Wrap thrown errors in JS Error objects with stacks

We noticed in our usage of this package that thrown errors (eg: "Unknown frame descriptor") don't have a useful .stack property. This makes debugging harder. It seems this is expected behavior for errors created via napi at least on V8; it seems that the best way to remedy this is to recreate Error objects on the JS side?

Author: sophiebits

index.js

@@ -151,5 +151,19 @@ if (!nativeBinding) {
 
 const { compress, decompress } = nativeBinding;
 
-module.exports.compress = compress;
-module.exports.decompress = decompress;
+// Error objects created via napi don't have JS stacks; wrap them so .stack is present
+// https://github.com/nodejs/node/issues/25318#issuecomment-451068073
+module.exports.compress = async function (data) {
+  try {
+    return await compress(data);
+  } catch (e) {
+    throw new Error(`zstd: ${e.message}`);
+  }
+};
+module.exports.decompress = async function (data) {
+  try {
+    return await decompress(data);
+  } catch (e) {
+    throw new Error(`zstd: ${e.message}`);
+  }
+};

test/index.test.js

@@ -37,4 +37,17 @@ describe('zstd', () => {
       });
     });
   });
+
+  describe('#decompress', () => {
+    context('when decompressing invalid data', () => {
+      it('includes a stack trace', async () => {
+        try {
+          await decompress(Buffer.from('invalid'));
+        } catch (error) {
+          expect(error.message).to.be('zstd: Unknown frame descriptor');
+          expect(error.stack).to.match(/at decompress/);
+        }
+      }
+    });
+  });
 });