Add failOnError option to fail-fast on bad input image data (#976)

lib/constructor.js

@@ -93,6 +93,9 @@ const debuglog = util.debuglog('sharp');
  *  a String containing the path to an JPEG, PNG, WebP, GIF, SVG or TIFF image file.
  *  JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data can be streamed into the object when not present.
  * @param {Object} [options] - if present, is an Object with optional attributes.
+ * @param {Boolean} [options.failOnError=false] - by default apply a "best effort"
+ *  to decode images, even if the data is corrupt or invalid. Set this flag to true
+ *  if you'd rather halt processing and raise an error when loading invalid images.
  * @param {Number} [options.density=72] - integral number representing the DPI for vector images.
  * @param {Object} [options.raw] - describes raw pixel input image data. See `raw()` for pixel ordering.
  * @param {Number} [options.raw.width]

lib/input.js

@@ -9,7 +9,7 @@ const sharp = require('../build/Release/sharp.node');
  * @private
  */
 function _createInputDescriptor (input, inputOptions, containerOptions) {
-  const inputDescriptor = {};
+  const inputDescriptor = { failOnError: false };
   if (is.string(input)) {
     // filesystem
     inputDescriptor.file = input;
@@ -26,6 +26,14 @@ function _createInputDescriptor (input, inputOptions, containerOptions) {
     throw new Error('Unsupported input ' + typeof input);
   }
   if (is.object(inputOptions)) {
+    // Fail on error
+    if (is.defined(inputOptions.failOnError)) {
+      if (is.bool(inputOptions.failOnError)) {
+        inputDescriptor.failOnError = inputOptions.failOnError;
+      } else {
+        throw new Error('Invalid failOnError (boolean) ' + inputOptions.failOnError);
+      }
+    }
     // Density
     if (is.defined(inputOptions.density)) {
       if (is.integer(inputOptions.density) && is.inRange(inputOptions.density, 1, 2400)) {