.stdout, expected_stdout.as_bytes());
+        assert!(out.stderr.is_empty());
+    }
+}
+
+#[test]
+fn framework_failures_keep_the_child_exit_status() {
+    for framework in ["vitest", "jest"] {
+        let fixture = Fixture::new(true, None);
+        let out = fixture.run(&[framework], FAIL_JSON, "", 7);
+        let mut expected = vec![framework];
+        expected.extend(framework_args(framework));
+        fixture.assert_invocation(&expected);
+        assert_eq!(out.status.code(), Some(7));
+        let shown = String::from_utf8_lossy(&out.stdout);
+        assert!(shown.contains("FAIL (1)"), "{shown}");
+        assert!(shown.contains("fails deliberately"), "{shown}");
+        assert!(shown.contains("expected true, got false"), "{shown}");
+        assert!(out.stderr.is_empty());
+    }
+}
+
+#[test]
+fn explicit_reporter_keeps_stderr_diagnostics_and_failure_status() {
+    let fixture = Fixture::new(true, None);
+    let stdout = " Tests  2 passed (2)\n";
+    let stderr = "reporter teardown failed\n";
+    let out = fixture.run(&["vitest", "--reporter=verbose"], stdout, stderr, 3);
+    fixture.assert_invocation(&["vitest", "run", "--reporter=verbose"]);
+    assert_eq!(out.status.code(), Some(3));
+    assert_eq!(out.stdout, format!("{stdout}{stderr}").as_bytes());
+    assert!(out.stderr.is_empty());
+}
+
+#[test]
+fn native_spawn_preserves_argument_boundaries_and_metacharacters() {
+    for framework in ["vitest", "jest"] {
+        let fixture = Fixture::new(true, None);
+        let user_args = [
+            "src/a.test.ts",
+            "--",
+            "-literal",
+            "a;$(echo unsafe)&b",
+            "quote\"and\\slash",
+        ];
+        let args: Vec<_> = [framework].into_iter().chain(user_args).collect();
+        let out = fixture.run(&args, PASS_JSON, "", 0);
+        let mut expected = vec![framework];
+        expected.extend(framework_args(framework));
+        expected.extend(user_args);
+        fixture.assert_invocation(&expected);
+        assert_eq!(out.status.code(), Some(0));
+        assert_eq!(out.stdout, b"PASS (2) FAIL (0)\n");
+        assert!(out.stderr.is_empty());
+    }
+}
+
+#[test]
+fn reporter_passthrough_also_reaches_the_package_manager() {
+    let fixture = Fixture::new(false, Some("pnpm-lock.yaml"));
+    let out = fixture.run(&["vitest", "--reporter", "json"], PASS_JSON, "", 0);
+    fixture.assert_invocation(&["pnpm", "exec", "--", "vitest", "run", "--reporter", "json"]);
+    assert_eq!(out.status.code(), Some(0));
+    assert_eq!(
+        String::from_utf8_lossy(&out.stdout),
+        format!("{PASS_JSON}\n")
+    );
+    assert!(out.stderr.is_empty());
+}
+
+#[test]
+fn explicit_reporter_preserves_empty_and_terminated_output() {
+    for (raw, expected) in [
+        ("", ""),
+        ("report", "report\n"),
+        ("report\n", "report\n"),
+        ("report\n\n", "report\n\n"),
+        ("report\r\n", "report\r\n"),
+    ] {
+        let fixture = Fixture::new(true, None);
+        let out = fixture.run(&["vitest", "--reporter=verbose"], raw, "", 0);
+        fixture.assert_invocation(&["vitest", "run", "--reporter=verbose"]);
+        assert_eq!(out.status.code(), Some(0));
+        assert_eq!(out.stdout, expected.as_bytes(), "report input: {raw:?}");
+        assert!(out.stderr.is_empty());
+    }
+}