fix failing exif extraction for some photos

gatsby/createExifFields.js

@@ -2,40 +2,22 @@ const fastExif = require('fast-exif')
 const Fraction = require('fraction.js')
 const dms2dec = require('dms2dec')
 
-exports.createExifFields = (node, createNodeField) => {
-  fastExif
-    .read(node.absolutePath, true)
-    .then(exifData => {
-      if (!exifData) return
-      constructExifFields(exifData, createNodeField, node)
-    })
-    .catch(() => null) // just silently fail when exif can't be extracted
+exports.createExifFields = async (node, createNodeField) => {
+  let exifData
+  try {
+    exifData = await fastExif.read(node.absolutePath, true)
+    if (!exifData) return
+    constructExifFields(exifData, createNodeField, node)
+  } catch (error) {
+    // console.error(`${node.name}: ${error.message}`)
+    return null // just silently fail when exif can't be extracted
+  }
 }
 
-const constructExifFields = (exifData, createNodeField, node) => {
-  const { Model } = exifData.image
-  const {
-    ISO,
-    FNumber,
-    ExposureTime,
-    FocalLength,
-    ExposureBiasValue
-  } = exifData.exif
-  const {
-    GPSLatitudeRef,
-    GPSLatitude,
-    GPSLongitudeRef,
-    GPSLongitude
-  } = exifData.gps
+const getGps = gpsData => {
+  if (!gpsData) return
 
-  const { n, d } = new Fraction(ExposureTime)
-  const exposureShortened = parseFloat(ExposureBiasValue.toFixed(2))
-
-  const model = `${Model}`
-  const iso = `ISO ${ISO}`
-  const fstop = `ƒ ${FNumber}`
-  const shutterspeed = `${n}/${d}s`
-  const focalLength = `${FocalLength}mm`
+  const { GPSLatitudeRef, GPSLatitude, GPSLongitudeRef, GPSLongitude } = gpsData
 
   const GPSdec = dms2dec(
     GPSLatitude,
@@ -47,16 +29,52 @@ const constructExifFields = (exifData, createNodeField, node) => {
   const latitude = GPSdec[0]
   const longitude = GPSdec[1]
 
+  return { latitude, longitude }
+}
+
+const getExposure = exposureMode => {
+  const exposureShortened = parseFloat(exposureMode.toFixed(2))
   let exposure
 
-  if (ExposureBiasValue === 0) {
+  if (exposureMode === 0) {
     exposure = `+/- ${exposureShortened} ev`
-  } else if (ExposureBiasValue > 0) {
+  } else if (exposureMode > 0) {
     exposure = `+ ${exposureShortened} ev`
   } else {
     exposure = `${exposureShortened} ev`
   }
 
+  return exposure
+}
+
+const constructExifFields = (exifData, createNodeField, node) => {
+  const { Model } = exifData.image
+  const {
+    ISO,
+    FNumber,
+    ExposureTime,
+    FocalLength,
+    ExposureBiasValue,
+    ExposureMode
+  } = exifData.exif
+
+  const model = `${Model}`
+  const iso = `ISO ${ISO}`
+  const fstop = `ƒ ${FNumber}`
+  const focalLength = `${FocalLength}mm`
+
+  // Shutter speed
+  const { n, d } = new Fraction(ExposureTime)
+  const shutterspeed = `${n}/${d}s`
+
+  // GPS
+  let latitude
+  let longitude
+  if (exifData.gps) ({ latitude, longitude } = getGps(exifData.gps))
+
+  // Exposure
+  const exposure = getExposure(ExposureBiasValue || ExposureMode)
+
   // add exif fields to type File
   createNodeField({
     node,
@@ -68,10 +86,7 @@ const constructExifFields = (exifData, createNodeField, node) => {
       shutterspeed,
       focalLength,
       exposure,
-      gps: {
-        latitude,
-        longitude
-      }
+      gps: { latitude, longitude }
     }
   })
 }

src/components/atoms/Exif.tsx

@@ -28,7 +28,9 @@ export default function Exif({ exif }: { exif: ExifProps }) {
         {iso && <span title="ISO">{iso}</span>}
         {focalLength && <span title="Focal length">{focalLength}</span>}
       </div>
-      <div className={styles.map}>{gps && <ExifMap gps={gps} />}</div>
+      {gps.latitude && (
+        <div className={styles.map}>{gps && <ExifMap gps={gps} />}</div>
+      )}
     </aside>
   )
 }