Add test explicitly for image error handling

3 files changed, 26 insertions, 1 deletions

diff --git a/lib/document-to-html.js b/lib/document-to-html.js
index e022946..6094803 100644
--- a/lib/document-to-html.js
+++ b/lib/document-to-html.js
@@ -193,7 +193,9 @@ function DocumentConversion(options, comments) {
     
     function recoveringConvertImage(convertImage) {
         return function(image, messages) {
-            return convertImage(image, messages).caught(function(error) {
+            return promises.attempt(function() {
+                return convertImage(image, messages);
+            }).caught(function(error) {
                 messages.push(results.error(error));
                 return [];
             });
diff --git a/lib/promises.js b/lib/promises.js
index 24dc34a..010631f 100644
--- a/lib/promises.js
+++ b/lib/promises.js
@@ -9,6 +9,7 @@ exports.props = bluebird.props;
 exports.reject = bluebird.reject;
 exports.promisify = bluebird.promisify;
 exports.mapSeries = bluebird.mapSeries;
+exports.attempt = bluebird.attempt;
 
 exports.nfcall = function(func) {
     var args = Array.prototype.slice.call(arguments, 1);
diff --git a/test/document-to-html.tests.js b/test/document-to-html.tests.js
index cc8aff5..59eba49 100644
--- a/test/document-to-html.tests.js
+++ b/test/document-to-html.tests.js
@@ -590,6 +590,28 @@ test('can add custom handler for images', function() {
     });
 });
 
+test('when custom image handler throws error then error is stored in error message', function() {
+    var error = new Error("Failed to convert image");
+    var image = new documents.Image({
+        readImage: function(encoding) {
+            return promises.when(new Buffer().toString(encoding));
+        },
+        contentType: "image/png"
+    });
+    var converter = new DocumentConverter({
+        convertImage: function(element, messages) {
+            throw error;
+        }
+    });
+    return converter.convertToHtml(image).then(function(result) {
+        assert.equal(result.value, '');
+        assert.equal(result.messages.length, 1);
+        var message = result.messages[0];
+        assert.equal("error", message.type);
+        assert.equal("Failed to convert image", message.message);
+    });
+});
+
 test('long documents do not cause stack overflow', function() {
     var paragraphs = [];
     for (var i = 0; i < 1000; i++) {