How to make snakeyaml fail fast when reading multiple yaml documents in one file

[Chris Kelly]

Say I have the following YAML file

a: 1
---
Some comment 


b: 2

c: 3
---

I have a invalid YAML on line 3. It should be a comment i.e. # Some comment

If I use yaml.loadAll, then the parser dosen’t fail but only gives me content it can parse i.e. a: 1. I would like it to fast-fail on any errors but the parser just seems to skip them.

This is a contrived example but I’m using snakeyaml to parse Spring application YAML files to see the YAML is well formed. When I use this, it only gives the part of the yaml up to the first error and nothing else.

I can’t see any a way either in loader options or looking at the code to make the parser fast-fail.

If I use yaml.load with a file that only has a single document and that has a invalid content, then the parser does fail with the expected error.

[Andrey Somov]

One of the important features of streaming is that the error happens only when you process the data.

If a user does not pull data, no parsing happens (and no error may occur). In your case you have to call the iterator to parsed all the data. I have added an example: https://bitbucket.org/asomov/snakeyaml/src/master/src/test/java/org/yaml/snakeyaml/issues/issue500/FailIteratorOnlyWhenErrorFoundTest.java
Basically, you need to call next() until it is empty of an error happens.

No need to change anything in SnakeYAML