fix: do not hang on errors during HTML checking

- Add a try/catch block in the code executed within
  Nightmare.js’s runtime, and dispatch the error to
  the callback
- Improve error reporting:
  - log verbose cause and throw a generic error
  - invite CLI users to re-run in verbose mode

Closes #39.

src/checker/checker-nightmare.js

@@ -74,6 +74,10 @@ function checkSingle(spineItem, epub, nightmare) {
         });
       }
       return results;
+    })
+    .catch((err) => {
+      winston.debug(`Error when running nightmare: ${JSON.stringify(err, null, 2)}`);
+      throw new Error('Failed to check HTML content');
     });
 }
 
@@ -93,4 +97,4 @@ module.exports.check = (epub) => {
         return results;
       })), Promise.resolve([]))
   .then(results => nightmare.end(() => results));
-}
+};

src/cli/cli.js

@@ -86,5 +86,6 @@ ace(cli.input[0], {
 })
 .catch((err) => {
   if (err) winston.error(err.message);
+  console.log(`Re-run Ace using the --verbose option to enable full debug logging.`)
   process.exit(1);
 });

src/core/ace.js

@@ -74,7 +74,8 @@ module.exports = function ace(epubPath, options) {
       resolve(jobId);
     })
     .catch((err) => {
-      winston.error(`Unexpected error: ${err}`);
+      winston.error(`Unexpected error: ${(err.message !== undefined) ? err.message : err}`);
+      if (err.stack !== undefined) winston.debug(err.stack);
       reject(jobId);
     });
   });

src/scripts/ace-axe.js

@@ -92,9 +92,13 @@ daisy.ace.run = function(done) {
 
       aceResult.axe = axeResult;
 
-      daisy.ace.createReport(aceResult);
+      try {
+        daisy.ace.createReport(aceResult);
+        done(null, aceResult);
+      } catch(e) {
+        done(e, null);
+      }
 
-      done(null, aceResult);
     }
   );
 };

tests/__tests__/__snapshots__/cli.test.js.snap

@@ -64,7 +64,9 @@ exports[`test no input 2`] = `
 "
 `;
 
-exports[`test unexisting input 1`] = `
+exports[`test unexisting input 1`] = `"Re-run Ace using the --verbose option to enable full debug logging."`;
+
+exports[`test unexisting input 2`] = `
 "error:   Couldn’t find EPUB file 'unexisting.epub'
 "
 `;

tests/__tests__/cli.test.js

@@ -37,7 +37,7 @@ test('test version --version', () => {
 test('test unexisting input', () => {
   const { stdout, stderr, status } = ace(['unexisting.epub']);
   expect(status).toBe(1);
-  expect(stdout.trim()).toBe('');
+  expect(stdout.trim()).toMatchSnapshot();
   expect(stderr).toMatchSnapshot();
 });