Added tests

package.json

@@ -10,7 +10,9 @@
     "build": "npm run build:library && npm run build:readme && npm run fmt",
     "build:website": "npm run build && node genwebsite.js",
     "build:website:netlify": "./build.sh",
-    "fmt": "prettier --write ./{,{src,rollup-plugins}/**/}*.{mjs,js,md}"
+    "fmt": "prettier --write ./{,{src,rollup-plugins}/**/}*.{mjs,js,md}",
+    "fmt_test": "test $(prettier -l ./{,{src,rollup-plugins}/**/}*.{mjs,js,md} | wc -l) -eq 0",
+    "test": "npm run fmt_test && npm run build && node --no-warnings test/index.js"
   },
   "repository": "GoogleChromeLabs/wasm-feature-detect",
   "keywords": [],

test/index.js

@@ -0,0 +1,45 @@
+/**
+ * Copyright 2019 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const assert = require('assert');
+
+process.on("unhandledRejection", err => {
+  throw err;
+});
+
+// We try to import the generated module
+const features = require(__dirname+'/../dist/cjs');
+
+const isBoolean = function (value) {
+  return value === true || value === false;
+}
+
+const checkFeature = function (featureName) {
+  const feature = features[featureName];
+  assert(feature, `The feature ${featureName} doesn't exist`);
+  feature().then(function(result) {
+    console.log(`The feature ${featureName} returned: ${result}`);
+    assert(isBoolean(result), `The feature ${featureName} returned: ${result}`);
+  })
+}
+
+checkFeature("bulkMemory");
+checkFeature("exceptions");
+checkFeature("multiValue");
+checkFeature("mutableGlobals");
+checkFeature("referenceTypes");
+checkFeature("saturatedFloatToInt");
+checkFeature("signExtensions");
+checkFeature("simd");
+checkFeature("tailCall");
+checkFeature("threads");