Passes `extra_options` to `cargo build --tests` when running `wasm-pack test`.

Issue #698

src/build/mod.rs

@@ -112,11 +112,24 @@ pub fn cargo_build_wasm(
     Ok(())
 }
 
-/// Run `cargo build --tests` targetting `wasm32-unknown-unknown`.
+/// Runs `cargo build --tests` targeting `wasm32-unknown-unknown`.
 ///
 /// This generates the `Cargo.lock` file that we use in order to know which version of
 /// wasm-bindgen-cli to use when running tests.
-pub fn cargo_build_wasm_tests(path: &Path, debug: bool) -> Result<(), Error> {
+///
+/// Note that the command to build tests and the command to run tests must use the same parameters, i.e. features to be
+/// disabled / enabled must be consistent for both `cargo build` and `cargo test`.
+///
+/// # Parameters
+///
+/// * `path`: Path to the crate directory to build tests.
+/// * `debug`: Whether to build tests in `debug` mode.
+/// * `extra_options`: Additional parameters to pass to `cargo` when building tests.
+pub fn cargo_build_wasm_tests(
+    path: &Path,
+    debug: bool,
+    extra_options: &[String],
+) -> Result<(), Error> {
     let mut cmd = Command::new("cargo");
 
     cmd.current_dir(path).arg("build").arg("--tests");
@@ -131,6 +144,8 @@ pub fn cargo_build_wasm_tests(path: &Path, debug: bool) -> Result<(), Error> {
 
     cmd.arg("--target").arg("wasm32-unknown-unknown");
 
+    cmd.args(extra_options);
+
     child::run(cmd, "cargo build").context("Compilation of your program failed")?;
     Ok(())
 }

src/command/test.rs

@@ -243,7 +243,7 @@ impl Test {
     fn step_build_tests(&mut self) -> Result<(), Error> {
         info!("Compiling tests to wasm...");
 
-        build::cargo_build_wasm_tests(&self.crate_path, !self.release)?;
+        build::cargo_build_wasm_tests(&self.crate_path, !self.release, &self.extra_options)?;
 
         info!("Finished compiling tests to wasm.");
         Ok(())

tests/all/test.rs

@@ -337,3 +337,56 @@ fn test_output_is_printed_once_in_both_stdout_and_failures() {
             out.matches("YABBA DABBA DOO").count() == log_cnt * 2
         }));
 }
+
+#[test]
+fn extra_options_is_passed_to_cargo_when_building_tests() {
+    let fixture = fixture::Fixture::new();
+    fixture
+        .readme()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+                authors = []
+
+                [dev-dependencies]
+                wasm-bindgen-test = "0.2"
+
+                [features]
+                default = ["native"]
+                native = []
+            "#,
+        )
+        .file(
+            "src/lib.rs",
+            r#"
+                pub fn foo() -> u32 {
+                    #[cfg(feature = "native")]
+                    compile_error!("Test should pass through `--no-default-features` for this to pass.");
+
+                    1
+                }
+            "#,
+        )
+        .file(
+            "tests/foo.rs",
+            r#"
+                extern crate wasm_bindgen_test;
+                use wasm_bindgen_test::*;
+
+                #[wasm_bindgen_test]
+                fn smoke() {
+                    foo::foo();
+                }
+            "#,
+        )
+        .install_local_wasm_bindgen();
+    let _lock = fixture.lock();
+    fixture
+        .wasm_pack()
+        .args(&["test", "--node", "--", "--no-default-features"])
+        .assert()
+        .success();
+}