test(build): running with no rust should err

Author: ashleygwilliams

tests/all/build.rs

@@ -19,3 +19,20 @@ fn build_in_non_crate_directory_doesnt_panic() {
     let err_msg = result.unwrap_err().to_string();
     assert!(err_msg.contains("missing a `Cargo.toml`"));
 }
+
+#[test]
+fn build_with_no_rust_is_err() {
+    let fixture = utils::fixture::not_a_crate();
+    let cli = Cli::from_iter_safe(vec![
+        "wasm-pack",
+        "build",
+        &fixture.path.display().to_string(),
+    ]).unwrap();
+    let logger = logger::new(&cli.cmd, cli.verbosity).unwrap();
+    let result = command::run_wasm_pack(cli.cmd, &logger);
+    assert!(
+        result.is_err(),
+        "running wasm-pack with no Rust should fail, but it should not panic"
+    );
+    let err_msg = result.unwrap_err().to_string();
+}