update changelog + documentation and bump version to 1.4.0

Author: striezel

changelog.md

@@ -11,6 +11,33 @@ application, major version changes in Plotly.js will also trigger a major
 version change in this application.
 
 
+## Version 1.4.0 (2021-04-18)
+
+__[improvement]__
+The generated names for PNG files are using UUIDs (version 4) instead of a
+Unix timestamp in their name from now on. That is, the JSON output of a
+successful render will change from something like
+
+    {
+      "success": true,
+      "filename": "graph-1604764778687.png"
+    }
+
+to something like
+
+    {
+      "success": true,
+      "filename": "graph-25273999-dea9-4da2-aad2-dbdf2e38a0c9.png"
+    }
+
+instead. While it is highly unlikely that rendering of a plot with Plotly.js and
+JavaScript is so fast that two PNG files are created within the same millisecond
+this change makes sure we are on the safe side here.
+
+Also note that the application never gave any guarantees for the naming pattern
+of the generated files in the first place. Therefore, anyone consuming the JSON
+response should treat the `filename` value as a purely random file name.
+
 ## Version 1.3.0
 
 The version of Plotly.js is bumped from 1.57.1 to 1.58.4.

documentation/graph-1604764778687.png renamed to documentation/graph-25273999-dea9-4da2-aad2-dbdf2e38a0c9.png

@@ -1,6 +1,6 @@
 {
   "name": "plotly-node-export-server",
-  "version": "1.3.0",
+  "version": "1.4.0",
   "description": "Plotly.js Node.js export server",
   "repository": {
     "url": "https://gitlab.com/striezel/plotly-node-export-server.git",

export-server/package-lock.json

@@ -68,15 +68,15 @@ will generate a JSON response like e.g.:
 
     {
       "success": true,
-      "filename": "graph-1604764778687.png"
+      "filename": "graph-25273999-dea9-4da2-aad2-dbdf2e38a0c9.png"
     }
 
 The field _filename_ in the response indicates the location of the generated
 image file on the server. In the example above you could then get the image from
-<http://localhost:3000/graph-1604764778687.png>. Given the data above the image
-would look like this:
+<http://localhost:3000/graph-25273999-dea9-4da2-aad2-dbdf2e38a0c9.png>. Given
+the data above the image would look like this:
 
-![Generated image example](./documentation/graph-1604764778687.png)
+![Generated image example](./documentation/graph-25273999-dea9-4da2-aad2-dbdf2e38a0c9.png)
 
 ## Troubleshooting