Content-ID gets lost when parsing and then building an eml file

[cloudify]

Hi! 👋

Firstly, thanks for your work on this project! 🙂

Today I used patch-package to patch eml-format@0.6.1 for the project I'm working on.

The problem I've been facing is that if I just parse and build an eml file, without making any change, all the inline images break out - by looking at the content of the generated eml file I noticed that the Content-ID header gets lost in the process. Then I looked at the code and I noticed that during the parse step, the attach ID is stored in the id attribute while during the build step, the id is expected to be found in the cid attribute.

Here is the diff that solved my problem:

diff --git a/node_modules/eml-format/lib/eml-format.js b/node_modules/eml-format/lib/eml-format.js
index 575e557..412f02b 100644
--- a/node_modules/eml-format/lib/eml-format.js
+++ b/node_modules/eml-format/lib/eml-format.js
@@ -419,6 +419,8 @@ emlformat.build = function(data, options, callback) {
         eml += 'Content-Disposition: ' + (attachment.inline ? "inline" : "attachment") + '; filename="' + (attachment.filename || attachment.name || ("attachment_" + (i + 1))) + '"' + EOL;
         if (attachment.cid) {
           eml += 'Content-ID: <' + attachment.cid + ">" + EOL;
+        } else if (attachment.id) {
+          eml += 'Content-ID: <' + attachment.id + ">" + EOL;
         }
         eml += EOL;
         if (typeof attachment.data == "string") {

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