fix: ParseError message handling

src/ParseError.js

@@ -20,9 +20,25 @@ class ParseError extends Error {
   constructor(code, message) {
     super(message);
     this.code = code;
+
+    const stringify = obj => {
+      let log = '';
+      for (const k in obj) {
+        log += `${obj[k]} `;
+      }
+      return log.trim();
+    };
+
     Object.defineProperty(this, 'message', {
       enumerable: true,
-      value: message,
+      value:
+        typeof message === 'string'
+          ? message
+          : typeof message === 'object' &&
+            typeof message.toString === 'function' &&
+            !message.toString().includes('[object Object]')
+            ? message.toString()
+            : stringify(message),
     });
   }
 

src/__tests__/ParseError-test.js

@@ -27,4 +27,51 @@ describe('ParseError', () => {
       code: 123,
     });
   });
+
+  it('message can be a string', () => {
+    const someRandomError = 'oh no';
+
+    const error = new ParseError(1337, someRandomError);
+
+    expect(JSON.parse(JSON.stringify(error))).toEqual({
+      message: someRandomError,
+      code: 1337,
+    });
+  });
+
+  it('message can be an object passed trough some external dependency', () => {
+    const someRandomError = { code: '420', message: 'time to chill', status: '🎮' };
+
+    const error = new ParseError(1337, someRandomError);
+
+    expect(JSON.parse(JSON.stringify(error))).toEqual({
+      message: '420 time to chill 🎮',
+      code: 1337,
+    });
+  });
+
+  it('message can be an Error instance *receiving a string* passed trough some external dependency', () => {
+    const someRandomError = new Error('good point');
+
+    const error = new ParseError(1337, someRandomError);
+
+    expect(JSON.parse(JSON.stringify(error))).toEqual({
+      message: 'Error: good point',
+      code: 1337,
+    });
+  });
+
+  it('message can be an Error instance *receiving an object* passed trough some external dependency', () => {
+    const someRandomErrorWrong = new Error({
+      code: 'WRONG',
+      message: 'this is not how errors should be handled',
+    });
+
+    const error = new ParseError(1337, someRandomErrorWrong);
+
+    expect(JSON.parse(JSON.stringify(error))).toEqual({
+      message: '', // <-- Yeah because we can't parse errors used like that
+      code: 1337,
+    });
+  });
 });