Better error handling

Wrap in a bluebird.try to catch synchronous errors.
bluebird.resolve doesn't catch those!

src/ffmpeg.js

@@ -32,49 +32,46 @@ function getFfmpegPath() {
 }
 
 function cut(filePath, format, cutFrom, cutTo) {
-  const ext = path.extname(filePath) || format;
-  const outFileAppend = `${util.formatDuration(cutFrom)}-${util.formatDuration(cutTo)}`;
-  const outFile = `${filePath}-${outFileAppend}.${ext}`;
+  return bluebird.try(() => {
+    const ext = path.extname(filePath) || format;
+    const outFileAppend = `${util.formatDuration(cutFrom)}-${util.formatDuration(cutTo)}`;
+    const outFile = `${filePath}-${outFileAppend}.${ext}`;
 
-  console.log('Cutting from', cutFrom, 'to', cutTo);
+    console.log('Cutting from', cutFrom, 'to', cutTo);
 
-  const ffmpegArgs = [
-    '-i', filePath, '-y', '-vcodec', 'copy', '-acodec', 'copy',
-    '-ss', cutFrom, '-t', cutTo - cutFrom,
-    '-f', format,
-    outFile,
-  ];
+    const ffmpegArgs = [
+      '-i', filePath, '-y', '-vcodec', 'copy', '-acodec', 'copy',
+      '-ss', cutFrom, '-t', cutTo - cutFrom,
+      '-f', format,
+      outFile,
+    ];
 
-  console.log('ffmpeg', ffmpegArgs.join(' '));
+    console.log('ffmpeg', ffmpegArgs.join(' '));
 
-  return getFfmpegPath()
-    .then(ffmpegPath => execa(ffmpegPath, ffmpegArgs))
-    .then((result) => {
-      console.log(result.stdout);
-    })
-    .catch((err) => {
-      if (err.code === 1) {
-        alert('Whoops! ffmpeg was unable to cut this video. It may be of an unknown format or codec combination');
-        return;
-      }
-      showFfmpegFail(err);
-    });
+    return getFfmpegPath()
+      .then(ffmpegPath => execa(ffmpegPath, ffmpegArgs))
+      .then((result) => {
+        console.log(result.stdout);
+      });
+  });
 }
 
 function getFormats(filePath) {
-  console.log('getFormat', filePath);
+  return bluebird.try(() => {
+    console.log('getFormat', filePath);
 
-  return getFfmpegPath()
-    .then(ffmpegPath => path.join(path.dirname(ffmpegPath), getWithExt('ffprobe')))
-    .then(ffprobePath => execa(ffprobePath, [
-      '-of', 'json', '-show_format', '-i', filePath,
-    ]))
-    .then((result) => {
-      const formatsStr = JSON.parse(result.stdout).format.format_name;
-      console.log('formats', formatsStr);
-      const formats = formatsStr.split(',');
-      return formats;
-    });
+    return getFfmpegPath()
+      .then(ffmpegPath => path.join(path.dirname(ffmpegPath), getWithExt('ffprobe')))
+      .then(ffprobePath => execa(ffprobePath, [
+        '-of', 'json', '-show_format', '-i', filePath,
+      ]))
+      .then((result) => {
+        const formatsStr = JSON.parse(result.stdout).format.format_name;
+        console.log('formats', formatsStr);
+        const formats = formatsStr.split(',');
+        return formats;
+      });
+  });
 }
 
 module.exports = {

src/renderer.jsx

@@ -70,7 +70,7 @@ class App extends React.Component {
       resetState();
 
       this.setState({ working: true });
-      return bluebird.resolve(ffmpeg.getFormats(filePath))
+      return ffmpeg.getFormats(filePath)
         .then((formats) => {
           if (formats.length < 1) return alert('Unsupported file');
           return this.setState({ filePath, fileFormat: formats[0] });
@@ -188,7 +188,14 @@ class App extends React.Component {
     }
 
     this.setState({ working: true });
-    return bluebird.resolve(ffmpeg.cut(filePath, this.state.fileFormat, cutStartTime, cutEndTime))
+    return ffmpeg.cut(filePath, this.state.fileFormat, cutStartTime, cutEndTime)
+      .catch((err) => {
+        if (err.code === 1) {
+          alert('Whoops! ffmpeg was unable to cut this video. It may be of an unknown format or codec combination');
+          return;
+        }
+        ffmpeg.showFfmpegFail(err);
+      })
       .finally(() => this.setState({ working: false }));
   }