Move test synchronization to tests, not in wasm-pack

In `wasm-pack` it can't do cross-process synchronization, and in tests
there's now multiple processes which need to be synchronized.

src/test/mod.rs

@@ -22,12 +22,6 @@ where
     K: AsRef<OsStr>,
     V: AsRef<OsStr>,
 {
-    use std::sync::Mutex;
-    lazy_static! {
-        static ref ONE_TEST_AT_A_TIME: Mutex<()> = Mutex::new(());
-    }
-    let _locked = ONE_TEST_AT_A_TIME.lock().unwrap();
-
     let output = {
         let mut cmd = Command::new("cargo");
         cmd.envs(envs);

tests/all/build.rs

@@ -17,7 +17,9 @@ fn build_in_non_crate_directory_doesnt_panic() {
         "running wasm-pack in a non-crate directory should fail, but it should not panic"
     );
     let err = result.unwrap_err();
-    assert!(err.iter_chain().any(|e| e.to_string().contains("missing a `Cargo.toml`")));
+    assert!(err
+        .iter_chain()
+        .any(|e| e.to_string().contains("missing a `Cargo.toml`")));
 }
 
 #[test]

tests/all/main.rs

@@ -1,5 +1,7 @@
 extern crate failure;
 #[macro_use]
+extern crate lazy_static;
+#[macro_use]
 extern crate serde_derive;
 extern crate serde_json;
 #[macro_use]

tests/all/test.rs

@@ -98,7 +98,10 @@ fn it_can_run_failing_tests() {
         mode: build::BuildMode::Noinstall,
         ..Default::default()
     });
-    assert_err(fixture.run(cmd), "Running Wasm tests with wasm-bindgen-test failed");
+    assert_err(
+        fixture.run(cmd),
+        "Running Wasm tests with wasm-bindgen-test failed",
+    );
 }
 
 #[test]
@@ -121,6 +124,8 @@ fn it_can_find_a_webdriver_on_path() {
     paths.insert(0, local_wasm_bindgen.parent().unwrap().to_path_buf());
     let path = env::join_paths(paths).unwrap();
 
+    let _lock = fixture.lock();
+
     let mut me = env::current_exe().unwrap();
     me.pop();
     me.pop();

tests/all/utils/fixture.rs

@@ -4,7 +4,7 @@ use std::fs;
 use std::mem::ManuallyDrop;
 use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
-use std::sync::{Once, ONCE_INIT};
+use std::sync::{MutexGuard, Once, ONCE_INIT};
 use std::thread;
 use tempfile::TempDir;
 use wasm_pack;
@@ -208,6 +208,7 @@ impl Fixture {
         let logger = wasm_pack::logger::new(&cmd, 3)?;
         match cmd {
             wasm_pack::command::Command::Test(cmd) => {
+                let _lock = self.lock();
                 let mut test = wasm_pack::command::test::Test::try_from_opts(cmd)?;
                 test.set_cache(self.cache());
                 test.run(&logger)
@@ -220,6 +221,14 @@ impl Fixture {
             _ => unreachable!(),
         }
     }
+
+    pub fn lock(&self) -> MutexGuard<'static, ()> {
+        use std::sync::Mutex;
+        lazy_static! {
+            static ref ONE_TEST_AT_A_TIME: Mutex<()> = Mutex::new(());
+        }
+        ONE_TEST_AT_A_TIME.lock().unwrap_or_else(|e| e.into_inner())
+    }
 }
 
 impl Drop for Fixture {